We present a detailed analysis of a large sample of spectroscopically
confirmed ultra-massive quiescent galaxies
($log(M_\ast/M_ødot)\sim11.5$) at $z\gtrsim2$. This sample
comprises 15 galaxies selected in the COSMOS and UDS fields by their bright
K-band magnitudes and followed up with VLT/X-shooter spectroscopy and HST/WFC3
$H_F160W$ imaging. These observations allow us to unambiguously confirm their
redshifts ascertain their quiescent nature and stellar ages, and to reliably
assess their internal kinematics and effective radii. We find that these
galaxies are compact, consistent with the high mass end of the mass-size
relation for quiescent galaxies at $z=2$. Moreover, the distribution of the
measured stellar velocity dispersions of the sample is consistent with the most
massive local early-type galaxies from the MASSIVE Survey showing that
evolution in these galaxies, is dominated by changes in size. The HST images
reveal, as surprisingly high, that $40\ \%$ of the sample have tidal features
suggestive of mergers and companions in close proximity, including three
galaxies experiencing ongoing major mergers. The absence of velocity dispersion
evolution from $z=2$ to $0$, coupled with a doubling of the stellar mass, with
a factor of four size increase and the observed disturbed stellar morphologies
support dry minor mergers as the primary drivers of the evolution of the
massive quiescent galaxies over the last 10 billion years.
Description
X-shooter Spectroscopy and HST Imaging of 15 Ultra Massive Quiescent Galaxies at $z\gtrsim2$
%0 Generic
%1 stockmann2019xshooter
%A Stockmann, Mikkel
%A Toft, Sune
%A Gallazzi, Anna
%A Zibetti, Stefano
%A Conselice, Christopher J.
%A Margalef-Bentabol, Berta
%A Zabl, Johannes
%A Jørgensen, Inger
%A Magdis, Georgios E.
%A Gómez-Guijarro, Carlos
%A Valentino, Francesco M.
%A Brammer, Gabriel B.
%A Ceverino, Daniel
%A Cortzen, Isabella
%A Davidzon, Iary
%A Demarco, Richardo
%A Faisst, Andreas
%A Hirschmann, Michaela
%A Krogager, Jens-Kristian
%A Lagos, Claudia D.
%A Man, Allison W. S.
%A Mundy, Carl J.
%A Peng, Yingjie
%A Selsing, Jonatan
%A Steinhardt, Charles L.
%A Whitaker, Kathrine E.
%D 2019
%K merger stellar-velocity-dispersion
%T X-shooter Spectroscopy and HST Imaging of 15 Ultra Massive Quiescent
Galaxies at $z\gtrsim2$
%U http://arxiv.org/abs/1912.01619
%X We present a detailed analysis of a large sample of spectroscopically
confirmed ultra-massive quiescent galaxies
($log(M_\ast/M_ødot)\sim11.5$) at $z\gtrsim2$. This sample
comprises 15 galaxies selected in the COSMOS and UDS fields by their bright
K-band magnitudes and followed up with VLT/X-shooter spectroscopy and HST/WFC3
$H_F160W$ imaging. These observations allow us to unambiguously confirm their
redshifts ascertain their quiescent nature and stellar ages, and to reliably
assess their internal kinematics and effective radii. We find that these
galaxies are compact, consistent with the high mass end of the mass-size
relation for quiescent galaxies at $z=2$. Moreover, the distribution of the
measured stellar velocity dispersions of the sample is consistent with the most
massive local early-type galaxies from the MASSIVE Survey showing that
evolution in these galaxies, is dominated by changes in size. The HST images
reveal, as surprisingly high, that $40\ \%$ of the sample have tidal features
suggestive of mergers and companions in close proximity, including three
galaxies experiencing ongoing major mergers. The absence of velocity dispersion
evolution from $z=2$ to $0$, coupled with a doubling of the stellar mass, with
a factor of four size increase and the observed disturbed stellar morphologies
support dry minor mergers as the primary drivers of the evolution of the
massive quiescent galaxies over the last 10 billion years.
@misc{stockmann2019xshooter,
abstract = {We present a detailed analysis of a large sample of spectroscopically
confirmed ultra-massive quiescent galaxies
(${\rm{log}}(M_{\ast}/M_{\odot})\sim11.5$) at $z\gtrsim2$. This sample
comprises 15 galaxies selected in the COSMOS and UDS fields by their bright
K-band magnitudes and followed up with VLT/X-shooter spectroscopy and HST/WFC3
$H_{F160W}$ imaging. These observations allow us to unambiguously confirm their
redshifts ascertain their quiescent nature and stellar ages, and to reliably
assess their internal kinematics and effective radii. We find that these
galaxies are compact, consistent with the high mass end of the mass-size
relation for quiescent galaxies at $z=2$. Moreover, the distribution of the
measured stellar velocity dispersions of the sample is consistent with the most
massive local early-type galaxies from the MASSIVE Survey showing that
evolution in these galaxies, is dominated by changes in size. The HST images
reveal, as surprisingly high, that $40\ \%$ of the sample have tidal features
suggestive of mergers and companions in close proximity, including three
galaxies experiencing ongoing major mergers. The absence of velocity dispersion
evolution from $z=2$ to $0$, coupled with a doubling of the stellar mass, with
a factor of four size increase and the observed disturbed stellar morphologies
support dry minor mergers as the primary drivers of the evolution of the
massive quiescent galaxies over the last 10 billion years.},
added-at = {2019-12-09T16:38:41.000+0100},
author = {Stockmann, Mikkel and Toft, Sune and Gallazzi, Anna and Zibetti, Stefano and Conselice, Christopher J. and Margalef-Bentabol, Berta and Zabl, Johannes and Jørgensen, Inger and Magdis, Georgios E. and Gómez-Guijarro, Carlos and Valentino, Francesco M. and Brammer, Gabriel B. and Ceverino, Daniel and Cortzen, Isabella and Davidzon, Iary and Demarco, Richardo and Faisst, Andreas and Hirschmann, Michaela and Krogager, Jens-Kristian and Lagos, Claudia D. and Man, Allison W. S. and Mundy, Carl J. and Peng, Yingjie and Selsing, Jonatan and Steinhardt, Charles L. and Whitaker, Kathrine E.},
biburl = {https://www.bibsonomy.org/bibtex/23e5c4f5e88933d5b78f3aa40aad2bd7a/heh15},
description = {X-shooter Spectroscopy and HST Imaging of 15 Ultra Massive Quiescent Galaxies at $z\gtrsim2$},
interhash = {bbd1e9d60b62f1e10a57b77938c3a36b},
intrahash = {3e5c4f5e88933d5b78f3aa40aad2bd7a},
keywords = {merger stellar-velocity-dispersion},
note = {cite arxiv:1912.01619Comment: 30 pages, 10 figures, accepted in ApJ},
timestamp = {2019-12-09T16:38:41.000+0100},
title = {X-shooter Spectroscopy and HST Imaging of 15 Ultra Massive Quiescent
Galaxies at $z\gtrsim2$},
url = {http://arxiv.org/abs/1912.01619},
year = 2019
}