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Author |
HAWC Collaboration (Albert, A. et al); Salesa Greus, F. |
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Title |
Evidence of 200 TeV Photons from HAWC J1825-134 |
Type |
Journal Article |
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Year |
2021 |
Publication |
Astrophysical Journal Letters |
Abbreviated Journal |
Astrophys. J. Lett. |
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Volume |
907 |
Issue |
2 |
Pages |
L30 - 9pp |
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Keywords |
Gamma-ray astronomy; Gamma-ray sources; Gamma-rays; Gamma-ray observatories |
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Abstract |
The Earth is bombarded by ultrarelativistic particles, known as cosmic rays (CRs). CRs with energies up to a few PeV (=10(15) eV), the knee in the particle spectrum, are believed to have a Galactic origin. One or more factories of PeV CRs, or PeVatrons, must thus be active within our Galaxy. The direct detection of PeV protons from their sources is not possible since they are deflected in the Galactic magnetic fields. Hundred TeV gamma-rays from decaying pi(0), produced when PeV CRs collide with the ambient gas, can provide the decisive evidence of proton acceleration up to the knee. Here we report the discovery by the High Altitude Water Cerenkov (HAWC) observatory of the gamma-ray source, HAWC J1825-134, whose energy spectrum extends well beyond 200 TeV without a break or cutoff. The source is found to be coincident with a giant molecular cloud. The ambient gas density is as high as 700 protons cm(-3). While the nature of this extreme accelerator remains unclear, CRs accelerated to energies of several PeV colliding with the ambient gas likely produce the observed radiation. |
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Address |
[Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.; Kunde, G. J.; Malone, K.] Los Alamos Natl Lab, Phys Div, Los Alamos, NM USA, Email: sabrina.casanova@ifj.edu.pl; |
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Publisher |
Iop Publishing Ltd |
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English |
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ISSN |
2041-8205 |
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Notes |
WOS:000612623100001 |
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no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4703 |
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Permanent link to this record |
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Author |
HAWC Collaboration (Albert, A. et al); Salesa Greus, F. |
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Title |
HAWC J2227+610 and Its Association with G106.3+2.7, a New Potential Galactic PeVatron |
Type |
Journal Article |
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Year |
2020 |
Publication |
Astrophysical Journal Letters |
Abbreviated Journal |
Astrophys. J. Lett. |
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Volume |
896 |
Issue |
2 |
Pages |
L29 - 9pp |
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Keywords |
Gamma-ray astronomy; Gamma-ray sources; Gamma-rays; Cosmic ray sources; Supernova remnants; Gamma-ray observatories |
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Abstract |
We present the detection of very-high-energy gamma-ray emission above 100 TeV from HAWC J2227+610 with the High-Altitude Water Cherenov Gamma-Ray Observatory (HAWC) observatory. Combining our observations with previously published results by the Very Energetic Radiation Imaging Telescope Array System (VERTIAS), we interpret the gamma-ray emission from HAWC J2227+610 as emission from protons with a lower limit in their cutoff energy of 800 TeV. The most likely source of the protons is the associated supernova remnant G106.3+2.7, making it a good candidate for a Galactic PeVatron. However, a purely leptonic origin of the observed emission cannot be excluded at this time. |
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Address |
[Albert, A.; Dingus, B. L.; Harding, J. P.; Malone, K.; Sinnis, G.] Los Alamos Natl Lab, Phys Div, Los Alamos, NM 87545 USA, Email: hfleisch@mtu.edu |
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Publisher |
Iop Publishing Ltd |
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English |
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2041-8205 |
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Notes |
WOS:000542724600001 |
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no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4445 |
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Author |
HAWC Collaboration (Albert, A. et al); Salesa Greus, F. |
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Title |
3HWC: The Third HAWC Catalog of Very-high-energy Gamma-Ray Sources |
Type |
Journal Article |
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Year |
2020 |
Publication |
Astrophysical Journal |
Abbreviated Journal |
Astrophys. J. |
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Volume |
905 |
Issue |
1 |
Pages |
76 - 14pp |
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Keywords |
Gamma-ray astronomy; Gamma-ray observatories; High energy astrophysics; Cosmic ray sources |
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Abstract |
We present a new catalog of TeV gamma-ray sources using 1523 days of data from the High-Altitude Water Cherenkov (HAWC) Observatory. The catalog represents the most sensitive survey of the northern gamma-ray sky at energies above several TeV, with three times the exposure compared to the previous HAWC catalog, 2HWC. We report 65 sources detected at >= 5 sigma significance, along with the positions and spectral fits for each source. The catalog contains eight sources that have no counterpart in the 2HWC catalog, but are within 1 degrees of previously detected TeV emitters, and 20 sources that are more than 1 degrees away from any previously detected TeV source. Of these 20 new sources, 14 have a potential counterpart in the fourth Fermi Large Area Telescope catalog of gamma-ray sources. We also explore potential associations of 3HWC sources with pulsars in the Australia Telescope National Facility (ATNF) pulsar catalog and supernova remnants in the Galactic supernova remnant catalog. |
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Address |
[Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.; Malone, K.; Sinnis, G.; Ukwatta, T. N.] Los Alamos Natl Lab, Div Phys, Los Alamos, NM USA, Email: hfleisch@mtu.edu; |
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Publisher |
Iop Publishing Ltd |
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English |
Summary Language |
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ISSN |
0004-637x |
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Conference |
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Notes |
WOS:000599109900001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4639 |
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Permanent link to this record |
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Author |
Zago, L. et al; Gadea, A.; Algora, A. |
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Title |
High-spin states in Po-212 above the alpha-decaying (18(+)) isomer |
Type |
Journal Article |
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Year |
2022 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
834 |
Issue |
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Pages |
137457 - 5pp |
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Keywords |
gamma spectroscopy; Isomer spectroscopy; High-spin spectroscopy |
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Abstract |
The nucleus Po-212 has been produced through the fragmentation of a U-238 primary beam at 1GeV/nucleon at GSI, separated with the FRagment Separator, FRS, and studied via isomer gamma-decay spectroscopy with the RISING setup. Two delayed previously unknown gamma rays have been observed. One has been attributed to the E3 decay of a 21(-) isomeric state feeding the alpha-emitting 45-s (18(+)) high-spin isomer. The other gamma-ray line has been assigned to the decay of a higher-lying 23(+) metastable state. These are the first observations of high-spin states above the Po-212 (18(+)) isomer, by virtue of the selectivity obtained via ion-by-ion identification of U-238 fragmentation products. Comparison with shell-model calculations points to shortfalls in the nuclear interactions involving high- jproton and neutron orbitals, to which the region around Z similar to 100 is sensitive. |
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Address |
[Zago, L.; Lunardi, S.; Lenzi, S. M.; Mengoni, D.] Univ Padua, Dipartimento Fis, I-35131 Padua, Italy, Email: luca.zago@lnl.infn.it |
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Publisher |
Elsevier |
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Language |
English |
Summary Language |
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Edition |
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ISSN |
0370-2693 |
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Notes |
WOS:000890050000015 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5457 |
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Permanent link to this record |
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Author |
Doncel, M.; Cederwall, B.; Gadea, A.; Gerl, J.; Kojouharov, I.; Martin, S.; Palit, R.; Quintana, B. |
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Title |
Performance and imaging capabilities of the DEGAS high-resolution gamma-ray detector array for the DESPEC experiment at FAIR |
Type |
Journal Article |
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Year |
2017 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
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Volume |
873 |
Issue |
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Pages |
36-38 |
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Keywords |
Gamma spectroscopy; Imaging; Position-sensitive Ge detectors |
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Abstract |
Monte Carlo simulations of one of the possible configurations of the imaging phase for the DEGAS spectrometer situated at the DESPEC/NUSTAR experiment have been performed. The geometry consists of the coupling of the high-resolution gamma spectroscopy array, AGATA, with a high-resolution segmented planar detector utilized as an implantation detector in a compact configuration. The sensitivity and performance of the array in terms of efficiency and imaging capability is deduced. |
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Address |
[Doncel, M.] Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool, Merseyside, England, Email: doncel@liverpool.ac.uk |
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Publisher |
Elsevier Science Bv |
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English |
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Edition |
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ISSN |
0168-9002 |
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Notes |
WOS:000413823100008 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3349 |
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Permanent link to this record |
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Author |
Amerio, A.; Cuoco, A.; Fornengo, N. |
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Title |
Extracting the gamma-ray source-count distribution below the Fermi-LAT detection limit with deep learning |
Type |
Journal Article |
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Year |
2023 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
09 |
Issue |
9 |
Pages |
029 - 39pp |
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Keywords |
gamma ray theory; Machine learning |
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Abstract |
We reconstruct the extra-galactic gamma-ray source-count distribution, or dN/dS, of resolved and unresolved sources by adopting machine learning techniques. Specifically, we train a convolutional neural network on synthetic 2-dimensional sky-maps, which are built by varying parameters of underlying source-counts models and incorporate the FermiLAT instrumental response functions. The trained neural network is then applied to the Fermi-LAT data, from which we estimate the source count distribution down to flux levels a factor of 50 below the Fermi-LAT threshold. We perform our analysis using 14 years of data collected in the (1, 10) GeV energy range. The results we obtain show a source count distribution which, in the resolved regime, is in excellent agreement with the one derived from cataloged sources, and then extends as dN/dS " S-2 in the unresolved regime, down to fluxes of 5 center dot 10-12 cm-2 s-1. The neural network architecture and the devised methodology have the flexibility to enable future analyses to study the energy dependence of the source-count distribution. |
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Address |
[Amerio, A.] Univ Valencia, Inst Fis Corpuscular IFIC, Calle Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: aurelio.amerio@ific.uv.es; |
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Publisher |
IOP Publishing Ltd |
Place of Publication |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1475-7516 |
ISBN |
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Expedition |
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Conference |
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Notes |
WOS:001097055700001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5785 |
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Permanent link to this record |
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Author |
Amerio, A.; Calore, F.; Serpico, P.D.; Zaldivar, B. |
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Title |
Deepening gamma-ray point-source catalogues with sub-threshold information |
Type |
Journal Article |
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Year |
2024 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
03 |
Issue |
3 |
Pages |
055 - 18pp |
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Keywords |
gamma ray theory; Frequentist statistics |
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Abstract |
We propose a novel statistical method to extend Fermi-LAT catalogues of highlatitude -y-ray sources below their nominal threshold. To do so, we rely on the determination of the differential source -count distribution of sub -threshold sources which only provides the statistical flux distribution of faint sources. By simulating ensembles of synthetic skies, we assess quantitatively the likelihood for pixels in the sky with relatively low -test statistics to be due to sources, therefore complementing the source -count distribution with spatial information. Besides being useful to orient efforts towards multi -messenger and multi -wavelength identification of new -y-ray sources, we expect the results to be especially advantageous for statistical applications such as cross -correlation analyses. |
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Address |
[Amerio, Aurelio; Zaldivar, Bryan] Univ Valencia, Inst Fis Corpuscular IFIC, Calle Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: aurelio.amerio@ific.uv.es; |
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Publisher |
IOP Publishing Ltd |
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English |
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ISSN |
1475-7516 |
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Expedition |
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Conference |
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Notes |
WOS:001194945600003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
6032 |
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Permanent link to this record |
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Author |
Caron, S.; Gomez-Vargas, G.A.; Hendriks, L.; Ruiz de Austri, R. |
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Title |
Analyzing gamma rays of the Galactic Center with deep learning |
Type |
Journal Article |
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Year |
2018 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
05 |
Issue |
5 |
Pages |
058 - 24pp |
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Keywords |
gamma ray experiments; dark matter simulations |
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Abstract |
We present the application of convolutional neural networks to a particular problem in gamma ray astronomy. Explicitly, we use this method to investigate the origin of an excess emission of GeV gamma rays in the direction of the Galactic Center, reported by several groups by analyzing Fermi-LAT data. Interpretations of this excess include gamma rays created by the annihilation of dark matter particles and gamma rays originating from a collection of unresolved point sources, such as millisecond pulsars. We train and test convolutional neural networks with simulated Fermi-LAT images based on point and diffuse emission models of the Galactic Center tuned to measured gamma ray data. Our new method allows precise measurements of the contribution and properties of an unresolved population of gamma ray point sources in the interstellar diffuse emission model. The current model predicts the fraction of unresolved point sources with an error of up to 10% and this is expected to decrease with future work. |
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Address |
[Caron, Sascha; Hendriks, Luc] Radboud Univ Nijmegen, Fac Sci, Inst Math Astrophys & Particle Phys, Mailbox 79,POB 9010, NL-6500 GL Nijmegen, Netherlands, Email: scaron@cern.ch; |
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Publisher |
Iop Publishing Ltd |
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English |
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ISSN |
1475-7516 |
ISBN |
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Expedition |
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Conference |
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Notes |
WOS:000432869300005 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3582 |
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Permanent link to this record |
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Author |
Lerendegui-Marco, J.; Babiano-Suarez, V.; Balibrea-Correa, J.; Caballero, L.; Calvo, D.; Ladarescu, I.; Domingo-Pardo, C. |
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Title |
Simultaneous Gamma-Neutron Vision device: a portable and versatile tool for nuclear inspections |
Type |
Journal Article |
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Year |
2024 |
Publication |
EPJ Techniques and Instrumentation |
Abbreviated Journal |
EPJ Tech. Instrum. |
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Volume |
11 |
Issue |
1 |
Pages |
2 - 17pp |
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Keywords |
Gamma imaging; Neutron imaging; Nuclear inspections; Homeland security; Nuclear waste characterization |
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Abstract |
This work presents GN-Vision, a novel dual gamma-ray and neutron imaging system, which aims at simultaneously obtaining information about the spatial origin of gamma-ray and neutron sources. The proposed device is based on two position sensitive detection planes and exploits the Compton imaging technique for the imaging of gamma-rays. In addition, spatial distributions of slow- and thermal-neutron sources (<100 eV) are reconstructed by using a passive neutron pin-hole collimator attached to the first detection plane. The proposed gamma-neutron imaging device could be of prime interest for nuclear safety and security applications. The two main advantages of this imaging system are its high efficiency and portability, making it well suited for nuclear applications were compactness and real-time imaging is important. This work presents the working principle and conceptual design of the GN-Vision system and explores, on the basis of Monte Carlo simulations, its simultaneous gamma-ray and neutron detection and imaging capabilities for a realistic scenario where a Cf-252 source is hidden in a neutron moderating container. |
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Address |
[Lerendegui-Marco, Jorge; Babiano-Suarez, Victor; Balibrea-Correa, Javier; Caballero, Luis; Calvo, David; Ladarescu, Ion; Domingo-Pardo, Cesar] Univ Valencia, Inst Fis Corpuscular, CSIC, Valencia, Spain, Email: jorge.lerendegui@ific.uv.es |
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Publisher |
Springer |
Place of Publication |
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English |
Summary Language |
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Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2195-7045 |
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Conference |
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Notes |
WOS:001171512700001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
5975 |
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Permanent link to this record |
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Author |
T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Molina Bueno, L.; Novella, P. |
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Title |
Scintillator ageing of the T2K near detectors fro 2010 to 2021 |
Type |
Journal Article |
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Year |
2022 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
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Volume |
17 |
Issue |
10 |
Pages |
P10028 - 36pp |
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Keywords |
Gamma detectors (scintillators, CZT, HPGe, HgI etc); Neutrino detectors; Performance of High Energy Physics Detectors; Scintillators; scintillation and light emission processes (solid, gas and liquid scintillators) |
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Abstract |
The T2K experiment widely uses plastic scintillator as a target for neutrino interactions and an active medium for the measurement of charged particles produced in neutrino interactions at its near detector complex. Over 10 years of operation the measured light yield recorded by the scintillator based subsystems has been observed to degrade by 0.9-2.2% per year. Extrapolation of the degradation rate through to 2040 indicates the recorded light yield should remain above the lower threshold used by the current reconstruction algorithms for all subsystems. This will allow the near detectors to continue contributing to important physics measurements during the T2K-II and Hyper-Kamiokande eras. Additionally, work to disentangle the degradation of the plastic scintillator and wavelength shifting fibres shows that the reduction in light yield can be attributed to the ageing of the plastic scintillator. The long component of the attenuation length of the wavelength shifting fibres was observed to degrade by 1.3-5.4% per year, while the short component of the attenuation length did not show any conclusive degradation. |
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Address |
[Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, ES-28049 Madrid, Spain, Email: m.lawe@lancaster.ac.uk |
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Publisher |
IOP Publishing Ltd |
Place of Publication |
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Language |
English |
Summary Language |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1748-0221 |
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Conference |
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Notes |
WOS:000898723700007 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5442 |
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Permanent link to this record |