J/ApJ/950/14 NIR and Optical LCs and spectra of Type Ic SN2021krf (Ravi+, 2023)
Near-infrared and optical observations of Type Ic SN 2021krf: luminous late-time
emission and dust formation.
Ravi A.P., Rho J., Park S., Park S.H., Yoon S.-C., Geballe T.R., Vinko J.,
Tinyanont S., Bostroem K.A., Burke J., Hiramatsu D., Howell D.A.,
McCully C., Newsome M., Gonzalez E.P., Pellegrino C., Cartier R.,
Pritchard T., Andersen M., Blinnikov S., Dong Y., Blanchard P.,
Kilpatrick C.D., Hoeflich P., Valenti S., Filippenko A.V., Suntzeff N.B.,
Seok Ji Y., Konyves-Toth R., Foley R.J., Siebert M.R., Jones D.O.
<Astrophys. J., 950, 14 (2023)>
=2023ApJ...950...14R 2023ApJ...950...14R
ADC_Keywords: Photometry, ugriz; Spectra, optical; Spectra, infrared; Supernovae
Keywords: Supernovae ; Core-collapse supernovae ; Explosive nucleosynthesis ;
Type Ic supernovae
Abstract:
We present near-infrared (NIR) and optical observations of the Type Ic
supernova (SN Ic) SN 2021krf obtained between days 13 and 259 at
several ground-based telescopes. The NIR spectrum at day 68 exhibits a
rising K-band continuum flux density longward of ∼2.0µm, and a
late-time optical spectrum at day 259 shows strong [OI]6300 and
6364Å emission-line asymmetry, both indicating the presence of
dust, likely formed in the SN ejecta. We estimate a carbon-grain dust
mass of ∼2x10-5M☉ and a dust temperature of ∼900-1200K
associated with this rising continuum and suggest the dust has formed
in SN ejecta. Utilizing the one-dimensional multigroup
radiation-hydrodynamics code STELLA, we present two degenerate
progenitor solutions for SN 2021krf, characterized by C-O star masses
of 3.93 and 5.74M☉, but with the same best-fit 56Ni mass of
0.11M☉ for early times (0-70 days). At late times (70-300 days),
optical light curves of SN 2021krf decline substantially more slowly
than those expected from 56Co radioactive decay. Lack of H and He
lines in the late-time SN spectrum suggests the absence of significant
interaction of the ejecta with the circumstellar medium. We reproduce
the entire bolometric light curve with a combination of radioactive
decay and an additional powering source in the form of a central
engine of a millisecond pulsar with a magnetic field smaller than that
of a typical magnetar.
Description:
Here we assume that the explosion date of SN 2021krf (t0) was
2021-Apr-26 (MJD59330±4.5), which is the midpoint between the ZTF
first discovery date (MJD59334) and its last date of nondetection,
2021 April 21 (MJD59325).
We observed SN 2021krf at optical and NIR wavelengths as summarized in
Table 1.
We obtained NIR (0.8-2.5um) spectra of SN 2021krf with the Gemini
Near-Infrared Spectrograph (GNIRS, R∼1200) on the 8.1m Frederic C.
Gilett Gemini North telescope on 2021 June 8 and 2021 July 3, as part
of observing program GN-2021A-Q-126.
We observed SN 2021krf with the short cross-dispersion (SXD) mode of
the SpeX spectrograph (R∼1000) on the NASA InfraRed Facility Telescope
(IRTF) on 2021 May 9.
We obtained eight sets of optical spectra at the LCO with the FLOYDS
spectrographs mounted on the 2m Faulkes Telescope North (FTN) at
Haleakala (USA) and the identical 2m Faulkes Telescope South (FTS) at
Siding Spring (Australia), through the Global Supernova Project
(Howell 2019), between 2021 May 8 and 2021 July 6.
We obtained optical spectra with the Kast spectrograph on the 3m Shane
telescope at Lick Observatory on 2021 May 10 and 2021 June.
We obtained an optical spectrum with the Goodman spectrograph
mounted on the SOAR telescope on 2021 July 7.
We observed SN 2021krf with the Deep Imaging Multi-Object Spectrograph
(DEIMOS) on the Keck II 10 m telescope on 2022 January 9.
See Section 2.1.
We performed optical photometry (U, B, g, V, r, and i filters) of
SN2021krf with follow-up LCO observations utilizing a worldwide
network of telescopes under the Global Supernova Project
(Howell 2019AAS...23325816H 2019AAS...23325816H).
See Section 2.2.
Objects:
------------------------------------------------------
RA (ICRS) DE Designation(s)
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12 51 17.44 +00 31 14.7 SN 2021krf = ZTF21aaxtctv
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1a.dat 64 13 Optical spectroscopy of SN 2021krf
table1b.dat 64 3 NIR spectroscopy of SN 2021krf
fig1.dat 54 159 Multicolor light curves of SN 2021krf
fig6.dat 45 35301 Optical spectra of SN 2021krf
fig7.dat 30 13174 NIR Spectra of SN 2021krf
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See also:
J/A+A/508/371 : UBVRIJHK observations of SN 2007gr (Hunter+, 2009)
J/ApJ/756/173 : Phot. of type IIn SNe 2005ip and 2006jd (Stritzinger+, 2012)
J/ApJ/785/37 : Type Ic SN 2010mb optical photometry (Ben-Ami+, 2014)
J/MNRAS/438/L101 : First month on SN 2013ej (Valenti+, 2014)
J/ApJ/821/57 : Photometry of the Type Ib/c SN2013ge (Drout+, 2016)
J/MNRAS/459/3939 : Type II supernova light curves (Valenti+, 2016)
J/A+A/609/A134 : CSP-I photometry for 34 supernovae (Stritzinger+, 2018)
J/ApJ/887/75 : NIR sp. of SN 2014C 1-5yr post-explosion (Tinyanont+, 2019)
J/A+A/656/A61 : SN Ib nebular phase properties (Dessart+, 2021)
J/ApJ/913/143 : Opt. light curves of the type Ic SN 2019stc (Gomez+, 2021)
J/ApJ/908/232 : SN 2020bvc optical and near-IR spectra (Rho+, 2021)
Byte-by-byte Description of file: table1*.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 "Y/M/D" Date Date of observation (UT)
13- 17 I5 d MJD [59330/59589] Modified Julian Date
19- 21 F3.1 d e_MJD [4.5/4.5]? MJD uncertainty
23- 25 I3 d Day [0/259] Days after explosion
26 A1 --- f_Day [a] Flag on Day (1)
28- 46 A19 --- Tel Telescope
48 A1 --- f_Tel [c] Flag on Tel (1)
50- 53 I4 s Exp [1200/3600]? Total exposure time
55- 58 F4.2 arcsec Slit [0.45/2]? Slit width
60 A1 --- u_Res [~] Uncertainty flag on Res
61- 64 I4 --- Res [400/1600]? Resolution,
R (λ/Δλ)
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Note (1): Flag as follows:
a = The estimated explosion date, 2021 April 26, is taken to be the
middle point between the last nondetection reported by
ZTF (2021 April 21) and the first detection (2021 April 30).
c = Spectrophotometry of GNIRS spectra on 2020608 and 20210703 yield the
approximate magnitudes: J, H, K = 16.3, 16.0, 16.1, and 16.8, 16.4,
16.5 mag, respectively.
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Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 yr Obs.Y [2021/2022] Year of the observation
6- 7 I2 "month" Obs.M Month of the observation
9- 10 I2 d Obs.D Day of the observation
12- 22 F11.5 d MJD [59334.2/59663.9] Modified Julian Date
24- 30 F7.4 mag mag [16.66/22.42] Apparent magnitude in Filt (1)
32- 37 F6.4 mag e_mag [0/0.5] Uncertainty in mag
39- 50 A12 --- Tel Telescope identifier
52 A1 --- Filt [UBVgir] Filter identifier
54 A1 --- l_mag [U] Upper limit flag on mag
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Note (1): The subtracted gri images utilizing SDSS templates were calibrated
to AB magnitudes. For U, B, and V, LCO images taken respectively on
2022-Jan-14 (MJD=59593), 2022-Mar-10 (MJD=59648), and 2022-Feb-17
(MJD=59627) were chosen as templates for difference imaging. The
subtracted UBV data were calibrated to Vega magnitudes.
See Section 2.2.
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Byte-by-byte Description of file: fig6.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Inst Telescope/Instrument; column added by CDS
12- 14 I3 --- Epoch [0/259]?=0 Days after discovery (1)
16- 24 F9.3 0.1nm lambda [0/10895]?=0 Wavelength; Angstroms
26- 35 E10.3 --- Flux [-170800/85370]?=0 Observed flux density
37- 45 E9.3 --- e_Flux [0/59680]?=0 Uncertainty in Flux
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Note (1): Observation details as follows:
12 = 2021 May 08: FTN-FLOYDS, flux units erg/s/cm2/Angstroms;
14 = 2021 May 10: Shane 3m-Kast, flux units 4e-16 erg/s/cm2/Angstroms;
15 = 2021 May 11: FTN-FLOYDS, flux units erg/s/cm2/Angstroms;
21 = 2021 May 17: FTS-FLOYDS, flux units erg/s/cm2/Angstroms;
39 = 2021 Jun 04: Shane 3m-Kast, flux units 4e-16 erg/s/cm2/Angstroms;
40 = 2021 Jun 05: FTS-FLOYDS, flux units erg/s/cm2/Angstroms;
48 = 2021 Jun 13: FTS-FLOYDS, flux units erg/s/cm2/Angstroms;
56 = 2021 Jun 21: FTS-FLOYDS, flux units erg/s/cm2/Angstroms;
71 = 2021 Jul 06: FTS-FLOYDS, flux units erg/s/cm2/Angstroms;
77 = 2021 Jul 12: SOAR-Goodman, flux units erg/s/cm2/Angstroms;
259 = 2022 Jan 09: Keck-DEIMOS, flux units 1e-17 erg/s/cm2/Angstroms.
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Byte-by-byte Description of file: fig7.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Epoch [13/68] Days after discovery (1)
4- 9 F6.4 um lambda [0.69/2.6] Wavelength
11- 20 E10.3 --- Flux [-4.81e-13/7.5e-14] Observed flux density
22- 30 E9.3 --- e_Flux [0/1.5e-11]?=0 Uncertainty in Flux
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Note (1): Observation details as follows:
13 = 2021 May 09: IRTF-SpeX, flux units erg/s/cm2/Angstroms;
43 = 2021 Jun 08: Gemini-GNIRS, flux units W/m2/micron;
68 = 2021 Jul 03: Gemimi-GNIRS, flux units W/m2/micron.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 25-Jul-2025