BeppoSAX broad-band observations of low-redshift quasars: Spectral curvature and iron K_alpha lines

Details BeppoSAX broad-band observations of low-redshift quasars: Spectral curvature and iron K_alpha lines BeppoSAX broad-band observations of low-redshift quasars: Spectral curvature and iron K_alpha lines

2000-05-30

arxiv.org/abs/astro-ph/0005567v1

Astronomy and Astrophysics

Astrophysics

14 pages, 7 figures, accepted by A&A

Scientific paper

We present results from BeppoSAX observations of 10 low redshift quasars. The quasars are part of the Laor et al. (1997) sample of 23 optically selected PG quasars with redshift <0.4 and low Galactic absorption along the line of sight. Significant spectral curvature is detected for the 6 quasars with the highest signal to noise ratio in their low energy spectra. The average curvature can be parameterized as a flattening of the underlying power law by Delta_alpha ~ 0.5 above ~1 keV. We find that quasars with a steeper soft X-ray (0.1-2 keV) spectrum tend to be steeper also at higher (2-10 keV) energies. The distribution of the best fit 2-10 keV slopes is similar to that found for other radio-quiet AGN and characterized by a large dispersion around the mean: alpha_E ~ 1.0+/-0.3. Iron K_alpha lines are detected in 4 quasars. In the narrow-line quasar PG 1115+407, the rest frame line energy (6.69+/-0.11 keV) and equivalent width (580+/-280 eV) are consistent with those found in a few low redshift narrow-line Seyfert 1 galaxies (NLSy1). This, together with the similarity of the 0.1-10 keV X-ray continuum, suggests that this quasar is the higher redshift and luminosity analog of a NLSy1. In the broad line quasar PG 0947+396, the rest-frame line energy suggests fluorescence from cold iron. The line equivalent width (> 400 eV) is however about 2-3 times higher than that usually found in Seyfert 1 galaxies. The high energy power-law slopes and the iron line emission properties seem to be unrelated to the X-ray luminosity.

Affiliated with

Also associated with

No associations

Rating

BeppoSAX broad-band observations of low-redshift quasars: Spectral curvature and iron K_alpha lines 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 BeppoSAX broad-band observations of low-redshift quasars: Spectral curvature and iron K_alpha lines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and BeppoSAX broad-band observations of low-redshift quasars: Spectral curvature and iron K_alpha lines will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-636509