HerMES: THE REST-FRAME UV EMISSION AND A LENSING MODEL FOR THE z = 6.34 LUMINOUS DUSTY STARBURST GALAXY HFLS3

• Published in: The Astrophysical journal 2014-07, Vol.790 (1), p.1-10
• Main Authors: Cooray, Asantha, Calanog, Jae, Wardlow, Julie L, Bock, J, Bridge, C, Burgarella, D, Bussmann, R S, Casey, C M, Clements, D, Conley, A
• Format: Article
• Language: English
• Subjects: Adaptive optics; Astrophysics; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COLOR; Confidence; Continuums; EMISSION; ENERGY SPECTRA; GALAXIES; GRAVITATIONAL LENSES; Imaging; MASS; OPTICS; Photometry; RED SHIFT; Sciences of the Universe; Spectral energy distribution; STARS; ULTRAVIOLET RADIATION; WAVELENGTHS
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/790/1/40

We discuss the rest-frame ultraviolet emission from the starbursting galaxy HFLS3 at a redshift of 6.34. The galaxy was discovered in Herschel/SPIRE data due to its red color in the submillimeter wavelengths from 250 to 500 mu m. Keck/NIRC2 Ks-band adaptive optics imaging data showed two potential near-IR counterparts near HFLS3. Previously, the northern galaxy was taken to be in the foreground at z = 2.1, while the southern galaxy was assumed to be HFLS3's near-IR counterpart. The recently acquired Hubble/WFC3 and Advanced Camera for Surveys (ACS) imaging data show conclusively that both optically bright galaxies are in the foreground at z < 6. A new lensing model based on the Hubble imaging data and the millimeter-wave continuum emission yields a magnification factor of 2.2 + or - 0.3, with a 95% confidence upper limit on the magnification of 3.5. When corrected for lensing, the instantaneous star formation rate is 1320 M sub([middot in circle]) yr super(-1), with the 95% confidence lower limit around 830 M[middot in circle] yr super(-1). The dust and stellar masses of HFLS3 from the same spectral energy distribution (SED) models are at the level of 3 x 10 super(8) M sub([middot in circle]) and ~5 x 10 super(10) M sub([middot in circle]), respectively, with large systematic uncertainties on assumptions related to the SED model. With Hubble/WFC3 images, we also find diffuse near-IR emission about 0.5 arcsec (~3 kpc) to the southwest of HFLS3 that remains undetected in the ACS imaging data. The emission has a photometric redshift consistent with either z ~ 6 or a dusty galaxy template at z ~ 2.