EDP Sciences
Free access
Volume 429, Number 2, January II 2005
Page(s) 427 - 431
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20041871

A&A 429, 427-431 (2005)
DOI: 10.1051/0004-6361:20041871

INTEGRAL observations of the field of the BL Lacertae object S5 0716+714

E. Pian1, 2, L. Foschini2, V. Beckmann3, 4, A. Sillanpää5, S. Soldi6, G. Tagliaferri7, L. Takalo5, P. Barr8, G. Ghisellini7, G. Malaguti2, L. Maraschi9, G. G. C. Palumbo10, A. Treves11, T. J.-L. Courvoisier6, 12, G. Di Cocco2, N. Gehrels3, P. Giommi13, R. Hudec14, E. Lindfors5, A. Marcowith15, K. Nilsson5, M. Pasanen5, T. Pursimo16, C. M. Raiteri17, T. Savolainen5, M. Sikora18, M. Tornikoski19, G. Tosti20, M. Türler6, E. Valtaoja5, M. Villata17 and R. Walter6, 12

1  INAF - Osservatorio Astronomico di Trieste, via GB Tiepolo 11, 34131 Trieste, Italy
    e-mail: pian@ts.astro.it
2  IASF-CNR, Sezione di Bologna, via Gobetti 101, 40129 Bologna, Italy
3  NASA Goddard Space Flight Center, Code 661, Greenbelt, MD 20771, USA
4  Joint Center for Astrophysics, Department of Physics, University of Maryland, Baltimore County, MD 21250, USA
5  Tuorla Observatory, University of Turku, 21500 Piikkiö, Finland
6  INTEGRAL Science Data Center, Chemin d'Écogia 16, 1290 Versoix, Switzerland
7  INAF - Osservatorio Astronomico di Brera, via E Bianchi, 46, 23807 Merate (LC), Italy
8  ESA-ESTEC, RSSD, Keplerlaan 1, Postbus 299, 2200 AG Noordwijk, The Netherlands
9  INAF - Osservatorio Astronomico di Brera, via Brera 28, 20121 Milano, Italy
10  Department of Astronomy, University of Bologna, via Ranzani 1, 40127 Bologna, Italy
11  Dipartimento di Fisica e Matematica, University of Insubria, via Valleggio 11, 22100 Como, Italy
12  Observatoire de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland
13  ASI Science Data Center, via Galileo Galilei, 00044 Frascati, Italy
14  Astronomical Institute, 251 65 Ondrejov, Czech Republic
15  Centre d'Étude Spatiale de Rayonnements, 31028 Toulouse, France
16  Nordic Optical Telescope, Apartado 474, 38700 Santa Cruz de La Palma, Spain
17  INAF - Osservatorio Astronomico di Torino, via Osservatorio 20, 10025 Pino Torinese (TO), Italy
18  Nikolaus Copernicus Astronomical Center, Bartycka 18, 00-716 Warsaw, Poland
19  Metsähovi Radio Observatory, Metsähovintie 114, 02540 Kylmälä, Finland
20  Department of Physics, University of Perugia, via A Pascoli, 06123 Perugia, Italy

(Received 20 August 2004 / Accepted 26 August 2004 )

We have performed observations of the blazar S5 0716+714 with INTEGRAL on 2-6 April 2004. In the first months of 2004, the source had increased steadily in optical brightness and had undergone two outbursts. During the latter outburst, that occurred in March, it reached the extreme level of R = 12.1 mag, which triggered our INTEGRAL program. The target has been detected with IBIS/ISGRI up to 60 keV, with a flux of $\sim $ $3 \times 10^{-11}$ erg s -1 cm -2 in the 30-60 keV interval, a factor of ~2 higher than observed by the BeppoSAX PDS in October 2000. In the field of S5 0716+714 we have also detected the Flat Spectrum Radio Quasar S5 0836+710 and the two Seyfert galaxies Mkn 3 and Mkn 6. Their IBIS/ISGRI spectra are rather flat, albeit consistent with those measured by BeppoSAX. In the spectrum of Mkn 3 we find some evidence of a break between ~60 and ~100 keV, reminiscent of the high energy cut-offs observed in other Seyfert galaxies. This is the first report of INTEGRAL spectra of weak Active Galactic Nuclei.

Key words: galaxies: active -- gamma-rays: observations

SIMBAD Objects

© ESO 2004