The Grism Lens-Amplified Survey from Space (GLASS). XI. Detection of C iv in Multiple Images of the z = 6.11 Lyα Emitter behind RXC J2248.7–4431

Journal Article · Mon Apr 10 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA68A3· OSTI ID:22872810

Schmidt, K. B. ^[1]; Huang, K. -H.; Hoag, A.; Bradač, M.; Jones, T. A. ^[2]; Treu, T.; Mason, C.; Malkan, M.; Morishita, T.; Wang, X. ^[3]; Henry, A. L. ^[4]; Pentericci, L. ^[5]; Trenti, M.

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1. Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482, Potsdam (Germany)
2. Department of Physics, University of California, Davis, CA, 95616 (United States)
3. Department of Physics and Astronomy, UCLA, Los Angeles, CA, 90095-1547 (United States)
4. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD, 21218 (United States)
5. INAF—Osservatorio Astronomico di Roma Via Frascati 33-00040 Monte Porzio Catone (Italy)

The C iii] and C iv rest-frame UV emission lines are powerful probes of the ionization states of galaxies. They have furthermore been suggested as alternatives for spectroscopic redshift confirmation of objects at the epoch of reionization (z>6), where the most frequently used redshift indicator, Lyα, is attenuated by the high fraction of neutral hydrogen in the intergalactic medium. However, currently only very few confirmations of carbon UV lines at these high redshifts exist, making it challenging to quantify these claims. Here, we present the detection of C iv λλ1548, 1551 Å in Hubble Space Telescope slitless grism spectroscopy obtained by GLASS of a Lyα emitter at z = 6.11 multiply imaged by the massive foreground galaxy cluster RXC J2248.7–4431. The C iv emission is detected at the 3σ–5σ level in two images of the source, with marginal detection in two other images. We do not detect significant C iii]λλ1907, 1909 Å emission implying an equivalent width EW{sub CIII]}<20 Å (1σ) and C IV/C III>0.7 (2σ). Combined with limits on the rest-frame UV flux from the He ii λ1640 Å emission line and the O iii]λλ1661, 1666 Å doublet, we put constraints on the metallicity and the ionization state of the galaxy. The estimated line ratios and equivalent widths do not support a scenario where an AGN is responsible for ionizing the carbon atoms. SED fits, including nebular emission lines, imply a source with a mass of log(M/M {sub ⊙}) ∼ 9, SFR of around 10 M {sub ⊙} yr{sup −1}, and a young stellar population <50 Myr old. The source shows a stronger ionizing radiation field than objects with detected C iv emission at z<2 and adds to the growing sample of low-mass (log(M/M {sub ⊙}) ≲ 9) galaxies at the epoch of reionization with strong radiation fields from star formation.

• OSTI ID: 22872810
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 839; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ATOMS
CARBON
DETECTION
EMISSION
GALACTIC EVOLUTION
GALAXIES
GALAXY CLUSTERS
HYDROGEN
IONIZATION
IONIZING RADIATIONS
LYMAN LINES
MASS
METALLICITY
RED SHIFT
SPACE
SPECTROSCOPY
STARS
TELESCOPES