scholarly journals High-Ionization Nuclear Emission-Line Region in the Seyfert Galaxy Tololo 0109−383

1998 ◽  
Vol 115 (2) ◽  
pp. 460-471 ◽  
Author(s):  
Takashi Murayama ◽  
Yoshiaki Taniguchi ◽  
Kazushi Iwasawa
Keyword(s):  
Emission Line ◽  
Seyfert Galaxy ◽  
Line Region ◽  
High Ionization

scholarly journals Extended High-Ionization Nuclear Emission-Line Region in the Seyfert Galaxy NGC 4051

2000 ◽  
Vol 119 (2) ◽  
pp. 620-630 ◽  
Author(s):  
Tohru Nagao ◽  
Takashi Murayama ◽  
Yoshiaki Taniguchi ◽  
Michitoshi Yoshida
Keyword(s):  
Emission Line ◽  
Seyfert Galaxy ◽  
Line Region ◽  
High Ionization ◽  
Ngc 4051

High Velocity Outflow in the Extended Emission-Line Region of the Seyfert Galaxy NGC 7319

1996 ◽  
Vol 111 ◽  
pp. 140 ◽  
Author(s):  
Kentaro Aoki ◽  
Hiroshi Ohtani ◽  
Michitosh Yoshida ◽  
George Kosugi
Keyword(s):  
Emission Line ◽  
High Velocity ◽  
Seyfert Galaxy ◽  
Line Region ◽  
Extended Emission

scholarly journals The extended emission-line region of the Seyfert galaxy Mrk 573

1999 ◽  
Vol 309 (1) ◽  
pp. 1-25 ◽  
Author(s):  
P. Ferruit ◽  
A. S. Wilson ◽  
H. Falcke ◽  
C. Simpson ◽  
E. Pecontal ◽  
...  
Keyword(s):  
Emission Line ◽  
Seyfert Galaxy ◽  
Line Region ◽  
Extended Emission

scholarly journals High-Ionization Nuclear Emission-Line Region of Seyfert Galaxies

2000 ◽  
Vol 119 (6) ◽  
pp. 2605-2628 ◽  
Author(s):  
Tohru Nagao ◽  
Yoshiaki Taniguchi ◽  
Takashi Murayama
Keyword(s):  
Emission Line ◽  
Seyfert Galaxies ◽  
Line Region ◽  
High Ionization

scholarly journals Area Spectroscopy of the Extended Emission Line Region in the Seyfert Galaxy NGC 3516

1995 ◽  
Vol 149 ◽  
pp. 203-204
Author(s):  
K. Aoki ◽  
H. Ohtani ◽  
G. Kosugi ◽  
M. Yoshida
Keyword(s):  
Emission Line ◽  
Radiation Field ◽  
Seyfert Galaxy ◽  
Hii Regions ◽  
Nuclear Radiation ◽  
Ngc 4151 ◽  
Dust Clouds ◽  
Line Region ◽  
Extended Emission

The researches into extended emission line region (EELR) give us the valuable informations about the nucleus. A recent study of the EELR in the Seyfert 1 galaxy NGC 4151 by Yoshida and Ohtani (1993) have revealed that a strongly asymmetric radiation field in this typical Seyfert 1. They have suggested the anisotropy may be caused inside the BLR. It is important to examine if any other Seyfert 1 galaxy has an anisotropic nuclear radiation.The famous Seyfert 1 galaxy NGC 3516 has EELR which extends ∼ 10” on either side of the nucleus. The morphology of the EELR is Z-shape. This nearby (D=38.9Mpc) galaxy is of type SBO for which the object is expected to be free from contamination by HII regions and dust clouds.

scholarly journals Tri-dimensional Spectroscopy of the Seyfert Galaxy NGC 1275: Kinematics and Excitation of the Cooling-Flow Gas

1997 ◽  
Vol 159 ◽  
pp. 353-354
Author(s):  
M. Yoshida ◽  
G. Kosugi ◽  
K. Aoki
Keyword(s):  
Emission Line ◽  
Seyfert Galaxy ◽  
Optical Emission ◽  
Two Dimensional ◽  
X Ray ◽  
Cooling Flow ◽  
Gas Kinematics ◽  
Line Region ◽  
Ngc 1275 ◽  
Perseus Cluster

NGC 1275, the Perseus cluster cD galaxy, is a well-known Seyfert 1 galaxy and also one of the strongest extragalactic radio sources (3C84). Although many studies have been done on the extended optical emission-line region of NGC 1275, which is thought to be associated with the X-ray cooling-flow phenomenon (e.g., Heckman et al. 1989, Ferruit and Pecontal 1994), the excitation mechanism of the emission-line gas and two-dimensional gas kinematics are still unclear. We made tri-dimensional spectroscopy of NGC 1275 in order to reveal two-dimensional kinematics and- the relation between the gas motion and the excitation of the emission lines.

Subaru Spectropolarimetry of Markarian 573: The Hidden High-Ionization Nuclear Emission-Line Region inside the Dusty Torus

2004 ◽  
Vol 128 (5) ◽  
pp. 2066-2072 ◽  
Author(s):  
Tohru Nagao ◽  
Koji S. Kawabata ◽  
Takashi Murayama ◽  
Youichi Ohyama ◽  
Yoshiaki Taniguchi ◽  
...  
Keyword(s):  
Emission Line ◽  
Line Region ◽  
High Ionization ◽  
Dusty Torus

scholarly journals High-Velocity Outflow in the Extended Emission-Line Region of the Seyfert Galaxy NGC 7319

1997 ◽  
Vol 159 ◽  
pp. 357-358
Author(s):  
Kentaro Aoki
Keyword(s):  
Velocity Field ◽  
Compact Group ◽  
Emission Line ◽  
High Velocity ◽  
Seyfert Galaxy ◽  
Line Region ◽  
Systemic Velocity ◽  
Extended Emission

NGC 7319 is a member of the compact group of galaxies known as Stephan’s Quintet. The systemic velocity 6740 km s−1 gives a distance of 90Mpc (H0= 75 kms−1 Mpc−1) for NGC 7319. This galaxy has a tail and/or ring which suggests interaction with a neighboring pair of galaxies, NGC 7318A and B (e.g., Arp 1973). Durret & Warrin (1990) and Durret (1994) performed optical long-slit spectroscopy and found an extended emission-line region (EELR) in NGC 7319. They detected highly excited gas over along PA = 61° and 10″ along PA – 151°. Apart from these works, there have not been any studies on the velocity field and excitation of the gas in the EELR of NGC 7319. More details were published by Aoki et al. (1996).

scholarly journals Reverberation Mapping Analysis of the Broad-Line Region in Seyfert Galaxy NGC 4151

1998 ◽  
Vol 188 ◽  
pp. 424-425
Author(s):  
S.J. Xue ◽  
F.Z. Cheng
Keyword(s):  
Emission Line ◽  
Time Lag ◽  
Seyfert Galaxy ◽  
Broad Line ◽  
Reverberation Mapping ◽  
Ngc 4151 ◽  
Broad Line Region ◽  
Spectroscopic Monitoring ◽  
Line Region ◽  
The Continuum

One of the primary goals of AGN variability studies has been to determine the size of broad-line region (BLR) through the reverberation mapping technique. In a recent international multiwavelength spectroscopic monitoring campaign, NGC 4151 has been observed intensively by ground-based telescopes for a period of over 2 months, with a typical temporal resolution of 1 day. The main result from this optical campaign is that finding the variation in the emission line flux (Hβ or Hα) lagging the continuum by 0-3 days (1993 campaign: Kaspi et al. 1996). This is in contrast to the past results in which a time lag of 9±2 days was found for the same emission line (1988 campaign: Maoz et al. 1991). Such a BLR “size problem” may be caused by a different variability timescale of the ionizing continuum or a real change in BLR gas distribution in the 5.5 yr interval between the two watch campaigns. In order to clarify which of the two possibilities is most likely the real case, we performed further reverberation analysis on both optical datasets.

scholarly journals Emission-Line Variability in AGN

1989 ◽  
Vol 134 ◽  
pp. 100-102
Author(s):  
Dan Maoz
Keyword(s):  
Emission Line ◽  
Cross Correlation ◽  
Time Lag ◽  
Correlation Method ◽  
Seyfert Galaxy ◽  
Light Curves ◽  
Broad Line ◽  
Line Region ◽  
Order Of Magnitude

It has been apparent for some time that comparison of continuum and emission-line light curves of AGN may enable determination of the dimensions and structure of the Broad Line Region (BLR)(see Peterson 1988, and references therein). Observations to this end (Antonucci and Cohen 1983, Peterson et al. 1985, Clavel et al. 1987) and their analysis using cross-correlation to find the time lag between line and continuum variations (Gaskell and Sparke 1986), indicate BLR sizes an order of magnitude smaller than allowed by standard photoionization models for several AGN. Gaskell and Peterson (1987) analyzed errors in the cross-correlation method as applied to AGN time series in general and specifically to the Seyfert galaxy Akn120. In order to generalize and extend their analysis we investigated the significance of BLR sizes derived by cross-correlation under different model assumptions and observational circumstances (Maoz and Netzer 1988).

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