Luminous Compact Blue Galaxies up to z~1 in the HST Ultra Deep Field: I. Small galaxies, or blue centers of massive disks?

Details Luminous Compact Blue Galaxies up to z~1 in the HST Ultra Deep Field: I. Small galaxies, or blue centers of massive disks? Luminous Compact Blue Galaxies up to z~1 in the HST Ultra Deep Field: I. Small galaxies, or blue centers of massive disks?

2006-02-28

arxiv.org/abs/astro-ph/0602610v1

Astrophys.J. 640 (2006) L143-L146

Astronomy and Astrophysics

Astrophysics

11 pages, 2 figures, AASTeX; accepted for publication in Astrophysical Journal Letters

Scientific paper

10.1086/503556

We analyze 26 Luminous Compact Blue Galaxies (LCBGs) in the HST/ACS Ultra Deep Field (UDF) at z ~ 0.2-1.3, to determine whether these are truly small galaxies, or rather bright central starbursts within existing or forming large disk galaxies. Surface brightness profiles from UDF images reach fainter than rest-frame 26.5 B mag/arcsec^2 even for compact objects at z~1. Most LCBGs show a smaller, brighter component that is likely star-forming, and an extended, roughly exponential component with colors suggesting stellar ages >~ 100 Myr to few Gyr. Scale lengths of the extended components are mostly >~ 2 kpc, >1.5-2 times smaller than those of nearby large disk galaxies like the Milky Way. Larger, very low surface brightness disks can be excluded down to faint rest-frame surface brightnesses (>~ 26 B mag/arcsec^2). However, 1 or 2 of the LCBGs are large, disk-like galaxies that meet LCBG selection criteria due to a bright central nucleus, possibly a forming bulge. These results indicate that >~ 90% of high-z LCBGs are small galaxies that will evolve into small disk galaxies, and low mass spheroidal or irregular galaxies in the local Universe, assuming passive evolution and no significant disk growth. The data do not reveal signs of disk formation around small, HII-galaxy-like LCBGs, and do not suggest a simple inside-out growth scenario for larger LCBGs with a disk-like morphology. Irregular blue emission in distant LCBGs is relatively extended, suggesting that nebular emission lines from star-forming regions sample a major fraction of an LCBG's velocity field.

Affiliated with

Also associated with

No associations

Rating

Luminous Compact Blue Galaxies up to z~1 in the HST Ultra Deep Field: I. Small galaxies, or blue centers of massive disks? 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 Luminous Compact Blue Galaxies up to z~1 in the HST Ultra Deep Field: I. Small galaxies, or blue centers of massive disks?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Luminous Compact Blue Galaxies up to z~1 in the HST Ultra Deep Field: I. Small galaxies, or blue centers of massive disks? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-387683