scholarly journals The 2dF Gravitational Lens Survey

2001 ◽  
Vol 18 (2) ◽  
pp. 192-194 ◽  
Author(s):  
Daniel J. Mortlock ◽  
Darren S. Madgwick ◽  
Ofer Lahav
Keyword(s):  
Cross Correlation ◽  
High Redshift ◽  
Point Sources ◽  
Gravitational Lens ◽  
Multiple Point ◽  
Quasar Spectra ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Components Analysis ◽  
Correlation Techniques

AbstractThe 2 degree Field (2dF) galaxy redshift survey will involve obtaining spectra of approximately 2.5 105 objects which have previously been identified as galaxy candidates on morphological grounds. Included in these spectra should be about ten gravitationally-lensed quasars, all with low-redshift galaxies as deflectors (as the more common lenses with high-redshift deflectors will be rejected from the survey as multiple point-sources). The lenses will appear as superpositions of galaxy and quasar spectra, and either cross-correlation techniques or principal components analysis should be able to identify candidates systematically. With the 2dF survey approximately half-completed it is now viable to begin a methodical search for these spectroscopic lenses, and the first steps of this project are described here.

scholarly journals Spectroscopic Gravitational Lens Candidates in the CNOC2 Field Galaxy Redshift Survey

2000 ◽  
Vol 120 (4) ◽  
pp. 1660-1667 ◽  
Author(s):  
Patrick B. Hall ◽  
H. K. C. Yee ◽  
Huan Lin ◽  
Simon L. Morris ◽  
Michael D. Gladders ◽  
...  
Keyword(s):  
Gravitational Lens ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Field Galaxy

scholarly journals Survey of Gravitationally Lensed Objects in HSC Imaging (SuGOHI) – VII. Discovery and confirmation of three strongly lensed quasars†

2021 ◽  
Vol 502 (1) ◽  
pp. 1487-1493
Author(s):  
Anton T Jaelani ◽  
Cristian E Rusu ◽  
Issha Kayo ◽  
Anupreeta More ◽  
Alessandro Sonnenfeld ◽  
...  
Keyword(s):  
Spectroscopic Data ◽  
Point Sources ◽  
Sloan Digital Sky Survey ◽  
Early Type ◽  
Blue Point ◽  
X Ray ◽  
Quasar Spectra ◽  
Strategic Program ◽  
Early Type Galaxy

ABSTRACT We present spectroscopic confirmation of three new two-image gravitationally lensed quasars, compiled from existing strong lens and X-ray catalogues. Images of HSC J091843.27–022007.5 show a red galaxy with two blue point sources at either side, separated by 2.26 arcsec. This system has a source and a lens redshifts zs = 0.804 and zℓ = 0.459, respectively, as obtained by our follow-up spectroscopic data. CXCO J100201.50+020330.0 shows two point sources separated by 0.85 arcsec on either side of an early-type galaxy. The follow-up spectroscopic data confirm the fainter quasar has the same redshift with the brighter quasar from the Sloan Digital Sky Survey (SDSS) fiber spectrum at zs = 2.016. The deflecting foreground galaxy is a typical early-type galaxy at a redshift of zℓ = 0.439. SDSS J135944.21+012809.8 has two point sources with quasar spectra at the same redshift zs = 1.096, separated by 1.05 arcsec, and fits to the HSC images confirm the presence of a galaxy between these. These discoveries demonstrate the power of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP)’s deep imaging and wide sky coverage. Combined with existing X-ray source catalogues and follow-up spectroscopy, the HSC-SSP provides us unique opportunities to find multiple-image quasars lensed by a foreground galaxy.

scholarly journals THE DEEP2 GALAXY REDSHIFT SURVEY: THE VORONOI-DELAUNAY METHOD CATALOG OF GALAXY GROUPS

2012 ◽  
Vol 751 (1) ◽  
pp. 50 ◽  
Author(s):  
Brian F. Gerke ◽  
Jeffrey A. Newman ◽  
Marc Davis ◽  
Alison L. Coil ◽  
Michael C. Cooper ◽  
...  
Keyword(s):  
Galaxy Groups ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Deep2 Galaxy Redshift Survey

scholarly journals A faint galaxy redshift survey to B=24

1995 ◽  
Vol 273 (1) ◽  
pp. 157-168 ◽  
Author(s):  
K. Glazebrook ◽  
R. Ellis ◽  
M. Colless ◽  
T. Broadhurst ◽  
J. Allington-Smith ◽  
...  
Keyword(s):  
Faint Galaxy ◽  
Redshift Survey ◽  
Galaxy Redshift

scholarly journals The CNOC2 field galaxy redshift survey

1999 ◽  
Vol 357 (1750) ◽  
pp. 167-183 ◽  
Author(s):  
R. G Carlberg ◽  
H. K. C. Yee ◽  
S. L. Morris ◽  
H. Lin ◽  
M. Sawicki ◽  
...  
Keyword(s):  
Redshift Survey ◽  
Galaxy Redshift ◽  
Field Galaxy

scholarly journals FORECASTS OF DARK ENERGY CONSTRAINTS FROM BARYON ACOUSTIC OSCILLATIONS

2010 ◽  
Vol 25 (37) ◽  
pp. 3093-3113 ◽  
Author(s):  
YUN WANG
Keyword(s):  
Dark Energy ◽  
Figure Of Merit ◽  
Real Space ◽  
Number Density ◽  
Acoustic Oscillations ◽  
Energy Constraints ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Baryon Acoustic Oscillations ◽  
Systematic Noise

The measurement of baryon acoustic oscillations (BAO) from a galaxy redshift survey provides one of the most promising methods for probing dark energy. In this paper, we clarify the assumptions that go into the forecasts of dark energy constraints from BAO. We show that assuming a constant nP0.2/G2(z) (where P0.2 is the real space galaxy power spectrum at k = 0.2 h/ Mpc and redshift z) gives a good approximation of the observed galaxy number density expected from a realistic flux-limited galaxy redshift survey. We find that assuming nP0.2/G2(z) = 10 gives very similar dark energy constraints to assuming nP0.2 = 3, but the latter corresponds to a galaxy number density larger than ~70% at z = 2. We show how the Figure-of-Merit (FoM) for constraining dark energy depends on the assumed galaxy number density, redshift accuracy, redshift range, survey area, and the systematic errors due to calibration and uncertainties in the theory of nonlinear evolution and galaxy biasing. We find that an additive systematic noise of up to 0.4–0.5% per Δz = 0.1 redshift slice does not lead to significant decrease in the BAO FoM.

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