Investigation of weak absorption lines of gases with a laser spectrophone

1974 ◽  
Vol 4 (6) ◽  
pp. 740-742 ◽  
Author(s):  
A B Antipov ◽  
Yu N Ponomarev
Keyword(s):  
Absorption Lines ◽  
Weak Absorption

scholarly journals Optical Spectra of Nuclei of Early Type Galaxies

1980 ◽  
Vol 5 ◽  
pp. 193-193
Author(s):  
Gerhard F. O. Schnur ◽  
W. A. Sherwood
Keyword(s):  
Spectral Resolution ◽  
Strong Absorption ◽  
Emission Lines ◽  
Absorption Lines ◽  
Nuclear Region ◽  
Early Type ◽  
Ionized Gas ◽  
Balmer Series ◽  
Weak Absorption ◽  
Normal Galaxies

Early type galaxies classified as SO by Sandage or lenticulars and SO/a appearing in RCBG have been observed with the IDS on the ESO 3.6 m telescope. The slit was 1” × 4” and the spectral resolution was 9 Å from 3900 Å to 7000 Å. Statistics for the first 50 galaxies observed are given.18% of the sample show the [OIII] doublet stronger than Hß; 32% have spectra dominated by the Balmer series progressing from mainly emission through strong absorption series to weak absorption; 20% have only [NII] or [SII] in emission while 30% show absorption lines and bands. That is, 70% show emission lines toward the nuclear region. Among the 50 galaxies, HI at 21 cm has been detected in 21 galaxies: 16 of these show ionized gas to be present. NGC5273 has Seyfert characteristics with strong [OIII]; Hß has a width of ˜1000 kms-1. The low luminosity end of the Seyfert distribution may be found among normal galaxies.

scholarly journals The SLUGGS survey: globular cluster stellar population trends from weak absorption lines in stacked spectra

2014 ◽  
Vol 446 (1) ◽  
pp. 369-390 ◽  
Author(s):  
Christopher Usher ◽  
Duncan A. Forbes ◽  
Jean P. Brodie ◽  
Aaron J. Romanowsky ◽  
Jay Strader ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Stellar Population ◽  
Population Trends ◽  
Absorption Lines ◽  
Weak Absorption

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 Influence of Gravitational Lensing on Estimates of Ω in Neutral Hydrogen

1996 ◽  
Vol 173 ◽  
pp. 97-98
Author(s):  
Matthias Bartelmann ◽  
Abraham Loeb
Keyword(s):  
Observational Data ◽  
Gravitational Lensing ◽  
Column Density ◽  
Spiral Galaxies ◽  
Neutral Hydrogen ◽  
Absorption Lines ◽  
Gravitational Lenses ◽  
High Column

A wealth of observational data supports the commonly held view that damped Lyman-α (Lyα) absorption in QSO spectra is associated with neutral-hydrogen (HI) disks in spiral galaxies. Most of the HI probed by QSO absorption lines is traced by damped Lyα lines because of their high column densities, N > 1020 cm–2. The spiral galaxies hosting the HI disks can act as gravitational lenses on the QSOs. If the HI column density increases towards the center of the disks, as suggested by observations of local galaxies, the magnification bias preferentially selects for high column-density systems. The estimates of HI in damped Lyα systems can then systematically be distorted by gravitational lensing.

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