J/MNRAS/494/4426 Effect of host galaxies on SN luminosity (Smith+, 2020)
First cosmology results using type Ia supernovae from the Dark Energy Survey:
the effect of host galaxy properties on supernova luminosity.
Smith M., Sullivan M., Wiseman P., Kessler R., Scolnic D., Brout D.,
D'Andrea C.B., Davis T.M., Foley R.J., Frohmaier C., Galbany L.,
Gupta R.R., Gutierrez C.P., Hinton S.R., Kelsey L., Lidman C., Macaulay E.,
Moller A., Nichol R.C., Nugent P., Palmese A., Pursiainen M., Sako M.,
Swann E., Thomas R.C., Tucker B.E., Vincenzi M., Carollo D., Lewis G.F.,
Sommer N.E., Abbott T.M.C., Aguena M., Allam S., Avila S., Bertin E.,
Bhargava S., Brooks D., Buckley-Geer E., Burke D.L., Carnero Rosell A.,
Carrasco Kind M., Costanzi M., da Costa L.N., De Vicente J., Desai S.,
Diehl H.T., Doel P., Eifler T.F., Everett S., Flaugher B., Fosalba P.,
Frieman J., Garcia-Bellido J., Gaztanaga E., Glazebrook K., Gruen D.,
Gruendl R.A., Gschwend J., Gutierrez G., Hartley W.G., Hollowood D.L.,
Honscheid K., James D.J., Krause E., Kuehn K., Kuropatkin N., Lima M.,
MacCrann N., Maia M.A.G., Marshall J.L., Martini P., Melchior P.,
Menanteau F., Miquel R., Paz-Chinchon F., Plazas A.A., Romer A.K.,
Roodman A., Rykoff E.S., Sanchez E., Scarpine V., Schubnell M., Serrano S.,
Sevilla-Noarbe I., Suchyta E., Swanson M.E.C., Tarle G., Thomas D.,
Tucker D.L., Varga T.N., Walker A.R., (the DES Collaboration)
<Mon. Not. R. Astron. Soc., 494, 4426-4447 (2020)>
=2020MNRAS.494.4426S 2020MNRAS.494.4426S (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Surveys ; Redshifts ; Galaxies, photometry ; Optical
Keywords: surveys - supernovae: general - distance scale -
cosmology: observations - transients: supernovae
Abstract:
We present improved photometric measurements for the host galaxies of
206 spectroscopically confirmed type Ia supernovae discovered by the
Dark Energy Survey Supernova Program (DES-SN) and used in the first
DES-SN cosmological analysis. For the DES-SN sample, when considering
a 5D (z, x1, c, α, β) bias correction, we find evidence
of a Hubble residual 'mass step', where SNe Ia in high-mass galaxies
(>1010M☉) are intrinsically more luminous (after correction)
than their low-mass counterparts by γ=0.040±0.019mag. This
value is larger by 0.031mag than the value found in the first DES-SN
cosmological analysis. This difference is due to a combination of
updated photometric measurements and improved star formation histories
and is not from host-galaxy misidentification. When using a 1D
(redshift-only) bias correction the inferred mass step is larger, with
γ=0.066±0.020mag. The 1D-5D γ difference for DES-SN is
0.026±0.009mag. We show that this difference is due to a strong
correlation between host galaxy stellar mass and the x1 component of
the 5D distance-bias correction. Including an intrinsic correlation
between the observed properties of SNe Ia, stretch and colour, and
stellar mass in simulated SN Ia samples, we show that a 5D fit
recovers γ with -9mmag bias compared to a +2mmag bias for a 1D
fit. This difference can explain part of the discrepancy seen in the
data. Improvements in modelling correlations between galaxy properties
and SN is necessary to ensure unbiased precision estimates of the dark
energy equation of state as we enter the era of LSST.
Description:
The DES-SN Program was a 5yr rolling search using the 570 Megapixel
Dark Energy Camera (DECam; Flaugher et al. 2015AJ....150..150F 2015AJ....150..150F) on the
4-m Blanco telescope at the Cerro Tololo Inter-American Observatory
(CTIO), giving a 2.7deg2 field of view. DES-SN observed two 'deep'
fields and eight 'shallow' fields in griz filters approximately every
7d, to single-visit depths of ∼24.5 and ∼23.5mag, respectively.
Transient events were detected using a difference-imaging pipeline
(Kessler et al. 2015AJ....150..172K 2015AJ....150..172K), with machine-learning algorithms
used to remove spurious candidates (Goldstein et al.
2015AJ....150...82G 2015AJ....150...82G). During the first 3yr, 251 SNe Ia were
spectroscopically classified. Quality cuts, based on the light-curve
coverage, are applied to the sample (see Brout et al.
2019ApJ...874..150B 2019ApJ...874..150B, Cat. J/ApJ/874/150 for details), which removes 45
SNe Ia. This leaves 206 SNe Ia in the fiducial DES sample.
Photometric data for the host galaxies of the DES3YR cosmology
analysis (Brout et al. 2019ApJ...874..150B 2019ApJ...874..150B, Cat. J/ApJ/874/150) were
determined from the DES SVA1-GOLD catalogue. This catalogue has
10σ limiting magnitudes of (g, r, i, z) = (24.0, 23.8, 23.0,
22.3). It was constructed from DES Science Verification data collected
prior to the DES-SN data used in the DES3YR sample. In this paper, we
upgrade from the DES SVA1-GOLD catalogue and instead determine
photometric properties of the DES SNe Ia host galaxies from DES deep
stack photometry (Wiseman et al. 2020MNRAS.495.4040W 2020MNRAS.495.4040W) utilizing images
from all 5yr of DES-SN.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 97 206 Host galaxy photometric measurements and derived
properties for the DES-SN sample
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See also:
II/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)
J/ApJ/874/150 : The first 3yrs of DES-SN (DES-SN3YR) (Brout+, 2019)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Supernova name (DESNNANaaaa)
13- 19 I7 --- SNID Supernova identifier
21- 26 F6.4 --- z Redshift (1)
28- 32 F5.2 mag gmag ? g-band AB magnitude (2)
34- 37 F4.2 mag e_gmag ? Error on gmag
39- 43 F5.2 mag rmag ? r-band AB magnitude (2)
45- 48 F4.2 mag e_rmag ? Error on rmag
50- 54 F5.2 mag imag ? i-band AB magnitude (2)
56- 59 F4.2 mag e_imag ? Error on imag
61- 65 F5.2 mag zmag ? z-band AB magnitude (2)
67- 70 F4.2 mag e_zmag ? Error on zmag
72- 76 F5.2 [Msun] logMass ? Logarithm of the stellar mass (3)
78- 81 F4.2 [Msun] e_logMass ? Error on logMass (3)
83- 88 F6.2 [Msun/yr] logSFR ? Logarithm of the star formation rate (3)
90- 97 A8 --- Ref Photometric catalogue (4)
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Note (1): Redshift quoted to 4 decimal places when determined from galaxy
emission/absorption features or 2 decimal places when determined from
SN template matches
Note (2): The magnitudes are corrected for MW extinction
Note (3): See Section 2.2.2 of the article for information on the estimation of
the stellar mass and the star-formation rate for each host
Note (4): Reference as follows:
W19 = Wiseman et al. (2020MNRAS.495.4040W 2020MNRAS.495.4040W) (201/206)
hostless = Supernova with no galaxy matching our selection criteria (see
Section 2.2.1 for more details) (5/206)
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 01-Jun-2023