The HDUV Survey: Six Lyman Continuum Emitter Candidates at z ∼ 2 Revealed by HST UV Imaging

Journal Article · Wed Sep 20 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA8863· OSTI ID:22875801

Naidu, R. P. ^[1]; Oesch, P. A.; Montes, M.; Dokkum, P. G. van ^[2]; Reddy, N. ^[3]; Holden, B.; Illingworth, G. D.; Magee, D. ^[4]; Steidel, C. C. ^[5]; Atek, H. ^[6]; Bouwens, R. J.; Labbé, I. ^[7]; Carollo, C. M. ^[8]; Cibinel, A.; Wilkins, S. ^[9]; Morselli, L. ^[10]

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1. Yale-NUS College, 12 College Avenue West, 138614 (Singapore)
2. Astronomy Department, Yale University, New Haven, CT 06511 (United States)
3. University of California, Riverside, 900 University Avenue, Riverside, CA 92507 (United States)
4. UCO/Lick Observatory, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)
5. Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States)
6. Institut d’astrophysique de Paris, 98bis Boulevard Arago, F-75014 Paris (France)
7. Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands)
8. Institute for Astronomy, ETH Zurich, 8092 Zurich (Switzerland)
9. Astronomy Centre, Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH (United Kingdom)
10. Excellence Cluster Universe, Boltzmannstr. 2, D-85748 Garching bei München (Germany)

We present six galaxies at z∼2 that show evidence of Lyman continuum (LyC) emission based on the newly acquired UV imaging of the Hubble Deep UV legacy survey (HDUV) conducted with the WFC3/UVIS camera on the Hubble Space Telescope (HST). At the redshift of these sources, the HDUV F275W images partially probe the ionizing continuum. By exploiting the HST multiwavelength data available in the HDUV/GOODS fields, models of the UV spectral energy distributions, and detailed Monte Carlo simulations of the intergalactic medium absorption, we estimate the absolute ionizing photon escape fractions of these galaxies to be very high—typically >60% (>13% for all sources at 90% likelihood). Our findings are in broad agreement with previous studies that found only a small fraction of galaxies with high escape fraction. These six galaxies compose the largest sample yet of LyC leaking candidates at z∼2 whose inferred LyC flux has been observed at HST resolution. While three of our six candidates show evidence of hosting an active galactic nucleus, two of these are heavily obscured and their LyC emission appears to originate from star-forming regions rather than the central nucleus. Extensive multiwavelength data in the GOODS fields, especially the near-IR grism spectra from the 3D-HST survey, enable us to study the candidates in detail and tentatively test some recently proposed indirect methods to probe LyC leakage. High-resolution spectroscopic follow-up of our candidates will help constrain such indirect methods, which are our only hope of studying f {sub esc} at z∼5−9 in the JWST era.

• OSTI ID: 22875801
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 847; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
COMPUTERIZED SIMULATION
EMISSION
ENERGY SPECTRA
GALACTIC EVOLUTION
GALAXIES
GALAXY NUCLEI
LYMAN LINES
MONTE CARLO METHOD
RED SHIFT
SPACE
STARS
TELESCOPES