On the origin of the radio, optical emission-line, and X-ray structure of M87

1980 ◽  
Vol 242 ◽  
pp. 511 ◽  
Author(s):  
D. S. de Young ◽  
H. Butcher ◽  
J. J. Condon
Keyword(s):  
Emission Line ◽  
Optical Emission ◽  
X Ray

X-ray and optical emission-line filaments in the cooling flow cluster 2A 0335 + 096

1992 ◽  
Vol 397 ◽  
pp. L31 ◽  
Author(s):  
Craig L. Sarazin ◽  
Robert W. O'Connell ◽  
Brian R. McNamara
Keyword(s):  
Emission Line ◽  
Optical Emission ◽  
X Ray ◽  
Cooling Flow

On the Relationship between the Optical Emission‐Line and X‐Ray Luminosities in Seyfert 1 Galaxies

2004 ◽  
Vol 607 (2) ◽  
pp. 794-799 ◽  
Author(s):  
S. B. Kraemer ◽  
I. M. George ◽  
D. M. Crenshaw ◽  
J. R. Gabel
Keyword(s):  
Emission Line ◽  
Optical Emission ◽  
X Ray ◽  
The Relationship

scholarly journals Emission Line Properties of Seyfert 1 Type AGN from RASS

2003 ◽  
Vol 214 ◽  
pp. 273-274
Author(s):  
D. W. Xu ◽  
S. Komossa ◽  
J. Y. Wei ◽  
X. Z. Zheng ◽  
Y. Qian
Keyword(s):  
Correlation Analysis ◽  
Emission Line ◽  
Optical Emission ◽  
Strong Correlations ◽  
X Ray ◽  
Narrow Component ◽  
Broad Component

We present the optical emission line properties of a sample of 155 bright X-ray selected ROSAT Seyfert 1 type AGN. The measured properties are gathered for correlation analysis. The strong correlations between Hβ redshift, flux ratios of Fe II to Hβ broad component and [O III] to Hβ narrow component are found.

scholarly journals X-ray Observations of SNR E0102.2-72.2 in the SMC

1988 ◽  
Vol 101 ◽  
pp. 125-128
Author(s):  
John P. Hughes
Keyword(s):  
High Resolution ◽  
Emission Line ◽  
Spectral Data ◽  
Proportional Counter ◽  
High Velocity ◽  
Supernova Remnant ◽  
Optical Emission ◽  
Small Magellanic Cloud ◽  
X Ray ◽  
Best Fit

AbstractThe supernova remnant (SNR) E0102.2-72.2 is the brightest in the Small Magellanic Cloud (SMC) at X-ray wavelengths. This object, which is remarkable because of its high velocity (∼4000 km s−1) oxygen-rich optical emission, appears to be similarly remarkable at X-ray wavelengths. The high resolution imager (HRI) data can be quite well described by a thick ring with a radius of ∼19" (6 pc at a distance of 63 kpc). The imaging proportional counter (IPC) X-ray spectral data can be best fit by a single emission line of energy ∼0.9 keV. It seems likely that this is the emission from a plasma of almost pure neon.

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.

scholarly journals Are LINERs Starbursts or Mini-quasars? A Comparative Study of their Ultraviolet Spectra

1999 ◽  
Vol 194 ◽  
pp. 71-74
Author(s):  
Anuradha Koratkar
Keyword(s):  
Emission Line ◽  
Hubble Space Telescope ◽  
Optical Emission ◽  
Uv Spectra ◽  
High Mass ◽  
X Ray ◽  
Compact Source ◽  
Continuum Source ◽  
Liner Galaxies ◽  
Super Star Clusters

Low Ionization Nuclear Emission Line Regions (LINERs) are found in ˜30% of all bright galaxies. The nuclear luminosities in these objects are such that they can be produced by a number of mechanisms and there have been heated debates on the nature of ionizing sources in LINERs. The variety of ionizing mechanisms suggested are low luminosity AGNs, starbursts, shocks, or any combination of these. We have studied Hubble Space Telescope (HST) ultraviolet (UV) spectra of seven LINERs having compact nuclear UV sources.The picture emerging from this comparison is that the compact source observed in these LINER galaxies, at least in some cases, is a nuclear star cluster rather than a low-luminosity active galactic nucleus (AGN). In these cases, the UV luminosity is driven by tens of thousands of O-type stars, depending on the assumed extinction for these objects. The O-stars could be the high-mass end of a bound stellar population, similar to those seen in super star clusters. Our data do not exclude the possibility that a similar stellar continuum source could dominate in all the LINERs. Alternatively, there may be two types of UV-bright LINERs: those where the UV continuum is produced by a starburst, and those where it is nonstellar.The “clearly-stellar”, weak [O I] emitters, LINERs have relatively weak X-ray emission, and their stellar populations probably provide enough ionizing photons to explain the observed optical emission-line flux. The other LINERs, strong [O I] emitters, have severe ionizing photon deficits, for reasonable extrapolations of their UV spectra beyond the Lyman limit, but have an X-ray/UV power ratio that is higher by two orders of magnitudes than that of the “clearly-stellar” LINERs. A component which emits primarily in the extreme-UV may be the main photoionizing agent in these objects.Recent results show that nuclear-starburst and quasar-like activity are often intermingled. Our results extend this result to the lower luminosities of the LINERs.

scholarly journals On the X-ray, optical emission line and black hole mass properties of local Seyfert galaxies

2006 ◽  
Vol 455 (1) ◽  
pp. 173-185 ◽  
Author(s):  
F. Panessa ◽  
L. Bassani ◽  
M. Cappi ◽  
M. Dadina ◽  
X. Barcons ◽  
...  
Keyword(s):  
Black Hole ◽  
Emission Line ◽  
Optical Emission ◽  
Seyfert Galaxies ◽  
Black Hole Mass ◽  
X Ray ◽  
Mass Properties

scholarly journals Is There a Relation Between Optical Emission Line Strengths and Continuum Shapes?

1989 ◽  
Vol 134 ◽  
pp. 187-188
Author(s):  
Belinda J. Wilkes ◽  
Martin Elvis ◽  
Jonathan McDowell
Keyword(s):  
Emission Line ◽  
Optical Emission ◽  
Emission Lines ◽  
X Ray ◽  
Line Strengths

Until recently there have been very few measurements of the ionizing continuum in quasars. With the combination of Einstein X-ray slopes and IUE spectra for a sample of quasars, this continuum can now be better constrained. Here we take a preliminary look for relations between the shape of this continuum and the emission lines produced over the observed range of continuum properties.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

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