J/ApJ/943/L20 Photometric obs. of SN 2022ilv and SN 2020hvf (Srivastav+, 2023)
The luminous type Ia supernova 2022ilv and its early excess emission.
Srivastav S., Smartt S.J., Huber M.E., Dimitriadis G., Chambers K.C.,
Fulton M.D., Moore T., Callan F.P., Gillanders J.H., Maguire K.,
Nicholl M., Shingles L.J., Sim S.A., Smith K.W., Anderson J.P.,
de Boer T., Chen T.-W., Gao H., Young D.R.
<Astrophys. J., 943, L20 (2023)>
=2023ApJ...943L..20S 2023ApJ...943L..20S
ADC_Keywords: Supernovae; Photometry; Optical; Spectra, optical
Keywords: Supernovae ; Type Ia supernovae
Abstract:
We present observations and analysis of the hostless and luminous Type
Ia supernova 2022ilv, illustrating it is part of the 2003fg-like
family, often referred to as super-Chandrasekhar (Ia-SC) explosions.
The Asteroid Terrestrial-impact Last Alert System light curve shows
evidence of a short-lived, pulse-like early excess, similar to that
detected in another luminous Type Ia supernova (SN 2020hvf). The light
curve is broad, and the early spectra are remarkably similar to those
of SN 2009dc. Adopting a redshift of z=0.026±0.005 for SN 2022ilv
based on spectral matching, our model light curve requires a large
56Ni mass in the range 0.7-1.5M☉ and a large ejecta mass in
the range 1.6-2.3M☉. The early excess can be explained by
fast-moving SN ejecta interacting with a thin, dense shell of
circumstellar material close to the progenitor (∼1013cm) a few hours
after the explosion. This may be realized in a double-degenerate
scenario, wherein a white dwarf merger is preceded by the ejection of
a small amount (∼10-3-10-2M☉) of hydrogen and helium-poor
tidally stripped material. A deep pre-explosion Pan-STARRS1 stack
indicates no host galaxy to a limiting magnitude of r∼24.5. This
implies a surprisingly faint limit for any host of Mr≳-11,
providing further evidence that these types of explosions occur
predominantly in low-metallicity environments.
Description:
SN 2022ilv was discovered by the Zwicky Transient Facility (ZTF) on
2022 April 24.30 UT, or MJD 59693.30, at a magnitude of r=18.32±0.07.
The Asteroid Terrestrial-impact Last Alert System (ATLAS) units
covered the position of SN 2022ilv on four epochs between 59689.39 and
59992.48, all before the ZTF discovery (see Section 3.1).
We triggered follow-up photometric and spectroscopic observations of
SN 2022ilv at the 2m Liverpool Telescope (LT) under programs PL22A20
and PL22B16 (PI Srivastav), and PL22A13 (PI Dimitriadis).
We also obtained images in the iz bands using the 1.8m Pan-STARRS2
(PS2) telescope.
SN 2022ilv was also observed by the Ultraviolet and Optical Telescope
(UVOT) on Swift. Four epochs of imaging were obtained.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
15 10 44.25 -11 35 57.9 SN 2022ilv = ZTF22aahhywm
11 21 26.44 +03 00 52.8 SN 2020hvf = SN 2020hvf
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 39 434 The photometric observations of SN 2022ilv and
SN 2020hvf
spectra.dat 91 21 Summary of LT/SPRAT spectra; table added by CDS
sp/* . 21 Individual LT/SPRAT spectra of SN 2022ilv and
SN 2020hvf
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See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
J/AJ/130/873 : BQS objects in the SDSS DR3 area (Jester+, 2005)
J/MNRAS/383/1485 : BVRI light curves of SN 2003jd (Valenti+, 2008)
J/AJ/137/4517 : UVOT light curves of supernovae (Brown+, 2009)
J/MNRAS/410/585 : SN 2009dc BVRI light curves (Silverman+, 2011)
J/MNRAS/446/3895 : The rising light curves of Type Ia supernovae (Firth+, 2015)
J/ApJS/218/10 : HET Massive Galaxy Survey (HETMGS) (van den Bosch+, 2015)
J/ApJ/867/105 : ATLAS all-sky stellar ref. cat. ATLAS-REFCAT2 (Tonry+, 2018)
J/ApJ/870/13 : K2 LC alternative analysis of ASASSN-18bt (Shappee+, 2019)
J/ApJ/900/140 : CSP-II: sp. obs. of LSQ14fmg (Hsiao+, 2020)
J/A+A/634/A37 : TURTLS Light curves of 56Ni distributions (Magee+, 2020)
J/ApJ/923/L8 : Follow-up phot. & sp. of SNIa 2020hvf (Jiang+, 2021)
J/ApJ/927/78 : Follow-up of type Ia SN2020esm (Dimitriadis+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- SN Supernova identifier
9- 16 F8.2 d MJD [58960.39/59818.99] Modified Julian Date
18 A1 --- l_mag Limit flag on mag
19- 23 F5.2 mag mag [12.59/20.62] Apparent magnitude in Filter
25- 28 F4.2 mag e_mag [0/0.5]? Uncertainty in mag
30- 34 A5 --- Inst Instrument (1)
36- 39 A4 --- Filt Filter
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Note (1): Instrument as follows:
LT = the 2m Liverpool Telescope (182 occurrences)
ATLAS = the Asteroid Terrestrial-impact Last Alert System (161 occurrences)
UVOT = Swift Ultraviolet and Optical Telescope (88 occurrences)
PS2 = the 1.8m Pan-STARRS2 telescope (3 occurrences)
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Byte-by-byte Description of file: spectra.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- SN Supernova identifier
9- 31 A23 "datime" Date Observation date
33- 40 A8 --- Inst Telescope / Instrument ("LT/SPRAT")
42- 91 A50 --- FileName Name of the file in subdirectory "sp"
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History:
From electronic version of the journal for Table 1
Spectra downloaded on WISeREP:
http://www.wiserep.org/object/14554 and
http://www.wiserep.org/object/20641
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 13-Jan-2025