|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'504'928
Articles rated: 2609
25 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
The beginning of the star formation epoch | | F. Mannucci
; H. Buttery
; R. Maiolino
; A. Marconi
; L. Pozzetti
; | | Date: |
7 Jul 2006 | | Abstract: | Aimes: We intend to use the current data on large deep fields to look for high-redshift galaxies in the rest-frame UV wavelength range and study the evolution of the cosmic star-formation density at z~7. Methods: Deep HST/ACS and VLT/ISAAC data of the GOODS-South field were used to survey 130 sq.arcmin down to a limiting magnitude of about (J+Ks)AB=25.5 looking for drop-out objects in the z’ ACS filter. The large sampled area would allow for the detection of galaxies which are 20 times less numerous and 1-2 magnitudes brighter than similar studies using HST/NICMOS near-IR data. Results: Two objects were initially selected as promising candidates of galaxies at z~7, but have subsequently been dismissed and identified as Galactic brown dwarfs through a detailed analysis of their morphology and Spitzer colors, as well as through spectroscopic information. As a consequence, we conclude that there are no galaxies at z~7 down to our limiting magnitude in the field we investigated. Our non detection of galaxies at z~7 provides clear evidence for a strong evolution of the luminosity function between z=6 and z=7, i.e. over a time interval of only ~170Myr. Our constraints also provide evidence for a significant decline of the total star formation rate at z=7, which must be less than 40% of that at z=3 and 40-80% of that at z=6. We also derive an upper limit to the ionizing flux at z=7, which is only marginally consistent with that required to completely ionize the Universe. This result suggests that at z=7 we are approaching the beginning of the star formation epoch. | | Source: | arXiv, astro-ph/0607143 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER