We present first results from the KMOS Redshift One Spectroscopic Survey
(KROSS), an ongoing large kinematical survey of a thousand, z~1 star forming
galaxies, with VLT KMOS. Out of the targeted galaxies (~500 so far), we detect
and spatially resolve Ha emission in ~90% and 77% of the sample respectively.
Based on the integrated Ha flux measurements and the spatially resolved maps we
derive a median star formation rate (SFR) of ~7.0 Msun/yr and a median physical
size of <r$_e$> = 5.1kpc. We combine the inferred SFRs and effective
radii measurements to derive the star formation surface densities (\SigmaSFR)
and present a "resolved" version of the star formation main sequence (MS) that
appears to hold at sub-galactic scales, with similar slope and scatter as the
one inferred from galaxy integrated properties. Our data also yield a trend
between \SigmaSFR and \Delta(sSFR) (distance from the MS) suggesting that
galaxies with higher sSFR are characterised by denser star formation activity.
Similarly, we find evidence for an anti-correlation between the gas phase
metallicity (Z) and the \Delta(sSFR), suggesting a 0.2dex variation in the
metal content of galaxies within the MS and significantly lower metallicities
for galaxies above it. The origin of the observed trends between \SigmaSFR -
\Sigma(sSFR) and Z - \Delta(sSFR) could be driven by an interplay between
variations of the gas fraction or the star formation efficiency of the galaxies
along and off the MS. To address this, follow-up observations of the our sample
that will allow gas mass estimates are necessary.
Description
[1601.04713] KROSS: Mapping the Ha emission across the star-formation sequence at z~1
%0 Generic
%1 magdis2016kross
%A Magdis, Georgios E.
%A Bureau, M.
%A Stott, J. P.
%A Tiley, A.
%A Swinbank, A. M.
%A Bower, R.
%A Bunker, A. J.
%A Jarvis, M.
%A Johnson, H.
%A Sharples, R.
%D 2016
%K Ha emission evolution formation star
%T KROSS: Mapping the Ha emission across the star-formation sequence at z~1
%U http://arxiv.org/abs/1601.04713
%X We present first results from the KMOS Redshift One Spectroscopic Survey
(KROSS), an ongoing large kinematical survey of a thousand, z~1 star forming
galaxies, with VLT KMOS. Out of the targeted galaxies (~500 so far), we detect
and spatially resolve Ha emission in ~90% and 77% of the sample respectively.
Based on the integrated Ha flux measurements and the spatially resolved maps we
derive a median star formation rate (SFR) of ~7.0 Msun/yr and a median physical
size of <r$_e$> = 5.1kpc. We combine the inferred SFRs and effective
radii measurements to derive the star formation surface densities (\SigmaSFR)
and present a "resolved" version of the star formation main sequence (MS) that
appears to hold at sub-galactic scales, with similar slope and scatter as the
one inferred from galaxy integrated properties. Our data also yield a trend
between \SigmaSFR and \Delta(sSFR) (distance from the MS) suggesting that
galaxies with higher sSFR are characterised by denser star formation activity.
Similarly, we find evidence for an anti-correlation between the gas phase
metallicity (Z) and the \Delta(sSFR), suggesting a 0.2dex variation in the
metal content of galaxies within the MS and significantly lower metallicities
for galaxies above it. The origin of the observed trends between \SigmaSFR -
\Sigma(sSFR) and Z - \Delta(sSFR) could be driven by an interplay between
variations of the gas fraction or the star formation efficiency of the galaxies
along and off the MS. To address this, follow-up observations of the our sample
that will allow gas mass estimates are necessary.
@misc{magdis2016kross,
abstract = {We present first results from the KMOS Redshift One Spectroscopic Survey
(KROSS), an ongoing large kinematical survey of a thousand, z~1 star forming
galaxies, with VLT KMOS. Out of the targeted galaxies (~500 so far), we detect
and spatially resolve Ha emission in ~90% and 77% of the sample respectively.
Based on the integrated Ha flux measurements and the spatially resolved maps we
derive a median star formation rate (SFR) of ~7.0 Msun/yr and a median physical
size of <r$_{\rm e}$> = 5.1kpc. We combine the inferred SFRs and effective
radii measurements to derive the star formation surface densities ({\Sigma}SFR)
and present a "resolved" version of the star formation main sequence (MS) that
appears to hold at sub-galactic scales, with similar slope and scatter as the
one inferred from galaxy integrated properties. Our data also yield a trend
between {\Sigma}SFR and {\Delta}(sSFR) (distance from the MS) suggesting that
galaxies with higher sSFR are characterised by denser star formation activity.
Similarly, we find evidence for an anti-correlation between the gas phase
metallicity (Z) and the {\Delta}(sSFR), suggesting a 0.2dex variation in the
metal content of galaxies within the MS and significantly lower metallicities
for galaxies above it. The origin of the observed trends between {\Sigma}SFR -
{\Sigma}(sSFR) and Z - {\Delta}(sSFR) could be driven by an interplay between
variations of the gas fraction or the star formation efficiency of the galaxies
along and off the MS. To address this, follow-up observations of the our sample
that will allow gas mass estimates are necessary.},
added-at = {2016-01-20T10:10:26.000+0100},
author = {Magdis, Georgios E. and Bureau, M. and Stott, J. P. and Tiley, A. and Swinbank, A. M. and Bower, R. and Bunker, A. J. and Jarvis, M. and Johnson, H. and Sharples, R.},
biburl = {https://www.bibsonomy.org/bibtex/2cf97cca6cf2538763d9bfb5a39286332/miki},
description = {[1601.04713] KROSS: Mapping the Ha emission across the star-formation sequence at z~1},
interhash = {d3c444d9bd9510eb5627edc104780d2e},
intrahash = {cf97cca6cf2538763d9bfb5a39286332},
keywords = {Ha emission evolution formation star},
note = {cite arxiv:1601.04713Comment: Accepted for publication in MNRAS, ref. MN-15-2214-MJ.R2 14/12/15)},
timestamp = {2016-01-20T10:10:26.000+0100},
title = {KROSS: Mapping the Ha emission across the star-formation sequence at z~1},
url = {http://arxiv.org/abs/1601.04713},
year = 2016
}