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| Paper: |
SEDs and NIR Morphologies of Old and Dusty Galaxies at z∼2 |
| Volume: |
446, Galaxy Evolution: Infrared to Millimeter Wavelength Perspective |
| Page: |
303 |
| Authors: |
Wang, T.; Huang, J.; Wuyts, S.; Fang, G.; Fazio, G.; Chen, Z.; Kong, X.; Gu, Q. |
| Abstract: |
We explore the nature of the IRAC-selected Extremely Red Objects
(IEROs; z′ – [3.6] > 3.25 and [3.6] < 21.5) using the most
extensive data set in GOODS-South. The majority of these IEROs are
proved to be at 1.4 < z < 2.5 with typical stellar mass of ∼
1011Mmsol. In particular, we show that they dominate the
high-mass end of the stellar mass function, and contribute ∼
90% of all the most massive (M* > 1 × 1011M☉)
galaxies at the redshift interval. We show these galaxies can be
cleanly separated into old and dusty galaxies using simple H –
[8.0] color: the old galaxies primarily have H – [8.0] < 1.2 and
the dusty galaxies are much redder. Such a classification scheme is
further shown to be broadly consistent with that using MIPS 24 μm, rest-frame U–V and V–J color and SSP
fitting. In addition, with new NIR imaging from HST/WFC3 we show
that these massive old and dusty galaxies exhibit distinct
morphologies: the old galaxies are primarily compact and spheroidal
whereas the dusty galaxies show more extended and disturbed
morphologies. With the clean and consistent separation between old
and dusty galaxies, we derive the fraction of quiescent massive
galaxies to be ∼ 25%, which is the same if we only take the
most massive galaxies into account. |
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