The effects of emission line identification on the redshift distribution of QSO's

1983 ◽  
Vol 97 (1) ◽  
pp. 63-71 ◽  
Author(s):  
You-Yuan Zhou ◽  
Zu-Gan Deng ◽  
Zheng-Long Zhou
Keyword(s):  
Emission Line ◽  
Redshift Distribution ◽  
Line Identification

Emission line redshift distribution of QSOs

1985 ◽  
Vol 112 (1) ◽  
pp. 93-110 ◽  
Author(s):  
You-Yuan Zhou ◽  
Zu-Gan Deng ◽  
He-Jun Dai
Keyword(s):  
Emission Line ◽  
Redshift Distribution ◽  
Line Redshift

scholarly journals Introducing EMILI: Computer‐aided Emission Line Identification

2003 ◽  
Vol 149 (1) ◽  
pp. 157-187 ◽  
Author(s):  
Brian Sharpee ◽  
Robert Williams ◽  
Jack A. Baldwin ◽  
Peter A. M. van Hoof
Keyword(s):  
Emission Line ◽  
Line Identification ◽  
Computer Aided

scholarly journals The US and Other Optically Selected Bright QSO Samples

2002 ◽  
Vol 184 ◽  
pp. 53-58
Author(s):  
Kenneth J. Mitchell ◽  
Peter D. Usher
Keyword(s):  
Emission Line ◽  
Selection Bias ◽  
Luminosity Function ◽  
Line Flux ◽  
Redshift Distribution ◽  
The Us ◽  
Show Evidence ◽  
Line Selection

AbstractThe US Bright Quasar Sample (UBQS) is a color-selected sample of quasars with B < 17 that has been constructed with an eye towards completeness within well-defined selection limits. The redshift distribution of the UBQS shows an interesting spike at z ~ 0.55. The significance of this enhancement increases when the UBQS is combined with other bright quasar samples which also show evidence of high levels of completeness. Reconstitution of this combined bright quasar sample after removal of the emission-line flux from the B magnitudes indicates that the z ~ 0.55 spike is not caused by an emission-line selection bias. Rather, the largest effect of these sample corrections would be to depress the high end of the optical luminosity function that is derivable from this combined sample.

Redshift Distribution & Nature of μ-Jy Radio Sources

1996 ◽  
Vol 175 ◽  
pp. 559-560 ◽  
Author(s):  
F. Hammer ◽  
D. Crampton ◽  
S. Lilly ◽  
O. LE Fèvre
Keyword(s):  
Radio Emission ◽  
Emission Line ◽  
Starburst Galaxies ◽  
Radio Sources ◽  
Complete Disappearance ◽  
Redshift Distribution ◽  
Deep Imaging ◽  
Emission Line Galaxies ◽  
Intermediate Redshifts ◽  
Narrow Emission

During the preliminary deep imaging phase of our large spectroscopic survey of faint field galaxies (CFRS), one of our fields (10 arcmin × 10 arcmin) was chosen to coincide with the Fomalont et al (1991, A.J. 102,1258, hereafter FWKK) radio source field, including 36 S≃ 16μJy radio sources of their complete sample. All sources but two have been identified to V < 25 and/or IAB ≤ 24, and/or KAB ≤ 21.The microJy population is mainly constituted of three distinct populations of galaxies with different redshift regimes: early-type galaxies at z > 0.75 with a low powered AGN in their cores, post-starburst galaxies at intermediate redshifts (z = 0.375 to z = 0.8 or slightly > 1), and emission-line galaxies at z < 0.45 containing AGNs. The fraction of μJy sources with z > 1 could be as high as 30%. Most of the μJy radio sources (> 50%) are likely associated to AGNs, conversely to what is found at mJy levels (mostly starburst galaxies, Benn et al, 1993, MNRAS, 263, 98). Only one galaxy in our sample has a classical starburst spectrum.The strong decrease of the radio spectral index from sub-mJy to μJy counts appears to be due to a combination of three factors: (1) the emergence of an elliptical population at high redshifts with moderate radio emission (2) an increasing fraction of narrow emission-line AGNs (Seyfert 2 and LINER); (3) a higher contribution of the thermal radiation to the radio emission from spirals, and the almost complete disappearance of starburst galaxies. Details of the results summarized here can be found in Hammer et al (1995, MNRAS, 276, 1085).

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