We present 0".2-resolution Atacama Large Millimeter/submillimeter Array
observations at 870 um for 25 Halpha-seleced star-forming galaxies (SFGs)
around the main-sequence at z=2.2-2.5. We detect significant 870 um continuum
emission in 16 (64%) of these SFGs. The high-resolution maps reveal that the
dust emission is mostly radiated from a single region close to the galaxy
center. Exploiting the visibility data taken over a wide $uv$ distance range,
we measure the half-light radii of the rest-frame far-infrared emission for the
best sample of 12 SFGs. We find nine galaxies to be associated with extremely
compact dust emission with R_1/2,870um<1.5 kpc, which is more than a factor
of 2 smaller than their rest-optical sizes, R_1/2,1.6um=3.2 kpc, and is
comparable with optical sizes of massive quiescent galaxies at similar
redshifts. As they have an exponential disk with Sersic index of n=1.2 in the
rest-optical, they are likely to be in the transition phase from extended disks
to compact spheroids. Given their high star formation rate surface densities
within the central 1 kpc of Sigma SFR1kpc=40 Msol/yr/kpc^2, the intense
circumnuclear starbursts can rapidly build up a central bulge with Sigma
M*1kpc>1e10 Msol/kpc^2 in several hundred Myr, i.e. by z~2. Moreover, ionized
gas kinematics reveal that they are rotation-supported with an angular momentum
as large as that of typical SFGs at z=1-3. Our results suggest bulges are
commonly formed in extended rotating disks by internal processes, not involving
major mergers.
Beschreibung
[1608.05412] Bulge-forming galaxies with an extended rotating disk at z~2
%0 Generic
%1 tadaki2016bulgeforming
%A Tadaki, Ken-ichi
%A Genzel, Reinhard
%A Kodama, Tadayuki
%A Wuyts, Stijn
%A Wisnioski, Emily
%A Schreiber, Natascha M. Förster
%A Burkert, Andreas
%A Lang, Philipp
%A Tacconi, Linda J.
%A Lutz, Dieter
%A Belli, Sirio
%A Davies, Richard I.
%A Hatsukade, Bunyo
%A Hayashi, Masao
%A Herrera-Camus, Rodrigo
%A Ikarashi, Soh
%A Inoue, Shigeki
%A Kohno, Kotaro
%A Koyama, Yusei
%A Mendel, J. Trevor
%A Nakanishi, Kouichiro
%A Shimakawa, Rhythm
%A Suzuki, Tomoko L.
%A Tamura, Yoichi
%A Tanaka, Ichi
%A Übler, Hannah
%A Wilman, Dave J.
%D 2016
%K bulge compact dust main sequence sfr
%T Bulge-forming galaxies with an extended rotating disk at z~2
%U http://arxiv.org/abs/1608.05412
%X We present 0".2-resolution Atacama Large Millimeter/submillimeter Array
observations at 870 um for 25 Halpha-seleced star-forming galaxies (SFGs)
around the main-sequence at z=2.2-2.5. We detect significant 870 um continuum
emission in 16 (64%) of these SFGs. The high-resolution maps reveal that the
dust emission is mostly radiated from a single region close to the galaxy
center. Exploiting the visibility data taken over a wide $uv$ distance range,
we measure the half-light radii of the rest-frame far-infrared emission for the
best sample of 12 SFGs. We find nine galaxies to be associated with extremely
compact dust emission with R_1/2,870um<1.5 kpc, which is more than a factor
of 2 smaller than their rest-optical sizes, R_1/2,1.6um=3.2 kpc, and is
comparable with optical sizes of massive quiescent galaxies at similar
redshifts. As they have an exponential disk with Sersic index of n=1.2 in the
rest-optical, they are likely to be in the transition phase from extended disks
to compact spheroids. Given their high star formation rate surface densities
within the central 1 kpc of Sigma SFR1kpc=40 Msol/yr/kpc^2, the intense
circumnuclear starbursts can rapidly build up a central bulge with Sigma
M*1kpc>1e10 Msol/kpc^2 in several hundred Myr, i.e. by z~2. Moreover, ionized
gas kinematics reveal that they are rotation-supported with an angular momentum
as large as that of typical SFGs at z=1-3. Our results suggest bulges are
commonly formed in extended rotating disks by internal processes, not involving
major mergers.
@misc{tadaki2016bulgeforming,
abstract = {We present 0".2-resolution Atacama Large Millimeter/submillimeter Array
observations at 870 um for 25 Halpha-seleced star-forming galaxies (SFGs)
around the main-sequence at z=2.2-2.5. We detect significant 870 um continuum
emission in 16 (64%) of these SFGs. The high-resolution maps reveal that the
dust emission is mostly radiated from a single region close to the galaxy
center. Exploiting the visibility data taken over a wide $uv$ distance range,
we measure the half-light radii of the rest-frame far-infrared emission for the
best sample of 12 SFGs. We find nine galaxies to be associated with extremely
compact dust emission with R_{1/2,870um}<1.5 kpc, which is more than a factor
of 2 smaller than their rest-optical sizes, R_{1/2,1.6um}=3.2 kpc, and is
comparable with optical sizes of massive quiescent galaxies at similar
redshifts. As they have an exponential disk with Sersic index of n=1.2 in the
rest-optical, they are likely to be in the transition phase from extended disks
to compact spheroids. Given their high star formation rate surface densities
within the central 1 kpc of Sigma SFR1kpc=40 Msol/yr/kpc^2, the intense
circumnuclear starbursts can rapidly build up a central bulge with Sigma
M*1kpc>1e10 Msol/kpc^2 in several hundred Myr, i.e. by z~2. Moreover, ionized
gas kinematics reveal that they are rotation-supported with an angular momentum
as large as that of typical SFGs at z=1-3. Our results suggest bulges are
commonly formed in extended rotating disks by internal processes, not involving
major mergers.},
added-at = {2016-08-22T10:47:41.000+0200},
author = {Tadaki, Ken-ichi and Genzel, Reinhard and Kodama, Tadayuki and Wuyts, Stijn and Wisnioski, Emily and Schreiber, Natascha M. Förster and Burkert, Andreas and Lang, Philipp and Tacconi, Linda J. and Lutz, Dieter and Belli, Sirio and Davies, Richard I. and Hatsukade, Bunyo and Hayashi, Masao and Herrera-Camus, Rodrigo and Ikarashi, Soh and Inoue, Shigeki and Kohno, Kotaro and Koyama, Yusei and Mendel, J. Trevor and Nakanishi, Kouichiro and Shimakawa, Rhythm and Suzuki, Tomoko L. and Tamura, Yoichi and Tanaka, Ichi and Übler, Hannah and Wilman, Dave J.},
biburl = {https://www.bibsonomy.org/bibtex/24cf8ef60c0482969cea22185e19f87ab/miki},
description = {[1608.05412] Bulge-forming galaxies with an extended rotating disk at z~2},
interhash = {5dc10938471ea66a99f4958a73c2ae8d},
intrahash = {4cf8ef60c0482969cea22185e19f87ab},
keywords = {bulge compact dust main sequence sfr},
note = {cite arxiv:1608.05412Comment: 10 pages, 5 figures, 2 tables, submitted to ApJ},
timestamp = {2016-08-22T10:47:41.000+0200},
title = {Bulge-forming galaxies with an extended rotating disk at z~2},
url = {http://arxiv.org/abs/1608.05412},
year = 2016
}