Fermi Large Area Telescope Observation of a Gamma-ray Source at the Position of Eta Carinae

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope detected a γ-ray source that is spatially consistent with the location of Eta Carinae. This source has been persistently bright since the beginning of the LAT survey observations (from 2008 August to 2009 July, the time inte...

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Detalles Bibliográficos
Autores: Abdo, Aous A., Ackermann, Markus, Ajello, Marco, Allafort, Alice, Baldini, Luca, Ballet, Jean, Barbiellini, Guido, Bastieri, Denis, Bechtol, Keith, Bellazzini, Ronaldo, Berenji, Bijan, Gehrels, Neil, Uchiyama, Yasunobu, Usher, Tracy L., Cohen-Tanugi, Johan, Vandenbroucke, Justin, Vasileiou, Vlasios, Vilchez, Nicolás, Vitale, Vincenzo, Bregeon, Jean, Waite, Anthony P., Piron, Frédéric, Wallace, Eric, Germani, Stefano, Wang, Ping, Winer, Brian L., Wood, Kent S., Cominsky, Lynn R., Yang, Zhaoyu, Ylinen, Tomi, Ziegler, Marcus, Brez, Alessandro, Itoh, Ryosuke, Brigida, Monica, Bruel, Philippe, Giglietto, Nicola, Buehler, Rolf, Burnett, Thompson H., Caliandro, Giuseppe Andrea, Cameron, Robert A., Conrad, Jan, Caraveo, Patrizia A., Carrigan, Svenja, Jackson, Miranda S., Casandjian, Jean-Marc, Cecchi, Claudia, Çelik, Özlem, Giordano, Francesco, Chaty, Sylvain, Chekhtman, Alexandre, Cheung, C. C. Teddy, Dermer, Charles Dennison, Palma, Francesco de, Digel, Seth W., Murgia, Simona, Couto e Silva, Eduardo do, Monzani, Maria Elena, Drell, Persis S., Dubois, Richard, Godfrey, Gary, Dumora, Denis, Favuzzi, Cecilia, Fegan, Stephen J., Ferrara, Elizabeth C., Frailis, Marco, Johannesson, Gueolaugur, Fukazawa, Yasushi, Fusco, Piergiorgio, Gargano, Fabio, Grenier, Isabelle A., Grondin, Marie-Hélène, Grove, J. Eric, Guillemot, Lucas, Bonamente, Emanuele, Guiriec, Sylvain, Moskalenko, Igor V., Johnson, A. S., Hadasch, Daniela, Hanabata, Yoshitaka, Harding, Alice K., Hayashida, Masaaki, Hays, Elizabeth, Hill, Adam B., Horan, Deirdre, Hughes, Richard E., Johnson, W. Neil, Kamae, Tuneyoshi, Katagiri, Hideaki, Kataoka, Jun, Ciprini, Stefano, Kerr, Matthew, Porter, Troy A., Knödlseder, Jürgen, Kuss, M., Lande, Joshua, Nakamori, Takeshi, Latronico, Luca, Lee, Shiu-Hang, Lemoine-Goumard, Marianne, Livingstone, Maggie, Smith, Patrick D., Llena-Garde, Maja, Longo, Francesco, Rainò, Silvia, Loparco, Francesco, Lovellette, Michael N., Lubrano, Pasquale, Makeev, Andrey, Naumann-Godo, Melitta, Mazziotta, Mario Nicola, McEnery, Julie E., Spandre, Gloria, Mehault, Jeremie, Michelson, Peter F., Mitthumsiri, Warit, Rando, Riccardo, Mizuno, Takafumi, Moiseev, Alex A., Monte, Claudia, Nolan, Pat L., Norris, Jay P., Nuss, Eric, Bouvier, Aurelien, Ohsugi, Takashi, Blandford, Roger D., Okumura, Akira, Omodei, Nicola, Razzano, Massimiliano, Orlando, Elena, Ormes, Jonathan F., Ozaki, Masanobu, Panetta, Jim H., Parent, D., Spinelli, Paolo, Pelassa, Véronique, Pepe, Monica, Pesce-Rollins, Melissa, Reimer, Anita, Reimer, Olaf, Reposeur, Thierry, Rodríguez, Ana Yaiza, Chiang, James, Romani, Roger W., Borgland, Anders W., Strickman, Mark Samuel, Roth, Marshall, Sadrozinski, Hartmut F. W., Sander, Aaron, Saz Parkinson, Pablo M., Scargle, Jeffrey D., Sgrò, Carmelo, Siskind, Eric J., Smith, David A., Suson, Daniel Jeffrey, Takahashi, Hiromitsu, Takahashi, Tadayuki, Tanaka, Takaaki, Morselli, Aldo, Thayer, Jana B., Claus, Rachel, Thayer, John Gregg, Thompson, David J., Tibaldo, Luigi, Brandt, Theresa J., Tibolla, Omar, Torres, Diego F., Tosti, Gino, Tramacere, Andrea
Tipo de recurso: artículo
Fecha de publicación:2010
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/41403
Acceso en línea:http://hdl.handle.net/10261/41403
Access Level:acceso abierto
Palabra clave:Binaries: general
Stars: individual (Eta Carinae)
Supergiants
Descripción
Sumario:The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope detected a γ-ray source that is spatially consistent with the location of Eta Carinae. This source has been persistently bright since the beginning of the LAT survey observations (from 2008 August to 2009 July, the time interval considered here). The γ-ray signal is detected significantly throughout the LAT energy band (i.e., up to ~100 GeV). The 0.1-100 GeV energy spectrum is well represented by a combination of a cutoff power-law model (<10 GeV) and a hard power-law component (>10 GeV). The total flux (>100 MeV) is 3.7+0.3 –0.1 × 10–7 photons s–1 cm–2, with additional systematic uncertainties of 10%, and consistent with the average flux measured by AGILE. The light curve obtained by Fermi is consistent with steady emission. Our observations do not confirm the presence of a γ-ray flare in 2008 October, as reported by Tavani et al., although we cannot exclude that a flare lasting only a few hours escaped detection by the Fermi LAT. We also do not find any evidence for γ-ray variability that correlates with the large X-ray variability of Eta Carinae observed during 2008 December and 2009 January. We are thus not able to establish an unambiguous identification of the LAT source with Eta Carinae.