DISCOVERY OF HIGH-ENERGY GAMMA-RAY EMISSION FROM THE BINARY SYSTEM PSR B1259-63/LS 2883 AROUND PERIASTRON WITH FERMI

A. A. Abdo , Markus Ackermann , Marco Ajello , A. Allafort , Jean Ballet (1) , Guido Barbiellini , D. Bastieri , K. Bechtol , R. Bellazzini , B. Berenji , R. D. Blandford , E. Bonamente , A. W. Borgland , J. Bregeon , M. Brigida , Pascal Bruel (2) , R. Buehler , S. Buson , G. A. Caliandro , R. A. Cameron , F. Camilo , P. A. Caraveo , C. Cecchi , E. Charles , S. Chaty (1) , A. Chekhtman , M. Chernyakova , C. C. Cheung , J. Chiang , S. Ciprini , R. Claus , J. Cohen-Tanugi (3) , L. R. Cominsky , S. Corbel (4) , S. Cutini , F. d'Ammando , A. de Angelis , P. R. den Hartog , F. de Palma , C. D. Dermer , S. W. Digel , E. Do Couto E Silva2 , M. Dormody , P. S. Drell , A. Drlica-Wagner , R. Dubois , G. Dubus (5) , D. Dumora (6) , T. Enoto , C. M. Espinoza , C. Favuzzi , S. J. Fegan (2) , E. C. Ferrara , W. B. Focke , P. Fortin (2) , Y. Fukazawa , S. Funk , P. Fusco , F. Gargano , D. Gasparrini , N. Gehrels , S. Germani , N. Giglietto , P. Giommi , F. Giordano , M. Giroletti , T. Glanzman , G. Godfrey , I. A. Grenier (1) , M.-H. Grondin , J. E. Grove , E. Grundstrom , S. Guiriec , C. Gwon , D. Hadasch , A. K. Harding , M. Hayashida , E. Hays , G. J'Ohannesson , A. S. Johnson , T. J. Johnson , S. Johnston , T. Kamae , H. Katagiri , J. Kataoka , M. Keith , M. Kerr , Jürgen Knödlseder (7) , M. Kramer , M. Kuss , J. Lande , S.-H. Lee , M. Lemoine-Goumard (6) , F. Longo , F. Loparco , M. N. Lovellette , P. Lubrano , R. N. Manchester , M. Marelli , M. N. Mazziotta , P. F. Michelson , W. Mitthumsiri , T. Mizuno , A. A. Moiseev , C. Monte , M. E. Monzani , A. Morselli , I. V. Moskalenko , S. Murgia , T. Nakamori , M. Naumann-Godo (1) , A. Neronov , P. L. Nolan , J. P. Norris , A. Noutsos , E. Nuss (3) , T. Ohsugi , A. Okumura , N. Omodei , E. Orlando , D. Paneque , D. Parent , M. Pesce-Rollins , M. Pierbattista (1) , F. Piron (3) , T.A. Porter , A. Possenti , S. Rain'O , R. Rando , P. S. Ray , M. Razzano , S. Razzaque , A. Reimer , O. Reimer , T. Reposeur (6) , S. Ritz , H. F.-W. Sadrozinski , J. D. Scargle , C. Sgr'O , R. Shannon , E. J. Siskind , P. D. Smith , G. Spandre , P. Spinelli , M. S. Strickman , D. J. Suson , H. Takahashi , T. Tanaka , J. G. Thayer , J. B. Thayer , D. J. Thompson , S. E. Thorsett , L. Tibaldo , O. Tibolla , D. F. Torres , G. Tosti , E. Troja , Y. Uchiyama , T. L. Usher , J. Vandenbroucke , V. Vasileiou (3) , G. Vianello , V. Vitale , A. P. Waite , P. Wang , B. L. Winer , M. T. Wolff , D. L. Wood , K. S. Wood , Z. Yang , M. Ziegler , S. Zimmer

1 AIM (UMR7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
2 LLR - Laboratoire Leprince-Ringuet
3 LUPM - Laboratoire Univers et Particules de Montpellier
4 IUF - Institut universitaire de France
5 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble
6 GLAST
7 CESR - Centre d'étude spatiale des rayonnements

We report on the discovery of 100 MeV γ -rays from the binary system PSR B1259−63/LS 2883 using the Large Area Telescope (LAT) on board Fermi. The system comprises a radio pulsar in orbit around a Be star. We report on LAT observations from near apastron to ∼128 days after the time of periastron, tp, on 2010 December 15. No γ -ray emission was detected from this source when it was far from periastron. Faint γ -ray emission appeared as the pulsar approached periastron. At ∼tp + 30 days, the 100 MeV γ -ray flux increased over a period of a few days to a peak flux 20-30 times that seen during the pre-periastron period, but with a softer spectrum. For the following month, it was seen to be variable on daily timescales, but remained at ∼(1-4) × 10−6 cm−2 s−1 before starting to fade at ∼tp +57 days. The total γ -ray luminosity observed during this period is comparable to the spin-down power of the pulsar. Simultaneous radio and X-ray observations of the source showed no corresponding dramatic changes in radio and X-ray flux between the pre-periastron and post-periastron flares. We discuss possible explanations for the observed γ -ray-only flaring of the source.

Mots clés: binaries: eclipsing; gamma rays: stars; pulsars: individual (PSR B1259−63); X-rays: binaries

Domaines: Astrophysique stellaire et solaire [astro-ph.SR]; Astrophysique stellaire et solaire [astro-ph.SR]; Phénomènes cosmiques de haute energie [astro-ph.HE]; Phénomènes cosmiques de haute energie [astro-ph.HE]

A. A. Abdo, Markus Ackermann, Marco Ajello, A. Allafort, Jean Ballet, et al.. DISCOVERY OF HIGH-ENERGY GAMMA-RAY EMISSION FROM THE BINARY SYSTEM PSR B1259-63/LS 2883 AROUND PERIASTRON WITH FERMI. The Astrophysical journal letters, 2011, 736, pp.L11. ⟨10.1088/2041-8205/736/1/L11⟩. ⟨in2p3-00654867⟩