J/ApJ/914/50 Opt. phot. and GMOS & NIRES spectra of SN2019yvq (Tucker+, 2021)
SN 2019yvq does not conform to SN Ia explosion models.
Tucker M.A., Ashall C., Shappee B.J., Vallely P.J., Kochanek C.S.,
Huber M.E., Anand G.S., Keane J.V., Hsiao E.Y., Holoien T.W.-S.
<Astrophys. J., 914, 50 (2021)>
=2021ApJ...914...50T 2021ApJ...914...50T
ADC_Keywords: Supernovae; Photometry; Spectra, optical; Spectra, infrared
Keywords: Type Ia supernovae ; White dwarf stars ;
Astrophysical explosive burning ; Nuclear astrophysics
Abstract:
We present new photometric and spectroscopic observations of
SN2019yvq, a Type Ia supernova (SN Ia) exhibiting several peculiar
properties including an excess of UV/optical flux within days of
explosion, a high Si ii velocity, and a low peak luminosity.
Photometry near the time of first light places new constraints on the
rapid rise of the UV/optical flux excess. A near-infrared spectrum at
+173 days after maximum light places strict limits on the presence of
H or He emission, effectively excluding the presence of a nearby
nondegenerate star at the time of explosion. New optical spectra,
acquired at +128 and +150 days after maximum light, confirm the
presence of [CaII]λ7300 and persistent CaII NIR triplet
emission as SN 2019yvq transitions into the nebular phase. The lack of
[OI]λ6300 emission disfavors the violent merger of two C/O
white dwarfs (WDs) but the merger of a C/O WD with a He WD cannot be
excluded. We compare our findings with several models in the
literature postulated to explain the early flux excess including
double-detonation explosions, 56Ni mixing into the outer ejecta
during ignition, and interaction with H- and He-deficient
circumstellar material. Each model may be able to explain both the
early flux excess and the nebular [CaII] emission, but none of the
models can reconcile the high photospheric velocities with the low
peak luminosity without introducing new discrepancies.
Description:
Our new photometry includes prediscovery nondetections and early
g-band photometry from the All-Sky Automated Survey for SuperNovae
(ASAS-SN; Shappee+ 2014, J/ApJ/788/48 ; Kochanek+ 2017PASP..129j4502K 2017PASP..129j4502K)
and postmaximum observations from the Transiting Exoplanet Survey
Satellite (TESS).
SN 2019yvq was observed by TESS during the mission's Sector 21 and 22
operations, from January 21.94 to 2020 March 17.96 UTC. These
observations narrowly miss the peak of the light curve, but provide
excellent high-cadence monitoring of its subsequent decline. TESS
observes in a single ∼6000-10000Å broadband filter with an
effective wavelength of ∼8000Å that is comparable to that of the
Johnson-Cousins I band.
New spectroscopic observations were acquired with the Gemini
Multi-Object Spectrograph (GMOS) on the Gemini-North telescope on
2020-May-22 (+128d) and 2020-June-13 (+150d) (wavelength range
4500-9100Å and R∼2000) and the Near-Infrared Echelle Spectrograph
(NIRES) on the Keck II telescope on 2020-July-08 (+173d) (wavelength
range 0.95-2.5um and R∼2700).
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
12 27 21.84 +64 47 59.8 SN 2019yvq = ZTF19adcecwu
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 33 2462 New ASAS-SN and TESS photometry of SN 2019yvq
fig4.dat 34 1861 Late-phase and nebular GMOS spectra of SN 2019yvq
fig5.dat 24 10240 NIRES spectrum of SN 2019yvq at +173 days
after maximum light (MJD59038.263)
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See also:
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
J/MNRAS/425/1789 : Berkeley supernova Ia program. I. (Silverman+, 2012)
J/A+A/554/A27 : 2011fe spectrophotometric time series (Pereira+, 2013)
J/ApJ/795/142 : Defining phot. peculiar SNe Ia (Gonzalez-Gaitan+, 2014)
J/MNRAS/444/3258 : Velocities and EW of PTF SNe Ia (Maguire+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/MNRAS/451/1973 : Type Ia supernovae igh-velocity features (Silverman+, 2015)
J/AJ/152/50 : Cosmicflows-3 catalog (CF3) (Tully+, 2016)
J/ApJ/843/16 : Galaxy groups within 3500km/s (Kourkchi+, 2017)
J/AJ/154/211 : CSP (DR3): photometry of low-z SNe Ia (Krisciunas+, 2017)
J/A+A/611/A58 : SN 2007on and SN 2011iv light curves (Gall+, 2018)
J/A+A/630/A76 : SN2016hnk photometry and spectroscopy (Galbany+, 2019)
J/ApJ/883/111 : UV-Opt LCs of ASASSN-19bt detected by TESS (Holoien+, 2019)
J/ApJ/886/152 : ZTF early observations of Type Ia SNe. I. LCs (Yao+, 2019)
J/ApJ/902/48 : ZTF early obs. of type Ia supernovae. III. (Bulla+, 2020)
J/ApJ/898/56 : UVOT, ZTF gri LCs & sp. of the SN Ia 2019yvq (Miller+, 2020)
J/ApJ/908/51 : TESS early LCs of type Ia Supernovae (Fausnaugh+, 2021)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Source Observation source (1)
9- 20 F12.6 d MJD [58812.47/58925.97] Modified Julian Date
22- 27 F6.3 mJy Flux [-0.026/3.99] Observed flux density
29- 33 F5.3 mJy e_Flux [0.014/0.13] Uncertainty in Flux
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Note (1): Source as follows:
ASAS-SN = g-band photometry from the All-Sky Automated Survey for SuperNovae;
14 occurrences
TESS = the Transiting Exoplanet Survey Satellite; 2448 occurrences
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Byte-by-byte Description of file: fig4.dat
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Bytes Format Units Label Explanations
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1- 3 I3 d Epoch [128/150] Observation epoch; days after
time of maximum light
5- 8 I4 0.1nm lambda [4550/9200] Wavelength in Angstroms
10- 21 E12.6 cW/m2/nm Flux [7.97e-21/2.5e-16] Flux
in erg/s/cm2/Angstroms
23- 34 E12.6 cW/m2/nm e_Flux [2.8e-21/1.5e-16] Uncertainty in Flux
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Byte-by-byte Description of file: fig5.dat
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Bytes Format Units Label Explanations
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1 I1 --- Order [3/7] NIRES order number
3- 10 F8.6 um lambda [0.8/2.5] Wavelength
12- 24 E13.6 cW/m2/nm Flux [-2.62e-12/1.82e-13] Relative flux
in erg/s/cm2/Angstroms
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 08-Dec-2022