Zobrazeno 1 - 10
of 134
pro vyhledávání: '"Pesce J"'
Publikováno v:
Astron.Astrophys. 407 (2003) 503-514
We present Chandra observations of the X-ray environment of a sample of 6 BL Lacertae objects. The improved sensitivity of the ACIS experiment allows us to separate the core X-ray emission from the contribution of diffuse emission from the host galax
Externí odkaz:
http://arxiv.org/abs/astro-ph/0305407
Autor:
Gambill, J. K., Sambruna, R. M., Chartas, G., Cheung, C. C., Maraschi, L., Tavecchio, F., Urry, C. M., Pesce, J. E.
Publikováno v:
Astron.Astrophys. 401 (2003) 505-518
We present the X-ray properties of a sample of 17 radio sources observed with the Chandra X-ray Observatory as part of a project aimed at studying the X-ray emission from their radio jets. In this paper, we concentrate on the X-ray properties of the
Externí odkaz:
http://arxiv.org/abs/astro-ph/0302265
Autor:
Pian, E., Falomo, R., Hartman, R. C., Maraschi, L., Tavecchio, F., Tornikoski, M., Treves, A., Urry, C. M., Ballo, L., Mukherjee, R., Scarpa, R., Thompson, D. J., Pesce, J. E.
PKS 0537-441, a bright gamma-ray emitting blazar, was observed at radio, optical, UV and X-ray frequencies during various EGRET pointings, often quasi-simultaneously. In 1995 the object was found in an intense emission state at all wavelengths. Beppo
Externí odkaz:
http://arxiv.org/abs/astro-ph/0207355
Publikováno v:
New Astron.Rev. 46 (2002) 159-162
We analyze images of BL Lacertae objects obtained with the {\it Hubble Space Telescope} WFPC2 and the F814W filter. The nine objects cover a redshift range of 0.19 to 0.997. The relatively deep images are sufficient to detect galaxies at least one ma
Externí odkaz:
http://arxiv.org/abs/astro-ph/9908344
Autor:
Pian, E., Urry, C. M., Maraschi, L., Madejski, G., McHardy, I. M., Koratkar, A., Treves, A., Chiappetti, L., Grandi, P., Hartman, R. C., Kubo, H., Leach, C. M., Pesce, J. E., Imhoff, C., Thompson, R., Wehrle, A. E.
The gamma-ray blazar 3C 279 was monitored on a nearly daily basis with IUE, ROSAT and EGRET for three weeks between December 1992 and January 1993. During this period, the blazar was at a historical minimum at all wavelengths. Here we present the UV
Externí odkaz:
http://arxiv.org/abs/astro-ph/9906326
We present HST observations of seven unusual objects from the HST ``snapshot survey'' of BL Lac objects, of which four are gravitational lens candidates. In three cases a double point sources is observed: 0033+595, with 1.58 arcsec separation, and 05
Externí odkaz:
http://arxiv.org/abs/astro-ph/9902333
We present ASCA observations of the radio-selected BL Lacertae objects 1749+096 (z=0.32) and 2200+420 (BL Lac, z=0.069) performed in 1995 Sept and Nov, respectively. The ASCA spectra of both sources can be described as a first approximation by a powe
Externí odkaz:
http://arxiv.org/abs/astro-ph/9810319
Autor:
Pian, E., Koratkar, A., Maraschi, L., Urry, C. M., Madejski, G., McHardy, I. M., Pesce, J. E., Treves, A., Grandi, P., Leach, C. M.
Archival IUE SWP and HST FOS spectra show the presence of a relatively strong, broad Lyman alpha emission line superposed onto the UV spectral continuum of the blazar 3C 279. As opposed to a factor ~50 variation of the continuum flux during eight yea
Externí odkaz:
http://arxiv.org/abs/astro-ph/9805005
Autor:
Urry, C. Megan, Treves, A., Maraschi, L., Marshall, H., Kii, T., Madejski, G., Penton, S., Pesce, J. E., Pian, E., Celotti, A., Fujimoto, R., Makino, F., Otani, C., Sambruna, R. M., Sasaki, K., Shull, J. M., Smith, P., Takahashi, T., Tashiro, M.
In May 1994 the BL Lac object PKS 2155-304 was observed continuously for ~10 d with IUE and EUVE and for 2 d with ASCA, as well as with ROSAT and with ground- based radio, IR, and optical telescopes. The light curves show a well-defined X-ray flare (
Externí odkaz:
http://arxiv.org/abs/astro-ph/9704194
Autor:
Pesce, J. E., Urry, C. M., Maraschi, L., Treves, A., Grandi, P., Kollgaard, R., Pian, E., Smith, P., Aller, H. Aller M., Barth, A., Buckley, D., Covino, E., Filippenko, A., Hooper, E., Kedziora-Chudczer, M. Joner L., Kilkenny, D., Knee, L., Kunkel, M., Layden, A., Magalhaes, A., Marang, F., Margoniner, V., Palma, C., Pereyra, A., Rodrigues, C., Schutte, A., Sitko, M., Tornikoski, M., van der Walt, J., van Wyk, F., Whitelock, P., Wolk, S.
Optical, near-infrared, and radio observations of the BL Lac object PKS2155-304 were obtained simultaneously with a continuous UV/EUV/X-ray monitoring campaign in 1994 May. Further optical observations were gathered throughout most of 1994. The radio
Externí odkaz:
http://arxiv.org/abs/astro-ph/9704195