Old elliptical galaxies at z=1.5 and the Kormendy relation

Details Old elliptical galaxies at z=1.5 and the Kormendy relation Old elliptical galaxies at z=1.5 and the Kormendy relation

2002-07-31

arxiv.org/abs/astro-ph/0207663v1

Mon.Not.Roy.Astron.Soc.336:1342,2002

Astronomy and Astrophysics

Astrophysics

Accepted for publication in MNRAS. 11 pages including 7 figures

Scientific paper

10.1046/j.1365-8711.2002.05870.x

Deep spectroscopy of the two mJy radio galaxies LBDS 53W069 and 53W091 has previously shown them to have old (>3 Gyr) stellar populations at z=1.5. Here we present the results of HST observations of these galaxies. 53W069 has an r^1/4 profile in both the F814W & F110W data with an effective radius of 0.30 arcsec (2.7 kpc). The restframe U-B colour gradient requires a stellar population of super-solar (3Z_sun) metallicity that formed on a very short timescale at high redshift (z>5). 53W091 has a regular r^1/4 profile in F110W with an effective radius of 0.32 arcsec (2.9 kpc). The F814W profile is more extended and is consistent with a blue exponential disk that contributes 20% of the flux within r_e. The restframe U-B colour gradient is significantly larger than that observed in field ellipticals at z<1, implying a stellar population of mixed metallicity (1-3Z_sun) that formed in a high-redshift rapid burst. We have compared these two LBDS radio galaxies with the Kormendy relation of ten 3CR radio galaxies at z=0.8. The LBDS galaxies follow the same relation as the more radio-luminous 3CR galaxies, assuming passive evolution of their stellar populations, although they are smaller than the 3CR galaxies whose mean effective radius is 12 kpc. Their sizes and radio luminosities are consistent with scaling relations applied to the 3CR galaxies, in which both radio power and effective radius scale with galaxy mass. Compared with a sample of z=0.4 cluster ellipticals, 53W069 & 53W091 lie well within the scatter of the Kormendy relation. We conclude that the hosts of these mJy radio sources at z=1.5 are passively-evolving elliptical galaxies that will evolve into ordinary L* ellipticals by the present day. (Abridged)

Affiliated with

Also associated with

No associations

Rating

Old elliptical galaxies at z=1.5 and the Kormendy relation 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 Old elliptical galaxies at z=1.5 and the Kormendy relation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Old elliptical galaxies at z=1.5 and the Kormendy relation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-476173