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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 |
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Language |
English |
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ISSN |
1475-7516 |
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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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Author |
AMON and ANTARES Collaborations (Ayala Solares, H.A. et al); Barrios-Marti, J.; Coleiro, A.; Colomer, M.; Gozzini, R.; Hernandez-Rey, J.J.; Illuminati, G.; Khan-Chowdhury, N.R.; Lotze, M.; Thakore, T.; Zornoza, J.D.; Zuñiga, J. |
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Title |
A Search for Cosmic Neutrino and Gamma-Ray Emitting Transients in 7.3 yr of ANTARES and Fermi LAT Data |
Type |
Journal Article |
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Year |
2019 |
Publication |
Astrophysical Journal |
Abbreviated Journal |
Astrophys. J. |
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Volume |
886 |
Issue |
2 |
Pages |
98 - 8pp |
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Keywords |
BL Lacertae objects: general; cosmic rays; gamma-ray burst: general; gamma rays: general; neutrinos |
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Abstract |
We analyze 7.3 yr of ANTARES high-energy neutrino and Fermi Large Area Telescope (LAT) gamma-ray data in search of cosmic neutrino + gamma-ray (nu + gamma) transient sources or source populations. Our analysis has the potential to detect either individual nu + gamma transient sources (durations delta t less than or similar to 1000 s), if they exhibit sufficient gamma-ray or neutrino multiplicity, or a statistical excess of nu + gamma transients of individually lower multiplicities. Individual high gamma-ray multiplicity events could be produced, for example, by a single ANTARES neutrino in coincidence with a LAT-detected gamma-ray burst. Treating ANTARES track and cascade event types separately, we establish detection thresholds by Monte Carlo scrambling of the neutrino data, and determine our analysis sensitivity by signal injection against these scrambled data sets. We find our analysis is sensitive to nu + gamma transient populations responsible for >5% of the observed gamma-coincident neutrinos in the track data at 90% confidence. Applying our analysis to the unscrambled data reveals no individual nu + gamma events of high significance; two ANTARES track + Fermi gamma-ray events are identified that exceed a once per decade false alarm rate threshold (p = 17%). No evidence for subthreshold nu + gamma source populations is found among the track (p = 39%) or cascade (p = 60%) events. Exploring a possible correlation of high-energy neutrino directions with Fermi gamma-ray sky brightness identified in previous work yields no added support for this correlation. While TXS.0506+056, a blazar and variable (nontransient) Fermi gamma-ray source, has recently been identified as the first source of high-energy neutrinos, the challenges in reconciling observations of the Fermi gamma-ray sky, the IceCube high-energy cosmic neutrinos, and ultrahigh-energy cosmic rays using only blazars suggest a significant contribution by other source populations. Searches for transient sources of high-energy neutrinos thus remain interesting, with the potential for either neutrino clustering or multimessenger coincidence searches to lead to discovery of the first nu + gamma transients. |
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Address |
[Solares, H. A. Ayala; Cowen, D. F.; DeLaunay, J. J.; Keivani, A.; Mostafa, M.; Murase, K.; Turley, C. F.] Penn State Univ, Dept Phys, 104 Davey Lab, University Pk, PA 16802 USA, Email: cft114@psu.edu |
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Corporate Author |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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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 |
0004-637x |
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Expedition |
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Conference |
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Notes |
WOS:000503245500001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4227 |
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Author |
AMON Team, ANTARES and HAWC Collaborations (Ayala Solares, H.A. et al); Alves Garres, S.; Calvo, D.; Carretero, V.; Gozzini, R.; Hernandez-Rey, J.J.; Manczak, J.; Pieterse, C.; Real, D.; Sanchez-Losa, A.; Zornoza, J. D.; Zuniga, J.; Salesa Greus, F. |
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Title |
Search for Gamma-Ray and Neutrino Coincidences Using HAWC and ANTARES Data |
Type |
Journal Article |
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Year |
2023 |
Publication |
Astrophysical Journal |
Abbreviated Journal |
Astrophys. J. |
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Volume |
944 |
Issue |
2 |
Pages |
166 - 9pp |
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Keywords |
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Abstract |
In the quest for high-energy neutrino sources, the Astrophysical Multimessenger Observatory Network has implemented a new search by combining data from the High Altitude Water Cherenkov (HAWC) Observatory and the Astronomy with a Neutrino Telescope and Abyss environmental RESearch (ANTARES) neutrino telescope. Using the same analysis strategy as in a previous detector combination of HAWC and IceCube data, we perform a search for coincidences in HAWC and ANTARES events that are below the threshold for sending public alerts in each individual detector. Data were collected between 2015 July and 2020 February with a live time of 4.39 yr. Over this time period, three coincident events with an estimated false-alarm rate of <1 coincidence per year were found. This number is consistent with background expectations. |
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Address |
[Solares, H. A. Ayala; Coutu, S.; Cowen, D.; Fox, D. B.; Gregoire, T.; Mostafa, M.; Murase, K.; Wissel, S.; Alonso, M. Fernandez; Whitaker, K.] Penn State Univ, Dept Phys, 104 Davey Lab, University Pk, PA 16802 USA, Email: hgayala@psu.edu |
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Corporate Author |
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Publisher |
IOP Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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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 |
0004-637x |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000989686100001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5566 |
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Author |
AMON Team, HAWC and IceCube Collaborations (Ayala Solares, H.A. et al); Salesa Greus, F. |
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Title |
Multimessenger Gamma-Ray and Neutrino Coincidence Alerts Using HAWC and IceCube Subthreshold Data |
Type |
Journal Article |
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Year |
2021 |
Publication |
Astrophysical Journal |
Abbreviated Journal |
Astrophys. J. |
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Volume |
906 |
Issue |
1 |
Pages |
63 - 10pp |
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Keywords |
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Abstract |
The High Altitude Water Cerenkov (HAWC) and IceCube observatories, through the Astrophysical Multimessenger Observatory Network (AMON) framework, have developed a multimessenger joint search for extragalactic astrophysical sources. This analysis looks for sources that emit both cosmic neutrinos and gamma rays that are produced in photohadronic or hadronic interactions. The AMON system is running continuously, receiving subthreshold data (i.e., data that are not suited on their own to do astrophysical searches) from HAWC and IceCube, and combining them in real time. Here we present the analysis algorithm, as well as results from archival data collected between 2015 June and 2018 August, with a total live time of 3.0 yr. During this period we found two coincident events that have a false-alarm rate (FAR) of <1 coincidence yr(-1), consistent with the background expectations. The real-time implementation of the analysis in the AMON system began on 2019 November 20 and issues alerts to the community through the Gamma-ray Coordinates Network with an FAR threshold of <4 coincidences yr(-1). |
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Address |
[Solares, H. A. Ayala; Coutu, S.; DeLaunay, J. J.; Fox, D. B.; Gregoire, T.; Keivani, A.; Krauss, F.; Mostafa, M.; Murase, K.; Turley, C. F.; Anderson, T.; Cowen, D. F.; Dunkman, M.; Eller, P.; Fienberg, A.; Huang, F.; Kheirandish, A.; Lanfranchi, J. L.; Li, Y.; Pankova, D. V.; Weiss, M. J.] Penn State Univ, Dept Phys, University Pk, PA 16802 USA, Email: hgayala@psu.edu |
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Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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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 |
0004-637x |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000605929400001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4679 |
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Author |
Amoroso, S.; Caron, S.; Jueid, A.; Ruiz de Austri, R.; Skands, P. |
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Title |
Estimating QCD uncertainties in Monte Carlo event generators for gamma-ray dark matter searches |
Type |
Journal Article |
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Year |
2019 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
05 |
Issue |
5 |
Pages |
007 - 44pp |
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Keywords |
dark matter simulations; dark matter theory; gamma ray theory |
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Abstract |
Motivated by the recent galactic center gamma-ray excess identified in the Fermi-LAT data, we perform a detailed study of QCD fragmentation uncertainties in the modeling of the energy spectra of gamma-rays from Dark-Matter (DM) annihilation. When Dark-Matter particles annihilate to coloured final states, either directly or via decays such as W(*) -> qq-', photons are produced from a complex sequence of shower, hadronisation and hadron decays. In phenomenological studies their energy spectra are typically computed using Monte Carlo event generators. These results have however intrinsic uncertainties due to the specific model used and the choice of model parameters, which are difficult to asses and which are typically neglected. We derive a new set of hadronisation parameters (tunes) for the PYTHIA 8.2 Monte Carlo generator from a fit to LEP and SLD data at the Z peak. For the first time we also derive a conservative set of uncertainties on the shower and hadronisation model parameters. Their impact on the gamma-ray energy spectra is evaluated and discussed for a range of DM masses and annihilation channels. The spectra and their uncertainties are also provided in tabulated form for future use. The fragmentation-parameter uncertainties may be useful for collider studies as well. |
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Address |
[Amoroso, Simone] DESY, Notkestr 85, D-22607 Hamburg, Germany, Email: simone.amoroso@desy.de; |
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Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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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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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000467288200002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4006 |
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| Permanent link to this record |
