New bright soft X-ray selected ROSAT AGN: I. Infrared-to-X-ray spectral energy distributions

Details New bright soft X-ray selected ROSAT AGN: I. Infrared-to-X-ray spectral energy distributions New bright soft X-ray selected ROSAT AGN: I. Infrared-to-X-ray spectral energy distributions

1997-10-27

arxiv.org/abs/astro-ph/9710298v1

Astronomy and Astrophysics

Astrophysics

13 pages, including 7 fugures and 4 tables, to appear in A&A

Scientific paper

We present results of an infrared-to-X-ray study of 76 bright soft X-ray selected Seyfert galaxies discovered in the ROSAT All-Sky Survey. These objects are characterized by steep X-ray spectra in the 0.2-2.0 keV bandpass with power law energy spectral indices in the range of 1.3 to 8 and a lack of internal absorption by neutral hydrogen. Our sample selection based on hardness ratio yields a mean X-ray slope of alpha-X = 2.1, steeper than in any other known AGN population. At optical wavelengths, the soft AGN have significantly bluer spectra than a comparison sample of AGN with a canonical, harder X-ray spectrum, whereas the slope between 5500 Angstrom and 1 keV is the same. This is consistent with a more pronounced Big Blue Bump emission component in the soft X-ray selected AGN. The blueness of the optical spectra increases with the softness of the X-ray spectra and with the luminosity, saturating at an approximate F_nu proportional to nu^+0.3 spectrum. Such properties are expected if most of the Big Blue Bump emission originates in a (comptonized) accretion disk and accretion rate to mass ratio is higher than in AGN with a hard X-ray spectrum.

Affiliated with

Also associated with

No associations

Rating

New bright soft X-ray selected ROSAT AGN: I. Infrared-to-X-ray spectral energy distributions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with New bright soft X-ray selected ROSAT AGN: I. Infrared-to-X-ray spectral energy distributions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and New bright soft X-ray selected ROSAT AGN: I. Infrared-to-X-ray spectral energy distributions will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-107159