Astronomy and Astrophysics – Astrophysics
Scientific paper
2002-11-28
Astronomy and Astrophysics
Astrophysics
accepted for publication in MNRAS 15 pages
Scientific paper
10.1046/j.1365-8711.2003.06350.x
We have observed two blank fields of approximately 30 by 23 arcminutes using the William Herschel Telescope. The fields have been studied as part of the CNOC2 survey, and spectroscopic redshifts are available for 1125 galaxies in the two fields. We measured the lensing signal caused by large scale structure, and found that the result is consistent with current, more accurate measurements. We study the galaxy-galaxy lensing signal of three overlapping samples of lenses, and detect a significant signal in all cases. The estimates for the velocity dispersion of an L* galaxy agree well for the various samples. The best fit singular isothermal sphere model to the ensemble averaged tangential distortion around the galaxies with redshifts yields a velocity dispersion of \sigma_*=130^{+15}_{-17} km/s, in good agreement with other studies. We use a maximum likelihood analysis, where a parameterized mass model is compared to the data, to study the extent of galaxy dark matter halos. Making use of all available data, we find \sigma_*=111\pm12 km/s (68.3% confidence) for a truncated isothermal sphere model in which all galaxies have the same mass-to-light ratio. The value of the truncation parameter is not constrained that well, and we find s_*=260^{+124}_{-73} h^{-1} kpc (68.3% confidence The galaxy-galaxy lensing analysis allows us to estimate the average mass-to-light ratio of the field, which can be used to estimate \Omega_m. The current result, however, depends strongly on the assumed scaling relation for s.
Carlberg Ray G.
Franx Marijn
Hoekstra Henk
Kuijken Koen
Yee Howard K. C.
No associations
LandOfFree
Lensing by galaxies in CNOC2 fields does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Lensing by galaxies in CNOC2 fields, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lensing by galaxies in CNOC2 fields will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-419440