| 1. |
- Adrian-Martinez, S., et al.
(author)
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A first search for coincident gravitational waves and high energy neutrinos using LIGO, Virgo and ANTARES data from 2007
- 2013
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In: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :6
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Journal article (peer-reviewed)abstract
- We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.
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| 2. |
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| 3. |
- Adrian-Martinez, S., et al.
(author)
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The First Combined Search For Neutrino Point-Sources In The Southern Hemisphere With The Antares And Icecube Neutrino Telescopes
- 2016
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In: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 823:1
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Journal article (peer-reviewed)abstract
- We present the results of searches for point-like sources of neutrinos based on the first combined analysis of data from both the ANTARES and IceCube neutrino telescopes. The combination of both detectors, which differ in size and location, forms a window in the southern sky where the sensitivity to point sources improves by up to a factor of 2 compared with individual analyses. Using data recorded by ANTARES from 2007 to 2012, and by IceCube from 2008 to 2011, we search for sources of neutrino emission both across the southern sky and from a preselected list of candidate objects. No significant excess over background has been found in these searches, and flux upper limits for the candidate sources are presented for E-2.5 and E-2 power-law spectra with different energy cut-offs.
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| 4. |
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| 5. |
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| 6. |
- Feroci, M., et al.
(author)
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The large observatory for x-ray timing
- 2014
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In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9780819496126
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Conference paper (peer-reviewed)abstract
- The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final downselection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supranuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m2 effective area, 2-30 keV, 240 eV spectral resolution, 1° collimated field of view) and a Wide Field Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g. GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the status of the mission at the end of its Phase A study.
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| 7. |
- Ageron, M., et al.
(author)
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ANTARES : The first undersea neutrino telescope
- 2011
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 656:1, s. 11-38
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Journal article (peer-reviewed)abstract
- The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given. (C) 2011 Elsevier B.V. All rights reserved.
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| 8. |
- Ageron, M., et al.
(author)
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The ANTARES optical beacon system
- 2007
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 578:3, s. 498-509
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Journal article (peer-reviewed)abstract
- ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three-dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular, when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented. (C) 2007 Elsevier B.V. All rights reserved.
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| 9. |
- Ageron, M., et al.
(author)
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Studies of a full-scale mechanical prototype line for the ANTARES neutrino telescope and tests of a prototype instrument for deep-sea acoustic measurements
- 2007
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 581:3, s. 695-708
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Journal article (peer-reviewed)abstract
- full-scale mechanical prototype line was deployed to a depth of 2500 m to test the leak tightness of the electronics containers and the pressure-resistant properties of an electromechanical cable under evaluation for use in the ANTARES deep-sea neutrino telescope. During a month-long immersion study, line parameter data were taken using miniature autonomous data loggers and shore-based optical time domain reflectometry. Details of the mechanical prototype line, the electromechanical cable and data acquisition are presented. Data taken during the immersion study revealed deficiencies in the pressure resistance of the electromechanical cable terminations at the entry points to the electronics containers. The improvements to the termination, which have been integrated into subsequent detection lines, are discussed. The line also allowed deep-sea acoustic measurements with a prototype hydrophone system. The technical setup of this system is described, and the first results of the data analysis are presented. (c) 2007 Elsevier B.V. All rights reserved.
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| 10. |
- Aguilar, J. A., et al.
(author)
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First results of the instrumentation line for the deep-sea ANTARES neutrino telescope
- 2006
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In: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 26:4-5, s. 314-324
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Journal article (peer-reviewed)abstract
- In 2005, the ANTARES Collaboration deployed and operated at a depth of 2500 m a so-called Mini Instrumentation Line equipped with Optical Modules (MILOM) at the ANTARES site. The various data acquired during the continuous operation from April to December 2005 of the MILOM confirm the satisfactory performance of the Optical Modules, their front-end electronics and readout system. as well as the calibration devices of the detector. The in situ measurement of the Optical Module time response yields a resolution better than 0.5 ns. The performance of the acoustic positioning system, which enables the spatial reconstruction of the ANTARES detector with a precision of about 10 cm, is verified. These results demonstrate that with the full ANTARES neutrino telescope the design angular resolution of better than 0.3 degrees can be realistically achieved.
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| 11. |
- Aguilar, J. A., et al.
(author)
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The data acquisition system for the ANTARES neutrino telescope
- 2007
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 570:1, s. 107-116
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Journal article (peer-reviewed)abstract
- The ANTARES neutrino telescope is being constructed in the Mediterranean Sea. It consists of a large three-dimensional array of photo-multiplier tubes. The data acquisition system of the detector takes care of the digitisation of the photo-multiplier tube signals, data transport, data filtering, and data storage. The detector is operated using a control program interfaced with all elements. The design and the implementation of the data acquisition system are described. (c) 2006 Elsevier B.V. All rights reserved.
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| 12. |
- Feroci, M., et al.
(author)
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LOFT - The large observatory for x-ray timing
- 2012
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In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE - International Society for Optical Engineering. - 9780819491442 ; , s. 84432D-
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Conference paper (peer-reviewed)abstract
- The LOFT mission concept is one of four candidates selected by ESA for the M3 launch opportunity as Medium Size missions of the Cosmic Vision programme. The launch window is currently planned for between 2022 and 2024. LOFT is designed to exploit the diagnostics of rapid X-ray flux and spectral variability that directly probe the motion of matter down to distances very close to black holes and neutron stars, as well as the physical state of ultradense matter. These primary science goals will be addressed by a payload composed of a Large Area Detector (LAD) and a Wide Field Monitor (WFM). The LAD is a collimated (<1 degree field of view) experiment operating in the energy range 2-50 keV, with a 10 m2 peak effective area and an energy resolution of 260 eV at 6 keV. The WFM will operate in the same energy range as the LAD, enabling simultaneous monitoring of a few-steradian wide field of view, with an angular resolution of <5 arcmin. The LAD and WFM experiments will allow us to investigate variability from submillisecond QPO's to yearlong transient outbursts. In this paper we report the current status of the project.
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| 13. |
- George, T. S., et al.
(author)
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Organic phosphorus in the terrestrial environment : a perspective on the state of the art and future priorities
- 2018
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In: Plant and Soil. - : Springer Netherlands. - 0032-079X .- 1573-5036. ; 427:1-2, s. 191-208
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Journal article (peer-reviewed)abstract
- Background: The dynamics of phosphorus (P) in the environment is important for regulating nutrient cycles in natural and managed ecosystems and an integral part in assessing biological resilience against environmental change. Organic P (P-o) compounds play key roles in biological and ecosystems function in the terrestrial environment being critical to cell function, growth and reproduction.Scope: We asked a group of experts to consider the global issues associated with P-o in the terrestrial environment, methodological strengths and weaknesses, benefits to be gained from understanding the P-o cycle, and to set priorities for P-o research.Conclusions: We identified seven key opportunities for P-o research including: the need for integrated, quality controlled and functionally based methodologies; assessment of stoichiometry with other elements in organic matter; understanding the dynamics of P-o in natural and managed systems; the role of microorganisms in controlling P-o cycles; the implications of nanoparticles in the environment and the need for better modelling and communication of the research. Each priority is discussed and a statement of intent for the P-o research community is made that highlights there are key contributions to be made toward understanding biogeochemical cycles, dynamics and function of natural ecosystems and the management of agricultural systems.
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| 14. |
- Ageron, M., et al.
(author)
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Performance of the first ANTARES detector line
- 2009
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In: Astroparticle physics. - : Elsevier BV. - 0927-6505 .- 1873-2852. ; 31:4, s. 277-283
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Journal article (peer-reviewed)abstract
- In this paper we report on the data recorded with the first Antares detector line. The line was deployed on the 14th of February 2006 and was connected to the readout 2 weeks later. Environmental data for one and a half years of running are shown. Measurements of atmospheric muons from data taken from selected runs during the first 6 months of operation are presented. Performance figures in terms of time residuals and angular resolution are given. Finally the angular distribution of atmospheric muons is presented and from this the depth profile of the muon intensity is derived. (C) 2009 Elsevier B.V. All rights reserved.
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| 15. |
- Burd, Adrian B., et al.
(author)
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Assessing the Apparent Imbalance Between Geochemical and Biochemical Indicators of Meso- and Bathypelagic Biological Activity: What the @$#! is wrong with present calculations of carbon budgets?
- 2010
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In: Deep-sea research. Part II, Topical studies in oceanography. - : Elsevier BV. - 0967-0645 .- 1879-0100. ; 57:16, s. 1557-1571
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Journal article (peer-reviewed)abstract
- Metabolic activity in the water column below the euphotic zone is ultimately fuelled by the vertical flux of organic material from the surface. Over time, the deep ocean is presumably at steady state, with sources and sinks balanced. But recently compiled global budgets and intensive local field studies suggest that estimates of metabolic activity in the dark ocean exceed the influx of organic substrates. This imbalance indicates either the existence of unaccounted sources of organic carbon or that metabolic activity in the dark ocean is being over-estimated. Budgets of organic carbon flux and metabolic activity in the dark ocean have uncertainties associated with environmental variability, measurement capabilities, conversion parameters, and processes that are not well sampled. We present these issues and quantify associated uncertainties where possible, using a Monte Carlo analysis of a published data set to determine the probability that the imbalance can be explained purely by uncertainties in measurements and conversion factors. A sensitivity analysis demonstrates that the bacterial growth efficiencies and assumed cell carbon contents have the greatest effects on the magnitude of the carbon imbalance. Two poorly quantified sources, lateral advection of particles and a population of slowly settling particles, are discussed as providing a means of closing regional carbon budgets. Finally, we make recommendations concerning future research directions to reduce important uncertainties and allow a better determination of the magnitude and causes of the unbalanced carbon budgets. (C) 2010 Elsevier Ltd. All rights reserved.
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| 16. |
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| 17. |
- Barbieri, C., et al.
(author)
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Astronomical applications of quantum optics for extremely large telescopes
- 2007
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In: Journal of Modern Optics. - 0950-0340. ; 54:2-3, s. 191-197
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Journal article (peer-reviewed)abstract
- A programme has been started to investigate photon properties that are not currently exploited in astronomical instruments, namely second- and higher-order coherence functions encoded in their arrival time, and the orbital angular momentum. This paper expounds the first results achieved in the study of a novel astronomical photometer capable of pushing time tagging towards the picosecond region. This conceptual device has been developed as a possible focal plane instrument for the future OverWhelmingly Large Telescope (OWL) of the European Southern Observatory. This instrument has been named QuantEYE, that is, the Quantum Eye of OWL.
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| 18. |
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| 19. |
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| 20. |
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| 21. |
- Nagata, Toshi, et al.
(author)
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Emerging concepts on microbial processes in the bathypelagic ocean – ecology, biogeochemistry and genomics
- 2010
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In: Deep-sea research. Part II, Topical studies in oceanography. - : Elsevier BV. - 0967-0645 .- 1879-0100. ; 57:16, s. 1519-1536
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Journal article (peer-reviewed)abstract
- This paper synthesizes recent findings regarding microbial distributions and processes in the bathypelagic ocean (depth > 1000 m). Abundance, production and respiration of prokaryotes reflect supplies of particulate and dissolved organic matter to the bathypelagic zone. Better resolution of carbon fluxes mediated by deep microbes requires further testing on the validity of conversion factors. Archaea, especially marine Crenarchaeota Group I, are abundant in deep waters where they can fix dissolved inorganic carbon. Viruses appear to be important in the microbial loop in deep waters, displaying remarkably high virus to prokaryote abundance ratios in some oceanic regions. Sequencing of 18S rRNA genes revealed a tremendous diversity of small-sized protists in bathypelagic waters. Abundances of heterotrophic nanoflagellates (HNF) and ciliates decrease with depth more steeply than prokaryotes; nonetheless, data indicated that HNF consumed half of prokaryote production in the bathypelagic zone. Aggregates are important habitats for deep-water microbes, which produce more extracellular enzymes (on a per-cell basis) than surface communities. The theory of marine gel formation provides a framework to unravel complex interactions between microbes and organic polymers. Recent data on the effects of hydrostatic pressure on microbial activities indicate that bathypelagic microbial activity is generally higher under in situ pressure conditions than at atmospheric pressures. High-throughput sequencing of 16S rRNA genes revealed a remarkable diversity of Bacteria in the bathypelagic ocean. Metagenomics and comparative genomics of piezophiles reveal not only the high diversity of deep sea microbes but also specific functional attributes of these piezophilic microbes, interpreted as an adaptation to the deep water environment. Taken together, the data compiled on bathypelagic microbes indicate that, despite high-pressure and low-temperature conditions, microbes in the bathypelagic ocean dynamically interact with complex mixtures of organic matter, responding to changes in the ocean's biogeochemical state.
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| 22. |
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| 23. |
- Tamburini, F., et al.
(author)
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Photon orbital angular momentum and mass in a plasma vortex
- 2010
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In: Europhysics letters. - : IOP Publishing. - 0295-5075 .- 1286-4854. ; 90:4, s. 45001-
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Journal article (peer-reviewed)abstract
- We analyse the Anderson-Higgs mechanism of photon mass acquisition in a plasma and study the contribution to the mass from the orbital angular momentum acquired by a beam of photons when it crosses a spatially structured charge distribution. To this end we apply Proca-Maxwell equations in a static plasma with a particular spatial distribution of free charges, notably a plasma vortex, that is able to impose orbital angular momentum (OAM) onto light. In addition to the mass acquisition of the conventional Anderson-Higgs mechanism, we find that the photon acquires an additional mass from the OAM and that this mass reduces the Proca photon mass.
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