| 11. |
- Labiano, A., et al.
(author)
-
Wavelength calibration and resolving power of the JWST MIRI Medium Resolution Spectrometer
- 2021
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 656
-
Journal article (peer-reviewed)abstract
- Context. The Mid-Infrared Instrument (MIRI) onboard the James Webb Space Telescope (JWST) will provide imaging, coronagraphy, low-resolution spectroscopy, and medium-resolution spectroscopy at unprecedented sensitivity levels in the mid-infrared wavelength range. The Medium Resolution Spectrometer (MRS) of MIRI is an integral field spectrograph that provides diffraction-limited spectroscopy between 4.9 and 28.3 μm, within a field of view (FOV) varying from ∼13 to ∼56 arcsec square. The design for MIRI MRS conforms with the goals of the JWST mission to observe high redshift galaxies and to study cosmology as well as observations of galactic objects, and stellar and planetary systems. Aims. From ground testing, we calculate the physical parameters essential for general observers and calibrating the wavelength solution and resolving power of the MRS which is critical for maximizing the scientific performance of the instrument. Methods. We have used ground-based observations of discrete spectral features in combination with Fabry-Perot etalon spectra to characterize the wavelength solution and spectral resolving power of the MRS. We present the methodology used to derive the MRS spectral characterization, which includes the precise wavelength coverage of each MRS sub-band, computation of the resolving power as a function of wavelength, and measuring slice-dependent spectral distortions. Results. The ground calibration of the MRS shows that it will cover the wavelength ranges from 4.9 to 28.3 μm, divided in 12 overlapping spectral sub-bands. The resolving power is R 3500 in channel 1, R 3000 in channel 2, R 2500 in channel 3, and R 1500 in channel 4. The MRS spectral resolution optimizes the sensitivity for detection of spectral features with a velocity width of ∼100 km s-1 which is characteristic of most astronomical phenomena JWST aims to study in the mid-infrared. Based on the ground test data, the wavelength calibration accuracy is estimated to be below one-tenth of a pixel (0.1 nm at 5 μm and 0.4 at 28 μm), with small systematic shifts due to the target position within a slice for unresolved sources that have a maximum amplitude of about 0.25 spectral resolution elements. The absolute wavelength calibration is presently uncertain at the level of 0.35 nm at 5 μm and 46 nm at 28 μm, and it will be refined using in-flight commissioning observations. Conclusions. Based on ground test data, the MRS complies with the spectral requirements for both the R and wavelength accuracy for which it was designed. We also present the commissioning strategies and targets that will be followed to update the spectral characterization of the MRS.
|
|
| 12. |
- Burillo, S. G., et al.
(author)
-
High-resolution imaging of the molecular outflows in two mergers: IRAS 17208-0014 and NGC 1614
- 2015
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 580
-
Journal article (peer-reviewed)abstract
- Context. Galaxy evolution scenarios predict that the feedback of star formation and nuclear activity (AGN) can drive the transformation of gas-rich spiral mergers into (ultra) luminous infrared galaxies and, eventually, lead to the build-up of QSO/elliptical hosts. Aims. We study the role that star formation and AGN feedback have in launching and maintaining the molecular outflows in two starburst-dominated advanced mergers, NGC 1614 (DL = 66 Mpc) and IRAS 17208-0014 (DL = 181 Mpc), by analyzing the distribution and kinematics of their molecular gas reservoirs. Both galaxies present evidence of outflows in other phases of their ISM. Methods. We used the Plateau de Bure interferometer (PdBI) to image the CO(10) and CO(21) line emissions in NGC 1614 and IRAS 17208-0014, respectively, with high spatial resolution (0: 0051: 002). The velocity fields of the gas were analyzed and modeled to find the evidence of molecular outflows in these sources and characterize the mass, momentum, and energy of these components. Results. While most (95%) of the CO emission stems from spatially resolved (23 kpc-diameter) rotating disks, we also detect in both mergers the emission from high-velocity line wings that extend up to -500-700 km s1, well beyond the estimated virial range associated with rotation and turbulence. The kinematic major axis of the line-wing emission is tilted by 90 in NGC 1614 and by 180 in IRAS 17208-0014 relative to the major axes of their respective rotating disks. These results can be explained by the existence of non-coplanar molecular outflows in both systems: the outflow axis is nearly perpendicular to the rotating disk in NGC 1614, but it is tilted relative to the angular momentum axis of the rotating disk in IRAS 17208-0014. Conclusions. In stark contrast to NGC 1614, where star formation alone can drive its molecular outflow, the mass, energy, and momentum budget requirements of the molecular outflow in IRAS 17208-0014 can be best accounted for by the existence of a so far undetected (hidden) AGN of LAGN71011 L The geometry of the molecular outflow in IRAS 17208-0014 suggests that the outflow is launched by a non-coplanar disk that may be associated with a buried AGN in the western nucleus.
|
|
| 13. |
- Colina, L., et al.
(author)
-
Uncovering the stellar structure of the dusty star-forming galaxy GN20 at z=4.055 with MIRI/JWST
- 2023
-
In: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 673
-
Journal article (peer-reviewed)abstract
- Luminous infrared galaxies at high redshifts (z > 4) include extreme starbursts that build their stellar mass over short periods of time, that is, of 100 Myr or less. These galaxies are considered to be the progenitors of massive quiescent galaxies at intermediate redshifts (z similar to 2) but their stellar structure and buildup is unknown. Here, we present the first spatially resolved near-infrared (rest-frame 1.1 mu m) imaging of GN20, one of the most luminous dusty star-forming galaxies known to date, observed at an epoch when the Universe was only 1.5 Gyr old. The 5.6 mu m image taken with the JWST Mid-Infrared Instrument (MIRI/JWST) shows that GN20 is a very luminous galaxy (M-1.1 mu m,M- AB = 25.01, uncorrected for internal extinction), with a stellar structure composed of a conspicuous central source and an extended envelope. The central source is an unresolved nucleus that carries 9% of the total flux. The nucleus is co-aligned with the peak of the cold dust emission, and offset by 3.9 kpc from the ultraviolet stellar emission. The diffuse stellar envelope is similar in size (3.6 kpc effective radius) to the clumpy CO molecular gas distribution. The centroid of the stellar envelope is offset by 1 kpc from the unresolved nucleus, suggesting GN20 is involved in an interaction or merger event supported by its location as the brightest galaxy in a proto-cluster. Additional faint stellar clumps appear to be associated with some of the UV- and CO-clumps. The stellar size of GN20 is larger by a factor of about 3 to 5 than known spheroids, disks, and irregulars at z similar to 4, while its size and low Sersic index are similar to those measured in dusty, infrared luminous galaxies at redshift 2 of the same mass (similar to 10(11) M-circle dot). GN20 has all the ingredients necessary for evolving into a massive spheroidal quiescent galaxy at intermediate redshift: it is a large, luminous galaxy at z = 4.05 involved in a short and massive starburst centred in the stellar nucleus and extended over the entire galaxy, out to radii of 4 kpc, and likely induced by the interaction or merger with a member of the proto-cluster.
|
|
| 14. |
- Labiano, A., et al.
(author)
-
The MIRI Medium Resolution Spectrometer calibration pipeline
- 2016
-
In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9781510601994 ; 9910, s. 99102W-
-
Conference paper (peer-reviewed)abstract
- The Mid-Infrared Instrument (MIRI) Medium Resolution Spectrometer (MRS) is the only mid-IR Integral Field Spectrometer on board James Webb Space Telescope. The complexity of the MRS requires a very specialized pipeline, with some specific steps not present in other pipelines of JWST instruments, such as fringe corrections and wavelength offsets, with different algorithms for point source or extended source data. The MRS pipeline has also two different variants: the baseline pipeline, optimized for most foreseen science cases, and the optimal pipeline, where extra steps will be needed for specific science cases. This paper provides a comprehensive description of the MRS Calibration Pipeline from uncalibrated slope images to final scientific products, with brief descriptions of its algorithms, input and output data, and the accessory data and calibration data products necessary to run the pipeline.
|
|
| 15. |
- Zhang, Wennan, et al.
(author)
-
Process simulation of circulating fluidized beds with combustion/gasification of biomass.
- 2002
-
In: Twelfth European Biomass Conference - Biomass for Energy, Industry and Climate Protection. - Florence : ETA. - 889004425X ; , s. 1503-
-
Conference paper (peer-reviewed)abstract
- This paper briefly presents the work carried out for the 4th framework Joule project under the contract JOR3CT980306. The project is to build up an integrated mathematical model to predict reactor performance of biomass circulating fluidized bed boiler/gasifier when reactor design, operating conditions and fuel properties are defined. For CFB boilers, the sub-models of combustion, heat transfer, ash deposition on a heat transfer surface and NOx/N2O emission have been developed, and evaluated against the 12 MW Chalmers CFB boiler. For CFB gasifiers, the sub-models of gasification, heat transfer, NH3/HCN emission, alkali ash and tar emissions from the gasifiers are developed. The results have been checked on Sanya 6MW industrial biomass CFB gasifier.
|
|
| 16. |
- Álvarez-Márquez, J., et al.
(author)
-
Investigating the physical properties of galaxies in the Epoch of Reionization with MIRI/JWST spectroscopy
- 2019
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 629
-
Journal article (peer-reviewed)abstract
- The James Webb Space Telescope (JWST) will provide deep imaging and spectroscopy for sources at redshifts above 6, covering the entire Epoch of Reionization (EoR, 6 < z < 10), and enabling the detailed exploration of the nature of the different sources during the first 1 Gyr of the history of the Universe. The Medium Resolution Spectrograph (MRS) of the mid-IR Instrument (MIRI) will be the only instrument on board JWST able to observe the brightest optical emission lines H alpha and [OII]0.5007 mu m at redshifts above 7 and 9, respectively, providing key insights into the physical properties of sources during the early phases of the EoR. This paper presents a study of the Ha fluxes predicted by state-of-the-art FIRSTLIGHT cosmological simulations for galaxies at redshifts of 6.5-10.5, and its detectability with MIRI. Deep (40 ks) spectroscopic integrations with MRS will be able to detect (signal-to-noise ratio > 5) EoR sources at redshifts above 7 with intrinsic star formation rates (SFR) of more than 2M(circle dot) yr(-1), and stellar masses above 4-9 x 10(7) M-circle dot. These limits cover the upper end of the SFR and stellar mass distribution at those redshifts, representing similar to 6% and similar to 1% of the predicted FIRSTLIGHT population at the 6.5-7.5 and 7.5-8.5 redshift ranges, respectively. In addition, the paper presents realistic MRS simulated observations of the expected rest-frame optical and near-infrared spectra for some spectroscopically confirmed EoR sources recently detected by ALMA as [OIII]88 mu m emitters. The MRS simulated spectra cover a wide range of low metallicities from about 0.2-0.02Z(circle dot) and different [OIII]88 mu m/[OIII]0.5007 mu m line ratios. The simulated 10 ks MRS spectra show S/N in the range of 5-90 for H beta, [OIII]0.4959,0.5007 mu m, H alpha and HeI1.083 mu m emission lines of the currently highest spectroscopically confirmed EoR (lensed) source MACS1149-JD1 at a redshift of 9.11, independent of metallicity. In addition, deep 40 ksec simulated spectra of the luminous merger candidate B14-65666 at 7.15 shows the MRS capabilities of detecting, or putting strong upper limits on, the weak [NII]0.6584 mu m. [SII]0.6717,0.6731 mu m, and [SIII] 0.9069,0.9532 mu m emission lines. These observations will provide the opportunity of deriving accurate metallicities in bright EoR sources using the full range of rest-frame optical emission lines up to 1 mu m. In summary, MRS will enable the detailed study of key physical properties such as internal extinction, instantaneous star formation, hardness of the ionizing continuum, and metallicity in bright (intrinsic or lensed) EoR sources.
|
|
| 17. |
- Glasse, A., et al.
(author)
-
The throughput and sensitivity of the JWST mid-infrared instrument
- 2010
-
In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819482211 ; 7731
-
Conference paper (other academic/artistic)abstract
- The Verification Model (VM) of MIRI has recently completed an extensive programme of cryogenic testing, with the Flight Model (FM) now being assembled and made ready to begin performance testing in the next few months. By combining those VM test results which relate to MIRI's scientific performance with measurements made on FM components and sub-assemblies, we have been able to refine and develop the existing model of the instrument's throughput and sensitivity. We present the main components of the model, its correlation with the existing test results and its predictions for MIRI's performance on orbit. © 2010 SPIE.
|
|
| 18. |
- Pereira-Santaella, M., et al.
(author)
-
Physics of ULIRGs with MUSE and ALMA: The PUMA project: II. Are local ULIRGs powered by AGN: The subkiloparsec view of the 220 GHz continuum
- 2021
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 651
-
Journal article (peer-reviewed)abstract
- We analyze new high-resolution (400 pc) ∼220 GHz continuum and CO(2-1) Atacama Large Millimeter Array (ALMA) observations of a representative sample of 23 local (z < 0.165) ultra-luminous infrared systems (ULIRGs; 34 individual nuclei) as part of the "Physics of ULIRGs with MUSE and ALMA"(PUMA) project. The deconvolved half-light radii of the ∼220 GHz continuum sources, rcont, are between < 60 pc and 350 pc (median 80-100 pc). We associate these regions with the regions emitting the bulk of the infrared luminosity (LIR). The good agreement, within a factor of 2, between the observed ∼220 GHz fluxes and the extrapolation of the infrared gray-body as well as the small contributions from synchrotron and free-free emission support this assumption. The cold molecular gas emission sizes, rCO, are between 60 and 700 pc and are similar in advanced mergers and early interacting systems. On average, rCO are ∼2.5 times larger than rcont. Using these measurements, we derived the nuclear LIR and cold molecular gas surface densities (ςLIR = 1011.5-1014.3 L· kpc-2 and ςH2 = 102.9-104.2 M· pc-2, respectively). Assuming that the LIR is produced by star formation, the median ςLIR corresponds to ςSFR = 2500 M· yr-1 kpc-2. This ςSFR implies extremely short depletion times, ςH2/ςSFR < 1-15 Myr, and unphysical star formation efficiencies > 1 for 70% of the sample. Therefore, this favors the presence of an obscured active galactic nucleus (AGN) in these objects that could dominate the LIR. We also classify the ULIRG nuclei in two groups: (a) compact nuclei (rcont < 120 pc) with high mid-infrared excess emission (ΔL6-20 μm/LIR) found in optically classified AGN; and (b) nuclei following a relation with decreasing ΔL6-20 μm/LIR for decreasing rcont. The majority, 60%, of the nuclei in interacting systems lie in the low-rcont end (<120 pc) of this relation, while this is the case for only 30% of the mergers. This suggests that in the early stages of the interaction, the activity occurs in a very compact and dust-obscured region while, in more advanced merger stages, the activity is more extended, unless an optically detected AGN is present. Approximately two-thirds of the nuclei have nuclear radiation pressures above the Eddington limit. This is consistent with the ubiquitous detection of massive outflows in local ULIRGs and supports the importance of the radiation pressure in the outflow launching process.
|
|
| 19. |
- Pereira-Santaella, M., et al.
(author)
-
Spatially resolved cold molecular outflows in ULIRGs
- 2018
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 616
-
Journal article (peer-reviewed)abstract
- We present new CO(2-1) observations of three low-z (d similar to 350 Mpc) ultra-luminous infrared galaxy (ULIRG) systems (six nuclei) observed with the Atacama large millimeter/submillimeter array (ALMA) at high spatial resolution (similar to 500 pc). We detect massive cold molecular gas outflows in five out of six nuclei (M-out - (0.3-5) x 10(8) M-circle dot). These outflows are spatially resolved with deprojected effective radii between 250 pc and 1 kpc although high-velocity molecular gas is detected up to R-max similar to 0.5-1.8 kpc (1-6 kpc deprojected). The mass outflow rates are 12-400 M circle dot yr(-1) and the inclination corrected average velocity of the outflowing gas is 350-550 km s(-1) (v(max) = 500-900 km s(-1)). The origin of these outflows can be explained by the strong nuclear starbursts although the contribution of an obscured active galactic nucleus cannot be completely ruled out. The position angle (PA) of the outflowing gas along the kinematic minor axis of the nuclear molecular disk suggests that the outflow axis is perpendicular to the disk for three of these outflows. Only in one case is the outflow PA clearly not along the kinematic minor axis, which might indicate a different outflow geometry. The outflow depletion times are 15-80 Myr. These are comparable to, although slightly shorter than, the star-formation (SF) depletion times (30-80 Myr). However, we estimate that only 15-30% of the outflowing molecular gas will escape the gravitational potential of the nucleus. The majority of the outflowing gas will return to the disk after 5-10 Myr and become available to form new stars. Therefore, these outflows will not likely completely quench the nuclear starbursts. These star-forming powered molecular outflows would be consistent with being driven by radiation pressure from young stars (i.e., momentum-driven) only if the coupling between radiation and dust increases with increasing SF rates. This can be achieved if the dust optical depth is higher in objects with higher SF. This is the case in at least one of the studied objects. Alternatively, if the outflows are mainly driven by supernovae (SNe), the coupling efficiency between the interstellar medium and SNe must increase with increasing SF levels. The relatively small sizes (<1 kpc) and dynamical times (<3 Myr) of the cold molecular outflows suggests that molecular gas cannot survive longer in the outflow environment or that it cannot form efficiently beyond these distances or times. In addition, the ionized and hot molecular phases have been detected for several of these outflows, so this suggests that outflowing gas can experience phase changes and indicates that the outflowing gas is intrinsically multiphase, likely sharing similar kinematics, but different mass and, therefore, different energy and momentum contributions.
|
|
| 20. |
- Tengstrand, Olof, et al.
(author)
-
The X-ray view of giga-hertz peaked spectrum radio galaxies
- 2009
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 501:1, s. 89-102
-
Journal article (peer-reviewed)abstract
- Context. This paper presents the X-ray properties of a flux- and volume-limited complete sample of 16 giga-hertz peaked spectrum (GPS) galaxies. Aims. This study addresses three basic questions in our understanding of the nature and evolution of GPS sources: a) What is the physical origin of the X-ray emission in GPS galaxies? b) Which physical system is associated with the X-ray obscuration? c) What is the "endpoint" of the evolution of compact radio sources? Methods. We discuss in this paper the results of the X-ray spectral analysis, and compare the X-ray properties of the sample sources with radio observables. Results. We obtain a 100% (94%) detection fraction in the 0.5-2 keV (0.5-10 keV) energy band. GPS galaxy X-ray spectra are typically highly obscured (less than N-H(GPS)greater than = 3 x 10(22) cm(-2); sigma(NH) similar or equal to 0.5 dex). The X-ray column density is larger than the HI column density measured in the radio by a factor 10 to 100. GPS galaxies lie well on the extrapolation to high radio powers of the correlation between radio and X-ray luminosity known in low-luminosity FR I radio galaxies. On the other hand, GPS galaxies exhibit a comparable X-ray luminosity to FR II radio galaxies, notwithstanding their much larger radio luminosity. Conclusions. The X-ray to radio luminosity ratio distribution in our sample is consistent with the bulk of the high-energy emission being produced by the accretion disk, as well as with dynamical models of GPS evolution where X-rays are produced by Compton upscattering of ambient photons. Further support to the former scenario comes from the location of GPS galaxies in the X-ray to O[III] luminosity ratio versus N-H plane. We propose that GPS galaxies are young radio sources, which would reach their full maturity as classical FR II radio galaxies. However, column densities greater than or similar to 10(22) cm(-2) could lead to a significant underestimate of dynamical age determinations based on the hotspot recession velocity measurements.
|
|
