Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-01-18
Astrophys.J. 630 (2005) 764-770
Astronomy and Astrophysics
Astrophysics
18 pages, 3 figures, accepted version for ApJ (referee comments incorporated)
Scientific paper
10.1086/432435
We use the distribution of gravitationally-lensed image separations observed in the Cosmic Lens All-Sky Survey (CLASS) and the PMN-NVSS Extragalactic Lens Survey (PANELS), which are (nearly) complete for the image separation range $0''.3 \le \Delta \theta \le 6''$, to constrain a model velocity dispersion function (VF) of early-type galaxies. Assuming a current concordance cosmological model and adopting a singular isothermal ellipsoid (SIE) model for galactic potentials, we consider constraining both a characteristic velocity dispersion (parameter $\sigma_*$) and the shape of the function (parameters $\alpha$ and $\beta$; Sheth et al. 2003) for $0.3 \la z \la 1 $. If all three parameters are allowed to vary, then none of the parameters can be tightly constrained by the lensing data because of the small size of the sample. If we fix the shape of the function by either the SDSS local stellar VF or an inferred local stellar VF based on the SSRS2 galaxy sample, then the constrained values of $\sigma_*$ are nearly equal to the corresponding stellar values; we have $f_{\rm SIE/center} (\equiv \sigma_{*{\rm SIE}}/\sigma_{*{\rm center}})= 0.90\pm 0.18 {\rm (SDSS)}$ or $1.04 \pm 0.19 {\rm (SSRS2)}$ assuming non-evolution of the function between the present epoch and $z \sim 0.6$. Finally, using only the CLASS statistical sample (Browne et al. 2003) and thus including an absolute multiple-imaging probability, we find that the SDSS stellar VF may have significantly underestimated the abundance of morphologically early-type galaxies.
No associations
LandOfFree
Constraints on Velocity Dispersion Function of Early-type Galaxies from the Statistics of Strong Gravitational Lensing 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 Constraints on Velocity Dispersion Function of Early-type Galaxies from the Statistics of Strong Gravitational Lensing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Constraints on Velocity Dispersion Function of Early-type Galaxies from the Statistics of Strong Gravitational Lensing will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-704893