A TENTATIVE DETECTION OF AN EMISSION LINE AT 1.6 {mu}m FOR THE z {approx} 12 CANDIDATE UDFj-39546284

Journal Article · Fri Mar 01 00:00:00 EST 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/765/1/L2· OSTI ID:22130876

Brammer, Gabriel B. ^[1]; Van Dokkum, Pieter G.; Momcheva, Ivelina ^[2]; Illingworth, Garth D.; Oesch, Pascal A. ^[3]; Bouwens, Rychard J.; Labbe, Ivo; Franx, Marijn ^[4]

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1. European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago (Chile)
2. Department of Astronomy, Yale University, New Haven, CT 06520 (United States)
3. UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)
4. Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands)

We present deep WFC3 grism observations of the candidate z {approx} 12 galaxy UDFj-39546284 in the Hubble Space Telescope (HST) Ultra Deep Field (UDF), by combining spectroscopic data from the 3D-HST and CANDELS surveys. The total exposure time is 40.5 ks and the spectrum covers 1.10 < {lambda} < 1.65 {mu}m. We search for faint emission lines by cross-correlating the two-dimensional G141 spectrum with the observed H{sub 160} morphology, a technique that is unique to slitless spectroscopy at HST resolution. We find a 2.7{sigma} detection of an emission line at 1.599 {mu}m-just redward of the JH{sub 140} filter-with flux 3.5 {+-} 1.3 Multiplication-Sign 10{sup -18} erg s{sup -1} cm{sup -2}. Assuming that the line is real, it contributes 110% {+-} 40% of the observed H{sub 160} flux and has an observed equivalent width >7300 A. If the line is confirmed, it could be Ly{alpha} at z = 12.12. However, a more plausible interpretation, given current results, could be a lower redshift feature such as [O III]{lambda}4959,5007 at z = 2.19. We find two other 3D-HST [O III] emitters within 1000 km s{sup -1} of that redshift in the GOODS-South field. Additional support for this interpretation comes from the discovery of a bright ''[O III] blob'' with a secure G141 grism redshift of z = 1.605. This object has a strikingly large observed equivalent width of nearly 9000 A that results in similar ''dropout''colors as UDFj-39546284.

• OSTI ID: 22130876
• Journal Information: Astrophysical Journal Letters, Vol. 765, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
DETECTION
EMISSION
FILTERS
GALAXIES
RED SHIFT
RESOLUTION
SPACE
SPECTRA
SPECTROSCOPY
TELESCOPES
TWO-DIMENSIONAL CALCULATIONS