When did the Hubble sequence appear ? - Subaru observations of distant field and cluster galaxies

Toru Yamada

Research output: Contribution to journalConference articlepeer-review


We conducted deep NIR and optical imaging observations in general fields as well as the fields of cluster of galaxies and candidates at z > 1. In the observed rich cluster environment, massive galaxies have been well developed by z = 1.2 - 1.3. However, in a general field, HDF-N, we see conspicuous and sudden decrease of comoving number density of early-type galaxies above z = 1. There are few galaxies as massive as present-day L* galaxies at z=2-4 in HDF-N. Their rest-frame optical light is dominated by very young stellar population and their morphology also does not show any clear sequence. Thus formation/evolution of galaxies seems to strongly depend on their density environment and in general fields massive galaxies which form present-day Hubble sequence might have been formed between 1 < z < 2 while early type galaxies in clusters formed earlier epoch.

Original languageEnglish
Pages (from-to)329-336
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - 2002 Dec 1
EventDiscoveries and Research Prospects from 6- to 10- Meter-Class telescopes II - Waikoloa, HI, United States
Duration: 2002 Aug 222002 Aug 23


  • Galaxies-evolution
  • Galaxies-formation

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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