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Author De La Torre Luque, P.; Gaggero, D.; Grasso, D.; Fornieri, O.; Egberts, K.; Steppa, C.; Evoli, C.
Title Galactic diffuse gamma rays meet the PeV frontier Type Journal Article
Year 2023 Publication Astronomy & Astrophysics Abbreviated Journal Astron. Astrophys.
Volume (down) 672 Issue Pages A58 - 11pp
Keywords diffusion; cosmic rays; Galaxy; general; gamma rays; diffuse background
Abstract The Tibet AS gamma and LHAASO collaborations recently reported the observation of a gamma-ray diffuse emission with energy up to the PeV level from the Galactic plane.Aims. We discuss the relevance of non-uniform cosmic-ray transport scenarios and the implications of these results for cosmic-ray physics.Methods. We used the DRAGON and HERMES codes to build high-resolution maps and spectral distributions of that emission for several representative models under the condition that they reproduce a wide set of local cosmic-ray data up to 100 PeV.Results. We show that the energy spectra measured by Tibet AS gamma, LHAASO, ARGO-YBJ, and Fermi-LAT in several regions of interest in the sky can all be reasonably described in terms of the emission arising by the Galactic cosmic-ray “sea”. We also show that all our models are compatible with IceTop gamma-ray upper limits.Conclusions. We compare the predictions of conventional and space-dependent transport models with those data sets. Although the Fermi-LAT, ARGO-YBJ, and LHAASO preliminary data slightly favor this scenario, due to the still large experimental errors, the poorly known source spectral shape at the highest energies, the potential role of spatial fluctuations in the leptonic component, and a possible larger-than-expected contamination due to unresolved sources, a solid confirmation requires further investigations. We discuss which measurements will be most relevant in order to resolve the remaining degeneracy.
Address [Luque, P. De La Torre] Stockholm Univ, Alba Nova, S-10691 Stockholm, Sweden, Email: pedro.delatorreluque@fysik.su.se
Corporate Author Thesis
Publisher Edp Sciences S A Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6361 ISBN Medium
Area Expedition Conference
Notes WOS:000960963900005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5508
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Author HAWC Collaboration (Alfaro, R. et al); Salesa Greus, F.
Title Validation of standardized data formats and tools for ground-level particle-based gamma-ray observatories Type Journal Article
Year 2022 Publication Astronomy & Astrophysics Abbreviated Journal Astron. Astrophys.
Volume (down) 667 Issue Pages A36 - 12pp
Keywords methods; data analysis; gamma rays; general
Abstract Context. Ground-based gamma-ray astronomy is still a rather young field of research, with strong historical connections to particle physics. This is why most observations are conducted by experiments with proprietary data and analysis software, as is usual in the particle physics field. However, in recent years, this paradigm has been slowly shifting toward the development and use of open-source data formats and tools, driven by upcoming observatories such as the Cherenkov Telescope Array (CTA). In this context, a community-driven, shared data format (the gamma-astro-data-format, or GADF) and analysis tools such as Gammapy and ctools have been developed. So far, these efforts have been led by the Imaging Atmospheric Cherenkov Telescope community, leaving out other types of ground-based gamma-ray instruments. Aims. We aim to show that the data from ground particle arrays, such as the High-Altitude Water Cherenkov (HAWC) observatory, are also compatible with the GADF and can thus be fully analyzed using the related tools, in this case, Gammapy. Methods. We reproduced several published HAWC results using Gammapy and data products compliant with GADF standard. We also illustrate the capabilities of the shared format and tools by producing a joint fit of the Crab spectrum including data from six different gamma-ray experiments. Results. We find excellent agreement with the reference results, a powerful confirmation of both the published results and the tools involved. Conclusions. The data from particle detector arrays such as the HAWC observatory can be adapted to the GADF and thus analyzed with Gammapy. A common data format and shared analysis tools allow multi-instrument joint analysis and effective data sharing. To emphasize this, a sample of Crab nebula event lists is made public with this paper. Because of the complementary nature of pointing and wide-field instruments, this synergy will be distinctly beneficial for the joint scientific exploitation of future observatories such as the Southern Wide-field Gamma-ray Observatory and CTA.
Address [Albert, A.; Durocher, M.; Harding, J. P.] Los Alamos Natl Lab, Phys Div, Los Alamos, NM USA, Email: laura.olivera-nieto@mpi-hd.mpg.de
Corporate Author Thesis
Publisher Edp Sciences S A Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6361 ISBN Medium
Area Expedition Conference
Notes WOS:000879223700008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5408
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Author Stoppa, F.; Vreeswijk, P.; Bloemen, S.; Bhattacharyya, S.; Caron, S.; Johannesson, G.; Ruiz de Austri, R.; van den Oetelaar, C.; Zaharijas, G.; Groot, P.J.; Cator, E.; Nelemans, G.
Title AutoSourceID-Light Fast optical source localization via U-Net and Laplacian of Gaussian Type Journal Article
Year 2022 Publication Astronomy & Astrophysics Abbreviated Journal Astron. Astrophys.
Volume (down) 662 Issue Pages A109 - 8pp
Keywords astronomical databases; miscellaneous; methods; data analysis; stars; imaging; techniques; image processing
Abstract Aims. With the ever-increasing survey speed of optical wide-field telescopes and the importance of discovering transients when they are still young, rapid and reliable source localization is paramount. We present AutoSourceID-Light (ASID-L), an innovative framework that uses computer vision techniques that can naturally deal with large amounts of data and rapidly localize sources in optical images. Methods. We show that the ASID-L algorithm based on U-shaped networks and enhanced with a Laplacian of Gaussian filter provides outstanding performance in the localization of sources. A U-Net network discerns the sources in the images from many different artifacts and passes the result to a Laplacian of Gaussian filter that then estimates the exact location. Results. Using ASID-L on the optical images of the MeerLICHT telescope demonstrates the great speed and localization power of the method. We compare the results with SExtractor and show that our method outperforms this more widely used method. ASID-L rapidly detects more sources not only in low- and mid-density fields, but particularly in areas with more than 150 sources per square arcminute. The training set and code used in this paper are publicly available.
Address [Stoppa, F.; Vreeswijk, P.; Bloemen, S.; Groot, P. J.; Nelemans, G.] Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands, Email: f.stoppa@astro.ru.nl
Corporate Author Thesis
Publisher Edp Sciences S A Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6361 ISBN Medium
Area Expedition Conference
Notes WOS:000818665600009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5291
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Author Sanchis-Lozano, M.A.; Melia, F.; Lopez-Corredoira, M.; Sanchis-Gual, N.
Title Missing large-angle correlations versus even-odd point-parity imbalance in the cosmic microwave background Type Journal Article
Year 2022 Publication Astronomy & Astrophysics Abbreviated Journal Astron. Astrophys.
Volume (down) 660 Issue Pages A121 - 10pp
Keywords cosmological parameters; cosmic background radiation; cosmology: observations; cosmology: theory; inflation; large-scale structure of Universe
Abstract Context. The existence of a maximum correlation angle (theta(max) & 60 greater than or similar to degrees) in the two-point angular temperature correlations of cosmic microwave background (CMB) radiation, measured by WMAP and Planck, stands in sharp contrast to the prediction of standard inflationary cosmology, in which the correlations should extend across the full sky (i.e., 180 degrees). The introduction of a hard lower cuto ff (k(min)) in the primordial power spectrum, however, leads naturally to the existence of theta(max). Among other cosmological anomalies detected in these data, an apparent dominance of odd-over-even parity multipoles has been seen in the angular power spectrum of the CMB. This feature, however, may simply be due to observational contamination in certain regions of the sky. Aims. In attempting to provide a more detailed assessment of whether this odd-over-even asymmetry is intrinsic to the CMB, we therefore proceed in this paper, first, to examine whether this odd-even parity imbalance also manifests itself in the angular correlation function and, second, to examine in detail the interplay between the presence of theta(max) and this observed anomaly. Methods. We employed several parity statistics and recalculated the angular correlation function for di fferent values of the cuto ff kmin in order to optimize the fit to the di fferent Planck 2018 data. Results. We find a phenomenological connection between these features in the data, concluding that both must be considered together in order to optimize the theoretical fit to the Planck 2018 data. Conclusions. This outcome is independent of whether the parity imbalance is intrinsic to the CMB, but if it is, the odd-over-even asymmetry would clearly point to the emergence of new physics.
Address [Sanchis-Lozano, M-A] Ctr Mixto Univ Valencia, Inst Fis Corpuscular IFIC, CSIC, Dr Moliner 50, Burjassot, Spain, Email: Miguel.Angel.Sanchis@ific.uv.es;
Corporate Author Thesis
Publisher Edp Sciences S A Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6361 ISBN Medium
Area Expedition Conference
Notes WOS:000786712000002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5211
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Author Affolder, A. et al; Garcia, C.; Lacasta, C.; Marco, R.; Marti-Garcia, S.; Miñano, M.; Soldevila, U.
Title Silicon detectors for the sLHC Type Journal Article
Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 658 Issue 1 Pages 11-16
Keywords Silicon particle detectors; Radiation damage; Irradiation; Charge collection efficiency
Abstract In current particle physics experiments, silicon strip detectors are widely used as part of the inner tracking layers. A foreseeable large-scale application for such detectors consists of the luminosity upgrade of the Large Hadron Collider (LHC), the super-LHC or sLHC, where silicon detectors with extreme radiation hardness are required. The mission statement of the CERN RD50 Collaboration is the development of radiation-hard semiconductor devices for very high luminosity colliders. As a consequence, the aim of the R&D programme presented in this article is to develop silicon particle detectors able to operate at sLHC conditions. Research has progressed in different areas, such as defect characterisation, defect engineering and full detector systems. Recent results from these areas will be presented. This includes in particular an improved understanding of the macroscopic changes of the effective doping concentration based on identification of the individual microscopic defects, results from irradiation with a mix of different particle types as expected for the sLHC, and the observation of charge multiplication effects in heavily irradiated detectors at very high bias voltages.
Address [Barber, T.; Breindl, M.; Driewer, A.; Koehler, M.; Kuehn, S.; Parzefall, U.; Preiss, J.; Walz, M.; Wiik, L.] Univ Freiburg, Inst Phys, D-79104 Freiburg, Germany, Email: Ulrich.Parzefall@physik.uni-freiburg.de
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000297783300004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 836
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Author ANTARES Collaboration (Ageron, M. et al); Aguilar, J.A.; Bigongiari, C.; Carmona, E.; Dornic, D.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Mangano, S.; Real, D.; Roca, V.; Salesa, F.; Toscano, S.; Urbano, F.; Yepes, H.; Zornoza, J.D.; Zuñiga, J.
Title ANTARES: The first undersea neutrino telescope Type Journal Article
Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 656 Issue 1 Pages 11-38
Keywords Neutrino; Astroparticle; Neutrino astronomy; Deep sea detector; Marine technology; DWDM; Photomultiplier tube; Submarine cable; Wet mateable connector
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.
Address [Barbarito, E; Cassano, B; Ceres, A; Circella, M; Fiorello, C; Mongelli, M; Montaruli, T; Ruppi, M] Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy, Email: Marco.Circella@ba.infn.it
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000296129100003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 785
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Author Panes, B.; Eckner, C.; Hendriks, L.; Caron, S.; Dijkstra, K.; Johannesson, G.; Ruiz de Austri, R.; Zaharijas, G.
Title Identification of point sources in gamma rays using U-shaped convolutional neural networks and a data challenge Type Journal Article
Year 2021 Publication Astronomy & Astrophysics Abbreviated Journal Astron. Astrophys.
Volume (down) 656 Issue Pages A62 - 18pp
Keywords catalogs; gamma rays: general; astroparticle physics; methods: numerical; methods: data analysis; techniques: image processing
Abstract Context. At GeV energies, the sky is dominated by the interstellar emission from the Galaxy. With limited statistics and spatial resolution, accurately separating point sources is therefore challenging. Aims. Here we present the first application of deep learning based algorithms to automatically detect and classify point sources from gamma-ray data. For concreteness we refer to this approach as AutoSourceID. Methods. To detect point sources, we utilized U-shaped convolutional networks for image segmentation and k-means for source clustering and localization. We also explored the Centroid-Net algorithm, which is designed to find and count objects. Using two algorithms allows for a cross check of the results, while a combination of their results can be used to improve performance. The training data are based on 9.5 years of exposure from The Fermi Large Area Telescope (Fermi-LAT) and we used source properties of active galactic nuclei (AGNs) and pulsars (PSRs) from the fourth Fermi-LAT source catalog in addition to several models of background interstellar emission. The results of the localization algorithm are fed into a classification neural network that is trained to separate the three general source classes (AGNs, PSRs, and FAKE sources). Results. We compared our localization algorithms qualitatively with traditional methods and find them to have similar detection thresholds. We also demonstrate the robustness of our source localization algorithms to modifications in the interstellar emission models, which presents a clear advantage over traditional methods. The classification network is able to discriminate between the three classes with typical accuracy of similar to 70%, as long as balanced data sets are used in classification training. We published online our training data sets and analysis scripts and invite the community to join the data challenge aimed to improve the localization and classification of gamma-ray point sources.
Address [Panes, Boris] Pontificia Univ Catolica Chile, Ave Vicuna Mackenna 4860, Macul, Region Metropol, Chile, Email: bapanes@gmail.com
Corporate Author Thesis
Publisher Edp Sciences S A Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6361 ISBN Medium
Area Expedition Conference
Notes WOS:000725877600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5053
Permanent link to this record
 

 
Author Marinas, C.; Vos, M.
Title The Belle-II DEPFET pixel detector: A step forward in vertexing in the superKEKB flavour factory Type Journal Article
Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 650 Issue 1 Pages 59-63
Keywords SuperKEKB; Belle-II; DEPFET; Pixel detector; ASIC; Mechanics; Cooling; Resolution
Abstract An upgrade of the successful asymmetric e(+)e(-) collider in KEK (Tsukuba, Japan) is foreseen by the fall of 2013. This new Super Flavor Factory will deliver an increased instantaneous luminosity of up to L = 8 x 10(35) cm(-2) s(-1), 40 times larger than the current KEKB machine. To exploit these new conditions and provide high precision measurements of the decay vertex of the B meson systems, a new silicon vertex detector will be operated in Belle. This new detector will consist of two layers of DEPFET Active Pixel Sensors as close as possible to the interaction point. DEPFET is a field effect transistor, with an additional deep implant underneath the channel's gate, integrated on a completely depleted bulk. This technology offers detection and an in-pixel amplification stage, while keeping low the power consumption. Under these conditions, thin sensors with small pixel size and low intrinsic noise are possible. In this article, an overview of the full system will be described, including the sensor, the front-end electronics and both the mechanical and thermal proposed solutions as well as the expected performance.
Address [Marinas, C; Vos, M] CSIC UVEG, IFIC, Inst Fis Corpuscular, Valencia, Spain, Email: Carlos.Marinas.Pardo@cern.ch
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000295106500015 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 768
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Author Andricek, L. et al; Lacasta, C.; Marinas, C.; Vos, M.
Title Intrinsic resolutions of DEPFET detector prototypes measured at beam tests Type Journal Article
Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 638 Issue 1 Pages 24-32
Keywords Silicon pixel detector; Detector resolution; Spatial resolution; DEPFET; Beam test
Abstract The paper is based on the data of the 2009 DEPFET beam test at CERN SPS. The beam test used beams of pions and electrons with energies between 40 and 120 GeV, and the sensors tested were prototypes with thickness of 450 μm and pixel pitch between 20 and 32 μm. Intrinsic resolutions of the detectors are calculated by disentangling the contributions of measurement errors and multiple scattering in tracking residuals. Properties of the intrinsic resolution estimates and factors that influence them are discussed. For the DEPFET detectors in the beam test, the calculation yields intrinsic resolutions of approximate to 1 μm, with a typical accuracy of 0.1 μm. Bias scan, angle scan, and energy scan are used as example studies to show that the intrinsic resolutions are a useful tool in studies of detector properties. With sufficiently precise telescopes, detailed resolution maps can be constructed and used to study and optimize detector performance.
Address [Dolezal, Z.; Drasal, Z.; Kodys, P.; Kvasnicka, P.; Malina, L.; Scheirich, J.] Charles Univ Prague, Fac Math & Phys, Inst Particle & Nucl Phys, CR-18000 Prague, Czech Republic, Email: peter.kodys@mff.cuni.cz
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes ISI:000290082600005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 618
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Author ANTARES Collaboration (Aguilar, J.A. et al); Bigongiari, C.; Dornic, D.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Mangano, S.; Salesa, F.; Toscano, S.; Yepes, H.; Zornoza, J.D.; Zuñiga, J.
Title AMADEUS-The acoustic neutrino detection test system of the ANTARES deep-sea neutrino telescope Type Journal Article
Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 626 Issue Pages 128-143
Keywords AMADEUS; ANTARES; Neutrino telescope; Acoustic neutrino detection; Thermo-acoustic model
Abstract The AMADEUS (ANTARES Modules for the Acoustic Detection Under the Sea) system which is described in this article aims at the investigation of techniques for acoustic detection of neutrinos in the deep sea. It is integrated into the ANTARES neutrino telescope in the Mediterranean Sea. Its acoustic sensors, installed at water depths between 2050 and 2300 m, employ piezo-electric elements for the broad-band recording of signals with frequencies ranging up to 125 kHz. The typical sensitivity of the sensors is around – 145 dB re 1 V/mu Pa (including preamplifier). Completed in May 2008, AMADEUS consists of six “acoustic clusters”, each comprising six acoustic sensors that are arranged at distances of roughly 1 m from each other. Two vertical mechanical structures (so-called lines) of the ANTARES detector host three acoustic clusters each. Spacings between the clusters range from 14.5 to 340 m. Each cluster contains custom-designed electronics boards to amplify and digitise the acoustic signals from the sensors. An on-shore computer cluster is used to process and filter the data stream and store the selected events. The daily volume of recorded data is about 10 GB. The system is operating continuously and automatically, requiring only little human intervention. AMADEUS allows for extensive studies of both transient signals and ambient noise in the deep sea, as well as signal correlations on several length scales and localisation of acoustic point sources. Thus the system is excellently suited to assess the background conditions for the measurement of the bipolar pulses expected to originate from neutrino interactions.
Address [Anton, G.; Auer, R.; Eberl, T.; Fehr, F.; Fritsch, U.; Graf, K.; Herold, B.; Hoessl, J.; Kalekin, O.; Kappes, A.; Katz, U.; Kopper, C.; Kretschmer, W.; Lahmann, R.; Laschinsky, H.; Motz, H.; Neff, M.; Ostasch, R.; Richardt, C.; Schoeck, F.; Shanidze, R.] Univ Erlangen Nurnberg, Erlangen Ctr Astroparticle Phys, D-91058 Erlangen, Germany, Email: robert.lahmann@physik.uni-erlangen.de
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes ISI:000286793800020 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 578
Permanent link to this record