HUBBLE SPACE TELESCOPE IMAGING OF Ly{alpha} EMISSION AT z {approx} 4.4

Journal Article · Fri Jul 01 00:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/735/1/5· OSTI ID:21576583

Finkelstein, Steven L; Finkelstein, Keely D ^[1]; Cohen, Seth H; Windhorst, Rogier A; Malhotra, Sangeeta; Rhoads, James E ^[2]; Ryan, Russell E ^[3]; Hathi, Nimish P; McCarthy, Patrick J ^[4]; Anderson, Jay; Grogin, Norman A; Koekemoer, Anton M; Mutchler, Max; Bond, Howard E ^[5]; O'Connell, Robert W ^[6]; Balick, Bruce ^[7]; Calzetti, Daniela ^[8]; Disney, Michael J ^[9]; Dopita, Michael A ^[10]

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1. George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)
2. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States)
3. Department of Physics, University of California, Davis, CA 92616 (United States)
4. Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States)
5. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
6. Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States)
7. Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States)
8. Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)
9. School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom)
10. Research School of Astronomy and Astrophysics, The Australian National University, ACT 2611 (Australia)

We present the highest redshift detections of resolved Ly{alpha} emission, using Hubble Space Telescope (HST)/Advanced Camera for Surveys F658N narrowband-imaging data taken in parallel with the Wide Field Camera 3 Early Release Science program in the GOODS Chandra Deep Field-South. We detect Ly{alpha} emission from three spectroscopically confirmed z = 4.4 Ly{alpha} emitting galaxies (LAEs), more than doubling the sample of LAEs with resolved Ly{alpha} emission. Comparing the light distribution between the rest-frame ultraviolet continuum and narrowband images, we investigate the escape of Ly{alpha} photons at high redshift. While our data do not support a positional offset between the Ly{alpha} and rest-frame ultraviolet (UV) continuum emission, the half-light radius in one out of the three galaxies is significantly (>1{sigma}) larger in Ly{alpha} than in the rest-frame UV continuum. Stacking the three LAEs in both the narrowband and UV continuum images, we find that the Ly{alpha} light appears larger than the rest-frame UV at 4.2{sigma} significance. This Ly{alpha} flux detected with HST is a factor of 4-10 less than observed in similar filters from the ground. These results together imply that the Ly{alpha} emission is not strictly confined to its indigenous star-forming regions. Rather, for at least one object the Ly{alpha} emission is more extended, with the missing HST flux possibly existing in a diffuse outer halo. This suggests that the radiative transfer of Ly{alpha} photons in high-redshift LAEs is complicated, with the interstellar-medium geometry and/or outflows playing a significant role in galaxies at these redshifts.

• OSTI ID: 21576583
• Journal Information: Astrophysical Journal, Vol. 735, Issue 1; Other Information: DOI: 10.1088/0004-637X/735/1/5; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ALPHA DETECTION
EMISSION
GALACTIC EVOLUTION
GALAXIES
LYMAN LINES
RADIANT HEAT TRANSFER
RED SHIFT
CHARGED PARTICLE DETECTION
DETECTION
ENERGY TRANSFER
EVOLUTION
HEAT TRANSFER
RADIATION DETECTION