Stellarv sini and optical emission line widths in Be stars

1989 ◽  
Vol 161 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Reinhard W. Hanuschik
Keyword(s):  
Emission Line ◽  
Optical Emission ◽  
Be Stars ◽  
Line Widths

scholarly journals Be Stars as Rotating Stars: Observations: (Review Paper)

1976 ◽  
Vol 70 ◽  
pp. 123-136 ◽  
Author(s):  
Arne Slettebak
Keyword(s):  
Emission Line ◽  
Review Paper ◽  
Rotational Velocity ◽  
Be Stars ◽  
Rotating Stars ◽  
Line Widths

The classical rotational hypothesis for Be stars is reviewed and discussed. Methods of measuring rotational velocities are considered and the particular difficulties that Be stars pose in this respect are pointed out. Several tests of the rotational hypothesis are discussed and shown to support this idea. New observations of Balmer emission-line widths in the spectra of 46 Be stars show a correlation with rotational velocity, also in support of the rotational hypothesis. The very large emission widths found for some Be stars are discussed and possible reasons for the broadening are presented.

scholarly journals Optical Emission-Line Spectra of Be Stars (Review Paper)

1987 ◽  
Vol 92 ◽  
pp. 149-171 ◽  
Author(s):  
Joachim Dachs
Keyword(s):  
Emission Line ◽  
Near Infrared ◽  
Optical Emission ◽  
Rotating Disk ◽  
Circumstellar Envelope ◽  
Be Stars ◽  
Disk Model ◽  
Cycle Times ◽  
Star Models ◽  
Long Time

AbstractRecent observational work on spectra obtained at optical and near-infrared wavelengths is reviewed for “ordinary” (non-supergiant non-peculiar) Be and Be-shell stars, with particular emphasis on comparison between high-resolution spectral measurements and current Be star models. Emission-line profiles are interpreted in terms of geometry, dimensions and dynamics of a dense (N ≃ 1011 cm-3), cool (T ≃ 104 k) line-emitting region in the circumstellar envelope, separated from the thin, hot expanding stellar wind region. Present observations support a rotating-disk model for the cool, line-emitting region. Indications pointing towards structuring of cool circumstellar envelope regions are reported. Significant spectral variations are detected both on short (less than one day) and long time scales (months to years). Typical cycle times for large-amplitude V/R variations and intervals between shell episodes depend on spectral type, increasing with decreasing effective temperature of the central stars and ranging from a few years for early-Be type stars to a few decades for late Be stars.

scholarly journals Detection of accreting circumstellar gas around weak emission-line Herbig Ae/Be stars

1994 ◽  
Vol 212 (1-2) ◽  
pp. 107-114 ◽  
Author(s):  
C. A. Grady ◽  
M. R. P�rez ◽  
P. S. Th�
Keyword(s):  
Emission Line ◽  
Be Stars ◽  
Circumstellar Gas

scholarly journals Serendipitous Discovery of an Optical Emission-line Jet in NGC 232

2017 ◽  
Vol 850 (1) ◽  
pp. L17 ◽  
Author(s):  
C. López-Cobá ◽  
S. F. Sánchez ◽  
I. Cruz-González ◽  
L. Binette ◽  
L. Galbany ◽  
...  
Keyword(s):  
Emission Line ◽  
Optical Emission

scholarly journals A Catalogue of Be Stars

1982 ◽  
Vol 98 ◽  
pp. 261-263 ◽  
Author(s):  
M. Jaschek ◽  
D. Egret
Keyword(s):  
Emission Line ◽  
Data Center ◽  
Be Stars ◽  
Large Effort ◽  
Set Up ◽  
Available Information

We are presently undertaking, at the Stellar Data Center, a large effort to produce the Catalogue of Stellar Groups, which is a catalogue listing all the kinds of stars with spectral peculiarities existing up to now. The work is in progress and presently about fifty groups (Ap, Am, Be, WR, H and K emission line stars, etc.) are defined, gathering more than 25000 stars. The catalogue was started with the aim to set up lists defined by homogeneous criteria, because up to now the available information is scattered through the literature. We hope that the catalogue will be useful for formulating observing programs and for further detailed research on each of the groups.

scholarly journals Upper limits on the mass of supermassive black holes from STIS archival data

2007 ◽  
Vol 3 (S245) ◽  
pp. 233-234
Author(s):  
A. Beifiori ◽  
E. M. Corsini ◽  
E. Dalla Bontà ◽  
A. Pizzella ◽  
L. Coccato ◽  
...  
Keyword(s):  
Black Holes ◽  
Emission Line ◽  
Supermassive Black Holes ◽  
Archival Data ◽  
Early Type ◽  
Preliminary Results ◽  
Upper Limits ◽  
Nearby Galaxies ◽  
Line Widths

AbstractThe growth of supermassive black holes (SMBHs) appears to be closely linked with the formation of spheroids. There is a pressing need to acquire better statistics on SMBH masses, since the existing samples are preferentially weighted toward early-type galaxies with very massive SMBHs. With this motivation we started a project aimed at measuring upper limits on the mass of the SMBHs that can be present in the center of all the nearby galaxies (D < 100 Mpc) for which STIS/G750M spectra are available in the HST archive. These upper limits will be derived by modeling the central emission-line widths ([N II] λλ6548, 6583, Hα and [S II] λλ6716, 6731) observed over an aperture of ~01 (R < 50 pc). Here we present our preliminary results for a subsample of 76 bulges.

scholarly journals Optical emission line nebulae in galaxy cluster cores 1: the morphological, kinematic and spectral properties of the sample

2016 ◽  
Vol 460 (2) ◽  
pp. 1758-1789 ◽  
Author(s):  
S. L. Hamer ◽  
A. C. Edge ◽  
A. M. Swinbank ◽  
R. J. Wilman ◽  
F. Combes ◽  
...  
Keyword(s):  
Emission Line ◽  
Spectral Properties ◽  
Galaxy Cluster ◽  
Optical Emission ◽  
Cluster Cores

scholarly journals A Comparison of Rest-frame Ultraviolet and Optical Emission-line Diagnostics in the Lensed Galaxy SDSS J1723+3411 at Redshift z = 1.3293

2021 ◽  
Vol 908 (2) ◽  
pp. 154
Author(s):  
J. R. Rigby ◽  
Michael Florian ◽  
A. Acharyya ◽  
Matthew Bayliss ◽  
Michael D. Gladders ◽  
...  
Keyword(s):  
Emission Line ◽  
Rest Frame ◽  
Optical Emission

scholarly journals Kband SINFONI spectra of twoz~ 5 submillimeter galaxy systems: upper limits to the unobscured star formation from [O II] optical emission line searches

2016 ◽  
Vol 594 ◽  
pp. A74 ◽  
Author(s):  
Guilherme S. Couto ◽  
Luis Colina ◽  
Javier Piqueras López ◽  
Thaisa Storchi-Bergmann ◽  
Santiago Arribas
Keyword(s):  
Star Formation ◽  
Emission Line ◽  
Optical Emission ◽  
Line Searches ◽  
Upper Limits
Sign in / Sign up

Export Citation Format

Share Document