Astronomy and Astrophysics – Astrophysics
Scientific paper
1997-06-03
Mon.Not.Roy.Astron.Soc.298:945-965,1998
Astronomy and Astrophysics
Astrophysics
20 pages, Latex File+mn.sty, 16 Postscript figures, plus additional V-R color picture in gif format. Submitted to MNRAS
Scientific paper
10.1046/j.1365-8711.1998.01443.x
Using HST WFPC2 V- and R-band data of the z=0.37 cluster MS1512+36 we show that the z=2.72 `protogalaxy' cB58 is not extraordinarily luminous intrinsically but lensed into a gravitational fold arc by the cluster. The arc has a surface brightness weighted axis ratio of 1:7, is marginally resolved in width and about 3 arcsec long. Its counterimage was identified and found to be very compact r(1/2) = 2.4-4.0 / h50 kpc in a q0=0.05 cosmology). In addition, we found three further multiple image systems, one with five and two with three images each. The positions of the multiple images is explained by modelling the light deflection caused by the cluster and the cD-galaxy with elliptical isothermal potentials. Since the multiple images are within 8 arcsec around the cD galaxy, a cluster core radius - cluster velocity dispersion degeneracy arises. The cluster velocity dispersion and the core radius are limited to 540-670 km/s and 5 arcsec - 11\arcsec, respectively, and the brightness of the unlensed counterimage of cB58 is about 23.9 +- 0.3 (R-band), corresponding to a magnification and extinction corrected restframe-B band absolute magnitude of -24.75 +- 0.7 mag. The redshifts of the sources of the remaining three multiple image systems are predicted to be similar to that of cB58. That part of the source of cB58 which is mapped into the arc is reconstructed and its magnification is found to be mu(arc) > 50. This large magnification explains at least some of the untypical spectroscopic properties of cB58, e.g. that the star formation rate seems to be high and uniform and to take place in a large area.
Belloni Paola
Bender Ralf
Hopp Ulrich
Saglia Roberto P.
Seitz Stella
No associations
LandOfFree
The z=2.72 galaxy cB58: a gravitational fold arc lensed by the cluster MS 1512+36 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 z=2.72 galaxy cB58: a gravitational fold arc lensed by the cluster MS 1512+36, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The z=2.72 galaxy cB58: a gravitational fold arc lensed by the cluster MS 1512+36 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-116968