A deep Hubble Space Telescope and KECK search for definitive identification of Lyman continuum emitters at cic>∼3.1

Journal Article · Fri May 01 04:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/804/1/17· OSTI ID:22883259

Siana, Brian; Alavi, Anahita ^[1]; Shapley, Alice E.; Kulas, Kristin R.; Nestor, Daniel B. ^[2]; Steidel, Charles C.; Bridge, Carrie R. ^[3]; Teplitz, Harry I.; Colbert, James W. ^[4]; Brown, Thomas M.; Ferguson, Henry C. ^[5]; Conselice, Christopher J. ^[6]; Dickinson, Mark ^[7]; Giavalisco, Mauro ^[8]; Gardner, Jonathan P. ^[9]; Mello, Duilia F. de ^[10]

---

1. Department of Physics and Astronomy, University of California Riverside, Riverside, CA 92521 (United States)
2. Department of Astronomy, University of California Los Angeles, Los Angeles, CA 90095 (United States)
3. California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States)
4. Infrared Processing and Analysis Center, California Institute of Technology, 220-6, Pasadena, CA 91125 (United States)
5. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
6. University of Nottingham, Nottingham, NG7 2RD (United Kingdom)
7. National Optical Astronomy Observatory, 950 N. Cherry Ave., Tucson, AZ 85719 (United States)
8. University of Massachusetts, Department of Astronomy, Amherst, MA, 01003 (United States)
9. Astrophysics Science Division, Observational Cosmology Laboratory, Code 665, Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
10. Department of Physics, Catholic University of America, 620 Michigan Avenue, Washington DC 20064 (United States)

Narrowband imaging of the rest-frame Lyman continuum (LyC) of galaxies at z∼3.1 has produced a large number of candidate LyC-emitting galaxies. These samples are contaminated by galaxies at lower redshift. To better understand LyC escape, we need an uncontaminated sample of galaxies that emit strongly in the LyC. Here we present deep Hubble Space Telescope imaging of five bright galaxies at z∼3.1 that had previously been identified as candidate LyC emitters with ground-based images. The WFC3 F336W images probe the LyC of galaxies at z>3.06 and provide an order-of-magnitude increase in spatial resolution over ground-based imaging. The non-ionizing UV images often show multiple galaxies (or components) within ∼1{sup ′′} of the candidate LyC emission seen from the ground. In each case, only one of the components is emitting light in the F336W filter, which would indicate LyC escape if that component is at z>3.06. We use Keck/NIRSPEC near-IR spectroscopy to measure redshifts of these components to distinguish LyC emitters from foreground contamination. We find that two candidates are low-redshift contaminants, one candidate had a previously misidentified redshift, and the other two cannot be confirmed as LyC emitters. The level of contamination is consistent with previous estimates. For the galaxies with z>3.06, we derive strong 1σ limits on the relative escape fraction between 0.07 and 0.09. We still do not have a sample of definitive LyC emitters, and a much larger study of low-luminosity galaxies is required. The combination of high-resolution imaging and deep spectroscopy is critical for distinguishing LyC emitters from foreground contaminants.

• OSTI ID: 22883259
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 804; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United Kingdom
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
EMISSION
GALAXIES
INFRARED SPECTRA
LUMINOSITY
LYMAN LINES
RED SHIFT
SPACE
SPATIAL RESOLUTION
SPECTROSCOPY
TELESCOPES
ULTRAVIOLET RADIATION