The Origin of the Strong Soft X-Ray Excess Found in a Seyfert Galaxy Discovered by ROSAT:CYCLE3 Medium

Details The Origin of the Strong Soft X-Ray Excess Found in a Seyfert Galaxy Discovered by ROSAT:CYCLE3 Medium The Origin of the Strong Soft X-Ray Excess Found in a Seyfert Galaxy Discovered by ROSAT:CYCLE3 Medium

Jul 1993

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993hst..prop.4275w&link_type=abstract

HST Proposal ID #4275

Physics

Hst Proposal Id #4275

Scientific paper

At least two emission components are merging in the soft X-ray spectra of Seyfert 1 galaxies, a flat non thermal hard X-ray powerlaw and a steeper soft X-ray excess. The study of 60 Seyfert 1 galaxies observed with IUE and ROSAT shows that there are two types of extreme ultraviolet continua among these objects. In 90% of the sample, the soft X-ray excess is very well correlated with the strength of the ultraviolet emission when it is compared to the hard X-ray flux, suggesting that there is a physical connection between the uv and soft X-ray components. However in 10% of the sources, ROSAT is detecting a strong soft X-ray excess when the optical to ultraviolet continuum is very faint. We propose to obtain the ultraviolet spectra of an extreme source in which the soft X-ray flux is at least 10 times more luminous than the far ultraviolet one extrapolated from an optical spectra that we have obtained. This ultraviolet spectrum is also 10 times too faint to be observed with IUE. The proposed observation will give a strong constraint on the spectral width of the soft X-ray emission and on its possible source in the core of the AGN. Simulations show that the spread in temperature in this component is probably smaller than a factor of 5, which is very small in comparison to what is expected from typical accretion disk models. These observations may give the first direct evidence for the existence of hot clouds or thick accretion discs in the core of active galactic nuclei.

Affiliated with

Also associated with

No associations

Rating

The Origin of the Strong Soft X-Ray Excess Found in a Seyfert Galaxy Discovered by ROSAT:CYCLE3 Medium 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 The Origin of the Strong Soft X-Ray Excess Found in a Seyfert Galaxy Discovered by ROSAT:CYCLE3 Medium, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Origin of the Strong Soft X-Ray Excess Found in a Seyfert Galaxy Discovered by ROSAT:CYCLE3 Medium will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1071300