H.E.S.S. observations of the globular clusters NGC 6388 and M 15 and search for a Dark Matter signal

A. Abramowski , Fabio Acero (1) , F. Aharonian , A. G. Akhperjanian , G. Anton , Agnès Balzer , A. Barnacka (2) , U. Barres de Almeida , A. R. Bazer-Bachi (3) , Y. Becherini (4, 5) , J. Becker , B. Behera , K. Bernlöhr , A. Bochow , C. Boisson (6) , J. Bolmont (7) , P. Bordas , V. Borrel (3) , J. Brucker , F. Brun (4) , P. Brun (2) , T. Bulik , I. Büsching , S. Carrigan , S. Casanova , M. Cerruti (6) , P. M. Chadwick , A. Charbonnier (7) , R. C. G. Chaves , A. Cheesebrough , L. -M. Chounet (4) , A. C. Clapson , G. Coignet (8) , J. Conrad , M. Dalton , M. K. Daniel , I. D. Davids , B. Degrange (4) , C. Deil , H. J. Dickinson , A. Djannati-Ataï (9) , W. Domainko , L. O'C. Drury , F. Dubois (8) , G. Dubus (10) , J. Dyks , M. Dyrda , K. Egberts , P. Eger , P. Espigat (5) , L. Fallon , C. Farnier (1) , S. Fegan (4) , F. Feinstein (1) , M. V. Fernandes , A. Fiasson (8) , G. Fontaine (4) , A. Förster , M. Füssling , Y. A. Gallant (1) , H. Gast , L. Gérard (5) , D. Gerbig , B. Giebels (4) , J. F. Glicenstein (2) , B. Glück , P. Goret (2) , D. Göring , S. Häffner , J. D. Hague , D. Hampf , M. Hauser , S. Heinz , G. Heinzelmann , G. Henri (10) , G. Hermann , J. A. Hinton , A. Hoffmann , W. Hofmann , P. Hofverberg , M. Holler , D. Horns , A. Jacholkowska (7) , O. C. de Jager , C. Jahn , M. Jamrozy , I. Jung , M. A. Kastendieck , K. Katarzynski , U. Katz , S. Kaufmann , D. Keogh , D. Khangulyan , B. Khélifi (4) , D. Klochkov , W. Kluzniak , T. Kneiske , Nu. Komin (8) , K. Kosack (2) , R. Kossakowski (8) , H. Laffon (4) , G. Lamanna (8) , D. Lennarz , T. Löhse , A. Lopatin , C. -C. Lu , V. Marandon (5) , A. Marcowith (1) , Julien Masbou (8) , D. Maurin (7) , N. Maxted , T. J. L. Mccomb , M. C. Medina (2) , J. Méhault (1) , R. Moderski , Emmanuel Moulin (2) , C. L. Naumann (7) , M. Naumann-Godo (2) , M. de Naurois (4) , D. Nedbal , D. Nekrassov , N. Nguyen , B. Nicholas , J. Niemiec , S. J. Nolan , S. Ohm , J-P. Olive (3) , E. de Oña Wilhelmi , B. Opitz , M. Ostrowski , M. Panter , M. Paz Arribas , G. Pedaletti , G. Pelletier (10) , P. -O. Petrucci (10) , S. Pita (5) , G. Pühlhofer , M. Punch (5) , A. Quirrenbach , M. Raue , S. M. Rayner , A. Reimer , O. Reimer , M. Renaud (1) , R. de Los Reyes , F. Rieger , J. Ripken , L. Rob , S. Rosier-Lees (8) , G. Rowell , B. Rudak , C. B. Rulten , J. Ruppel , F. Ryde , V. Sahakian , A. Santangelo , R. Schlickeiser , F. M. Schöck , A. Schulz , U. Schwanke , S. Schwarzburg , S. Schwemmer , M. Sikora , J. L. Skilton , H. Sol (6) , G. Spengle , L. Stawarz , R. Steenkamp , C. Stegmann , F. Stinzing , K. Stycz , I. Sushch , A. Szostek (10) , J. -P. Tavernet (7) , R. Terrier (5) , O. Tibolla , M. Tluczykont , K. Valerius , C. van Eldik , G. Vasileiadis (1) , C. Venter , J. P. Vialle (8) , A. Viana (2) , P. Vincent (7) , M. Vivier (2) , H. J. Völk , F. Volpe , S. Vorobiov (1) , M. Vorster , S. J. Wagner , M. Ward , A. Wierzcholska , M. Zacharias , A. Zajczyk , A. A. Zdziarski , A. Zech (6) , H. -S. Zechlin

1 LPTA - Laboratoire de Physique Théorique et Astroparticules
2 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
3 CESR - Centre d'étude spatiale des rayonnements
4 LLR - Laboratoire Leprince-Ringuet
5 APC (UMR_7164) - AstroParticule et Cosmologie
6 LUTH (UMR_8102) - Laboratoire Univers et Théories
7 LPNHE - Laboratoire de Physique Nucléaire et de Hautes Énergies
8 LAPP - Laboratoire d'Annecy de Physique des Particules
9 APC - AHE - APC - Astrophysique des Hautes Energies
10 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble

Observations of the globular clusters NGC 6388 and M 15 were carried out by the H.E.S.S. array of Cherenkov telescopes for a live time of 27.2 and 15.2 hours respectively. No gamma-ray signal is found at the nominal target position of NGC 6388 and M 15. In the primordial formation scenario, globular clusters are formed in a dark matter halo and dark matter could still be present in the baryon-dominated environment of globular clusters. This opens the possibility of observing a dark matter self-annihilation signal. The dark matter content of the globular clusters NGC 6388 and M 15 is modelled taking into account the astrophysical processes that can be expected to influence the dark matter distribution during the evolution of the globular cluster: the adiabatic contraction of dark matter by baryons, the adiabatic growth of a black hole in the dark matter halo and the kinetic heating of dark matter by stars. 95% confidence level exclusion limits on the dark matter particle velocity-weighted annihilation cross section are derived for these dark matter haloes. In the TeV range, the limits on the velocity-weighted annihilation cross section are derived at the 10-25 cm3 s-1 level and a few 10-24 cm3 s-1 for NGC 6388 and M 15 respectively.

Domaines: Phénomènes cosmiques de haute energie [astro-ph.HE]; Phénomènes cosmiques de haute energie [astro-ph.HE]

A. Abramowski, Fabio Acero, F. Aharonian, A. G. Akhperjanian, G. Anton, et al.. H.E.S.S. observations of the globular clusters NGC 6388 and M 15 and search for a Dark Matter signal. The Astrophysical Journal, 2011, 735, pp.12. ⟨10.1088/0004-637X/735/1/12⟩. ⟨in2p3-00591116⟩