scholarly journals New Findings Supporting the Presence of Several Distinct Structures of Circumstellar Matter in β Lyræ

2006 ◽  
Vol 2 (S240) ◽  
pp. 205-208 ◽  
Author(s):  
P. Chadima ◽  
P. Harmanec ◽  
H Ak ◽  
O. Demirçan ◽  
S. Yang ◽  
...  
Keyword(s):  
Spectral Line ◽  
Absorption Line ◽  
Accretion Disk ◽  
Electronic Spectra ◽  
Circumstellar Matter ◽  
Absorption Lines ◽  
Additional Absorption ◽  
Weak Absorption ◽  
New Findings ◽  
Absorption Of Light

Abstract(1) 52 photographic and 651 electronic spectra were disentangled using the program KOREL. This led to the detection of a number of weak absorption lines originating in the atmosphere of the accretion disk. So far, the detection of this disk spectrum was only reported for the Si 6347 and 6371 Å doublet. (2) The basic spectrophotometric quantities of 15 absorption lines of the primary were measured and corrected for the orbital light changes in order to eliminate the contribution of the secondary light to the observed continuum level. After the correction, a significant phase dependency of the spectral-line characteristics near the primary eclipse was detected. In all probability, another so far unknown absorption-line spectrum was thus found. This spectrum may be due to additional absorption of light of the primary in one of the jet-like structures and in the spherical gas envelope surrounding the accretion disk. Both these structures are seen projected against the primary during its eclipse.

scholarly journals The interstellar medium of the Magellanic Clouds from absorption lines

1991 ◽  
Vol 148 ◽  
pp. 401-406 ◽  
Author(s):  
Klaas S. De Boer
Keyword(s):  
Interstellar Medium ◽  
Absorption Line ◽  
Milky Way ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Absorption Lines ◽  
Small Magellanic Cloud ◽  
General Aspects

General aspects of ISM studies using absorption line studies are given and available data are reviewed. Topics are: galactic foreground gas, individual fields in the Magellanic Clouds (MCs) and MC coronae. Overall investigations are discussed. It is demonstrated that the metals in the gas of the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) are a factor of 3 and 10, respectively, in abundance below solar levels. The depletion pattern in the LMC is similar to that of the Milky Way.

scholarly journals Limits on the Variation of Physical Constants Derived from Molecular Absorption Lines

1999 ◽  
Vol 183 ◽  
pp. 167-167 ◽  
Author(s):  
T. Wiklind ◽  
F. Combes
Keyword(s):  
Absorption Line ◽  
High Redshift ◽  
Absorption Lines ◽  
Frequency Resolution ◽  
Radio Lines ◽  
Molecular Absorption ◽  
Diagnostic Application ◽  
Physical Constants ◽  
Resonance Transitions ◽  
Electronic Resonance

A potential diagnostic application of molecular rotational absorption lines at high redshift is to test the invariance of physical constants. This can be done by comparing the observed redshifted frequency of a molecular absorption line with redshifted lines from other types of transitions such as the 21cm hyperfine transition or electronic resonance transitions. In order to set stringent limits, it is necessary to achieve the greatest possible frequency resolution. This makes radio lines well suited for this purpose.

scholarly journals The Absorption Line Systems of the Supershell LMC2 in the Large Magellanic Cloud

1999 ◽  
Vol 190 ◽  
pp. 154-155
Author(s):  
Adeline Caulet
Keyword(s):  
Optical Absorption ◽  
Interstellar Medium ◽  
Gas Phase ◽  
Absorption Line ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Absorption Lines

The interstellar medium of LMC2, a well studied supershell in the Large Magellanic Cloud, has been probed in UV and optical absorption lines. The data allow to derive the kinematics, abundances and depletions of gas clouds in this supershell. The relative gas-phase abundances of observed elements with respect to sulphur are useful to determine the origins of the supershell absorption-line clouds.

Resonance Broadening and Oscillator strength of the Mercury Absorption Line 1850 Å

1975 ◽  
Vol 30 (4) ◽  
pp. 445-450 ◽  
Author(s):  
D. Gebhard ◽  
W. Behmenburg
Keyword(s):  
Absorption Line ◽  
Oscillator Strength ◽  
Resonance Absorption ◽  
New Method ◽  
Absorption Lines ◽  
Resonance Transition ◽  
Resonance Transitions ◽  
Resonance Broadening

Abstract A new method for the determination of f-values of resonance transitions from wing-measurements of selfbroadened resonance absorption lines is described. The method is applied to the mercury resonance transition 61 S0→61P1, λ 1850 Å. The resulting f-value of 1.08±0.05 agrees well with those obtained from other methods.

Xvoigt: An Interactive Absorption Line Fitting Program for the X Window System

1995 ◽  
Vol 12 (2) ◽  
pp. 239-243 ◽  
Author(s):  
David P. Max ◽  
Geoff Bailey
Keyword(s):  
Absorption Line ◽  
Column Density ◽  
Velocity Dispersion ◽  
Absorption Lines ◽  
Signal To Noise ◽  
Window System ◽  
Profile Fitting ◽  
X Window ◽  
Line Fitting ◽  
Line Analysis

AbstractWe have developed an easy-to-use, mouse-driven program for the interactive fitting of interstellar absorption lines in high-resolution astronomical spectra. The program, Xvoigt, gives values for the column density and velocity dispersion of the absorbing clouds. It runs under the popular X Window system available on most workstations, and offers significant enhancements over existing profile-fitting software. Xvoigt can be an important adjunct to automatic programs for fitting absorption lines in low to moderate signal-to-noise QSO or other spectra, and is ideal for demonstrating the details and difficulties of absorption line analysis.

scholarly journals Absorption Systems in High Redshift QSOs

1977 ◽  
Vol 74 ◽  
pp. 193-222 ◽  
Author(s):  
A. Boksenberg
Keyword(s):  
Emission Line ◽  
Absorption Line ◽  
High Redshift ◽  
Ground Level ◽  
Emission Lines ◽  
Absorption Lines ◽  
Absorption System ◽  
Characteristic Emission

In addition to the characteristic emission lines, absorption lines frequently are seen in the spectra of QSOs, usually those with high redshift (zem ≳ 1.8). About 10 percent of all QSOs listed in the compilation of Burbidge et al. (1976a) are recorded as having at least one ‘identified’ absorption system, meaning that a pattern of several selected observed lines can be matched with the apparent wavelengths of transitions (generally from the ground level) in a physical plausible group of atoms or ions at the same, although arbitrary, redshift (Bahcall 1968, Aaronson et al. 1975). Identified absorption line redshifts range from being comparable with the associated emission line redshifts, to having very much smaller values with relative velocities exceeding 0.5c in the QSO frame. Added to this, there are many QSOs having absorption lines not yet recognised as belonging to identified systems, both those objects already having one or more identifications, and others with none.

scholarly journals Wide-Angle Quasar Feedback

2015 ◽  
Vol 11 (S319) ◽  
pp. 58-58
Author(s):  
George Chartas ◽  
Sarah Strickland
Keyword(s):  
Black Holes ◽  
Spectral Line ◽  
Absorption Line ◽  
Inclination Angle ◽  
Solid Angle ◽  
Host Galaxy ◽  
Wide Angle ◽  
X Ray ◽  
Spectral Line Profile ◽  
Excess Component

AbstractWe present results from the detection of relativistic winds launched near the innermost stable circular orbits of supermassive black holes. A recent detection of a powerful wind in the X-ray-bright narrow absorption line (NAL) z=1.51 quasar HS 0810+2554 strengthens the case that quasars play a significant role in feedback. In both deep Chandra and XMM-Newton observations of HS 0810 we detected blueshifted absorption lines implying outflowing velocities ranging from 0.1c and 0.4c. The presence of both an emission line at 6.8 keV and an absorption line at 7.8 keV in the spectral line profile of HS 0810 is a characteristic feature of a P-Cygni profile supporting the presence of an expanding outflowing highly ionized Fe absorber. A hard excess component is detected in the XMM-Newton observation of HS 0810 possibly originating from reflection off the disk. Modelling of the XMM-Newton spectrum constrains the inclination angle to be < 35° (68% confidence). The presence of relativistic winds in both low inclination angle NAL quasars as well as in high inclination angle BAL quasars implies that the solid angle of quasar winds may be quite large. The larger solid angle of quasar winds would also indicate that their contribution to the regulation of the host galaxy may be more important than previously thought.

scholarly journals Ultraviolet Absorption Line Studies of Halo Gas

1997 ◽  
Vol 166 ◽  
pp. 433-441
Author(s):  
Klaas S. de Boer
Keyword(s):  
Absorption Line ◽  
Galactic Disk ◽  
Ultraviolet Absorption ◽  
Uv Absorption ◽  
Absorption Lines ◽  
The Status ◽  
Halo Gas

AbstractThe status of halo studies using UV absorption lines is assessed. Sin absorption is essentially only seen from gas with z ≤ 1 kpc, and shows a modest flow toward the galactic disk. CIV shows diffuse absorption in general only from gas with z ≥ 1 kpc with predominantly negative velocities. Three exceptional cases of gas showing CIV absorption without absorption by neutral components are discussed. Outflowing gas has not been detected thusfar.

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