Soft X-ray absorption by Fe0 to Fe15+ in active galactic nuclei

被引:132
作者
Behar, E
Sako, M
Kahn, SM
机构
[1] Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA
[2] Columbia Univ, Dept Phys, New York, NY 10027 USA
关键词
atomic data; atomic processes; galaxies : active; galaxies : nuclei; line : formation; X-rays : galaxies;
D O I
10.1086/323966
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
A full set of calculations is presented for inner-shell n = 2-3 photoexcitation of the 16 iron charge states : Fe0+ (Fe I) through Fe15+ (Fe XVI). The blend of the numerous absorption lines arising from these excitations (mainly 2p-3d) forms an unresolved transition array (UTA), which has been recently identified as a prominent feature between 16 and 17 Angstrom in the soft X-ray spectra of active galactic nuclei AZ (AGNs). Despite the blending within charge states, the ample separation between the individual-ion features enables precise diagnostics of the ionization range in the absorbing medium. Column density and turbulent velocity diagnostics are also possible, albeit to a lesser accuracy. An abbreviated set of atomic parameters useful for modeling the Fe 2p-3d UTA is given. It is shown that the effects of accompanying photoexcitation to higher levels (n greater than or equal to 4), as well as the associated photoionization edges, may also be relevant to AGN spectra.
引用
收藏
页码:497 / 504
页数:8
相关论文
共 15 条
[1]   HULLAC, an integrated computer package for atomic processes in plasmas [J].
Bar-Shalom, A ;
Klapisch, M ;
Oreg, J .
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER, 2001, 71 (2-6) :169-188
[2]   VARIANCE OF THE DISTRIBUTIONS OF ENERGY-LEVELS AND OF THE TRANSITION ARRAYS IN ATOMIC SPECTRA .3. CASE OF SPIN-ORBIT-SPLIT ARRAYS [J].
BAUCHEARNOULT, C ;
BAUCHE, J ;
KLAPISCH, M .
PHYSICAL REVIEW A, 1985, 31 (04) :2248-2259
[3]   Photoabsorption in dense plasmas [J].
Blenski, T .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 2000, 127 (02) :239-244
[4]  
Cowan R. D., 1981, The theory of atomic structure and spectra, V3
[5]  
KALLMAN TR, 1995, XSTAR SPECTRAL ANAL
[6]   High-resolution X-ray spectroscopy and modeling of the absorbing and emitting outflow in NGC 3783 [J].
Kaspi, S ;
Brandt, WN ;
Netzer, H ;
George, IM ;
Chartas, G ;
Behar, E ;
Sambruna, RM ;
Garmire, GP ;
Nousek, JA .
ASTROPHYSICAL JOURNAL, 2001, 554 (01) :216-232
[7]   Discovery of narrow X-ray absorption lines from NGC 3783 with the Chandra high energy transmission grating spectrometer [J].
Kaspi, S ;
Brandt, WN ;
Netzer, H ;
Sambruna, R ;
Chartas, G ;
Garmire, GP ;
Nousek, JA .
ASTROPHYSICAL JOURNAL, 2000, 535 (01) :L17-L20
[8]   1S-3P KBETA-LIKE X-RAY-SPECTRUM OF HIGHLY IONIZED IRON [J].
KLAPISCH, M ;
SCHWOB, JL ;
FRAENKEL, BS ;
OREG, J .
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA, 1977, 67 (02) :148-155
[10]  
Luc-Koenig E, 1972, PHYSICA, V62, P393