|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'503'724
Articles rated: 2609
24 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
Simultaneous EUVE/ASCA/RXTE Observations of NGC 5548 | | J. Chiang
; C. S. Reynolds
; O. M. Blaes
; M. A. Nowak
; N. Murray
; G. Madejski
; H. L. Marshall
; P. Magdziarz
; | | Date: |
9 Jul 1999 | | Subject: | astro-ph | | Affiliation: | 1,2), O. M. Blaes , M. A. Nowak , N. Murray , G. Madejski , H. L. Marshall , P. Magdziarz ( JILA, Hubble Fellow, UCSB, CITA, GSFC, MIT, Deceased | | Abstract: | We present simultaneous observations by EUVE, ASCA, and RXTE of the type~1 Seyfert galaxy NGC 5548. These data indicate that variations in the EUV emission (at $sim 0.2 $keV) appear to lead similar modulations in higher energy ($ga 1 $keV) X-rays by $sim$10--30 ks. This is contrary to popular models which attribute the correlated variability of the EUV, UV and optical emission in type~1 Seyferts to reprocessing of higher energy radiation. This behavior instead suggests that the variability of the optical through EUV emission is an important driver for the variability of the harder X-rays which are likely produced by thermal Comptonization. We also investigate the spectral characteristics of the fluorescent iron K$alpha$ line and Compton reflection emission. In contrast to prior measurements of these spectral features, we find that the iron K$alpha$ line has a relatively small equivalent width ($W_{Kalpha} sim 100 $eV) and that the reflection component is consistent with a covering factor which is significantly less than unity ($Omega/2pi sim 0.4$--0.5). Notably, although the 2--10 keV X-ray flux varies by $sim pm 25$% and the derived reflection fraction appears to be constant throughout our observations, the flux in the Fe~K$alpha$ line is also constant. This behavior is difficult to reconcile in the context of standard Compton reflection models. | | Source: | arXiv, astro-ph/9907114 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER