SPECTROSCOPIC CONFIRMATION OF A z = 6.740 GALAXY BEHIND THE BULLET CLUSTER
- Department of Physics, University of California, Davis, CA 95616 (United States)
- INAF, Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, 34131 Trieste (Italy)
- Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
- INAF, Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monteporzio (Italy)
- Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States)
- Department of Physics and Astronomy, Ohio University, Clippinger Labs 251B, Athens, OH 45701 (United States)
- Steward Observatory, University of Arizona, 933 N Cherry Ave., Tucson, AZ 85721 (United States)
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
We present the first results of our spectroscopic follow-up of 6.5 < z < 10 candidate galaxies behind clusters of galaxies. We report the spectroscopic confirmation of an intrinsically faint Lyman break galaxy (LBG) identified as a z{sub 850LP}-band dropout behind the Bullet Cluster. We detect an emission line at {lambda} = 9412 A at >5{sigma} significance using a 16 hr long exposure with FORS2 VLT. Based on the absence of flux in bluer broadband filters, the blue color of the source, and the absence of additional lines, we identify the line as Ly{alpha} at z = 6.740 {+-} 0.003. The integrated line flux is f = (0.7 {+-} 0.1 {+-} 0.3) Multiplication-Sign 10{sup -17} erg{sup -1} s{sup -1} cm{sup -2} (the uncertainties are due to random and flux calibration errors, respectively) making it the faintest Ly{alpha} flux detected at these redshifts. Given the magnification of {mu} = 3.0 {+-} 0.2 the intrinsic (corrected for lensing) flux is f {sup int} = (0.23 {+-} 0.03 {+-} 0.10 {+-} 0.02) Multiplication-Sign 10{sup -17} erg{sup -1} s{sup -1} cm{sup -2} (additional uncertainty due to magnification), which is {approx}2-3 times fainter than other such measurements in z {approx} 7 galaxies. The intrinsic H{sub 160W}-band magnitude of the object is m{sup int}{sub H{sub 1{sub 6{sub 0{sub W}}}}}=27.57{+-}0.17, corresponding to 0.5 L* for LBGs at these redshifts. The galaxy is one of the two sub-L* LBG galaxies spectroscopically confirmed at these high redshifts (the other is also a lensed z = 7.045 galaxy), making it a valuable probe for the neutral hydrogen fraction in the early universe.
- OSTI ID:
- 22047624
- Journal Information:
- Astrophysical Journal Letters, Vol. 755, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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