J/ApJ/934/134 UV and optical spectra of type IIP SN2021yja (Vasylyev+, 2022)
Early-time ultraviolet spectroscopy and optical follow-up observations of the
type IIP supernova 2021yja.
Vasylyev S.S., Filippenko A.V., Vogl C., Brink T.G., Brown P.J.,
de Jaeger T., Matheson T., Gal-Yam A., Mazzali P.A., Modjaz M.,
Patra K.C., Rowe M., Smith N., Van Dyk S.D., Williamson M., Yang Yi,
Zheng W., deGraw A., Fox O.D., Gates E.L., Jennings C., Rich R.M.
<Astrophys. J., 934, 134 (2022)>
=2022ApJ...934..134V 2022ApJ...934..134V
ADC_Keywords: Supernovae; Spectra, optical; Spectra, ultraviolet
Keywords: Type II supernovae ; Core-collapse supernovae ; Ultraviolet astronomy
Abstract:
We present three epochs of early-time ultraviolet (UV) and optical
HST/STIS spectroscopy of the young, nearby Type IIP supernova (SN)
2021yja. We complement the HST data with two earlier epochs of Swift
UVOT spectroscopy. The HST and Swift UVOT spectra are consistent with
those of other well-studied Type IIP SNe. The UV spectra exhibit rapid
cooling at early times, while less dramatic changes are seen in the
optical. We also present Lick/KAIT optical photometry up to the
late-time tail phase, showing a very long plateau and shallow decline
compared with other SNe IIP. Our modeling of the UV spectrum with the
TARDIS radiative transfer code produces a good fit for a high-velocity
explosion, a low total extinction E(B-V)=0.07mag, and a subsolar
metallicity. We do not find a significant contribution to the UV flux
from an additional heating source, such as interaction with the
circumstellar medium, consistent with the observed flat plateau.
Furthermore, the velocity width of the MgIIλ2798 line is
comparable to that of the hydrogen Balmer lines, suggesting that the
UV emission is confined to a region close to the photosphere.
Description:
The SN 2021yja was observed as an HST disruptive target of opportunity
on 2021 September 16 (+9d after explosion), 2021 September 21 (+14d),
and 2021 September 28 (+21d) using the CCD (52"x52" field of view)
detector of the Space Telescope Imaging Spectrograph (STIS).
See Section 2.1.
Optical spectra of SN 2021yja were obtained using the Kast Double
Spectrograph on the Shane 3m telescope at Lick Observatory. The
spectral sequence consists of 10 epochs and spans +4 to +121 days. All
observations cover a wavelength range from 3632 to 10754Å.
See Section 2.2.
Follow-up photometry of SN 2021yja was performed with images from the
0.76m Katzman Automatic Imaging Telescope (KAIT) as part of the Lick
Observatory Supernova Search, as well as with images from the 1m
Nickel telescope at Lick Observatory.
The SN 2021yja was observed photometrically and spectroscopically in
the UV with the Neil Gehrels Swift Observatory. See Section 2.3.
Objects:
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RA (ICRS) DE Designation(s)
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03 24 21.17 -21 33 56.2 SN 2021yja = ATLAS 21bidw
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 117 13 Kast spectroscopy of SN 2021yja in the
3632-10754Å range and Data behind Figure 3
for HST/STIS observations
sp-kast/* . 10 Kast individual spectra of SN 2021yja
in ASCII format (Data behind Figure 3)
sp-hst/* . 3 HST/STIS individual spectra of SN 2021yja
in ASCII format (Data behind Figure 3)
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See also:
II/183 : UBVRI Photometric Standards (Landolt 1992)
VIII/77 : HI spectral properties of galaxies (Springob+, 2005)
J/MNRAS/394/2266 : SN 2005cs one-year photometry (Pastorello+, 2009)
J/MNRAS/395/1409 : Type II-P SN progenitor constraints (Smartt+, 2009)
J/MNRAS/408/827 : Simulations of supernova explosions (Dessart+, 2010)
J/MNRAS/412/1441 : SNe luminosity functions (Li+, 2011)
J/MNRAS/425/1789 : Berkeley supernova Ia program. I. (Silverman+, 2012)
J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)
J/MNRAS/433/1871 : UBVRI griz light curves of SN 2012aw (Bose+, 2013)
J/MNRAS/442/844 : BVRI light curves of type II-P supernovae (Faran+, 2014)
J/MNRAS/438/L101 : First month on SN 2013ej (Valenti+, 2014)
J/MNRAS/448/2608 : UV and opt. photometric data for SN 2013by (Valenti+, 2015)
J/MNRAS/459/3939 : Type II supernova light curves (Valenti+, 2016)
J/ApJ/875/136 : BVRI, sp. & IR obs. of type II-P SN2017eaw (Van Dyk+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Inst Instrument ("Kast" or "STIS")
6- 15 A10 "Y/M/D" Date Date of observation (UT)
17- 19 I3 d Phase [4/121] Phase; days after explosion
(2021-sep-07)
21- 23 F3.1 --- Airmass [1.9/3]? Average airmass
25- 27 F3.1 arcsec Seeing [1.2/3]? Seeing
29- 32 I4 s Exp [500/1500]? Red channel total exposure time (1)
34 A1 --- f_Exp d: only one exposure was taken with the
red channel
36- 60 A25 --- FileName1 Name of the ASCII file in subdirectory "sp-hst"
62- 99 A38 --- FileName2 Name of the ASCII file in
subdirectory "sp-kast"
101-117 A17 --- Obs Observer
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Note (1): The blue channel exposure time was 60s longer on each date.
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Byte-by-byte Description of file: sp-kast/*
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.2 0.1nm lambda [3518/10766] Wavelength, Angstroms
10- 22 F13.9 10-17W/m2/nm Flux [-0.3/167] Flux,
10-15ergs/s/cm2/Å
23- 32 F10.7 10-17W/m2/nm e_Flux [0.01/12] Flux error
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Byte-by-byte Description of file: sp-hst/*
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Bytes Format Units Label Explanations
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1- 19 F19.13 0.1nm lambda [1663.4/10234.6] Wavelength, Angstroms
21- 43 E23.13 cW/m2/nm Flux [-1.4e-13/1.4e-13] Flux, ergs/s/cm2/Å
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 26-Jul-2024