The implications of hydrogen emission line ratios in quasi-stellar objects

1980 ◽  
Vol 236 ◽  
pp. L7 ◽  
Author(s):  
R. C. Canfield ◽  
R. C. Puetter
Keyword(s):  
Emission Line ◽  
Stellar Objects ◽  
Hydrogen Emission ◽  
Quasi Stellar Objects ◽  
Hydrogen Emission Line

scholarly journals Near infrared hydrogen emission line ratios as diagnostics of the broad emission line region

2012 ◽  
Vol 372 ◽  
pp. 012069
Author(s):  
Andrea J Ruff ◽  
David J E Floyd ◽  
Kirk T Korista ◽  
Rachel L Webster ◽  
Ryan L Porter ◽  
...  
Keyword(s):  
Emission Line ◽  
Near Infrared ◽  
Hydrogen Emission ◽  
Broad Emission ◽  
Line Region ◽  
Broad Emission Line ◽  
Hydrogen Emission Line

scholarly journals Long Baseline Optical Interferometry

1989 ◽  
Vol 8 ◽  
pp. 559-560
Author(s):  
S.T. Ridgway
Keyword(s):  
Emission Line ◽  
Spatial Resolution ◽  
Optical Interferometry ◽  
Hydrogen Emission ◽  
Long Baseline ◽  
Optical Interferometers ◽  
Imaging Science ◽  
Be Star ◽  
Hydrogen Emission Line ◽  
To Come

During the last three years significant results have been obtained from several operational, long baseline optical interferometers. Precision stellar angular diameters (accuracy of order 2% and better) have been reported in the infrared (DiBenedetto and Rabbia, 1987) and in the visible (Davis and Tango, 1986). Astrometric precision of order 20 milliarcsec has been demonstrated over large angles (Shao et al, in press). Spectro-spatial resolution of the disk of a Be star in the hydrogen emission line (Thom et al., 1986) suggests spectacular imaging science to come with many-telescope coherent and phased optical arrays.

Emission-line variability and the broad-line region of quasi-stellar objects. I - Time scales and photon densities

1987 ◽  
Vol 322 ◽  
pp. 164 ◽  
Author(s):  
Wei Zheng ◽  
E. Margaret Burbridge ◽  
Harding E. Smith ◽  
Ross D. Cohen ◽  
Steven E. Bradley
Keyword(s):  
Emission Line ◽  
Time Scales ◽  
Broad Line ◽  
Stellar Objects ◽  
Broad Line Region ◽  
Line Region ◽  
Quasi Stellar Objects

scholarly journals Quasi-stellar objects acting as potential strong gravitational lenses in the SDSS-III BOSS survey

2019 ◽  
Vol 625 ◽  
pp. A56 ◽  
Author(s):  
Romain A. Meyer ◽  
Timothée Delubac ◽  
Jean-Paul Kneib ◽  
Frédéric Courbin
Keyword(s):  
Emission Line ◽  
Sloan Digital Sky Survey ◽  
Emission Lines ◽  
Gravitational Lenses ◽  
Stellar Objects ◽  
Sky Survey ◽  
Quasi Stellar Objects ◽  
Unique Approach ◽  
Algorithmic Search ◽  
Emission Line Galaxies

We present a sample of 12 quasi-stellar objects (QSOs) that potentially act as strong gravitational lenses on background emission line galaxies (ELG) or Lyman-α emitters (LAEs) selected through a systematic search of the 297 301 QSOs in the Sloan Digital Sky Survey (SDSS)-III Data Release 12. Candidates were identified by looking for compound spectra, where emission lines at a redshift larger than that of the quasar can be identified in the residuals after a QSO spectral template is subtracted from the observed spectra. The narrow diameter of BOSS fibers (2″) then ensures that the object responsible for the additional emission lines must lie close to the line of sight of the QSO and hence provides a high probability of lensing. Among the 12 candidates identified, nine have definite evidence for the presence of a background ELG identified by at least four higher-redshift nebular emission lines. The remaining three probable candidates present a strong asymmetrical emission line attributed to a background Lyman-α emitter (LAE). The QSO-ELG (QSO-LAE) lens candidates have QSO lens redshifts in the range 0.24 ≲ zQSO ≲ 0.66 (0.75 ≲ zQSO ≲ 1.23 ) and background galaxy redshifts in the range 0.48 ≲ zS, ELG ≲ 0.94 (2.17 ≲ zS, LAE ≲ 4.48). We show that the algorithmic search is complete at > 90% for QSO-ELG systems, whereas it falls at 40−60% for QSO-LAE, depending on the redshift of the source. Upon confirmation of the lensing nature of the systems, this sample may quadruple the number of known QSOs acting as strong lenses. We have determined the completeness of our search, which allows future studies to compute lensing probabilities of galaxies by QSOs and differentiate between different QSO models. Future imaging of the full sample and lens modelling offers a unique approach to study and constrain key properties of QSOs.

Blueshifts in Emission Line Spectra of Quasi Stellar Objects

2001 ◽  
Vol 63 (5) ◽  
pp. 425-432 ◽  
Author(s):  
D Basu ◽  
S Haque-Copilah
Keyword(s):  
Emission Line ◽  
Stellar Objects ◽  
Quasi Stellar Objects
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