Astronomy and Astrophysics – Astrophysics
Scientific paper
1996-08-19
Astronomy and Astrophysics
Astrophysics
LaTeX, aas version 4 macros. Calibration error in original led to overestimate of cluster mass. Seven out of twelve figures in
Scientific paper
10.1086/118272
Multiply gravitationally lensed objects with known time delays can lead to direct determinations of H$_0$ independent of the distance ladder if the mass distribution of the lens is known. Currently, the double QSO 0957+561 is the only lensed object with a precisely known time delay. The largest remaining source of systematic error in the H$_0$ determination results from uncertainty in the mass distribution of the lens which is comprised of a massive galaxy (G1) and the cluster in which it resides. We have obtained V-band CCD images from CFHT in order to measure the mass distribution in the cluster from its gravitional distorting effect on the appearance of background galaxes. We use this data to constuct a two-dimensional mass map of the field. A mass peak is detected at the $4.5\sigma$ level, offset from, but consistent with, the position of G1. Simple tests reveal no significant substructure and the mass distribution is consistent with a spherical cluster. The peak in the number density map of bright galaxies is offset from G1 similarly to the mass peak. We constructed an azimuthally averaged mass profile centered on G1 out to 2 \arcmin ($400 h^{-1}$ kpc). It is consistent with an isothermal mass distribution with a small core ($r_c \approx 5 \arcsec = 17 h^{-1}$ kpc). The inferred mass within 1 Mpc is consistent with the dynamical mass estimate but $2\sigma$ higher than the upper limits from a ROSAT X-ray study. We discuss implications for H$_0$ in a future paper.
Bernstein Gary
Fischer Philippe
Rhee George
Tyson Anthony J.
No associations
LandOfFree
The Mass distribution of the Cluster 0957+561 from 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 The Mass distribution of the Cluster 0957+561 from Gravitational Lensing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Mass distribution of the Cluster 0957+561 from Gravitational Lensing will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-545749