| 1. |
- Abbasi, R., et al.
(author)
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Search for Continuous and Transient Neutrino Emission Associated with IceCube's Highest-energy Tracks: An 11 yr Analysis
- 2024
-
In: Astrophysical Journal. - : Institute of Physics (IOP). - 1538-4357 .- 0004-637X. ; 964:1
-
Journal article (peer-reviewed)abstract
- IceCube alert events are neutrinos with a moderate-to-high probability of having astrophysical origin. In this study, we analyze 11 yr of IceCube data and investigate 122 alert events and a selection of high-energy tracks detected between 2009 and the end of 2021. This high-energy event selection (alert events + high-energy tracks) has an average probability of >= 0.5 of being of astrophysical origin. We search for additional continuous and transient neutrino emission within the high-energy events' error regions. We find no evidence for significant continuous neutrino emission from any of the alert event directions. The only locally significant neutrino emission is the transient emission associated with the blazar TXS 0506+056, with a local significance of 3 sigma, which confirms previous IceCube studies. When correcting for 122 test positions, the global p-value is 0.156 and compatible with the background hypothesis. We constrain the total continuous flux emitted from all 122 test positions at 100 TeV to be below 1.2 x 10-15 (TeV cm2 s)-1 at 90% confidence assuming an E -2 spectrum. This corresponds to 4.5% of IceCube's astrophysical diffuse flux. Overall, we find no indication that alert events in general are linked to lower-energetic continuous or transient neutrino emission.
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| 2. |
- Abbasi, R., et al.
(author)
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Citizen science for IceCube: Name that Neutrino
- 2024
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In: European Physical Journal Plus. - 2190-5444. ; 139:6
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Journal article (peer-reviewed)abstract
- Name that Neutrino is a citizen science project where volunteers aid in classification of events for the IceCube Neutrino Observatory, an immense particle detector at the geographic South Pole. From March 2023 to September 2023, volunteers did classifications of videos produced from simulated data of both neutrino signal and background interactions. Name that Neutrino obtained more than 128,000 classifications by over 1800 registered volunteers that were compared to results obtained by a deep neural network machine-learning algorithm. Possible improvements for both Name that Neutrino and the deep neural network are discussed.
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| 3. |
- Abbasi, R., et al.
(author)
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Search for 10-1000 GeV Neutrinos from Gamma-Ray Bursts with IceCube
- 2024
-
In: Astrophysical Journal. - : Institute of Physics (IOP). - 1538-4357 .- 0004-637X. ; 964:2
-
Journal article (peer-reviewed)abstract
- We present the results of a search for 10-1000 GeV neutrinos from 2268 gamma-ray bursts (GRBs) over 8 yr of IceCube-DeepCore data. This work probes burst physics below the photosphere where electromagnetic radiation cannot escape. Neutrinos of tens of giga electronvolts are predicted in sub-photospheric collision of free-streaming neutrons with bulk-jet protons. In a first analysis, we searched for the most significant neutrino-GRB coincidence using six overlapping time windows centered on the prompt phase of each GRB. In a second analysis, we conducted a search for a group of GRBs, each individually too weak to be detectable, but potentially significant when combined. No evidence of neutrino emission is found for either analysis. The most significant neutrino coincidence is for Fermi-GBM GRB bn 140807500, with a p-value of 0.097 corrected for all trials. The binomial test used to search for a group of GRBs had a p-value of 0.65 after all trial corrections. The binomial test found a group consisting only of GRB bn 140807500 and no additional GRBs. The neutrino limits of this work complement those obtained by IceCube at tera electronvolt to peta electronvolt energies. We compare our findings for the large set of GRBs as well as GRB 221009A to the sub-photospheric neutron-proton collision model and find that GRB 221009A provides the most constraining limit on baryon loading. For a jet Lorentz factor of 300 (800), the baryon loading on GRB 221009A is lower than 3.85 (2.13) at a 90% confidence level.
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| 4. |
- Abbasi, R., et al.
(author)
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Search for decoherence from quantum gravity with atmospheric neutrinos
- 2024
-
In: Nature Physics. - 1745-2481 .- 1745-2473. ; 20:6, s. 913-920
-
Journal article (peer-reviewed)abstract
- Neutrino oscillations at the highest energies and longest baselines can be used to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, its fluctuations at the Planck scale are expected to introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavour composition at long distances and high energies. Here we use atmospheric neutrinos detected by the IceCube South Pole Neutrino Observatory in the energy range of 0.5-10.0 TeV to search for coherence loss in neutrino propagation. We find no evidence of anomalous neutrino decoherence and determine limits on neutrino-quantum gravity interactions. The constraint on the effective decoherence strength parameter within an energy-independent decoherence model improves on previous limits by a factor of 30. For decoherence effects scaling as E2, our limits are advanced by more than six orders of magnitude beyond past measurements compared with the state of the art. Interactions of atmospheric neutrinos with quantum-gravity-induced fluctuations of the metric of spacetime would lead to decoherence. The IceCube Collaboration constrains such interactions with atmospheric neutrinos.
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| 5. |
- Abbasi, R., et al.
(author)
-
Acceptance Tests of more than 10 000 Photomultiplier Tubes for the multi-PMT Digital Optical Modules of the IceCube Upgrade
- 2024
-
In: Journal of Instrumentation. - 1748-0221. ; 19:7
-
Journal article (peer-reviewed)abstract
- More than 10 000 photomultiplier tubes (PMTs) with a diameter of 80 mm will be installed in multi-PMT Digital Optical Modules (mDOMs) of the IceCube Upgrade. These have been tested and pre-calibrated at two sites. A throughput of more than 1000 PMTs per week with both sites was achieved with a modular design of the testing facilities and highly automated testing procedures. The testing facilities can easily be adapted to other PMTs, such that they can, e.g., be re-used for testing the PMTs for IceCube-Gen2. Single photoelectron response, high voltage dependence, time resolution, prepulse, late pulse, afterpulse probabilities, and dark rates were measured for each PMT. We describe the design of the testing facilities, the testing procedures, and the results of the acceptance tests.
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| 6. |
- Abbasi, R., et al.
(author)
-
Characterization of the astrophysical diffuse neutrino flux using starting track events in IceCube
- 2024
-
In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 2470-0010 .- 2470-0029. ; 110:2
-
Journal article (peer-reviewed)abstract
- A measurement of the diffuse astrophysical neutrino spectrum is presented using IceCube data collected from 2011-2022 (10.3 years). We developed novel detection techniques to search for events with a contained vertex and exiting track induced by muon neutrinos undergoing a charged-current interaction. Searching for these starting track events allows us to not only more effectively reject atmospheric muons but also atmospheric neutrino backgrounds in the southern sky, opening a new window to the sub-100 TeV astrophysical neutrino sky. The event selection is constructed using a dynamic starting track veto and machine learning algorithms. We use this data to measure the astrophysical diffuse flux as a single power law flux (SPL) with a best-fit spectral index of γ=2.58-0.09+0.10 and per-flavor normalization of φper-flavorAstro=1.68-0.22+0.19×10-18×GeV-1 cm-2 s-1 sr-1 (at 100 TeV). The sensitive energy range for this dataset is 3-550 TeV under the SPL assumption. This data was also used to measure the flux under a broken power law, however we did not find any evidence of a low energy cutoff.
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| 7. |
- Abbasi, R., et al.
(author)
-
Improved modeling of in-ice particle showers for IceCube event reconstruction
- 2024
-
In: Journal of Instrumentation. - 1748-0221. ; 19:6
-
Journal article (peer-reviewed)abstract
- The IceCube Neutrino Observatory relies on an array of photomultiplier tubes to detect Cherenkov light produced by charged particles in the South Pole ice. IceCube data analyses depend on an in-depth characterization of the glacial ice, and on novel approaches in event reconstruction that utilize fast approximations of photoelectron yields. Here, a more accurate model is derived for event reconstruction that better captures our current knowledge of ice optical properties. When evaluated on a Monte Carlo simulation set, the median angular resolution for in-ice particle showers improves by over a factor of three compared to a reconstruction based on a simplified model of the ice. The most substantial improvement is obtained when including effects of birefringence due to the polycrystalline structure of the ice. When evaluated on data classified as particle showers in the high-energy starting events sample, a significantly improved description of the events is observed.
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| 8. |
- Roelfsema, P. R., et al.
(author)
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SPICA-A Large Cryogenic Infrared Space Telescope : Unveiling the Obscured Universe
- 2018
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In: Publications Astronomical Society of Australia. - : Cambridge University Press (CUP). - 1323-3580 .- 1448-6083. ; 35
-
Journal article (peer-reviewed)abstract
- Measurements in the infrared wavelength domain allow direct assessment of the physical state and energy balance of cool matter in space, enabling the detailed study of the processes that govern the formation and evolution of stars and planetary systems in galaxies over cosmic time. Previous infrared missions revealed a great deal about the obscured Universe, but were hampered by limited sensitivity. SPICA takes the next step in infrared observational capability by combining a large 2.5-meter diameter telescope. cooled to below 8 K, with instruments employing ultra-sensitive detectors. A combination of passive cooling and mechanical coolers will be used to cool both the telescope and the instruments. With mechanical coolers the mission lifetime is not limited by the supply of cryogen. With the combination of low telescope background and instruments with state-of-the-art detectors SPICA provides a huge advance on the capabilities of previous missions. SPICA instruments offer spectral resolving power ranging from R similar to 50 through 11 000 in the 17-230 mu m domain and R similar to 28.000 spectroscopy between 12 and 18 mu m.SPICA will provide efficient 30-37 mu m broad band mapping, and small field spectroscopic and polarimetric imaging at 100, 200 and 350 mu m. SPICA will provide infrared spectroscopy with an unprecedented sensitivity of similar to 5 x 10(-20) W m (-2) (5 sigma/1 h)-over two orders of magnitude improvement over what earlier missions. This exceptional performance leap, will open entirely new domains in infrared astronomy; galaxy evolution and metal production over cosmic time, dust formation and evolution from very early epochs onwards, the formation history of planetary systems.
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| 9. |
- Benisty, H., et al.
(author)
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Low-loss photonic-crystal and monolithic InP integration : Bands, bends, lasers, filters
- 2004
-
In: Photonic Crystal Materials and Devices II. - : SPIE - International Society for Optical Engineering. - 0819452688 ; , s. 119-128
-
Conference paper (peer-reviewed)abstract
- Practical realizations of 2D (planar) photonics crystal (PhC) are either on a membrane or etched through a conventional heterostructure. While fascinating objects can emerge from the first approach, only the latter approach lends itself to a progressive integration of more compact PhC's towards monolithic PICs based on InP. We describe in this talk the various aspects from technology to functions and devices, as emerged from the European collaboration "PCIC". The main technology tour de force is deep-etching with aspect ratio of about 10 and vertical sidewall, achieved by three techniques (CAIBE, ICP-RIE, ECR-RIE). The basic functions explored are bends, splitters/combiners, mirrors, tapers, and the devices are filters and lasers. At the end of the talk, I will emphasize some positive aspects of "broad" multimode PhC waveguides, in view of compact add-drop filtering action, notably.
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| 10. |
- Dent, W. R. F., et al.
(author)
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GASPS-A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics
- 2013
-
In: Publications of the Astronomical Society of the Pacific. - : IOP Publishing. - 0004-6280 .- 1538-3873. ; 125:927, s. 477-505
-
Journal article (peer-reviewed)abstract
- We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the ACS instrument on the Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted similar to 250 young stars in narrow wavelength regions covering the [OI] fine structure line at 63 mu m the brightest far-infrared line in such objects. A subset of the brightest targets were also surveyed in [OI]145 mu m, [CII] at 157 mu m, as well as several transitions of H2O and high-excitation CO lines at selected wavelengths between 78 and 180 mu m. Additionally, GASPS included continuum photometry at 70, 100 and 160 mu m, around the peak of the dust emission. The targets were SED Class II-III T Tauri stars and debris disks from seven nearby young associations, along with a comparable sample of isolated Herbig AeBe stars. The aim was to study the global gas and dust content in a wide sample of circumstellar disks, combining the results with models in a systematic way. In this overview paper we review the scientific aims, target selection and observing strategy of the program. We summarise some of the initial results, showing line identifications, listing the detections, and giving a first statistical study of line detectability. The [OI] line at 63 mu m was the brightest line seen in almost all objects, by a factor of similar to 10. Overall [OI]63 mu m detection rates were 49%, with 100% of HAeBe stars and 43% of T Tauri stars detected. A comparison with published disk dust masses (derived mainly from sub-mm continuum, assuming standard values of the mm mass opacity) shows a dust mass threshold for [OI] 63 mu m detection of similar to 10(-5) M-circle dot. Normalising to a distance of 140 pc, 84% of objects with dust masses >= 10(-5) M-circle dot can be detected in this line in the present survey; 32% of those of mass 10(-6)-10(-5) M-circle dot, and only a very small number of unusual objects with lower masses can be detected. This is consistent with models with a moderate UV excess and disk flaring. For a given disk mass, [OI] detectability is lower for M stars compared with earlier spectral types. Both the continuum and line emission was, in most systems, spatially and spectrally unresolved and centred on the star, suggesting that emission in most cases was from the disk. Approximately 10 objects showed resolved emission, most likely from outflows. In the GASPS sample, [OI] detection rates in T Tauri associations in the 0.3-4 Myr age range were similar to 50%. For each association in the 5-20 Myr age range, similar to 2 stars remain detectable in [OI]63 mu m, and no systems were detected in associations with age >20 Myr. Comparing with the total number of young stars in each association, and assuming a ISM-like gas/dust ratio, this indicates that similar to 18% of stars retain a gas-rich disk of total mass similar to 1 M-Jupiter for 1-4 Myr, 1-7% keep such disks for 5-10 Myr, but none are detected beyond 10-20 Myr. The brightest [OI] objects from GASPS were also observed in [OI]145 mu m, [CII]157 mu m and CO J = 18 - 17, with detection rates of 20-40%. Detection of the [CII] line was not correlated with disk mass, suggesting it arises more commonly from a compact remnant envelope.
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| 11. |
- Grant, Sierra L., et al.
(author)
-
MINDS. The Detection of 13 CO 2 with JWST-MIRI Indicates Abundant CO 2 in a Protoplanetary Disk
- 2023
-
In: Astrophysical Journal Letters. - 2041-8213 .- 2041-8205. ; 947:1
-
Journal article (peer-reviewed)abstract
- We present JWST-MIRI Medium Resolution Spectrometer (MRS) spectra of the protoplanetary disk around the low-mass T Tauri star GW Lup from the MIRI mid-INfrared Disk Survey Guaranteed Time Observations program. Emission from 12CO213CO2, H2O, HCN, C2H2, and OH is identified with 13CO2 being detected for the first time in a protoplanetary disk. We characterize the chemical and physical conditions in the inner few astronomical units of the GW Lup disk using these molecules as probes. The spectral resolution of JWST-MIRI MRS paired with high signal-to-noise data is essential to identify these species and determine their column densities and temperatures. The Q branches of these molecules, including those of hot bands, are particularly sensitive to temperature and column density. We find that the 12CO2 emission in the GW Lup disk is coming from optically thick emission at a temperature of ∼400 K. 13CO2 is optically thinner and based on a lower temperature of ∼325 K, and thus may be tracing deeper into the disk and/or a larger emitting radius than 12CO2. The derived N CO 2 / N H 2 O ratio is orders of magnitude higher than previously derived for GW Lup and other targets based on Spitzer-InfraRed-Spectrograph data. This high column density ratio may be due to an inner cavity with a radius in between the H2O and CO2 snowlines and/or an overall lower disk temperature. This paper demonstrates the unique ability of JWST to probe inner disk structures and chemistry through weak, previously unseen molecular features.
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| 12. |
- Mathews, G. S., et al.
(author)
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GAS in Protoplanetary Systems (GASPS) I. First results
- 2010
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L127
-
Journal article (peer-reviewed)abstract
- Context. Circumstellar discs are ubiquitous around young stars, but rapidly dissipate their gas and dust on timescales of a few Myr. The Herschel Space Observatory allows for the study of the warm disc atmosphere, using far-infrared spectroscopy to measure gas content and excitation conditions, and far-IR photometry to constrain the dust distribution. Aims. We aim to detect and characterize the gas content of circumstellar discs in four targets as part of the Herschel science demonstration phase. Methods. We carried out sensitive medium resolution spectroscopy and high sensitivity photometry at gimel similar to 60-190 mu m using the Photodetector Array Camera and Spectrometer instrument on the Herschel Space Observatory. Results. We detect [OI] 63 mu m emission from the young stars HD 169142, TW Hydrae, and RECX 15, but not HD 181327. No other lines, including [CII] 158 and [OI] 145, are significantly detected. All four stars are detected in photometry at 70 and 160 mu m. Extensive models are presented in associated papers.
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| 13. |
- Meeus, G., et al.
(author)
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Gas in the protoplanetary disc of HD 169142: Herschel's view
- 2010
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L124
-
Journal article (peer-reviewed)abstract
- In an effort to simultaneously study the gas and dust components of the disc surrounding the young Herbig Ae star HD 169142, we present far-IR observations obtained with the PACS instrument onboard the Herschel Space Observatory. This work is part of the open time key program GASPS, which is aimed at studying the evolution of protoplanetary discs. To constrain the gas properties in the outer disc, we observed the star at several key gas-lines, including [OI] 63.2 and 145.5 mu m, [CII] 157.7 mu m, CO 72.8 and 90.2 mu m, and o-H2O 78.7 and 179.5 mu m. We only detect the [OI] 63.2 mu m line in our spectra, and derive upper limits for the other lines. We complement our data set with PACS photometry and (CO)-C-12/13 data obtained with the Submillimeter Array. Furthermore, we derive accurate stellar parameters from optical spectra and UV to mm photometry. We model the dust continuum with the 3D radiative transfer code MCFOST and use this model as an input to analyse the gas lines with the thermo-chemical code ProDIMo. Our dataset is consistent with a simple model in which the gas and dust are well-mixed in a disc with a continuous structure between 20 and 200 AU, but this is not a unique solution. Our modelling effort allows us to constrain the gas-to-dust mass ratio as well as the relative abundance of the PAHs in the disc by simultaneously fitting the lines of several species that originate in different regions. Our results are inconsistent with a gas-poor disc with a large UV excess; a gas mass of 5.0 +/- 2.0 x 10(-3) M-circle dot is still present in this disc, in agreement with earlier CO observations.
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| 14. |
- Perotti, G., et al.
(author)
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Water in the terrestrial planet-forming zone of the PDS 70 disk
- 2023
-
In: Nature. - 0028-0836 .- 1476-4687. ; 620:7974, s. 516-520
-
Journal article (peer-reviewed)abstract
- Terrestrial and sub-Neptune planets are expected to form in the inner (less than 10 AU) regions of protoplanetary disks1. Water plays a key role in their formation2,3,4, although it is yet unclear whether water molecules are formed in situ or transported from the outer disk5,6. So far Spitzer Space Telescope observations have only provided water luminosity upper limits for dust-depleted inner disks7, similar to PDS 70, the first system with direct confirmation of protoplanet presence8,9. Here we report JWST observations of PDS 70, a benchmark target to search for water in a disk hosting a large (approximately 54 AU) planet-carved gap separating an inner and outer disk10,11. Our findings show water in the inner disk of PDS 70. This implies that potential terrestrial planets forming therein have access to a water reservoir. The column densities of water vapour suggest in-situ formation via a reaction sequence involving O, H2 and/or OH, and survival through water self-shielding5. This is also supported by the presence of CO2 emission, another molecule sensitive to ultraviolet photodissociation. Dust shielding, and replenishment of both gas and small dust from the outer disk, may also play a role in sustaining the water reservoir12. Our observations also reveal a strong variability of the mid-infrared spectral energy distribution, pointing to a change of inner disk geometry.
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| 15. |
- Pinte, C., et al.
(author)
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The Herschel view of GAS in Protoplanetary Systems (GASPS) First comparisons with a large grid of models
- 2010
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L126
-
Journal article (peer-reviewed)abstract
- The Herschel GASPS key program is a survey of the gas phase of protoplanetary discs, targeting 240 objects which cover a large range of ages, spectral types, and disc properties. To interpret this large quantity of data and initiate self-consistent analyses of the gas and dust properties of protoplanetary discs, we have combined the capabilities of the radiative transfer code MCFOST with the gas thermal balance and chemistry code ProDiMo to compute a grid of approximate to 300 000 disc models (DENT). We present a comparison of the first Herschel/GASPS line and continuum data with the predictions from the DENT grid of models. Our objective is to test some of the main trends already identified in the DENT grid, as well as to define better empirical diagnostics to estimate the total gas mass of protoplanetary discs. Photospheric UV radiation appears to be the dominant gas-heating mechanism for Herbig stars, whereas UV excess and/or X-rays emission dominates for T Tauri stars. The DENT grid reveals the complexity in the analysis of far-IR lines and the difficulty to invert these observations into physical quantities. The combination of Herschel line observations with continuum data and/or with rotational lines in the (sub-)millimetre regime, in particular CO lines, is required for a detailed characterisation of the physical and chemical properties of circumstellar discs.
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| 16. |
- Röllig, M., et al.
(author)
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A photon dominated region code comparison study
- 2007
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 467:No. 1 (May III 2007), s. 187-206
-
Journal article (peer-reviewed)abstract
- Aims.We present a comparison between independent computer codes, modeling the physics and chemistry of interstellar photon dominated regions (PDRs). Our goal was to understand the mutual differences in the PDR codes and their effects on the physical and chemical structure of the model clouds, and to converge the output of different codes to a common solution.Methods. A number of benchmark models have been created, covering low and high gas densities n = 103,105.5 cm-3 and far ultraviolet intensities $\chi$ = 10, 105 in units of the Draine field (FUV: 6
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| 17. |
- Tabone, B., et al.
(author)
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A rich hydrocarbon chemistry and high C to O ratio in the inner disk around a very low-mass star
- 2023
-
In: Nature Astronomy. - 2397-3366. ; 7:7, s. 805-814
-
Journal article (peer-reviewed)abstract
- Carbon is an essential element for life but how much can be delivered to young planets is still an open question. The chemical characterization of planet-forming disks is a crucial step in our understanding of the diversity and habitability of exoplanets. Very low-mass stars (less than 0.2 M⊙) are interesting targets because they host a rich population of terrestrial planets. Here we present the James Webb Space Telescope detection of abundant hydrocarbons in the disk of a very low-mass star obtained as part of the Mid-InfraRed Instrument mid-INfrared Disk Survey (MINDS). In addition to very strong and broad emission from C2H2 and its 13C12CH2 isotopologue, C4H2, benzene and possibly CH4 are identified, but water, polycyclic aromatic hydrocarbons and silicate features are weak or absent. The lack of small silicate grains indicates that we can look deep down into this disk. These detections testify to an active warm hydrocarbon chemistry with a high C/O ratio larger than unity in the inner 0.1 astronomical units (AU) of this disk, perhaps due to destruction of carbonaceous grains. The exceptionally high C2H2/CO2 and C2H2/H2O column density ratios indicate that oxygen is locked up in icy pebbles and planetesimals outside the water iceline. This, in turn, will have important consequences for the composition of forming exoplanets.
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| 18. |
- Thi, W. F., et al.
(author)
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Herschel-PACS observation of the 10 Myr old T Tauri disk TW Hya Constraining the disk gas mass
- 2010
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L125
-
Journal article (peer-reviewed)abstract
- Planets are formed in disks around young stars. With an age of similar to 10 Myr, TW Hya is one of the nearest T Tauri stars that is still surrounded by a relatively massive disk. In addition a large number of molecules has been found in the TW Hya disk, making TW Hya the perfect test case in a large survey of disks with Herschel-PACS to directly study their gaseous component. We aim to constrain the gas and dust mass of the circumstellar disk around TW Hya. We observed the fine-structure lines of [OI] and [CII] as part of the open-time large program GASPS. We complement this with continuum data and ground-based (12) CO 3-2 and (CO)-C-13 3-2 observations. We simultaneously model the continuum and the line fluxes with the 3D Monte-Carlo code MCFOST and the thermo-chemical code ProDiMo to derive the gas and dust masses. We detect the [OI] line at 63 mu m. The other lines that were observed, [OI] at 145 mu m and [CII] at 157 mu m, are not detected. No extended emission has been found. Preliminary modeling of the photometric and line data assuming [(CO)-C-12]/[(CO)-C-13] = 69 suggests a dust mass for grains with radius
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| 19. |
- Gasman, Danny, et al.
(author)
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MINDS Abundant water and varying C/O across the disk of Sz 98 as seen by JWST/MIRI
- 2023
-
In: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 679
-
Journal article (peer-reviewed)abstract
- Context. The Mid-InfraRed Instrument (MIRI) Medium Resolution Spectrometer (MRS) on board the James Webb Space Telescope (JWST) allows us to probe the inner regions of protoplanetary disks, where the elevated temperatures result in an active chemistry and where the gas composition may dictate the composition of planets forming in this region. The disk around the classical T Tauri star Sz 98, which has an unusually large dust disk in the millimetre with a compact core, was observed with the MRS, and we examine its spectrum here.Aims. We aim to explain the observations and put the disk of Sz 98 in context with other disks, with a focus on the H2O emission through both its ro-vibrational and pure rotational emission. Furthermore, we compare our chemical findings with those obtained for the outer disk from Atacama Large Millimeter/submillimeter Array (ALMA) observations.Methods. In order to model the molecular features in the spectrum, the continuum was subtracted and local thermodynamic equilibrium (LTE) slab models were fitted. The spectrum was divided into different wavelength regions corresponding to H2O lines of different excitation conditions, and the slab model fits were performed individually per region.Results. We confidently detect CO, H2O, OH, CO2, and HCN in the emitting layers. Despite the plethora of H2O lines, the isotopo-logue (H2O)-O-18 is not detected. Additionally, no other organics, including C2H2, are detected. This indicates that the C/O ratio could be substantially below unity, in contrast with the outer disk. The H2O emission traces a large radial disk surface region, as evidenced by the gradually changing excitation temperatures and emitting radii. Additionally, the OH and CO2 emission is relatively weak. It is likely that H2O is not significantly photodissociated, either due to self-shielding against the stellar irradiation, or UV shielding from small dust particles. While H2O is prominent and OH is relatively weak, the line fluxes in the inner disk of Sz 98 are not outliers compared to other disks.Conclusions. The relative emitting strength of the different identified molecular features points towards UV shielding of H2O in the inner disk of Sz 98, with a thin layer of OH on top. The majority of the organic molecules are either hidden below the dust continuum, or not present. In general, the inferred composition points to a sub-solar C/O ratio (<0.5) in the inner disk, in contrast with the larger than unity C/O ratio in the gas in the outer disk found with ALMA.
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| 20. |
- Henning, Thomas, et al.
(author)
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MINDS : The JWST MIRI Mid-INfrared Disk Survey
- 2024
-
In: Publications of the Astronomical Society of the Pacific. - 0004-6280 .- 1538-3873. ; 136:5
-
Journal article (peer-reviewed)abstract
- The study of protoplanetary disks has become increasingly important with the Kepler satellite finding that exoplanets are ubiquitous around stars in our galaxy and the discovery of enormous diversity in planetary system architectures and planet properties. High-resolution near-IR and ALMA images show strong evidence for ongoing planet formation in young disks. The JWST MIRI mid-INfrared Disk Survey (MINDS) aims to (1) investigate the chemical inventory in the terrestrial planet-forming zone across stellar spectral type, (2) follow the gas evolution into the disk dispersal stage, and (3) study the structure of protoplanetary and debris disks in the thermal mid-IR. The MINDS survey will thus build a bridge between the chemical inventory of disks and the properties of exoplanets. The survey comprises 52 targets (Herbig Ae stars, T Tauri stars, very low-mass stars and young debris disks). We primarily obtain MIRI/MRS spectra with high signal-to-noise ratio (∼100–500) covering the complete wavelength range from 4.9 to 27.9 μm. For a handful of selected targets we also obtain NIRSpec IFU high resolution spectroscopy (2.87–5.27 μm). We will search for signposts of planet formation in thermal emission of micron-sized dust—information complementary to near-IR scattered light emission from small dust grains and emission from large dust in the submillimeter wavelength domain. We will also study the spatial structure of disks in three key systems that have shown signposts for planet formation, TW Hya and HD 169142 using the MIRI coronagraph at 15.5 μm and 10.65 μm respectively and PDS 70 using NIRCam imaging in the 1.87 μm narrow and the 4.8 μm medium band filter. We provide here an overview of the MINDS survey and showcase the power of the new JWST mid-IR molecular spectroscopy with the TW Hya disk spectrum where we report the detection of the molecular ion CH3+ and the robust confirmation of HCO+ earlier detected with Spitzer.
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| 21. |
- Kamp, Inga, et al.
(author)
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The chemical inventory of the inner regions of planet-forming disks - the JWST/MINDS program
- 2023
-
In: Faraday discussions. - 1359-6640 .- 1364-5498. ; 245, s. 112-137
-
Journal article (peer-reviewed)abstract
- The understanding of planet formation has changed recently, embracing the new idea of pebble accretion. This means that the influx of pebbles from the outer regions of planet-forming disks to their inner zones could determine the composition of planets and their atmospheres. The solid and molecular components delivered to the planet-forming region can be best characterized by mid-infrared spectroscopy. With Spitzer low-resolution (R = 100, 600) spectroscopy, this approach was limited to the detection of abundant molecules, such as H2O, C2H2, HCN and CO2. This contribution will present the first results of the MINDS (MIRI mid-INfrared Disk Survey, PI:Th Henning) project. Due do the sensitivity and spectral resolution provided by the James Webb Space Telescope (JWST), we now have a unique tool to obtain the full inventory of chemistry in the inner disks of solar-type stars and brown dwarfs, including also less-abundant hydrocarbons and isotopologues. The Integral Field Unit (IFU) capabilities will enable at the same time spatial studies of the continuum and line emission in extended sources such as debris disks, the flying saucer and also the search for mid-IR signatures of forming planets in systems such as PDS 70. These JWST observations are complementary to ALMA and NOEMA observations of outer-disk chemistry; together these datasets will provide an integral view of the processes occurring during the planet-formation phase.
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| 22. |
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| 23. |
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| 24. |
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| 25. |
- Rasmussen, Morten, et al.
(author)
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Ancient human genome sequence of an extinct Palaeo-Eskimo
- 2010
-
In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 463:7282, s. 757-762
-
Journal article (peer-reviewed)abstract
- We report here the genome sequence of an ancient human. Obtained from ∼4,000-year-old permafrost-preserved hair, the genome represents a male individual from the first known culture to settle in Greenland. Sequenced to an average depth of 20×, we recover 79% of the diploid genome, an amount close to the practical limit of current sequencing technologies. We identify 353,151 high-confidence single-nucleotide polymorphisms (SNPs), of which 6.8% have not been reported previously. We estimate raw read contamination to be no higher than 0.8%. We use functional SNP assessment to assign possible phenotypic characteristics of the individual that belonged to a culture whose location has yielded only trace human remains. We compare the high-confidence SNPs to those of contemporary populations to find the populations most closely related to the individual. This provides evidence for a migration from Siberia into the New World some 5,500 years ago, independent of that giving rise to the modern Native Americans and Inuit.
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| 26. |
- Schwarz, Kamber R., et al.
(author)
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MINDS. JWST/MIRI Reveals a Dynamic Gas-rich Inner Disk inside the Cavity of SY Cha
- 2024
-
In: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 962:1
-
Journal article (peer-reviewed)abstract
- SY Cha is a T Tauri star surrounded by a protoplanetary disk with a large cavity seen in the millimeter continuum but has the spectral energy distribution of a full disk. Here we report the first results from JWST/Mid-InfraRed Instrument (MIRI) Medium Resolution Spectrometer (MRS) observations taken as part of the MIRI mid-INfrared Disk Survey (MINDS) GTO Program. The much improved resolution and sensitivity of MIRI-MRS compared to Spitzer enables a robust analysis of the previously detected H2O, CO, HCN, and CO2 emission as well as a marginal detection of C2H2. We also report the first robust detection of mid-infrared OH and rovibrational CO emission in this source. The derived molecular column densities reveal the inner disk of SY Cha to be rich in both oxygen- and carbon-bearing molecules. This is in contrast to PDS 70, another protoplanetary disk with a large cavity observed with JWST, which displays much weaker line emission. In the SY Cha disk, the continuum, and potentially the line, flux varies substantially between the new JWST observations and archival Spitzer observations, indicative of a highly dynamic inner disk.
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| 27. |
- van der Wiel, M. H. D., et al.
(author)
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Signatures of warm carbon monoxide in protoplanetary discs observed with Herschel SPIRE
- 2014
-
In: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 444:4, s. 3911-3925
-
Journal article (peer-reviewed)abstract
- Molecular gas constitutes the dominant mass component of protoplanetary discs. To date, these sources have not been studied comprehensively at the longest far-infrared and shortest submillimetre wavelengths. This paper presents Herschel SPIRE FTS spectroscopic observations towards 18 protoplanetary discs, covering the entire 450-1540 GHz (666-195 mu m) range at upsilon/Delta upsilon approximate to 400-1300. The spectra reveal clear detections of the dust continuum and, in six targets, a significant amount of spectral line emission primarily attributable to (CO)-C-12 rotational lines. Other targets exhibit little to no detectable spectral lines. Low signal-to-noise detections also include signatures from (CO)-C-13, [C I] and HCN. For completeness, we present upper limits of non-detected lines in all targets, including low-energy transitions of H2O and CH+ molecules. The 10 (CO)-C-12 lines that fall within the SPIRE FTS bands trace energy levels of similar to 50-500 K. Combined with lower and higher energy lines from the literature, we compare the CO rotational line energy distribution with detailed physical-chemical models, for sources where these are available and published. Our (CO)-C-13 line detections in the disc around Herbig Be star HD 100546 exceed, by factors of similar to 10-30, the values predicted by a model that matches a wealth of other observational constraints, including the SPIRE (CO)-C-12 ladder. To explain the observed (CO)-C-12/(CO)-C-13 ratio, it may be necessary to consider the combined effects of optical depth and isotope selective (photo) chemical processes. Considering the full sample of 18 objects, we find that the strongest line emission is observed in discs around Herbig Ae/Be stars, although not all show line emission. In addition, two of the six T Tauri objects exhibit detectable (CO)-C-12 lines in the SPIRE range.
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| 28. |
- Barrado, David, et al.
(author)
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15NH3 in the atmosphere of a cool brown dwarf
- 2023
-
In: Nature. - 0028-0836 .- 1476-4687. ; 624:7991, s. 263-266
-
Journal article (peer-reviewed)abstract
- Brown dwarfs serve as ideal laboratories for studying the atmospheres of giant exoplanets on wide orbits, as the governing physical and chemical processes within them are nearly identical. Understanding the formation of gas-giant planets is challenging, often involving the endeavour to link atmospheric abundance ratios, such as the carbon-to-oxygen (C/O) ratio, to formation scenarios. However, the complexity of planet formation requires further tracers, as the unambiguous interpretation of the measured C/O ratio is fraught with complexity. Isotope ratios, such as deuterium to hydrogen and 14N/15N, offer a promising avenue to gain further insight into this formation process, mirroring their use within the Solar System. For exoplanets, only a handful of constraints on 12C/13C exist, pointing to the accretion of 13C-rich ice from beyond the CO iceline of the disks. Here we report on the mid-infrared detection of the 14NH3 and 15NH3 isotopologues in the atmosphere of a cool brown dwarf with an effective temperature of 380 K in a spectrum taken with the Mid-Infrared Instrument (MIRI) of JWST. As expected, our results reveal a 14N/15N value consistent with star-like formation by gravitational collapse, demonstrating that this ratio can be accurately constrained. Because young stars and their planets should be more strongly enriched in the 15N isotope, we expect that 15NH3 will be detectable in several cold, wide-separation exoplanets.
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| 29. |
- Cataldi, Gianni, et al.
(author)
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ALMA Resolves C i Emission from the β Pictoris Debris Disk
- 2018
-
In: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 861:1
-
Journal article (peer-reviewed)abstract
- The debris disk around β Pictoris is known to contain gas. Previous ALMA observations revealed a CO belt at ∼85 au with a distinct clump, interpreted as a location of enhanced gas production. Photodissociation converts CO into C and O within ∼50 a. We resolve C i emission at 492 GHz using ALMA and study its spatial distribution. C i shows the same clump as seen for CO. This is surprising, as C is expected to quickly spread in azimuth. We derive a low C mass (between 5 ×10-4and 3.1 ×10-3), indicating that gas production started only recently (within ∼5000 a). No evidence is seen for an atomic accretion disk inward of the CO belt, perhaps because the gas did not yet have time to spread radially. The fact that C and CO share the same asymmetry argues against a previously proposed scenario where the clump is due to an outward-migrating planet trapping planetesimals in a resonance, nor can the observations be explained by an eccentric planetesimal belt secularly forced by a planet. Instead, we suggest that the dust and gas disks should be eccentric. Such a configuration, we further speculate, might be produced by a recent tidal disruption event. Assuming that the disrupted body has had a CO mass fraction of 10%, its total mass would be 3 MMoon.
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| 30. |
- Cataldi, Gianni, et al.
(author)
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Constraints on the gas content of the Fomalhaut debris belt Can gas-dust interactions explain the belt's morphology?
- 2015
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 574
-
Journal article (peer-reviewed)abstract
- Context. The 440 Myr old main-sequence A-star Fomalhaut is surrounded by an eccentric debris belt with sharp edges. This sort of a morphology is usually attributed to planetary perturbations, but the orbit of the only planetary candidate detected so far, Fomalhaut b, is too eccentric to efficiently shape the belt. Alternative models that could account for the morphology without invoking a planet are stellar encounters and gas-dust interactions. Aims. We aim to test the possibility of gas-dust interactions as the origin of the observed morphology by putting upper limits on the total gas content of the Fomalhaut belt. Methods. We derive upper limits on the CII 158 mu m and 01 63 pint emission by using non detections from the Photocletector Array Camera and Spectrometer (PACS) onboard the Herschel Space Observatory. Line fluxes are converted into total gas mass using the non-local thermodynamic equilibrium (non-LTE) code RADEX. We consider two different cases for the elemental abundances of the gas: solar abundances and abundances similar to those observed for the gas in the beta Pictoris debris disc. Results. The gas mass is shown to be below the millimetre dust mass by a factor of at least similar to 3 (for solar abundances) respectively similar to 300 (for beta Pic-like abundances). Conclusions. The lack of gas co-spatial with the dust implies that gas-dust interactions cannot efficiently shape the Fomalhaut debris belt. The morphology is therefore more likely due to a yet unseen planet (Fomalhaut c) or stellar encounters.
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| 31. |
- Cataldi, Gianni, et al.
(author)
-
The Surprisingly Low Carbon Mass in the Debris Disk around HD 32297
- 2020
-
In: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 892:2
-
Journal article (peer-reviewed)abstract
- Gas has been detected in a number of debris disks. It is likely secondary, i.e., produced by colliding solids. Here, we report ALMA Band 8 observations of neutral carbon in the CO-rich debris disk around the 15-30 Myr old A-type star HD 32297. We find that C-0 is located in a ring at similar to 110 au with an FWHM of similar to 80 au and has a mass of (3.5 0.2) x 10(-3) M-circle plus. Naively, such a surprisingly small mass can be accumulated from CO photodissociation in a time as short as similar to 10(4) yr. We develop a simple model for gas production and destruction in this system, properly accounting for CO self-shielding and shielding by neutral carbon, and introducing a removal mechanism for carbon gas. We find that the most likely scenario to explain both C-0 and CO observations is one where the carbon gas is rapidly removed on a timescale of order a thousand years and the system maintains a very high CO production rate of similar to 15 M-circle plus Myr(-1), much higher than the rate of dust grind-down. We propose a possible scenario to meet these peculiar conditions: the capture of carbon onto dust grains, followed by rapid CO re-formation and rerelease. In steady state, CO would continuously be recycled, producing a CO-rich gas ring that shows no appreciable spreading over time. This picture might be extended to explain other gas-rich debris disks.
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| 32. |
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| 33. |
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| 34. |
- Kamp, F, et al.
(author)
-
Sulfonylureas rapidly cross phospholipid bilayer membranes by a free-diffusion mechanism
- 2003
-
In: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 52:10, s. 2526-2531
-
Journal article (peer-reviewed)abstract
- Because sulfonylureas directly activate the exocytotic machinery, we were interested in the extent to which these compounds penetrate the β-cell plasma membrane and the underlying molecular mechanism(s). We now provide evidence that sulfonylureas cross phospholipid bilayer membranes rapidly and effectively by a free-diffusion mechanism. Two sulfonylurea compounds investigated by 1H nuclear magnetic resonance spectroscopy, glibenclamide and tolbutamide, were found to incorporate into phospholipid bilayers, with the ionizable sulfonamide exposed to the aqueous interface and its apparent dissociation constant (pKa) increased to ∼7.0. Diffusion of weak amphiphilic acids across membranes is associated with a measurable change in pH. Thus, by using a fluorescence-based pH assay, we could investigate the diffusion of sulfonylurea compounds across phospholipid bilayer membranes. A fluorescent pH indicator (pyranin or [2′,7′-bis (2-carboxyethyl)-5(6)-carboxyfluorescein] [BCECF]) was trapped in egg phosphatidylcholine vesicles. Addition of glibenclamide decreased internal pH (pHin), and addition of albumin reversed this drop by 50%. With the same amount of tolbutamide, the decrease in pHin was much smaller, primarily because of the lower partitioning of tolbutamide into phospholipid bilayers. Using similar protocols, we also demonstrated diffusion by the same mechanism across the β-cell plasma membrane. Thus, we now provide a molecular mechanism by which sulfonylureas can penetrate the plasma membrane and reach intracellular sites regulating exocytosis.
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| 35. |
- Kamp, I., et al.
(author)
-
The formation of planetary systems with SPICA
- 2021
-
In: Publications Astronomical Society of Australia. - : Cambridge University Press (CUP). - 1323-3580 .- 1448-6083. ; 38
-
Journal article (peer-reviewed)abstract
- In this era of spatially resolved observations of planet-forming disks with Atacama Large Millimeter Array (ALMA) and large groundbased telescopes such as the Very Large Telescope (VLT), Keck, and Subaru, we still lack statistically relevant information on the quantity and composition of the material that is building the planets, such as the total disk gas mass, the ice content of dust, and the state of water in planetesimals. SPace Infrared telescope for Cosmology and Astrophysics (SPICA) is an infrared space mission concept developed jointly by Japan Aerospace Exploration Agency (JAXA) and European Space Agency (ESA) to address these questions. The key unique capabilities of SPICA that enable this research are (1) the wide spectral coverage 10-220 mu m, (2) the high line detection sensitivity of (1-2) x10(-19)Wm(-2) with R similar to 2 000-5 000 in the far-IR (SAFARI), and 10-20Wm(-2) with R similar to 29 000 in themid-IR (SPICA Mid-infrared Instrument (SMI), spectrally resolving line profiles), (3) the high far-IR continuum sensitivity of 0.45mJy (SAFARI), and (4) the observing efficiency for point source surveys. This paper details how mid- to far-IR infrared spectra will be unique in measuring the gas masses and water/ice content of disks and how these quantities evolve during the planet-forming period. These observations will clarify the crucial transition when disks exhaust their primordial gas and further planet formation requires secondary gas produced from planetesimals. The high spectral resolution mid-IR is also unique for determining the location of the snowline dividing the rocky and icy mass reservoirs within the disk and how the divide evolves during the build-up of planetary systems. Infrared spectroscopy (mid- to far-IR) of key solid-state bands is crucial for assessing whether extensive radial mixing, which is part of our Solar System history, is a general process occurring in most planetary systems and whether extrasolar planetesimals are similar to our Solar System comets/asteroids. We demonstrate that the SPICA mission concept would allow us to achieve the above ambitious science goals through large surveys of several hundred disks within similar to 2.5 months of observing time.
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| 36. |
- Krebs, Alice, et al.
(author)
-
Template for the Description of Cell-Based Toxicological Test Methods to Allow Evaluation and Regulatory Use of the Data
- 2019
-
In: Altex. - : ALTEX Edition. - 1868-596X .- 1868-8551. ; 36:4, s. 682-699
-
Journal article (other academic/artistic)abstract
- Only few cell-based test methods are described by Organisation for Economic Co-operation and Development (OECD) test guidelines or other regulatory references (e.g., the European Pharmacopoeia). The majority of toxicity tests still falls into the category of non-guideline methods. Data from these tests may nevertheless be used to support regulatory decisions or to guide strategies to assess compounds (e.g., drugs, agrochemicals) during research and development if they fulfill basic requirements concerning their relevance, reproducibility and predictivity. Only a method description of sufficient clarity and detail allows interpretation and use of the data. To guide regulators faced with increasing amounts of data from non-guideline studies, the OECD formulated Guidance Document 211 (GD211) on method documentation for the purpose of safety assessment. As GD211 is targeted mainly at regulators, it leaves scientists less familiar with regulation uncertain as to what level of detail is required and how individual questions should be answered. Moreover, little attention was given to the description of the test system (i.e., cell culture) and the steps leading to it being established in the guidance. To address these issues, an annotated toxicity test method template (ToxTemp) was developed (i) to fulfill all requirements of GD211, (ii) to guide the user concerning the types of answers and detail of information required, (iii) to include acceptance criteria for test elements, and (iv) to define the cells sufficiently and transparently. The fully annotated ToxTemp is provided here, together with reference to a database containing exemplary descriptions of more than 20 cell-based tests.
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| 37. |
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| 38. |
- Morrison, C. A., et al.
(author)
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Bird population declines and species turnover are changing the acoustic properties of spring soundscapes
- 2021
-
In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
-
Journal article (peer-reviewed)abstract
- Natural sounds, and bird song in particular, play a key role in building and maintaining our connection with nature, but widespread declines in bird populations mean that the acoustic properties of natural soundscapes may be changing. Using data-driven reconstructions of soundscapes in lieu of historical recordings, here we quantify changes in soundscape characteristics at more than 200,000 sites across North America and Europe. We integrate citizen science bird monitoring data with recordings of individual species to reveal a pervasive loss of acoustic diversity and intensity of soundscapes across both continents over the past 25 years, driven by changes in species richness and abundance. These results suggest that one of the fundamental pathways through which humans engage with nature is in chronic decline, with potentially widespread implications for human health and well-being.
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| 39. |
- Pennings, M., et al.
(author)
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KIF1A variants are a frequent cause of autosomal dominant hereditary spastic paraplegia
- 2020
-
In: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 28, s. 40-49
-
Journal article (peer-reviewed)abstract
- Variants in the KIF1A gene can cause autosomal recessive spastic paraplegia 30, autosomal recessive hereditary sensory neuropathy, or autosomal (de novo) dominant mental retardation type 9. More recently, variants in KIF1A have also been described in a few cases with autosomal dominant spastic paraplegia. Here, we describe 20 KIF1A variants in 24 patients from a clinical exome sequencing cohort of 347 individuals with a mostly ‘pure’ spastic paraplegia. In these patients, spastic paraplegia was slowly progressive and mostly pure, but with a highly variable disease onset (0–57 years). Segregation analyses showed a de novo occurrence in seven cases, and a dominant inheritance pattern in 11 families. The motor domain of KIF1A is a hotspot for disease causing variants in autosomal dominant spastic paraplegia, similar to mental retardation type 9 and recessive spastic paraplegia type 30. However, unlike these allelic disorders, dominant spastic paraplegia was also caused by loss-of-function variants outside this domain in six families. Finally, three missense variants were outside the motor domain and need further characterization. In conclusion, KIF1A variants are a frequent cause of autosomal dominant spastic paraplegia in our cohort (6–7%). The identification of KIF1A loss-of-function variants suggests haploinsufficiency as a possible mechanism in autosomal dominant spastic paraplegia. © 2019, The Author(s).
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| 40. |
- Ramírez-Tannus, María Claudia, et al.
(author)
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XUE : Molecular Inventory in the Inner Region of an Extremely Irradiated Protoplanetary Disk
- 2023
-
In: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 958:2
-
Journal article (peer-reviewed)abstract
- We present the first results of the eXtreme UV Environments (XUE) James Webb Space Telescope (JWST) program, which focuses on the characterization of planet-forming disks in massive star-forming regions. These regions are likely representative of the environment in which most planetary systems formed. Understanding the impact of environment on planet formation is critical in order to gain insights into the diversity of the observed exoplanet populations. XUE targets 15 disks in three areas of NGC 6357, which hosts numerous massive OB stars, including some of the most massive stars in our Galaxy. Thanks to JWST, we can, for the first time, study the effect of external irradiation on the inner (<10 au), terrestrial-planet-forming regions of protoplanetary disks. In this study, we report on the detection of abundant water, CO, 12CO2, HCN, and C2H2 in the inner few au of XUE 1, a highly irradiated disk in NGC 6357. In addition, small, partially crystalline silicate dust is present at the disk surface. The derived column densities, the oxygen-dominated gas-phase chemistry, and the presence of silicate dust are surprisingly similar to those found in inner disks located in nearby, relatively isolated low-mass star-forming regions. Our findings imply that the inner regions of highly irradiated disks can retain similar physical and chemical conditions to disks in low-mass star-forming regions, thus broadening the range of environments with similar conditions for inner disk rocky planet formation to the most extreme star-forming regions in our Galaxy.
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| 41. |
- Ross, Alastair, 1976, et al.
(author)
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Perspective: A Definition for Whole-Grain Food Products-Recommendations from the Healthgrain Forum
- 2017
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In: Advances in nutrition (Bethesda, Md.). - : Elsevier BV. - 2161-8313 .- 2156-5376. ; 8:4, s. 525-531
-
Journal article (peer-reviewed)abstract
- Whole grains are a key component of a healthy diet, and enabling consumers to easily choose foods with a high whole-grain content is an important step for better prevention of chronic disease. Several definitions exist for whole-grain foods, yet these do not account for the diversity of food products that contain cereals. With the goal of creating a relatively simple whole-grain food definition that aligns with whole-grain intake recommendations and can be applied across all product categories, the Healthgrain Forum, a not-for-profit consortium of academics and industry working with cereal foods, established a working group to gather input from academics and industry to develop guidance on labeling the whole-grain content of foods. The Healthgrain Forum recommends that a food may be labeled as "whole grain" if it contains ≥30% whole-grain ingredients in the overall product and contains more whole grain than refined grain ingredients, both on a dry-weight basis. For the purposes of calculation, added bran and germ are not considered refined-grain ingredients. Additional recommendations are also made on labeling whole-grain content in mixed-cereal foods, such as pizza and ready meals, and a need to meet healthy nutrition criteria. This definition allows easy comparison across product categories because it is based on dry weight and strongly encourages a move from generic whole-grain labels to reporting the actual percentage of whole grain in a product. Although this definition is for guidance only, we hope that it will encourage more countries to adopt regulation around the labeling of whole grains and stimulate greater awareness and consumption of whole grains in the general population.
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| 42. |
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| 43. |
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| 44. |
- Stansfeld, S A, et al.
(author)
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Aircraft and road traffic noise and children's cognition and health: a cross-national study.
- 2005
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In: Lancet. - 1474-547X .- 0140-6736. ; 365:9475, s. 1942-9
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Exposure to environmental stressors can impair children's health and their cognitive development. The effects of air pollution, lead, and chemicals have been studied, but there has been less emphasis on the effects of noise. Our aim, therefore, was to assess the effect of exposure to aircraft and road traffic noise on cognitive performance and health in children. METHODS: We did a cross-national, cross-sectional study in which we assessed 2844 of 3207 children aged 9-10 years who were attending 89 schools of 77 approached in the Netherlands, 27 in Spain, and 30 in the UK located in local authority areas around three major airports. We selected children by extent of exposure to external aircraft and road traffic noise at school as predicted from noise contour maps, modelling, and on-site measurements, and matched schools within countries for socioeconomic status. We measured cognitive and health outcomes with standardised tests and questionnaires administered in the classroom. We also used a questionnaire to obtain information from parents about socioeconomic status, their education, and ethnic origin. FINDINGS: We identified linear exposure-effect associations between exposure to chronic aircraft noise and impairment of reading comprehension (p=0.0097) and recognition memory (p=0.0141), and a non-linear association with annoyance (p<0.0001) maintained after adjustment for mother's education, socioeconomic status, longstanding illness, and extent of classroom insulation against noise. Exposure to road traffic noise was linearly associated with increases in episodic memory (conceptual recall: p=0.0066; information recall: p=0.0489), but also with annoyance (p=0.0047). Neither aircraft noise nor traffic noise affected sustained attention, self-reported health, or overall mental health. INTERPRETATION: Our findings indicate that a chronic environmental stressor-aircraft noise-could impair cognitive development in children, specifically reading comprehension. Schools exposed to high levels of aircraft noise are not healthy educational environments.
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| 45. |
- Sutcliffe, Laura M. E., et al.
(author)
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Harnessing the biodiversity value of Central and Eastern European farmland
- 2015
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In: Diversity & distributions. - : Wiley. - 1366-9516 .- 1472-4642. ; 21:6, s. 722-730
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Journal article (peer-reviewed)abstract
- A large proportion of European biodiversity today depends on habitat provided by low-intensity farming practices, yet this resource is declining as European agriculture intensifies. Within the European Union, particularly the central and eastern new member states have retained relatively large areas of species-rich farmland, but despite increased investment in nature conservation here in recent years, farmland biodiversity trends appear to be worsening. Although the high biodiversity value of Central and Eastern European farmland has long been reported, the amount of research in the international literature focused on farmland biodiversity in this region remains comparatively tiny, and measures within the EU Common Agricultural Policy are relatively poorly adapted to support it. In this opinion study, we argue that, 10years after the accession of the first eastern EU new member states, the continued under-representation of the low-intensity farmland in Central and Eastern Europe in the international literature and EU policy is impeding the development of sound, evidence-based conservation interventions. The biodiversity benefits for Europe of existing low-intensity farmland, particularly in the central and eastern states, should be harnessed before they are lost. Instead of waiting for species-rich farmland to further decline, targeted research and monitoring to create locally appropriate conservation strategies for these habitats is needed now.
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| 46. |
- van der Stel, Wanda, et al.
(author)
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New Approach Methods (NAMs) Supporting Read-Across : Two Neurotoxicity AOP-based IATA Case Studies
- 2021
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In: Altex. - : ALTEX Edition. - 1868-596X .- 1868-8551. ; 38:4, s. 615-635
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Journal article (peer-reviewed)abstract
- Read-across approaches are considered key in moving away from in vivo animal testing towards addressing data-gaps using new approach methods (NAMs). Ample successful examples are still required to substantiate this strategy. Here we present and discuss the learnings from two OECD IATA endorsed read-across case studies. They involve two classes of pesticides - rotenoids and strobilurins - each having a defined mode-of-action that is assessed for its neurological hazard by means of an AOP-based testing strategy coupled to toxicokinetic simulations of human tissue concentrations. The endpoint in question is potential mitochondrial respiratory chain mediated neurotoxicity, specifically through inhibition of complex I or III. An AOP linking inhibition of mitochondrial respiratory chain complex I to the degeneration of dopaminergic neurons formed the basis for both cases but was deployed in two different regulatory contexts. The two cases also exemplify several different read-across concepts: analogue versus category approach, consolidated versus putative AOP, positive versus negative prediction (i.e., neurotoxicity versus low potential for neurotoxicity), and structural versus biological similarity. We applied a range of NAMs to explore the toxicodynamic properties of the compounds, e.g., in silico docking as well as in vitro assays and readouts - including transcriptomics - in various cell systems, all anchored to the relevant AOPs. Interestingly, although some of the data addressing certain elements of the read-across were associated with high uncertainty, their impact on the overall read-across conclusion remained limited. Coupled to the elaborate regulatory review that the two cases underwent, we propose some generic learnings of AOP-based testing strategies supporting read-across.
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- Wiemerslage, Lyle, et al.
(author)
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A DNA methylation site within the KLF13 gene is associated with orexigenic processes based on neural responses and ghrelin levels
- 2017
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In: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 41:6, s. 990-994
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Journal article (peer-reviewed)abstract
- We investigated five methylation markers recently linked to body-mass index, for their role in the neuropathology of obesity. In neuroimaging experiments, our analysis involving 23 participants showed that methylation levels for the cg07814318 site, which lies within the KLF13 gene, correlated with brain activity in the claustrum, putamen, cingulate gyrus, and frontal gyri, some of which have been previously associated to food signaling, obesity, or reward. Methylation levels at cg07814318 also positively correlated with ghrelin levels. Moreover, expression of KLF13 was augmented in the brains of obese and starved mice. Our results suggest the cg07814318 site could be involved in orexigenic processes, and also implicate KLF13 in obesity. Our findings are the first to associate methylation levels in blood with brain activity in obesity-related regions, and further support previous findings between ghrelin, brain activity, and genetic differences.
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