Results 31 to 40 of about 2,168,923 (219)

Bright X-ray galaxies in SDSS filaments [PDF]

arXiv, 2013
Eighteen bright X-ray emitting galaxies were found in nearby filaments within SDSS region. Basic X-ray spectral parameters were estimated for these galaxies using power law model with photoelectric absorption. A close pair of X-ray galaxies was found.
arxiv  

Mirax: A Brazilian X-Ray Astronomy Satellite Mission [PDF]

, 2003
We describe the ``Monitor e Imageador de Raios-X'' (MIRAX), an X-ray astronomy satellite mission proposed by the high energy astrophysics group at the National Institute for Space Research (INPE) in Brazil to the Brazilian Space Agency.
Boella, Bouchet, Braga, Braga, Caroli, Dicke, E. Kendziorra, E. Kuulkers, F. D'Amico, F. Jablonski, Garcia, Gottesman, J. Braga, J. Heise, J. Matteson, J. Wilms, Jager, Levine, Levine, Paul, R. Remillard, R. Rothschild, R. Staubert, Roques, Shindler, Skinner, Sunyaev, W. Heindl, Willmore   +28 more
core   +2 more sources

New Problems for a New Century [PDF]

arXiv, 2002
A summary is presented of a symposium held to review recent progress in X-ray astronomy and to discuss prospects for the next generation of X-ray missions. The summary is organized around ten general, astrophysical questions that may provide scientific drivers for the design of new facilities.
arxiv  

The broad band spectrum and variability of Seyfert 1 [PDF]

, 2000
Recent results on the X-ray spectrum and variability of Seyfert 1 galaxies are reviewed. New spectral results from BeppoSAX observations are also presented and briefly discussed.
arxiv   +1 more source

Space Astronomy at TIFR: From Balloons to Satellites [PDF]

arXiv, 2023
Tata Institute of Fundamental Research (TIFR) has a very long tradition of conducting space astronomy experiments. Within a few years of the discovery of the first non-solar X-ray source in 1962, TIFR leveraged its expertise in balloon technology to make significant contributions to balloon-borne hard X-ray astronomy.
arxiv  

Optimization of grazing incidence mirrors and its application to surveying X-ray telescopes

, 2001
Grazing incidence mirrors for X-ray astronomy are usually designed in the parabola-hyperbola (Wolter I) configuration. This design allows for optimal images on-axis, which however degrade rapidly with the off-axis angle.
Aschenbach, Bavdaz, Borgani, Burrows, Campana, Cash, Cash, Citterio, Citterio, Citterio, Ghigo, Giacconi, Gioia, Giommi, Harvey, Lazzati, Nariai, Nariai, P. Conconi, Predehl, S. Campana, Serlemitsos, Tananbaum, Trümper, Turner, VanSpeybroeck, VanSpeybroeck, Voges, Werner, Wolter, Wolter   +30 more
core   +1 more source

Obscured Active Galactic Nuclei [PDF]

, 2000
The properties of the absorption in type 2, narrow line AGNs are reviewed by focusing on the X-ray indicators. I discuss the properties of the cold absorbing medium (the putative torus) and of the reprocessed components, as well as their implications for
Maiolino, R.
core   +3 more sources

On the X-ray properties of V Sge and its relation to the supersoft X-ray binaries [PDF]

arXiv, 1998
We investigate the ROSAT X-ray properties of V Sge, which has been proposed to be related to supersoft X-ray binaries. During optical bright states, V Sge is a faint hard X-ray source, while during optical faint states (V >=12 mag), V Sge is a `supersoft' X-ray source.
arxiv  

X-ray astronomy [PDF]

Various experiments in X-ray astronomy are described. The occurrence of lunar occultations of the Crab Nebula were utilized to determine the spatial distribution of X-ray emitting regions in the nebula.
Novick, R.
core   +1 more source

ROSAT Observations of BL Lacertae Objects [PDF]

arXiv, 1996
We present soft X-ray spectra of 74 BL Lacertae objects observed with the PSPC detector on board of the ROSAT satellite. The sample contains all BL Lac objects detected during the pointed observation phase as a target or serendipitously. We have investigated the soft X-ray and broad band spectral properties and discuss the consequences for the X-ray ...
arxiv