Bars do NOT disappear at z > 0.7: NICMOS Deep Field Observations
Kartik Sheth
Caltech
Résumé :
In the past decade, several optical studies have suggested
that barred spirals disappear at z > 0.5--0.7. The absence of bars can
severely constrain galaxy formation because bars are important
signposts of the formation of cold, rotationally-supported massive
disks. These studies however suffer from bandshifting and resolution
affects. I discuss our recent analysis of the NICMOS HDFN which shows
that there is no significant evidence for a decline in the bar fraction
beyond z~0.7! The data suggest that cold, massive disks and/or large
disks were present at least 7 Gyr ago (at z~1), consistent with star
formation history. I will conclude by briefly reviewing a proposed
study of the evolution of galaxy disks using the 2-sq. degree COSMOS
ACS survey, and future observations with SIRTF and CARMA. CARMA is the
new Combined Array for Research in Millimeter Astronomy.
