J/A+A/633/A159 Bright Lyman-alpha emitters in MUSE/COSMOS field (Rosani+, 2020)
Bright Lyman-alpha emitters among Spitzer SMUVS galaxies in the
MUSE/COSMOS field.
Rosani G., Caminha G.B., Caputi K.I., Deshmukh S.
<Astron. Astrophys. 633, A159 (2020)>
=2020A&A...633A.159R 2020A&A...633A.159R (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Redshifts ; Optical
Keywords: galaxies: high-redshift - galaxies: star formation -
cosmology: observations
Abstract:
We search for the presence of bright Ly-alpha emitters among Spitzer
SMUVS galaxies at z>2.9 making use of homogeneous MUSE spectroscopic
data. Although these data only cover 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 results
in an unbiased detection of all the brightest Ly-alpha emitters among
the SMUVS sources, which by design are stellar-mass selected galaxies.
Within the studied area, ∼14% of the SMUVS galaxies at z>2.9 have
Ly-alpha fluxes Fλ≳7x10-18erg/s/cm2. 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 galaxies which are MUSE detected and which are
not. After stellar-mass matching both populations, we find that the
MUSE detected galaxies have generally lower extinction than SMUVS-only
objects, while there is no clear intrinsic difference in the mass and
age distributions of the two samples. For the MUSE-detected SMUVS
galaxies, we compare the instantaneous SFR lower limit obtained from
the Ly-alpha line with its past average derived from SED fitting, and
find evidence for rejuvenation in some of our oldest objects. In
addition, we study the spectra of those Ly-alpha emitters which are
not detected in SMUVS in the same field. We find that the emission
line profile shown are 67% a single line, 3% a blue bump and 20% a red
tail profile. The difference in profile distribution could be ascribed
to the fainter Ly-alpha luminosities of the MUSE sources not detected
in SMUVS and an intrinsically different mass distribution. Finally, we
search for the presence of galaxy associations using the spectral
redshifts. MUSE's integral coverage reveals that these associations
are 20 times more likely than what is derived from all the other
existing spectral data in COSMOS, which is biased by target
pre-selection.
Description:
In this work we analyze archival data from MUSE (Bacon et al. 2010, in
Proc. SPIE, Vol. 7735, Groundbased and Airborne Instrumentation for
Astronomy III, 773508) in the COSMOS field (Scoville et al.,
2007ApJS..172....1S 2007ApJS..172....1S), over an area of 20.79 arcmin2 embedded in the
SMUVS footprint (Ashby et al., 2018, Cat. J/ApJS/237/39).
We managed to detect and measure the redshift of 691 objects,
of which 39 are located at z≥2R, in SMUVS/MUSE sample.
We also present 108 blind search detected high-redshift (z≥2.9)
Ly-alpha emitting sources in the COSMOS/MUSE GTO field.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 38 792 Full MUSE redshift catalogue
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See also:
J/ApJS/237/39 : Spitzer survey of UltraVISTA deep Stripes (SMUVS)
(Ashby+, 2018)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- ID SMUVS/MUSE ID (NNNNN) or MUSE/NS ID (NSNNN)
of the source
7- 17 F11.7 deg RAdeg Observed right ascension (J2000)
19- 29 F11.9 deg DEdeg Observed declination (J2000)
31- 36 F6.4 --- z spectroscopic redshift
38 I1 --- q_z [2/9] Redshift quality flag (1)
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Note (1): Redshift quality flag as follows:
2 = likely
3 = secure measurement
4 = very high-quality spectrum
9 = single line measurement
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History:
From Giulio Rosani, g.rosani(at)rug.nl
Acknowledgements:
when using these redshifts, please acknowledge the papers Rosani et
al. 2019 (arXiv:1910.04771), and the VLT programme IDs 095.A-0240,
096.A-0090, 097.A-0160, 098.A-0017
(End) Patricia Vannier [CDS] 11-Dec-2019