J/MNRAS/495/4040 SN host galaxies in the dark energy survey I (Wiseman+, 2020)
Supernova host galaxies in the dark energy survey: I.
Deep coadds, photometry, and stellar masses.
Wiseman P., Smith M., Childress M., Kelsey L., Moller A., Gupta R.R.,
Swann E., Angus C.R., Brout D., Davis T.M., Foley R.J., Frohmaier C.,
Galbany L., Gutierrez C.P., Inserra C., Kessler R., Lewis G.F., Lidman C.,
Macaulay E., Nichol R.C., Pursiainen M., Sako M., Scolnic D., Sommer N.E.,
Sullivan M., Tucker B.E., Abbott T.M.C., Aguena M., Allam S., Avila S.,
Bertin E., Brooks D., Buckley-Geer E., Burke D.L., Carnero Rosell A.,
Carollo D., Carrasco Kind M., da Costa L.N., De Vicente J., Desai S.,
Diehl H.T., Doel P., Eifler T.F., Everett S., Fosalba P., Frieman J.,
Garcia-Bellido J., Gaztanaga E., Gerdes D.W., Gill M.S.S., Glazebrook K.,
Gruendl R.A., Gschwend J., Hartley W.G., Hinton S.R., Hollowood D.L.,
Honscheid K., James D.J., Kuehn K., Kuropatkin N., Lima M., Maia M.A.G.,
March M., Martini P., Melchior P., Menanteau F., Miquel R., Ogando R.L.C.,
Paz-Chinchon F., Plazas A.A., Romer A.K., Roodman A., Sanchez E.,
Scarpine V., Serrano S., Suchyta E., Swanson M.E.C., Tarle G., Thomas D.,
Tucker D.L., Varga T.N., Walker A.R., Wilkinson R.D.,
(the DES Collaboration)
<Mon. Not. R. Astron. Soc., 495, 4040-4060 (2020)>
=2020MNRAS.495.4040W 2020MNRAS.495.4040W (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Galaxies ; Redshifts ; Photometry, ugriz ;
Stars, masses
Keywords: techniques: image processing - catalogues - supernovae: general
Abstract:
The 5-yr Dark Energy Survey Supernova Programme (DES-SN) is one of the
largest and deepest transient surveys to date in terms of volume and
number of supernovae. Identifying and characterizing the host galaxies
of transients plays a key role in their classification, the study of
their formation mechanisms, and the cosmological analyses. To derive
accurate host galaxy properties, we create depth-optimized coadds
using single-epoch DES-SN images that are selected based on sky and
atmospheric conditions. For each of the five DES-SN seasons, a
separate coadd is made from the other four seasons such that each SN
has a corresponding deep coadd with no contaminating SN emission. The
coadds reach limiting magnitudes of order ∼27 in g band, and have a
much smaller magnitude uncertainty than the previous DES-SN host
templates, particularly for faint objects. We present the resulting
multiband photometry of host galaxies for samples of spectroscopically
confirmed type Ia (SNe Ia), core-collapse (CCSNe), and superluminous
(SLSNe) as well as rapidly evolving transients (RETs) discovered by
DES-SN. We derive host galaxy stellar masses and probabilistically
compare stellar-mass distributions to samples from other surveys. We
find that the DES spectroscopically confirmed sample of SNe Ia selects
preferentially fewer high-mass hosts at high-redshift compared to
other surveys, while at low redshift the distributions are consistent.
DES CCSNe and SLSNe hosts are similar to other samples, while RET
hosts are unlike the hosts of any other transients, although these
differences have not been disentangled from selection effects.
Description:
The DES photometric bands, g, r, i, and z, correspond closely to their
SDSS analogues. Observations were taken in each band roughly every 7d
(although exposures failing quality cuts were repeated at the next
available opportunity) over 5yr, comprising 6-month observing seasons
during consecutive southern summers. Single-visit limiting magnitudes
are m_lim,single epoch_∼23.5 for shallow fields, and 24.5 for deep
fields. Further description of the SN survey and spectroscopic
targeting can be found in Kessler et al. (2015AJ....150..172K 2015AJ....150..172K) and
D'Andrea et al. (2019AAS...23322402D 2019AAS...23322402D).
The extensive observations obtained by DES-SN open up the possibility
for the creation of deep images by coadding the individual exposures.
While the deepest coadds are obtained by combining data from all five
seasons, for the purposes of studying SN host galaxies it is important
to remove those exposures that contain light from the SN. We create a
series of four-season coadds, for each one excluding all exposures
from the other season.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 34 200 Overview of the deep coadds
tableb1.dat 75 209 Host galaxy properties for the DES SN Ia sample
tableb2.dat 75 47 Host galaxy properties for the DES CCSN sample
tableb3.dat 77 22 Host galaxy properties for the DES SLSN sample
tableb4.dat 75 49 Host galaxy properties for the DES RET sample
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Field SN field (1)
7 A1 --- Band DES photometric band
9 I1 --- MY Minus-year cooad (2)
11- 14 F4.2 --- taucut Cut on the effective exposure time ratio (3)
16- 18 F3.1 --- PSFcut Cut on the PSF
20- 22 I3 --- Nexp Number of single exposures in the coadd
24- 28 F5.2 h texp Total exposure time
30- 34 F5.2 mag mlim Limiting magnitude determined from the sky
background
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Note (1): DES-SN consisted of a survey of 10 separate pointings, grouped into
four regions on the sky. Each of these fields was chosen to coincide
with a deep extragalactic legacy field: three overlapping with XMM-LSS
(the 'SN-X' fields; Pierre et al. 2004JCAP...09..011P 2004JCAP...09..011P); three with
the Chandra Deep Field - South (the 'SN-C' fields; Xue et al.
2011ApJS..195...10X 2011ApJS..195...10X, Cat. J/ApJS/195/10); two overlapping with the
Sloan Digital Sky Survey (SDSS) Stripe 82 (the 'SN-S' fields;
Adelman-McCarthy et al. 2007ApJS..172..634A 2007ApJS..172..634A, Cat. II/276;
Abazajian et al. 2009ApJS..182..543A 2009ApJS..182..543A, Cat. II/294); and two
overlapping with the Elais-S1 field (the 'SN-E' fields; Oliver et al.
2000MNRAS.316..749O 2000MNRAS.316..749O).
Note (2): We create a series of four-season coadds, for each one excluding all
exposures from the other season. We refer to such image stacks as
minus-year (MY) coadds: the coadd missing season one is referred to
as MY1, and so on.
Note (3): This is the ratio between the effective exposure time, given the
conditions, teff, and the true exposure time texp:
τ=η2(FWHM/0.9arcsec)-2(b/bdark)-1, where η is the
atmospheric transmission, b is the sky brightness, and FWHM
corresponds to the full width at half-maximum of the point spread
function (PSF) on a particular night.
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Byte-by-byte Description of file: tableb[124].dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Supernova name
13- 18 F6.4 --- z Redshift
20- 24 F5.2 mag gmag DES g-band magnitude (G1)
26- 29 F4.2 mag e_gmag Error on gmag (G1)
31- 35 F5.2 mag rmag DES r-band magnitude (G1)
37- 40 F4.2 mag e_rmag Error on rmag (G1)
42- 46 F5.2 mag imag DES i-band magnitude (G1)
48- 52 F5.2 mag e_imag ?=-1 Error on imag (G1)
54- 58 F5.2 mag zmag DES z-band magnitude (G1)
60- 64 F5.2 mag e_zmag ?=-1 Error on zmag (G1)
66- 70 F5.2 [Msun] logM Logarithm of the stellar mass
72- 75 F4.2 [Msun] e_logM Error on logM
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Byte-by-byte Description of file: tableb3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Supernova name
12- 16 F5.3 --- z Redshift
18- 22 F5.2 mag gmag DES g-band magnitude (G1)
24- 28 F5.2 mag e_gmag ?=-1 Error on gmag (G1)
30- 34 F5.2 mag rmag DES r-band magnitude (G1)
36- 40 F5.2 mag e_rmag ?=-1 Error on rmag (G1)
42- 46 F5.2 mag imag DES i-band magnitude (G1)
48- 52 F5.2 mag e_imag ?=-1 Error on imag (G1)
54- 58 F5.2 mag zmag DES z-band magnitude (G1)
60- 64 F5.2 mag e_zmag ?=-1 Error on zmag (G1)
66- 69 F4.2 [Msun] logM Logarithm of the stellar mass
71- 75 F5.2 [Msun] e_logM ?=-1 Error on logM (G1)
77 I1 --- f_Name [0/1] Flag on Name (1)
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Note (1): Flag as follows:
1 = We note that two of the DES SLSNe (DES14X3taz and DES15X1noe) have light
curves with detections in the season subsequent to discovery, meaning the
galaxy photometry could be contaminated by SN light from that season. We
compare the photometry for the host galaxy from the coadd with the main
season removed with one where the season removed is neither of those in
which the SN is bright. We find that the reported host magnitudes are
consistent within measurement uncertainties, and thus do not affect our
results substantially.
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Global Notes:
Note (G1): Magnitudes are given in the observer frame and are not corrected for
host galaxy extinction
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 22-Jun-2023