Massive galaxies in the distant Universe form stars at much higher rates than
today. Although direct resolution of the star forming regions of these galaxies
is still a challenge, recent molecular gas observations at the IRAM Plateau de
Bure interferometer enable us to study the star formation efficiency at
sub-galactic scales around redshift z = 1.2. We present a method to obtain the
gas and star formation rate (SFR) surface densities of ensembles of clumps
composing galaxies at this redshift, even though the corresponding scales are
not resolved. This method is based on the identification of these structures in
position-velocity diagrams corresponding to slices within the galaxies. We use
unique IRAM observations of the CO(3-2) rotational line and DEEP2 spectra of
four massive star forming distant galaxies - EGS13003805, EGS13004291,
EGS12007881 and EGS13019128 in the AEGIS terminology - to determine the gas and
SFR surface densities of the identifiable ensembles of clumps that constitute
them. The integrated CO line luminosity is assumed to be directly proportional
to the total gas mass, and the SFR is deduced from the OII recombination
line. We identify the ensembles of clumps with the angular resolution available
in both CO and OII spectroscopy, i.e. 1-1.5". SFR and gas surface densities
are averaged in areas of this size, which is also the thickness of the DEEP2
slits and of the extracted IRAM slices, and we derive a spatially resolved
Kennicutt-Schmidt (KS) relation at a scale of ~ 8 kpc. The data points globally
follow a power law of exponent N=1 corresponding to a depletion time of 1.0
Gyr, but with a large scatter, which means that the depletion time varies from
point to point within the galaxies. We find a depletion time of 1.4 +/- 0.9
Gyr.
Description
[1301.0628] Towards a resolved Kennicutt-Schmidt law at high redshift
%0 Generic
%1 freundlich2013towards
%A Freundlich, J.
%A Combes, F.
%A Tacconi, L. J.
%A Cooper, M. C.
%A Genzel, R.
%A Neri, R.
%A Bolatto, A.
%A Bournaud, F.
%A Burkert, A.
%A Cox, P.
%A Davis, M.
%A Schreiber, N. M. Förster
%A Garcia-Burillo, S.
%A Gracia-Carpio, J.
%A Lutz, D.
%A Naab, T.
%A Newman, S.
%A Sternberg, A.
%A Weiner, B.
%D 2013
%K formation high-z law resolved star
%T Towards a resolved Kennicutt-Schmidt law at high redshift
%U http://arxiv.org/abs/1301.0628
%X Massive galaxies in the distant Universe form stars at much higher rates than
today. Although direct resolution of the star forming regions of these galaxies
is still a challenge, recent molecular gas observations at the IRAM Plateau de
Bure interferometer enable us to study the star formation efficiency at
sub-galactic scales around redshift z = 1.2. We present a method to obtain the
gas and star formation rate (SFR) surface densities of ensembles of clumps
composing galaxies at this redshift, even though the corresponding scales are
not resolved. This method is based on the identification of these structures in
position-velocity diagrams corresponding to slices within the galaxies. We use
unique IRAM observations of the CO(3-2) rotational line and DEEP2 spectra of
four massive star forming distant galaxies - EGS13003805, EGS13004291,
EGS12007881 and EGS13019128 in the AEGIS terminology - to determine the gas and
SFR surface densities of the identifiable ensembles of clumps that constitute
them. The integrated CO line luminosity is assumed to be directly proportional
to the total gas mass, and the SFR is deduced from the OII recombination
line. We identify the ensembles of clumps with the angular resolution available
in both CO and OII spectroscopy, i.e. 1-1.5". SFR and gas surface densities
are averaged in areas of this size, which is also the thickness of the DEEP2
slits and of the extracted IRAM slices, and we derive a spatially resolved
Kennicutt-Schmidt (KS) relation at a scale of ~ 8 kpc. The data points globally
follow a power law of exponent N=1 corresponding to a depletion time of 1.0
Gyr, but with a large scatter, which means that the depletion time varies from
point to point within the galaxies. We find a depletion time of 1.4 +/- 0.9
Gyr.
@misc{freundlich2013towards,
abstract = {Massive galaxies in the distant Universe form stars at much higher rates than
today. Although direct resolution of the star forming regions of these galaxies
is still a challenge, recent molecular gas observations at the IRAM Plateau de
Bure interferometer enable us to study the star formation efficiency at
sub-galactic scales around redshift z = 1.2. We present a method to obtain the
gas and star formation rate (SFR) surface densities of ensembles of clumps
composing galaxies at this redshift, even though the corresponding scales are
not resolved. This method is based on the identification of these structures in
position-velocity diagrams corresponding to slices within the galaxies. We use
unique IRAM observations of the CO(3-2) rotational line and DEEP2 spectra of
four massive star forming distant galaxies - EGS13003805, EGS13004291,
EGS12007881 and EGS13019128 in the AEGIS terminology - to determine the gas and
SFR surface densities of the identifiable ensembles of clumps that constitute
them. The integrated CO line luminosity is assumed to be directly proportional
to the total gas mass, and the SFR is deduced from the [OII] recombination
line. We identify the ensembles of clumps with the angular resolution available
in both CO and [OII] spectroscopy, i.e. 1-1.5". SFR and gas surface densities
are averaged in areas of this size, which is also the thickness of the DEEP2
slits and of the extracted IRAM slices, and we derive a spatially resolved
Kennicutt-Schmidt (KS) relation at a scale of ~ 8 kpc. The data points globally
follow a power law of exponent N=1 corresponding to a depletion time of 1.0
Gyr, but with a large scatter, which means that the depletion time varies from
point to point within the galaxies. We find a depletion time of 1.4 +/- 0.9
Gyr.},
added-at = {2013-01-08T15:52:26.000+0100},
author = {Freundlich, J. and Combes, F. and Tacconi, L. J. and Cooper, M. C. and Genzel, R. and Neri, R. and Bolatto, A. and Bournaud, F. and Burkert, A. and Cox, P. and Davis, M. and Schreiber, N. M. Förster and Garcia-Burillo, S. and Gracia-Carpio, J. and Lutz, D. and Naab, T. and Newman, S. and Sternberg, A. and Weiner, B.},
biburl = {https://www.bibsonomy.org/bibtex/2aff3d6bc4d84d6c1d5152af07ee24f8c/miki},
description = {[1301.0628] Towards a resolved Kennicutt-Schmidt law at high redshift},
interhash = {a18b1d3a8bc4499ad5f02fd324ac29bd},
intrahash = {aff3d6bc4d84d6c1d5152af07ee24f8c},
keywords = {formation high-z law resolved star},
note = {cite arxiv:1301.0628Comment: 6 pages, 4 figures, 2 tables},
timestamp = {2013-01-08T15:52:26.000+0100},
title = {Towards a resolved Kennicutt-Schmidt law at high redshift},
url = {http://arxiv.org/abs/1301.0628},
year = 2013
}