J/MNRAS/476/4725 SC4K catalogue of candidate LAEs (Sobral+, 2018)
Slicing COSMOS with SC4K: the evolution of typical Lyα emitters and the
Lyα escape fraction from z ∼ 2 to 6.
Sobral D., Santos S., Matthee J., Paulino-Afonso A., Ribeiro B., Calhau J.,
Khostovan A.A.
<Mon. Not. R. Astron. Soc., 476, 4725-4752 (2018)>
=2018MNRAS.476.4725S 2018MNRAS.476.4725S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Ultraviolet ; Redshifts ; Photometry ;
Equivalent widths
Keywords: galaxies: evolution - galaxies: formation - galaxies: high-redshift -
galaxies: luminosity function, mass function - galaxies: statistics
Abstract:
We present and explore deep narrow- and medium-band data obtained with
the Subaru and the Isaac Newton Telescopes in the ∼2deg2 COSMOS
field. We use these data as an extremely wide, low-resolution
(R∼20-80) Integral Field Unit survey to slice through the COSMOS field
and obtain a large sample of ∼4000 Lyα emitters (LAEs) from z∼2
to 6 in 16 redshift slices (SC4K). We present new Ly α
luminosity functions (LFs) covering a comoving volume of ∼108Mpc3.
SC4K extensively complements ultradeep surveys, jointly covering over
4dex in Lyα luminosity and revealing a global (2.5<z<6) synergy
LF with α=-1.93+0.12-0.12,
log10Φ*Lyα=-3.45+0.22-0.29Mpc-3, and
log10L*Lyα=42.93+0.15-0.11erg/s. The Schechter
component of the Lyα LF reveals a factor ∼5 rise in
L*Lyα and a ∼7 x decline in Φ*Lyα from z∼2 to
6. The data reveal an extra power-law (or Schechter) component above
LLyα~=1043.3erg/s at z∼2.2-3.5 and we show that it is
partially driven by X-ray and radio active galactic nucleus (AGN), as
their Lyα LF resembles the excess. The power-law component
vanishes and/or is below our detection limits above z>3.5, likely
linked with the evolution of the AGN population. The Ly α
luminosity density rises by a factor ∼2 from z∼2 to 3 but is then
found to be roughly constant (1.1+0.2-0.2x1040erg/s/Mpc3) to
z∼6, despite the ∼0.7 dex drop in ultraviolet (UV) luminosity density.
The Lyα/UV luminosity density ratio rises from 4±1 per cent to
30±6 per cent from z∼2.2 to 6. Our results imply a rise of a factor
of ~=2 in the global ionization efficiency (ξion) and a factor
~=4±1 in the Lyα escape fraction from z∼2 to 6, hinting for
evolution in both the typical burstiness/stellar populations and even
more so in the typical interstellar medium conditions allowing
Lyα photons to escape.
Description:
The COSMOS field (Scoville et al., 2007ApJS..172....1S 2007ApJS..172....1S; Capak et al.,
2007ApJS..172...99C 2007ApJS..172...99C, Cat. II/284) is one of the most widely studied
regions of extragalactic sky, with a plethora of publicly available
multiwavelength coverage. Data in COSMOS include X-ray, UV, optical,
NIR, far-IR, and radio (see e.g. Ilbert et al., 2009, Cat.
J/ApJ/690/1236; Civano et al., 2016, Cat. J/ApJ/819/62; Laigle et al.,
2016, Cat. J/ApJS/224/24; Smolcic et al., 2017A&A...602A...6S 2017A&A...602A...6S). We
explore a range of NB and MB data (Capak et al., 2007ApJS..172...99C 2007ApJS..172...99C,
Cat. II/284; Taniguchi et al., 2007ApJS..172....9T 2007ApJS..172....9T,
2015PASJ...67..104T 2015PASJ...67..104T; Santos et al., 2016MNRAS.463.1678S 2016MNRAS.463.1678S; Sobral et
al., 2017, Cat. J/MNRAS/466/1242; Matthee et al., 2017, Cat.
J/MNRAS/471/629) over roughly the full COSMOS field in order to (1)
create detection catalogues for each band, (2) identify sources with
strong excess emission in those bands relative to their broad-band
(BB) counterparts, and (3) obtain dual-mode photometry on all other
bands available in order to further constrain the (photometric)
redshift of each source.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 178 3908 Our full SC4K catalogue of candidate LAEs
which we release with this paper
tablec1.dat 167 158 The global Lyα luminosity function and
for each of the medium0band filters
in SC4K/this study
tablec2.dat 95 171 A compilation of Lyα luminosity functions
used or compared with in this study
--------------------------------------------------------------------------------
See also:
II/284 : COSMOS Multi-Wavelength Photometry Catalog (Capak+, 2007)
J/ApJ/690/1236 : COSMOS photometric redshift catalog (Ilbert+, 2009)
J/ApJ/819/62 : The COSMOS-Legacy Survey (CLS) catalog (Civano+, 2016)
J/ApJS/224/24 : The COSMOS2015 catalog (Laigle+, 2016)
J/MNRAS/471/629 : Bootes-HiZELS. Em-line galaxies at z=0.4-4.7 (Matthee+, 2017)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- SC4K SC4K designation, SC4K-AAAAA-NNNNN (ID_SC4K)
20- 28 F9.5 deg RAdeg Right ascension (J2000) (RA)
30- 36 F7.5 deg DEdeg Declination (J2000) (DEC)
38- 42 A5 --- Band Observed band (1)
44- 50 F7.4 mag MBmag Medium-band or narrow-band magnitude (AB)
(MB_mag)
52- 57 F6.4 mag e_MBmag Medium-band or narrow-band magnitude error
(MBmagerr)
59- 65 F7.4 mag BBmag Broad-band magnitude (AB) (BB_mag)
67- 73 F7.4 mag e_BBmag Broad-band magnitude error (BBmagerr)
75- 86 E12.6 mW/m2 Flux Flux (Flux)
88- 99 E12.6 mW/m2 E_Flux Error on Flux (upper value) (Fluxerrup)
101-112 E12.6 mW/m2 e_Flux Error on Flux (lower value) (Fluxerrdown)
114-125 F12.5 0.1nm EW0 Equivalent width (EW_0)
127-137 F11.5 0.1nm E_EW0 Error on EW0 (upper value) (EW0err_up)
139-149 F11.5 0.1nm e_EW0 Error on EW0 (lower value) (EW0err_down)
151-157 F7.4 10-7W LyaLum Lymanα luminosity (Lya_Lum)
159-164 F6.4 10-7W E_LyaLum Error on LyaLum (upper value)
(Lyalumerr_up)
166-172 F7.4 10-7W e_LyaLum Error on LyaLum (lower value)
(Lyalumerr_down)
174 I1 --- Cosmos [0/1] C-COSMOS legagy coverage?
(CCOSMOSLEGACY_COVERAGE)
176 I1 --- XrayDet [0/1] X-ray detected? (XRAY_DET)
178 I1 --- RadioDet [0/1] Radio detected? (RADIO_DETECTED)
--------------------------------------------------------------------------------
Note (1): Bands as follows:
IA427 = 4263.5±207.3Å
IA464 = 4635.1±218.1Å
IA484 = 4849.2±229.1Å
IA505 = 5062.1±231.5Å
IA527 = 5261.1±242.7Å
IA574 = 5764.8±272.8Å
IA624 = 6232.9±299.9Å
IA679 = 6781.1±335.9Å
IA709 = 7073.6±316.3Å
IA738 = 7361.5±323.8Å
IA767 = 7684.9±365.0Å
IA827 = 8244.5±342.8Å
NB392 = 3920±52Å
NB501 = 5010±100Å
NB711 = 7120.04Å
NB816 = 8149.62Å
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablec1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Sample Sample (Sample)
18- 22 F5.2 [10-7W] logLumbin Lymanα luminosity (logLumbin)
24- 27 F4.2 [10-7W] e_logLumbin Lymanα luminosity error (delta_bin)
29- 31 I3 ct Counts Observed number of source (Counts)
33- 40 F8.5 ct e_Counts rms uncertainty on Counts (Counts_err)
42- 49 F8.5 Mpc-3 Phiobs Observed number density (Phi_obs)
51- 59 F9.7 Mpc-3 E_Phiobs Error on Phiobs (upper value)
(Phiobserr_up)
61- 69 F9.7 Mpc-3 e_Phiobs Error on Phiobs (lower value)
(Phiobserr_down)
71- 79 F9.7 Mpc-3 E_Phiobspert Observed+perturbed number density
(Phiobsperterrup)
81- 89 F9.7 Mpc-3 e_Phiobspert Error+perturbed on Phiobspert (upper value)
(Phiobsperterrdown)
91- 98 F8.5 Mpc-3 Phiobscomp Completeness corrected number density
(Phiobscomp)
100-108 F9.7 Mpc-3 E_Phiobscomp Error on Phiobscomp (upper value)
(Phiobscomperrup)
110-118 F9.7 Mpc-3 e_Phiobscomp Error on Phiobscomp (lower value)
(Phiobscomperrdown)
120-127 F8.5 Mpc-3 Phifinal Final number density(Phi_final)
129-137 F9.7 Mpc-3 E_Phi Error on Phi (upper value) (Phierrup)
139-147 F9.7 Mpc-3 e_Phi Error on Phi (lower value) (Phierrdown)
149-157 F9.7 Mpc-3 E_Phifinal Error on Phifinal (upper value)
(Phifinalerr_up)
159-167 F9.7 Mpc-3 e_Phifinal Error on Phifinal (lower value)
(Phifinalerr_down)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablec2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 F4.1 --- StudyN Study number (STUDY_N)
6- 27 A22 --- Ref References to the original paper
(Reference) (1)
29- 47 A19 --- Comm Comments paper (Comments_PAPER)
49- 52 F4.2 --- zmin Minimum redshift (z_min)
54- 57 F4.2 --- zmax Maximum redshift (z_max)
59- 64 F6.3 [10-7W] logL Lymanα luminosity (LogL)
66- 70 F5.3 [10-7W] e_logL Lymanα luminosity error (D_LogL)
72- 79 F8.5 [Mpc-3] logPhi Number density (LogPhi)
81- 87 F7.5 [Mpc-3] E_logPhi Error on logPhi (upper value) (DLogPhiup)
89- 95 F7.5 [Mpc-3] e_logPhi Error on logPhi (lower value) (DLogPhidown)
--------------------------------------------------------------------------------
Note (1): References as follows:
Bina+2016 = Bina et al. (2016A&A...590A..14B 2016A&A...590A..14B)
Cassata+2011 = Cassata et al. (2011A&A...525A.143C 2011A&A...525A.143C)
Dawson+2007 = Dawson et al. (2007ApJ...671.1227D 2007ApJ...671.1227D, Cat. J/ApJ/671/1227)
Drake+2017a = Drake et al. (2017MNRAS.471..267D 2017MNRAS.471..267D, Cat. J/MNRAS/471/267)
Drake+2017b = Drake et al. (2017A&A...608A...6D 2017A&A...608A...6D)
Konno+2016 = Konno et al. (2016ApJ...823...20K 2016ApJ...823...20K)
Konno+2017 = Konno et al. (2018PASJ...70S..16K 2018PASJ...70S..16K)
Matthee+2017 = Matthee et al. (2014MNRAS.440.2375M 2014MNRAS.440.2375M)
Ouchi+2008 = Ouchi et al. (2008ApJS..176..301O 2008ApJS..176..301O, Cat. J/ApJS/176/301)
Perez+inprep = Perez et al. (in prep.)
Santos+2016 = Santos et al. (2016MNRAS.463.1678S 2016MNRAS.463.1678S)
Sobral+2017 = Sobral et al. 2017 (J/MNRAS/466/1242)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 27-Apr-2021