J/ApJ/932/58 LCs and spectra of SNe 2021gno & 2021inl (Jacobson-Galan+, 2022)
The circumstellar environments of double-peaked, calcium-strong transients
2021gno and 2021inl.
Jacobson-Galan W.V., Venkatraman P., Margutti R., Khatami D., Terreran G.,
Foley R.J., Angulo R., Angus C.R., Auchettl K., Blanchard P.K.,
Bobrick A., Bright J.S., Brout D., Chambers K.C., Couch C.D.,
Coulter D.A., Clever K., Davis K.W., de Boer T.J.L., DeMarchi L.,
Dodd S.A., Jones D.O., Johnson J., Kilpatrick C.D., Khetan N., Lai Z.,
Langeroodi D., Lin C.-C., Magnier E.A., Milisavljevic D., Perets H.B.,
Pierel J.D.R., Raymond J., Rest S., Rest A., Ridden-Harper R., Shen K.J.,
Siebert M.R., Smith C., Taggart K., Tinyanont S., Valdes F., Villar V.A.,
Wang Q., Yadavalli S.K., Zenati Y., Zenteno A.
<Astrophys. J., 932, 58 (2022)>
=2022ApJ...932...58J 2022ApJ...932...58J
ADC_Keywords: Supernovae; Photometry, ugriz; Spectra, optical
Keywords: Supernovae ; X-ray transient sources ; X-ray telescopes ;
White dwarf stars
Abstract:
We present panchromatic observations and modeling of calcium-strong
supernovae (SNe) 2021gno in the star-forming host-galaxy NGC 4165 and
2021inl in the outskirts of elliptical galaxy NGC 4923, both monitored
through the Young Supernova Experiment transient survey. The light
curves of both, SNe show two peaks, the former peak being derived from
shock cooling emission (SCE) and/or shock interaction with
circumstellar material (CSM). The primary peak in SN 2021gno is
coincident with luminous, rapidly decaying X-ray emission
(Lx=5x1041erg/s) detected by Swift-XRT at δt=1d after
explosion, this observation being the second-ever detection of X-rays
from a calcium-strong transient. We interpret the X-ray emission in
the context of shock interaction with CSM that extends to
r<3x1014cm. Based on X-ray modeling, we calculate a CSM mass
MCSM=(0.3-1.6)x10-3M☉ and density n=(1-4)x1010cm-3.
Radio nondetections indicate a low-density environment at larger radii
(r>1016cm) and mass-loss rate of dM/dt<10-4M☉/yr. SCE
modeling of both primary light-curve peaks indicates an extended-
progenitor envelope mass Me=0.02-0.05M☉ and radius
Re=30-230R☉. The explosion properties suggest progenitor
systems containing either a low-mass massive star or a white dwarf
(WD), the former being unlikely given the lack of local star
formation. Furthermore, the environments of both SNe are consistent
with low-mass hybrid He/C/O WD + C/O WD mergers.
Description:
SN 2021gno was observed with the Ultraviolet Optical Telescope (UVOT)
on board the Neil Gehrels Swift Observatory from 2021 March 20 until
2021 April 21 (δt=0.84-33.0d since explosion).
Additional griz-band imaging of SN 2021gno and SN 2021inl was obtained
through the Young Supernova Experiment (YSE; Jones+ 2021ApJ...908..143J 2021ApJ...908..143J)
with the Pan-STARRS telescope (PS1) between 2021-Mar-24 and
2021-Jul-21 (δt=4.80-123.5d since explosion) and 2021 April 06
and 2021 June 10 (δt=0.97-66.0d since explosion),
respectively.
Furthermore, SN 2021gno was observed with the DECam Extension survey
of YSE between 2021 March 22 and 2022 January 09 (δt=1.49-294.7d)
on the Cerro Tololo Inter-American Observatory Blanco 4m telescope.
Both SNe 2021gno and 2021inl were observed with ATLAS
(δt=0.70-84.6 and δt=0.10-28.1d since explosion,
respectively), a twin 0.5m telescope system installed on Haleakala and
Mauna Loa in the Hawai'ian islands that robotically surveys the sky in
cyan (c) and orange (o) filters.
In addition to our observations, we include g/r-band photometry of
SNe 2021gno and 2021inl from the ZTF forced-photometry service, which
span from 2021 March 20 to 2021 June 15 (δt=0.54-87.5d since
explosion) and 2021 April 07 to 2021 May 08 (δt=1.85-32.9d since
explosion).
SNe 2021gno and 2021inl were observed with Shane/Kast and Keck/LRIS
between δt=3-54d and δt=25-111d relative to explosion,
respectively.
Spectra of SN 2021gno were also obtained with the Alhambra Faint
Object Spectrograph (ALFOSC) on The Nordic Optical Telescope (NOT), as
well as Binospec on MMT, and SpeX at the NASA Infrared Telescope
Facility (IRTF). See Section 2.2.
The X-Ray Telescope (XRT) on board the Swift spacecraft started
observing the field of SN 2021gno from 2021-Mar-20 to 2021-Nov-06
(δt=0.81-233.6d since explosion with a total exposure time of
28.8ks, IDs 14199 and 14214). See Section 2.3.
We observed SN 2021gno with the Arcminute Microkelvin Imager Large
Array (AMI-LA) on 2021 April 21, 25 and November 19 (δt=35, 39,
& 245d since explosion) and found no evidence for radio emission from
the SN. These data were all taken at a central frequency of 15.5GHz
across a 5GHz bandwidth consisting of 4096 channels, which we average
down to 8 for imaging. See Section 2.4.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
13 01 33.24 +27 49 55.1 SN 2021inl = ATLAS 21lqc
12 12 10.29 +13 14 57.0 SN 2021gno = ATLAS 21iro
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea2.dat 62 12 Optical Spectroscopy of SN 2021gno
tablea4.dat 44 4 Optical Spectroscopy of SN 2021inl
tablea7.dat 37 90 Optical photometry of SN 2021inl
tablea8.dat 39 251 Optical photometry of SN 2021gno
fig3/* . 4 Individual spectra in ASCII format of SN 2021inl
fig4/* . 11 Individual spectra in ASCII format of SN 2021gno
--------------------------------------------------------------------------------
See also:
VIII/76 : Leiden/Argentine/Bonn (LAB) Survey of Galactic HI (Kalberla+ 2005)
J/A+A/465/71 : 21cm observations of 452 galaxies (Theureau+, 2007)
J/MNRAS/383/1485 : BVRI light curves of SN 2003jd (Valenti+, 2008)
J/ApJ/721/1608 : Absolute UV magnitudes of type Ia SNe (Brown+, 2010)
J/ApJ/742/L18 : Follow-up phot. of the SN IIb PTF 11eon (Arcavi+, 2011)
J/MNRAS/425/1789 : Berkeley supernova Ia program. I. (Silverman+, 2012)
J/MNRAS/428/729 : GRB Swift X-ray light curves analysis (Margutti+, 2013)
J/MNRAS/429/3330 : AMI Galactic Plane Survey at 16GHz. I. (Perrott+, 2013)
J/ApJ/836/60 : Bgri LCs of PTF11kmb and PTF12bho (Lunnan+, 2017)
J/other/Sci/362.201 : iPTF 14gqr (SN 2014ft) photometry (De+, 2018)
J/ApJ/855/107 : PMAS Integral-field SN hosts COmpilation (Galbany+, 2018)
J/ApJ/867/105 : ATLAS all-sky stellar ref. cat. (Tonry+, 2018)
J/A+A/630/A76 : SN2016hnk photometry and spectroscopy (Galbany+, 2019)
J/ApJ/905/58 : Local universe with ZTF. I. Ca-rich gaps (De+, 2020)
J/ApJ/902/86 : Type Ic SN 2020bvc UV to NIR LCs and opt. sp. (Ho+, 2020)
J/ApJ/898/166 : UV to NIR obs. of SN 2019ehk (Jacobson-Galan+, 2020)
J/ApJ/896/165 : Opt. light curves of SN 2016hnk (Jacobson-Galan+, 2020)
J/ApJ/900/46 : UV, opt. & IR LC of supernova SN2019dge (Yao+, 2020)
J/ApJ/924/55 : UV & optical obs. of type Ic SN 2020oi (Gagliano+, 2022)
J/ApJ/924/15 : Final moments. I. SN 2020tlf (Jacobson-Galan+, 2022)
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "Y/M/D" Date Date of observation (UT)
12- 16 I5 d MJD [59295/59376] Modified Julian Date
18- 22 F5.1 d Phase [2.3/83.3] Phase relative to explosion
(MJD59292.7)
24- 42 A19 --- Tel Telescope
44- 51 A8 --- Inst Instrument
53- 62 A10 0.1nm Wave Wavelength range (Å)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "Y/M/D" Date Date of observation (UT)
12- 16 I5 d MJD [59317/59403] Modified Julian Date
18- 22 F5.1 d Phase [7.7/93.7] Phase relative to explosion
(MJD59309.4)
24- 28 A5 --- Tel Telescope
30- 33 A4 --- Inst Instrument ("Kast" or "LRIS")
35- 44 A10 0.1nm Wave Wavelength range (Å)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.2 --- MJD [59309.48/59414.28] Modified Julian Date of
observation (JD-2400000.5)
10- 16 F7.2 d Phase [0.09/105] Phase (1)
18- 18 A1 --- Filt Filter (griz, c, o, B)
20- 20 A1 --- l_omag Limit flag on omag
22- 26 F5.2 mag omag [19.44/25.92] Observed magnitude in Filter
28- 31 F4.2 mag e_omag [0.04/1.1]? Uncertainty in omag
33- 37 A5 --- Inst Instrument (2)
--------------------------------------------------------------------------------
Note (1): Relative to explosion (MJD 59309.4)
Note (2): Instrument as follows:
PS1 = the Pan-STARRS telescope (50 occurrences)
ATLAS = the Asteroid Terrestrial-impact Last Alert System twin 0.5m telescope
(22 occurrences)
ZTF = the Zwicky Transient Facility (14 occurrences)
Keck = 4 occurrences
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.2 --- MJD [59293.24/59595.35] Modified Julian Date of
observation (JD-2400000.5)
10- 16 F7.2 d Phase [0.5/303] Phase (1)
18- 19 A2 --- Filt Filter (ubvm2w1w2, oc, griz, Vir)
21- 21 A1 --- l_omag Limit flag on omag
23- 27 F5.2 mag omag [16.9/25.8] Observed magnitude in Filter
29- 32 F4.2 mag e_omag [0.01/0.5]? Uncertainty in omag
34- 39 A6 --- Inst Instrument (2)
--------------------------------------------------------------------------------
Note (1): Relative to explosion (MJD 59292.7)
Note (2): Instrument as follows:
ATLAS = the Asteroid Terrestrial-impact Last Alert System twin 0.5m telescope
(38 occurrences
ZTF = The Zwicky Transient Facility (59 occurrences)
Swift = Swift/UVOT telescope (78 occurrences)
DECam = The DECam on the Cerro Tololo Inter-American Observatory Blanco 4m
telescope (56 occurrences)
Nickel = The Nickel telescope (20 occurrences)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 04-Mar-2025