CLASH: Three Strongly Lensed Images of a Candidate z ~ 11 Galaxy
Abstract
We present a candidate for the most distant galaxy known to date with a photometric redshift z = 10.8 +/- 0.5 (95% confidence limits; with z < 9.5 galaxies of known types ruled out at 7-sigma). This J-dropout Lyman Break Galaxy, named MACS0647-JD, was discovered as part of the Cluster Lensing and Supernova survey with Hubble (CLASH). We observe three magnified images of this galaxy due to strong gravitational lensing by the galaxy cluster MACSJ0647.7+7015 at z = 0.59. The brighter two images are magnified by factors of ~8 and 7 to ~26th magnitude AB 0.15 uJy) in the WFC3/IR F160W filter 1.4-1.7 um) and ~27th magnitude in F140W 1.2-1.6 um). They are not significantly detected in 17 other filters observed with Hubble and Spitzer, as expected for a galaxy at this redshift. Given CLASH observations of 17 high mass clusters, our discoveries of MACS0647-JD at z ~ 10.8 and MACS1149-JD1 at z ~ 9.6 are consistent with a lensed luminosity function extrapolated from lower redshifts. This would suggest that low luminosity galaxies could have reionized the universe. However given the significant uncertainties based on only two galaxies, we cannot yet rule out the sharp drop off in number counts at z ~ 10 suggested by field searches.
- Publication:
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American Astronomical Society Meeting Abstracts #221
- Pub Date:
- January 2013
- Bibcode:
- 2013AAS...22120707C