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Persistent URL http://purl.org/net/epubs/work/10919452
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Record Id 10919452
Title Four IRAC sources with an extremely red H - [3.6] color: Passive or dusty galaxies at z > 4.5?
Abstract We report the detection of four IRAC sources in the GOODS-South field with an extremely red color of H - [3.6] > 4.5. The four sources are not detected in the deep Hubble Space Telescope WFC3 H-band image with H = 28.3mag. We find that only three types of SED templates can produce such a red H - [3.6] color: a very dusty SED with the Calzetti extinction of A = 16mag at z = 0.8; a very dusty SED with the SMC extinction of A = 8mag at z = 2.0- 2.2; and an 1Gyr SSP with A ?0.8 at z = 5.7. We argue that these sources are unlikely dusty galaxies at z ? 2.2 based on absent strong MIPS 24 ?m emission. The old stellar population model at z > 4.5 remains a possible solution for the 4 sources. At z > 4.5, these sources have stellar masses of log(M /M ) = 10.6-11.2. One source, ERS-1, is also a type-II X-ray QSO with L = 1.6 × 10 erg s. One of the four sources is an X-ray QSO and another one is a HyperLIRG, suggesting a galaxy-merging scenario for the formation of these massive galaxies at high redshifts. © 2011. The American Astronomical Society. All rights reserved.
Organisation STFC , RALSP , RALSP - SPD
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Language English (EN)
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Journal Article Astrophys J Lett 742 (2011): L13. doi:10.1088/2041-8205/742/1/L13 2011