The Astrophysical Journal

The Astrophysical Journal

Quick search Find article
Quick search
Find article
The Astrophysical Journal Volume 692 Number 2 Create an alert RSS this journal

I. Iwata et al. 2009 ApJ 692 1287 doi:10.1088/0004-637X/692/2/1287

DETECTIONS OF LYMAN CONTINUUM FROM STAR-FORMING GALAXIES AT z ~ 3 THROUGH SUBARU/SUPRIME-CAM NARROW-BAND IMAGING * **

FREE ISSUE

I. Iwata1, A. K. Inoue2, Y. Matsuda3,4,9, H. Furusawa5, T. Hayashino6, K. Kousai6, M. Akiyama5,7, T. Yamada7, D. Burgarella8 and J.-M. Deharveng8

Show affiliations

Tag this article Full text PDF (415 KB) View as HTML

Abstract References Cited By

Knowing the amount of ionizing photons from young star-forming galaxies is of particular importance to understanding the reionization process. Here we report initial results of a Subaru/Suprime-Cam deep imaging observation of the SSA22 proto-cluster region at z = 3.09, using a special narrow-band filter to optimally trace ionizing radiation from galaxies at z ~ 3. The unique wide field-of-view of Suprime-Cam enabled us to search for ionizing photons from 198 galaxies (73 Lyman break galaxies (LBGs) and 125 Lyα emitters (LAEs)) with spectroscopically measured redshifts z sime 3.1. We detected ionizing radiation from 7 LBGs, as well as from 10 LAE candidates. Some of the detected galaxies show significant spatial offsets of ionizing radiation from nonionizing UV emission. For some LBGs the observed nonionizing UV to Lyman continuum flux density ratios are smaller than values expected from population synthesis models with a standard Salpeter initial mass function (IMF) with moderate dust attenuation (which is suggested from the observed UV slopes), even if we assume very transparent intergalactic medium along the sightlines of these objects. This implies an intrinsically bluer spectral energy distribution, e.g., that produced by a top-heavy IMF, for these LBGs. The observed flux density ratios of nonionizing UV to ionizing radiation of 7 detected LBGs range from 2.4 to 23.8 and the median is 6.6. The observed flux density ratios of the detected LAEs are even smaller than LBGs, if they are truly at z sime 3.1. We find that the median value of the flux density ratio for the detected LBGs suggests that their escape fractions are likely to be higher than 4%, if the Lyman continuum escape is isotropic. The results imply that some of the LBGs in the proto-cluster at z ~ 3 have escape fraction significantly higher than that of galaxies (in a general field) at z ~ 1 studied previously.


Footnote
**  Some of the data presented in this paper were obtained from the Multimission Archive at the Space Telescope Science Institute (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.
Footnote
*  Based on data collected with the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.
Keywords

cosmology: observations; diffuse radiation; galaxies: evolution; galaxies: high-redshift; intergalactic medium


Dates

Issue 2 (2009 February 20)

Received 2008 May 21, accepted for publication 2008 October 27

Published 2009 February 24



Your last 10 viewed
  1. Detections of Lyman Continuum from Star-Forming Galaxies at z ~ 3 through Subaru/Suprime-Cam Narrow-Band Imaging

    I. Iwata et al. 2009 ApJ 692 1287

  2. Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy

    M Hannemann et al 2011 J. Breath Res. 5 027101

  3. Chronic intestinal Mycobacteria infection: discrimination via VOC analysis in exhaled breath and headspace of feces using differential ion mobility spectrometry

    Roman Purkhart et al 2011 J. Breath Res. 5 027103

  4. Fractional exhaled nitric oxide measurement with a handheld device

    Erhard Magori et al 2011 J. Breath Res. 5 027104

  5. Quantitative determination of metabolization dynamics by a real-time 13CO2 breath test

    T Rubin et al 2011 J. Breath Res. 5 027102

Users also read

What's this?
This innovative new feature generates a list of articles 'also read' by other users based on them reading the original article. Article abstracts citations and references are all considered and weighted accordingly. We hope that this will help you find relevant papers for your research.

  1. The Direct Detection of Lyman Continuum Emission from Star-forming Galaxies at z~3
  2. Narrowband Imaging of Escaping Lyman-continuum Emission in the SSA22 Field
  3. The Great Observatories Origins Deep Survey: Constraints on the Lyman Continuum Escape Fraction Distribution of Lyman-break Galaxies at 3.4 < z < 4.5
More

Share

View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.