| | |
| | |
Stat |
Members: 3645 Articles: 2'504'928 Articles rated: 2609
26 April 2024 |
|
| | | |
|
Article overview
| |
|
A Deep HST Search for Escaping Lyman Continuum Flux at z~1.3: Evidence for an Evolving Ionizing Emissivity | Brian Siana
; Harry I Teplitz
; Henry C. Ferguson
; Thomas M. Brown
; Mauro Giavalisco
; Mark Dickinson
; Ranga-Ram Chary
; Duilia F. de Mello
; Christopher J. Conselice
; Carrie R. Bridge
; Jonathan P. Gardner
; James W. Colbert
; Claudia Scarlata
; | Date: |
19 Jan 2010 | Abstract: | We have obtained deep Hubble Space Telescope far-UV images of 15 starburst
galaxies at z~1.3 in the GOODS fields to search for escaping Lyman continuum
photons. These are the deepest far-UV images m_{AB}=28.7, 3sigma, 1" diameter)
over this large an area (4.83 arcmin^2) and provide the best escape fraction
constraints for any galaxy at any redshift. We do not detect any individual
galaxies, with 3sigma limits to the Lyman Continuum (~700 AA) flux 50--149
times fainter (in f_nu) than the rest-frame UV (1500 AA) continuum fluxes.
Correcting for the mean IGM attenuation (factor ~2), as well as an intrinsic
stellar Lyman Break (~3), these limits translate to relative escape fraction
limits of f_{esc,rel}<[0.03,0.21]. The stacked limit is
f_{esc,rel}(3sigma)<0.02. We use a Monte Carlo simulation to properly account
for the expected distribution of IGM opacities. When including constraints from
previous surveys at z~1.3 we find that, at the 95% confidence level, no more
than 8% of star--forming galaxies at z~1.3 can have relative escape fractions
greater than 0.50. Alternatively, if the majority of galaxies have low, but
non-zero, escaping Lyman Continuum, the escape fraction can not be more than
0.04. Both the stacked limits, and the limits from the Monte Carlo simulation
suggest that the average ionizing emissivity (relative to non-ionizing UV
emissivity) at z~1.3 is significantly lower than has been observed in Lyman
Break Galaxies (LBGs) at z~3. If the ionizing emissivity of star-forming
galaxies is in fact increasing with redshift, it would help to explain the high
photoionization rates seen in the IGM at z>4 and reionization of the
intergalactic medium at z>6. [Abridged] | Source: | arXiv, 1001.3412 | 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:
| |