Search for dark matter annihilation signals from unidentified Fermi-LAT objects with H.E.S.S

H. Abdalla , F. Aharonian , F. Ait Benkhali , E.O. Angüner (1) , C. Arcaro , C. Armand (2) , T. Armstrong , H. Ashkar (3) , M. Backes , V. Baghmanyan , V. Barbosa Martins , A. Barnacka , M. Barnard , Y. Becherini , D. Berge , K. Bernlöhr , B. Bi , M. Böttcher , C. Boisson (4) , J. Bolmont (5) , M. de Bony de Lavergne (2) , M. Breuhaus , R. Brose , F. Brun (3) , P. Brun (3) , M. Bryan , M. Büchele , T. Bulik , T. Bylund , F. Cangemi , S. Caroff (5) , A. Carosi (2) , S. Casanova , P. Chambery , J. Catalano T. Chand , S. Chandra , A. Chen , G. Cotter , M. Curyło , H. Dalgleish , J. Damascene Mbarubucyeye , I.D. Davids , J. Davies , C. Deil , J. Devin (6) , L. Dirson , A. Djannati-Ataï (6) , A. Dmytriiev (4) , A. Donath , V. Doroshenko , L. Dreyer , L. Du Plessis , C. Duffy , J. Dyks , K. Egberts , F. Eichhorn , S. Einecke , G. Emery (5) , J.-P. Ernenwein (1) , K. Feijen , S. Fegan (7) , A. Fiasson (2) , G. Fichet de Clairfontaine (4) , G. Fontaine (7) , S. Funk , M. Füßling , S. Gabici (6) , Y.A. Gallant (8) , G. Giavitto , L. Giunti (6, 3) , D. Glawion , J.F. Glicenstein (3) , D. Gottschall , M.-H. Grondin (9) , S. Hattingh , J. Hahn , M. Haupt , G. Hermann , J.A. Hinton , W. Hofmann , C. Hoischen , T.L. Holch , M. Holler , M. Hörbe , D. Horns , Z. Huang , D. Huber , M. Jamrozy , D. Jankowsky , F. Jankowsky , A. Jardin-Blicq , V. Joshi , I. Jung-Richardt , E. Kasai , K. Katarzyński , U. Katz , D. Khangulyan , B. Khélifi (6) , S. Klepser , W. Kluźniak , Nu. Komin , R. Konno , K. Kosack (3) , D. Kostunin , M. Kreter , G. Kukec Mezek , A. Kundu , G. Lamanna (2) , A. Lemière (6) , M. Lemoine-Goumard (9) , J.-P. Lenain (5) , F. Leuschner , C. Levy (5) , T. Lohse , A. Luashvili , I. Lypova , J. Mackey , J. Majumdar , D. Malyshev , D. Malyshev , V. Marandon , P. Marchegiani , A. Marcowith (8) , A. Mares (9) , G. Martí-Devesa , R. Marx , G. Maurin (2) , P.J. Meintjes , M. Meyer , A. Mitchell , R. Moderski , L. Mohrmann , A. Montanari (3) , C. Moore , P. Morris , E. Moulin (3) , J. Muller (7) , T. Murach , K. Nakashima , A. Nayerhoda , M. de Naurois (7) , H. Ndiyavala , J. Niemiec , L. Oakes , H. Odaka , B. Peyaud (3) , Q. Piel (2) , A. Noel , L. Oberholzer , P. O'Brien , S. Ohm , L. Olivera-Nieto , E. de Ona Wilhelmi , M. Ostrowski , M. Panter , S. Panny , R.D. Parsons , G. Peron , S. Pita (6) , V. Poireau (2) , D.A. Prokhorov , H. Prokoph , G. Pühlhofer , M. Punch (6) , A. Quirrenbach , S. Raab , R. Rauth , P. Reichherzer (3) , A. Reimer , O. Reimer , Q. Remy , M. Renaud (8) , F. Rieger , L. Rinchiuso (3) , C. Romoli , G. Rowell , B. Rudak , H. Rueda Ricarte , E. Ruiz-Velasco , V. Sahakian , S. Sailer , H. Salzmann , D.A. Sanchez (2) , A. Santangelo , M. Sasaki , M. Scalici , J. Schäfer , F. Schüssler (3) , H.M. Schutte , U. Schwanke , M. Seglar-Arroyo (3) , M. Senniappan , A.S. Seyffert , N. Shafi , J.N.S. Shapopi , K. Shiningayamwe , R. Simoni , A. Sinha (6) , H. Sol (4) , H. Spackman , A. Specovius , S. Spencer , M. Spir-Jacob (6) , Ł. Stawarz , L. Sun , R. Steenkamp , C. Stegmann , S. Steinmassl , C. Steppa , T. Takahashi , T. Tanaka , T. Tavernier (3) , A.M. Taylor , R. Terrier (6) , C. Thorpe Morgan , J.H.E. Thiersen , D. Tiziani , M. Tluczykont , L. Tomankova , C. Trichard (7) , M. Tsirou (8) , M. Tsuji , R. Tuffs , Y. Uchiyama , D.J. van der Walt , C. van Eldik , C. van Rensburg , B. van Soelen , G. Vasileiadis (8) , J. Veh , C. Venter , A. Viana , P. Vincent (5) , J. Vink , H.J. Völk , Z. Wadiasingh , S.J. Wagner , J. Watson , F. Werner , R. White , A. Wierzcholska , Yu Wun Wong , H. Yassin , A. Yusafzai , M. Zacharias (4) , R. Zanin , D. Zargaryan , A.A. Zdziarski , A. Zech (4) , S.J. Zhu , A. Zmija , J. Zorn , S. Zouari (6) , N. Żywucka

1 CPPM - Centre de Physique des Particules de Marseille
2 LAPP - Laboratoire d'Annecy de Physique des Particules
3 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
4 LUTH (UMR_8102) - Laboratoire Univers et Théories
5 LPNHE (UMR_7585) - Laboratoire de Physique Nucléaire et de Hautes Énergies
6 APC (UMR_7164) - AstroParticule et Cosmologie
7 LLR - Laboratoire Leprince-Ringuet
8 LUPM - Laboratoire Univers et Particules de Montpellier
9 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan

Cosmological $N$-body simulations show that Milky Way-sized galaxies harbor a population of unmerged dark matter subhalos. These subhalos could shine in gamma-rays and be eventually detected in gamma-ray surveys as unidentified sources. We performed a thorough selection among unidentified Fermi-LAT Objects (UFOs) to identify them as possible TeV-scale dark matter subhalo candidates. We search for very-high-energy (E $\gtrsim$ 100 GeV) gamma-ray emissions using H.E.S.S. observations towards four selected UFOs. Since no significant very-high-energy gamma-ray emission is detected in any dataset of the four observed UFOs nor in the combined UFO dataset, strong constraints are derived on the product of the velocity-weighted annihilation cross section $\langle \sigma v \rangle$ by the $J$-factor for the dark matter models. The 95% C.L. observed upper limits derived from combined H.E.S.S. observations reach $\langle \sigma v \rangle J$ values of 3.7$\times$10$^{-5}$ and 8.1$\times$10$^{-6}$ GeV$^2$cm$^{-2}$s$^{-1}$ in the $W^+W^-$ and $\tau^+\tau^-$ channels, respectively, for a 1 TeV dark matter mass. Focusing on thermal WIMPs, the H.E.S.S. constraints restrict the $J$-factors to lie in the range 6.1$\times$10$^{19}$ - 2.0$\times$10$^{21}$ GeV$^2$cm$^{-5}$, and the masses to lie between 0.2 and 6 TeV in the $W^+W^-$ channel. For the $\tau^+\tau^-$ channel, the $J$-factors lie in the range 7.0$\times$10$^{19}$ - 7.1$\times$10$^{20}$ GeV$^2$cm$^{-5}$ and the masses lie between 0.2 and 0.5 TeV. Assuming model-dependent predictions from cosmological N-body simulations on the $J$-factor distribution for Milky Way-sized galaxies, the dark matter models with masses greater than 0.3 TeV for the UFO emissions can be ruled out at high confidence level.

Mots clés: gamma ray: emission; dark matter: mass; dark matter: annihilation; gamma ray: VHE; scale: TeV; cross section: annihilation; GeV; HESS; galaxy; GLAST; many-body problem; thermal; WIMP

Domaines: Physique [physics]; Astrophysique [astro-ph]

H. Abdalla, F. Aharonian, F. Ait Benkhali, E.O. Angüner, C. Arcaro, et al.. Search for dark matter annihilation signals from unidentified Fermi-LAT objects with H.E.S.S. Astrophys.J., 2021, 918, pp.17. ⟨10.3847/1538-4357/abff59⟩. ⟨hal-03262638⟩