Bright Lyman~$rm alpha$ emitters among {it Spitzer} SMUVS galaxies in the MUSE/COSMOS field. (arXiv:1910.04771v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Rosani_G/0/1/0/all/0/1">G. Rosani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Caminha_G/0/1/0/all/0/1">G. B. Caminha</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Caputi_K/0/1/0/all/0/1">K. I. Caputi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Deshmukh_S/0/1/0/all/0/1">S. Deshmukh</a>
We search for bright Ly$alpha$ emitters among Spitzer SMUVS galaxies at
$z>2.9$ with homogeneous MUSE data. Although it only covers a small region of
COSMOS, MUSE has the unique advantage of providing spectral information over
the entire field, without the need of target pre-selection. This gives an
unbiased detection of all the brightest Ly$alpha$ emitters among SMUVS
sources, which by design are stellar-mass selected galaxies. Within the studied
area, $sim 14$% of the SMUVS galaxies at $z>2.9$ have Ly$alpha$ fluxes
$F_lambdagtrsim 7times 10^{-18}, erg, s^{-1}, cm^{-2}$. These Ly$alpha$
emitters are characterized by three types of emission, 47% show a single line
profile, 19% present a double peak or a blue bump and 31% show a red tail.
One object (3%) shows both a blue bump and a red tail. We also investigate the
spectral energy distribution (SED) properties of the SMUVS MUSE-detected
galaxies and MUSE non-detections. After stellar-mass matching both populations,
we find that MUSE detected galaxies have generally lower extinction than
SMUVS-only objects, while there is no clear intrinsic difference in the mass
and age distributions. For the MUSE-detected SMUVS galaxies, we compare the
instantaneous SFR lower limit given by Ly$alpha$ flux with its past average
derived from SED fitting, and find evidence for rejuvenation in some of our
oldest objects. We also study the spectra of those Ly$rm alpha$ emitters
which are not detected in SMUVS in the same field. We find different
distributions of the emission line profiles, which could be ascribed to the
fainter Ly$alpha$ luminosities of the MUSE-only sources and an intrinsically
different mass distribution. Finally, we search for the presence of galaxy
associations. MUSE’s integral coverage is 20 times more likely to find
associations than all other existing spectral data in COSMOS, biased by target
pre-selection.
We search for bright Ly$alpha$ emitters among Spitzer SMUVS galaxies at
$z>2.9$ with homogeneous MUSE data. Although it only covers a small region of
COSMOS, MUSE has the unique advantage of providing spectral information over
the entire field, without the need of target pre-selection. This gives an
unbiased detection of all the brightest Ly$alpha$ emitters among SMUVS
sources, which by design are stellar-mass selected galaxies. Within the studied
area, $sim 14$% of the SMUVS galaxies at $z>2.9$ have Ly$alpha$ fluxes
$F_lambdagtrsim 7times 10^{-18}, erg, s^{-1}, cm^{-2}$. These Ly$alpha$
emitters are characterized by three types of emission, 47% show a single line
profile, 19% present a double peak or a blue bump and 31% show a red tail.
One object (3%) shows both a blue bump and a red tail. We also investigate the
spectral energy distribution (SED) properties of the SMUVS MUSE-detected
galaxies and MUSE non-detections. After stellar-mass matching both populations,
we find that MUSE detected galaxies have generally lower extinction than
SMUVS-only objects, while there is no clear intrinsic difference in the mass
and age distributions. For the MUSE-detected SMUVS galaxies, we compare the
instantaneous SFR lower limit given by Ly$alpha$ flux with its past average
derived from SED fitting, and find evidence for rejuvenation in some of our
oldest objects. We also study the spectra of those Ly$rm alpha$ emitters
which are not detected in SMUVS in the same field. We find different
distributions of the emission line profiles, which could be ascribed to the
fainter Ly$alpha$ luminosities of the MUSE-only sources and an intrinsically
different mass distribution. Finally, we search for the presence of galaxy
associations. MUSE’s integral coverage is 20 times more likely to find
associations than all other existing spectral data in COSMOS, biased by target
pre-selection.
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