J/A+A/644/A176 Sample of 141 SNe Ia (Rigault+, 2020)
Strong dependence of Type Ia supernova standardization on the local specific
star formation rate.
Rigault M., Brinnel V., Aldering G., Antilogus P., Aragon C., Bailey S.,
Baltay C., Barbary K., Bongard S., Boone K., Buton C., Childress M.,
Chotard N., Copin Y., Dixon S., Fagrelius P., Feindt U., Fouchez D.,
Gangler E., Hayden B., Hillebrandt W., Howell D.A., Kim A., Kowalski M.,
Kuesters D., Leget P.-F., Lombardo S., Lin Q., Nordin J., Pain R.,
Pecontal E., Pereira R., Perlmutter S., Rabinowitz D., Runge K., Rubin D.,
Saunders C., Smadja G., Sofiatti C., Suzuki N., Taubenberger S., Tao C.,
Thomas R.C.
<Astron. Astrophys. 644, A176 (2020)>
=2020A&A...644A.176R 2020A&A...644A.176R (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Photometry ; Optical
Keywords: cosmology: observations - cosmological parameters - dark energy
Abstract:
As part of an on-going effort to identify, understand and correct for
astrophysics biases in the standardization of Type Ia supernovae (SN
Ia) for cosmology, we have statistically classified a large sample of
nearby SNe Ia into those that are located in predominantly younger or
older environments. This classification is based on the specific star
formation rate measured within a projected distance of 1kpc from each
SN location (LsSFR). This is an important refinement compared to using
the local star formation rate directly, as it provides a normalization
for relative numbers of available SN progenitors and is more robust
against extinction by dust. We find that the SNe Ia in predominantly
younger environments are {DELTA}Y=0.163±0.029mag (5.7σ)
fainter than those in predominantly older environments after
conventional light-curve standardization. This is the strongest
standardized SN Ia brightness systematic connected to the host-galaxy
environment measured to date. The well-established step in
standardized brightnesses between SNe Ia in hosts with lower or higher
total stellar masses is smaller, at {DELTA}M=0.119±0.032mag
(4.5σ), for the same set of SNe Ia. When fit simultaneously, the
environment-age offset remains very significant, with
{DELTA}Y=0.129±0.032mag (4.0σ), while the global stellar mass
step is reduced to {DELTA}M=0.064±0.029mag (2.2σ). Thus,
approximately 70% of the variance from the stellar mass step is due to
an underlying dependence on environment-based progenitor age. Also, we
verify that using the local star formation rate alone is not as
powerful as LsSFR at sorting SNe Ia into brighter and fainter subsets.
Standardization that only uses the SNe Ia in younger environments
reduces the total dispersion from 0.142±0.008mag to
0.120±0.010mag. We show that as environment-ages evolve with
redshift, a strong bias, especially on the measurement of the
derivative of the dark energy equation of state, can develop.
Fortunately, data that measure and correct for this effect using our
local specific star formation rate indicator, are likely to be
available for many next-generation SN Ia cosmology experiments.
Description:
Using a large sample of SNe Ia from the Nearby Supernova Factory we
have developed and quantified the importance of an improved local host
environment indicator - the local specific star formation rate,
LsSFR. Our sample of 141 SNe Ia is almost twice that available in
Rigault et al. (2013A&A...560A..66R 2013A&A...560A..66R). We derived the local star
formation rate from spatially-resolved Hα emission using the
methods initially developed in Rigault et al. (2013A&A...560A..66R 2013A&A...560A..66R),
and the local and global stellar masses using SDSS and SNIFS g- and
i-band imaging.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 120 141 Magnitudes for the SNe Ia used in this analysis
table2.dat 129 141 Data for the SNe Ia used in this analysis
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name SN Name
18- 26 F9.4 deg RAdeg SN Right ascension (J2000)
28- 35 F8.4 deg DEdeg SN Declination (J2000)
37- 45 F9.4 deg RAHdeg Host galaxy Right ascension (J2000)
47- 54 F8.4 deg DEHdeg Host galaxy Declination (J2000)
56- 60 F5.2 mag gmag Local g magnitude
62- 65 F4.2 mag E_gmag Error on Local g magnitude (upper value)
67- 70 F4.2 mag e_gmag Error on Local g magnitude (lower value)
72- 76 F5.2 mag imag Local i magnitude
78- 81 F4.2 mag E_imag Error on Local i magnitude (upper value)
83- 86 F4.2 mag e_imag Error on Local i magnitude (lower value)
88- 92 F5.2 mag gmagG Global g magnitude
94- 97 F4.2 mag E_gmagG Error on Global g magnitude (upper value)
99-102 F4.2 mag e_gmagG Error on Global g magnitude (lower value)
104-108 F5.2 mag imagG Global i magnitude
110-113 F4.2 mag E_imagG Error on Global i magnitude (upper value)
115-118 F4.2 mag e_imagG Error on Global i magnitude (lower value)
120 A1 --- Note [a] Note (1)
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Note (1): a indicates cases where SNIFS host galaxy imaging is used.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name SN Name
18- 22 F5.2 mag DBmagcorr Corrected decline rate,
{DELTA}mBcorr (1)
24- 27 F4.2 mag e_DBmagcorr rms uncertainty on DBmagcorr
29- 34 F6.4 --- zCMB Heliocentric redshift (2)
35 A1 --- n_zCMB [*] * for zCMB derived from our local
Hα measurements (2)
37- 41 F5.2 --- c SALT2 colour
43- 46 F4.2 --- e_c rms uncertainty on c
48- 52 F5.2 --- x1 SALT2 light-curve width
54- 57 F4.2 --- e_x1 rms uncertainty on x1
59- 62 F4.2 [Msun] logML Local mass
64- 67 F4.2 [Msun] E_logML Error on Local mass (upper value)
69- 72 F4.2 [Msun] e_logML Error on Local mass (lower value)
74- 78 F5.2 [Msun/yr/kpc+2] logSFR Local SFR
80- 83 F4.2 [Msun/yr/kpc+2] E_logSFR Error on Local SFR (upper value)
85- 88 F4.2 [Msun/yr/kpc+2] e_logSFR Error on Local SFR (lower value)
90- 94 F5.1 [1/yr/kpc+2] logsSFR Local sSFR
96- 98 F3.1 [1/yr/kpc+2] E_logsSFR Error on Local sSFR (upper value)
100-102 F3.1 [1/yr/kpc+2] e_logsSFR Error on Local sSFR (lower value)
104-108 F5.2 [Msun] logMG Global mass
110-113 F4.2 [Msun] E_logMG Error on Global mass (upper value)
115-118 F4.2 [Msun] e_logMG Error on Global mass (lower value)
120-122 I3 % PY [0/100] Probability for statistical
classification for a SN Ia to be
young
124-126 I3 % PM [0/100] Probability for the global
stellar mass of the SN host galaxy
to be higher than
log(M*/M☉)=10.
128-129 I2 --- Refs ? References (3)
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Note (1): ΔmBcorr includes a 0.094mag residual dispersion.
Note (2): Heliocentric redshifts are taken from childress2013b,
except for LSQ12ekl, LSQ13vy, PTF10wnm PTF10xyt, PTF10zdk, and PTF11mty, for
which heliocentric redshifts were derived from our local Hα
measurements (* in n_zCMB).
Note (3): References for external discoveries as follows:
1 = Drake et al., 2009ApJ...696..870D 2009ApJ...696..870D, Cat. J/ApJ/696/870
2 = Maguire et al., 2012MNRAS.426.2359M 2012MNRAS.426.2359M
3 = Barone-Nugent et al., 2012MNRAS.425.1007B 2012MNRAS.425.1007B
4 = Maguire et al., 2013MNRAS.436..222M 2013MNRAS.436..222M
5 = Weyant et al., 2014ApJ...784..105W 2014ApJ...784..105W
6 = Maguire et al., 2014MNRAS.444.3258M 2014MNRAS.444.3258M, Cat. J/MNRAS/444/3258
7 = Boles; Armstrong
8 = del Olmo, Martinez, Pedraz, Alises; Trondal, Schwartz
9 = Sako et al., 2008AJ....135..348S 2008AJ....135..348S, Cat. J/AJ/135/348
10 = Quimby et al
11 = kelly et al., 2010ApJ...715..743K 2010ApJ...715..743K
12 = LOSS
13 = Blondin et al., 2012AJ....143..126B 2012AJ....143..126B, Cat. J/AJ/143/126
14 = Ciabattari, Donati, Mazzoni
15 = Arbour
16 = Ciabattari et al.
17 = Zhang et al., 2015RAA....15..215Z 2015RAA....15..215Z
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Acknowledgements:
Mickael Rigault, m.rigault(at)ipnl.in2p3.fr
(End) Patricia Vannier [CDS] 30-Sep-2020