J/ApJ/902/48 ZTF early observations of type Ia supernovae. III. (Bulla+, 2020)
ZTF early observations of type Ia supernovae.
III. Early-time colors as a test for explosion models and multiple populations.
Bulla M., Miller A.A., Yao Y., Dessart L., Dhawan S., Papadogiannakis S.,
Biswas R., Goobar A., Kulkarni S.R., Nordin J., Nugent P., Polin A.,
Sollerman J., Bellm E.C., Coughlin M.W., Dekany R., Golkhou V.Z.,
Graham M.J., Kasliwal M.M., Kupfer T., Laher R.R., Masci F.J., Porter M.,
Rusholme B., Shupe D.L.
<Astrophys. J., 902, 48 (2020)>
=2020ApJ...902...48B 2020ApJ...902...48B
ADC_Keywords: Supernovae; Surveys; Models
Keywords: Surveys ; Supernovae ; Type Ia supernovae
Abstract:
Colors of Type Ia supernovae (SNe Ia) in the first few days after
explosion provide a potential discriminant between different models.
In this paper, we present g-r colors of 65 SNe Ia discovered within 5d
from first light by the Zwicky Transient Facility in 2018, a sample
that is about three times larger than that in the literature. We find
that g-r colors are intrinsically rather homogeneous at early phases,
with about half of the dispersion attributable to photometric
uncertainties (σnoise~σint∼0.18mag). Colors are nearly
constant starting from 6 days after first light (g-r~-0.15mag), while
the time evolution at earlier epochs is characterized by a continuous
range of slopes, from events rapidly transitioning from redder to
bluer colors (slope of ~-0.25mag/day) to events with a flatter
evolution. The continuum in the slope distribution is in good
agreement both with models requiring some amount of 56Ni mixed in
the outermost regions of the ejecta and with "double-detonation"
models having thin helium layers (MHe=0.01M☉) and varying
carbon-oxygen core masses. At the same time, six events show evidence
for a distinctive "red bump" signature predicted by double-detonation
models with larger helium masses. We finally identify a significant
correlation between the early-time g-r slopes and supernova
brightness, with brighter events associated to flatter color evolution
(p-value=0.006). The distribution of slopes, however, is consistent
with being drawn from a single population, with no evidence for two
components as claimed in the literature based on B-V colors.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 93 65 Properties of the 65 SNe Ia in our sample
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See also:
J/A+A/578/A9 : Optical and NIR spectra of SN iPTF13ebh (Hsiao+, 2015)
J/ApJ/826/144 : Follow-up observations of SNIa ASASSN-14lp (Shappee+, 2016)
J/ApJ/869/56 : Updated calibration of the CSP-I SNe Ia sample (Burns+, 2018)
J/A+A/614/A71 : SNF20080514-002 and LSQ12fxd spectra (Nordin+, 2018)
J/ApJ/870/L1 : K2 obs. of type Ia supernova SN 2018oh (Dimitriadis+, 2019)
J/ApJ/870/13 : K2 LC alternative analysis of ASASSN-18bt (Shappee+, 2019)
J/ApJ/886/152 : ZTF early observations of Type Ia SNe. I. LCs (Yao+, 2019)
J/ApJ/896/165 : Optical light curves of SN 2016hnk (Jacobson-Galan+, 2020)
J/ApJ/902/47 : ZTF early obs. of type Ia SNe. II. Rise time (Miller+, 2020)
J/A+A/634/A37 : TURTLS Light curves of 56Ni distributions (Magee+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- ZTF ZTF identifier
14- 23 A10 --- Name TNS identifier
25- 33 A9 --- sType SN Ia subtype (1)
34 A1 --- f_sType [*] *=classification could not be reliably
determined from spectroscopy alone
36- 41 F6.4 --- z [0.018/0.15] Spectroscopic redshift from
Paper I (Yao+, 2019, J/ApJ/886/152)
43 A1 --- n_z Flag on z (2)
45- 48 F4.2 d t-tfl [0.46/4.96] Rest-frame time of first detection
in both g and r relative to first light tfl
(Tg-rfirst-tfl)
50- 53 F4.2 d e_t-tfl [0.07/2.87] Lower uncertainty on t-tfl
55- 58 F4.2 d E_t-tfl [0.07/3.12] Upper uncertainty on t-tfl
60- 64 F5.2 mag/d dg-r/dt [-0.28/0.23]? g-r linear slope
(Δg-r/Δt) (3)
66- 69 F4.2 mag/d e_dg-r/dt [0/0.25]? dg-r/dt uncertainty
71- 75 F5.2 --- x1 [-2.53/4.14] SALT x1 parameter from
Paper I (Yao+, 2019, J/ApJ/886/152)
77- 80 F4.2 --- e_x1 [0.02/0.66] x1 uncertainty
82- 86 F5.3 mag E(B-V) [0/0.77] Host reddening inferred using
SNooPy (Burns+ 2014ApJ...789...32B 2014ApJ...789...32B)
88- 93 F6.3 mag Kgr [-0.009/0.1] Averaged K-correction (4)
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Note (1): Classification from Yao et al. (2019, J/ApJ/886/152)
Note (2): Redshift from Yao+, 2019, J/ApJ/886/152 with:
u = inferred from the snid fit of SN spectra (3 significant decimals)
h = SN host galaxy is known (4 significant decimals)
Note (3): g-r linear slope in the first 6 days for the 35 SNe with at least
three data points in this time window.
Note (4): Averaged K-correction in the first 5 days since tfl inferred
using SNooPy (Burns+ 2014ApJ...789...32B 2014ApJ...789...32B).
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History:
From electronic version of the journal
References:
Yao et al. Paper I. 2019ApJ...886..152Y 2019ApJ...886..152Y Cat. J/ApJ/886/152
Yao et al. Paper II. 2020ApJ...902...47M 2020ApJ...902...47M Cat. J/ApJ/902/47
Bulla et al. Paper III. 2020ApJ...902...48B 2020ApJ...902...48B This catalog
(End) Emmanuelle Perret [CDS] 11-Apr-2022