中文
相关论文

相关论文: Subtleties in Measuring Iron K Lines in AGN

200 篇论文

We present the results of a systematic analysis of Fe K emission lines in low-luminosity AGNs (LLAGNs) observed with ASCA. We used a sample of LLAGNs with small intrinsic absorption to compare with luminous AGNs and accretion models. Some…

天体物理学 · 物理学 2007-05-23 Yuichi Terashima , Naoko Iyomoto , Luis C. Ho , Andrew F. Ptak

The ASCA calibration has evolved considerably since launch and indeed, is still evolving. There have been concerns in the literature that changes in the ASCA calibration have resulted in the Fe-Kalpha lines in active galaxies (AGN) now…

天体物理学 · 物理学 2009-11-07 T. Yaqoob , U. Padmanabhan , T. Dotani , K. Nandra

We discuss some topical issues related to the Fe K emission lines in AGNs. We show remarkable agreement between non-contemporaneous ASCA and Chandra grating data and explain why there has been terrible confusion about the ASCA and post-ASCA…

天体物理学 · 物理学 2007-05-23 Tahir Yaqoob

We present an analysis of the Fe K line profile of NGC 4151 by using long ASCA observation data obtained in May 1995. The unprecedented good data quality, which is much better in the energy band around 6.4 keV than that of the famous…

天体物理学 · 物理学 2009-10-31 Junxian. Wang , Youyuan. Zhou , Tinggui. Wang

The highest spectral resolution data for the Fe-K lines in type I AGN, as observed with the Chandra High Energy Grating (HEG), reveal a variety of line shapes. However, the energies of the most prominent peak are all clustered tightly…

天体物理学 · 物理学 2007-05-23 T. Yaqoob , U. Padmanabhan

The 6.4 keV Fe Ka emission line is a ubiquitous feature in X-ray spectra of AGN, and its properties track the interaction between the variable primary X-ray continuum and the surrounding structure from which it arises. We clarify the nature…

We review what we have learnt with ASCA from studying the Fe-K lines in AGN and describe a program to deconvolve the narrow, non-disk components of the lines with Chandra. This is necessary to derive the correct profiles of the broad,…

天体物理学 · 物理学 2007-05-23 T. Yaqoob

We present results of new ASCA observations of the low-luminosity AGN (LLAGN) NGC 4579 obtained on 1998 December 18 and 28, and we report on detection of variability of an iron K emission line. The X-ray luminosities in the 2--10 keV band…

天体物理学 · 物理学 2009-10-31 Y. Terashima , L. C. Ho , A. F. Ptak , T. Yaqoob , H. Kunieda , K. Misaki , P. J. Serlemitsos

We present an analysis of the narrow Fe K-alpha line in Chandra/HETGS observations of the Seyfert AGN, NGC 4151. The sensitivity and resolution afforded by the gratings reveal asymmetry in this line. Models including weak Doppler boosting,…

Iron K$\alpha$ (Fe K$\alpha$) emission is observed ubiquitously in AGN, and it is a powerful probe of their circumnuclear environment. Examinations of the emission line play a pivotal role in understanding the disk geometry surrounding the…

高能天体物理现象 · 物理学 2024-03-22 Victor Liu , Abderahmen Zoghbi , Jon M. Miller

We report the detection of a narrow Fe-K emission line in the Seyfert 1 galaxy NGC 5548 with the Chandra High-Energy Transmission Gratings. In the galaxy frame we measure a center energy of 6.40 \pm 0.03 keV, a FWHM of 4515 (+3525,-2645)…

天体物理学 · 物理学 2009-10-31 T. Yaqoob , I. M. George , K. Nandra , T. J. Turner , P. J. Serlemitsos , R. F. Mushotzky

XMM-Newton observations of type I AGN are presented. The properties of the iron K emission line are reviewed, the majority of AGN observed by XMM-Newton show narrow, unresolved (by XMM) iron lines at 6.4 keV from cold matter that must…

天体物理学 · 物理学 2007-05-23 James Reeves

We compile a sample of 89 Seyfert galaxies with both [OIV] 25.89 um line luminosities observed by Spitzer IRS and X-ray spectra observed by XMM EPIC. Using [OIV] emission as proxy of AGN intrinsic luminosity, we find that although type 2…

高能天体物理现象 · 物理学 2013-01-16 Teng Liu , Jun-Xian Wang

We present new results from a Chandra HETG observation of NGC 5548 and give a comparison of absorption and emission features found in other Seyfert 1 galaxies using Chandra grating observations. Deep soft X-ray edges are seen in Mkn 509 and…

天体物理学 · 物理学 2007-05-23 T. Yaqoob , I. M. George , T. J. Turner

Preliminary results from an X-ray spectral study of Seyfert 1 galaxies with ASCA and RXTE are presented. From an analysis of X-ray reprocessing features of Compton reflection and Fe K-alpha fluorescence, it is found that iron line strength…

天体物理学 · 物理学 2009-10-31 K. A. Weaver

We present preliminary results on the properties of relativistically broadened Fe K-alpha lines in a collection of more then 100 Active Galactic Nuclei (AGN) observed by the XMM-Newton EPIC-pn camera. Our main conclusions can be summarized…

天体物理学 · 物理学 2009-11-11 M. Guainazzi , S. Bianchi , M. Dovciak

We report results from a 2007 Suzaku observation of the Seyfert 1 AGN NGC 4593. The narrow Fe K alpha emission line has a FWHM width ~4000 km/s, indicating emission from >~ 5000 Rg. There is no evidence for a relativistically broadened Fe K…

高能天体物理现象 · 物理学 2014-11-20 A. Markowitz , J. N. Reeves

In active galactic nuclei (AGN), fluorescent Fe K$\alpha$ (iron) line emission is generally interpreted as originating from obscuring material around a supermassive black hole (SMBH) on the scale of a few parsecs (pc). However, recent…

We analyze X-ray spectra of heavily obscured (N_H > 10^{24} cm^{-2}) active galaxies obtained with Chandra, concentrating on the iron K alpha fluorescence line. We measure very large equivalent widths in most cases, up to 5 keV in the most…

天体物理学 · 物理学 2009-11-07 N. A. Levenson , J. H. Krolik , P. T. Zycki , T. M. Heckman , K. A. Weaver , H. Awaki , Y. Terashima

We present an analysis of the relativistic iron K-alpha line in the Seyfert 1 galaxy NGC 3516, based on a continuous, five-day ASCA observation. The broad profile which has been found in several other AGN is confirmed in NGC 3516 with…

天体物理学 · 物理学 2009-10-31 K. Nandra , I. M. George , R. F. Mushotzky , T. J. Turner , T. Yaqoob
‹ 上一页 1 2 3 10 下一页 ›