J/ApJ/902/6 UV to visible-light observations of SN 2018fif (Soumagnac+, 2020)
SN 2018fif: the explosion of a large red supergiant discovered in its infancy
by the Zwicky Transient Facility.
Soumagnac M.T., Ganot N., Irani I., Gal-yam A., Ofek E.O., Waxman E.,
Morag J., Yaron O., Schulze S., Yang Yi, Rubin A., Cenko S.B., Sollerman J.,
Perley D.A., Fremling C., Nugent P., Neill J.D., Karamehmetoglu E.,
Bellm E.C., Bruch R.J., Burruss R., Cunningham V., Dekany R., Golkhou V.Z.,
Graham M.J., Kasliwal M.M., Konidaris N.P., Kulkarni S.R., Kupfer T.,
Laher R.R., Masci F.J., Riddle R., Rigault M., Rusholme B., van Roestel J.,
Zackay B.
<Astrophys. J., 902, 6 (2020)>
=2020ApJ...902....6S 2020ApJ...902....6S
ADC_Keywords: Photometry, ultraviolet; Photometry, ugriz; Supernovae;
Magnitudes, absolute
Keywords: Supernovae ; Type II supernovae ; Astronomy data modeling ;
Observational astronomy ; Ultraviolet transient sources ;
Transient sources
Abstract:
High-cadence transient surveys are able to capture supernovae closer
to their first light than ever before. Applying analytical models to
such early emission, we can constrain the progenitor stars'
properties. In this paper, we present observations of SN 2018fif
(ZTF18abokyfk). The supernova was discovered close to first light and
monitored by the Zwicky Transient Facility (ZTF) and the Neil Gehrels
Swift Observatory. Early spectroscopic observations suggest that the
progenitor of SN 2018fif was surrounded by relatively small amounts of
circumstellar material compared to all previous cases. This
particularity, coupled with the high-cadence multiple-band coverage,
makes it a good candidate to investigate using shock-cooling models.
We employ the SOPRANOS code, an implementation of the model by Sapir &
Waxman and its extension to early times by Morag et al. Compared with
previous implementations, SOPRANOS has the advantage of including a
careful account of the limited temporal validity domain of the
shock-cooling model as well as allowing usage of the entirety of the
early UV data. We find that the progenitor of SN 2018fif was a large
red supergiant with a radius of R=744.0-128.0+183.0R☉ and an
ejected mass of Mej=9.3-5.8+0.4M☉. Our model also gives
information on the explosion epoch, the progenitor's inner structure,
the shock velocity, and the extinction. The distribution of radii is
double- peaked, with smaller radii corresponding to lower values of
the extinction, earlier recombination times, and a better match to the
early UV data. If these correlations persist in future objects, denser
spectroscopic monitoring constraining the time of recombination, as
well as accurate UV observations (e.g., with ULTRASAT), will help
break the extinction/radius degeneracy and independently determine
both.
Description:
SN 2018fif was first detected on 2018 August 21 at 8:46 UT by the ZTF
wide-field camera mounted on the 1.2m Samuel Oschin Telescope (P48) at
Palomar Observatory. Previous ZTF observations were obtained in the
months prior to the SN explosion and the most recent nondetection was
on 2018 August 20 at 9:37:26.40 UT, i.e., less than 24hr before the
first detection. SN 2018fif was photometrically followed in multiple
bands for ∼5 months. The photometry is reported in Table 2.
Swift observations of the SN 2018fif field started on 2018 August 21
and 11 observations were obtained with a cadence of ∼1 day.
Observations from P48 were obtained using the ZTF mosaic camera
through r-band and g-band filters of the SDSS.
Observations from the robotic 1.52m telescope at Palomar (P60) were
obtained using the rainbow camera arm of the SED Machine spectrograph,
equipped with a 2048x2048 pixel CCD camera and with g', r', and i'
SDSS filters.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
00 09 26.55 +47 21 14.7 SN 2018fif = ZTF18abokyfk
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 78 543 Photometric observations of SN 2018fif
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See also:
J/PASP/111/438 : Updated Zwicky catalog (UZC) (Falco+, 1999)
J/MNRAS/408/827 : Simulations of supernova explosions (Dessart+, 2010)
J/ApJ/736/159 : Photometry monitoring of the SN PTF10vdl (Gal-Yam+, 2011)
J/MNRAS/438/L101 : First month on SN 2013ej (Valenti+, 2014)
J/A+A/593/A68 : PTF12os & iPTF13bvn spectra & light curves (Fremling+, 2016)
J/ApJ/820/33 : R-band light curves of type II supernovae (Rubin+, 2016)
J/MNRAS/478/3138 : Luminous supergiants in Magellanic Clouds (Davies+, 2018)
J/ApJ/861/63 : Type IIP SN 2016bkv LCs and spectra (Hosseinzadeh+, 2018)
J/ApJ/901/61 : LCs of 4 superluminous SNe from ZTF (Lunnan+, 2020)
J/A+A/657/A64 : Supernovae ZTF light curves (Sollerman+, 2022)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d JD [2458321.9/2458490.7] Julian Date of
the observation
15- 19 F5.2 mag mag [17.5/21.4]?=99 Apparent AB magnitude in Filt
21- 25 F5.2 mag e_mag [0.01/0.8]?=99 Uncertainty in mag
27- 35 E9.3 cW/m2/nm Flux [4.8e-49/1.1e-15] Flux density;
in erg/s/cm2/Å units
37- 45 E9.3 cW/m2/nm e_Flux [4.4e-47/1.7e-14] Uncertainty in Flux
46 A1 --- neFlux [a] a: uncertainty is very suspicious;
note added by CDS
48- 53 F6.2 mag Mag [-16.8/-12.9]?=99 Absolute magnitude in Filt
55- 59 F5.2 mag e_Mag [0.01/0.8]?=99 Uncertainty in Mag
61- 67 A7 --- Filt Filter used in the observation
69- 78 A10 --- Inst Instrument used in the observation (1)
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Note (1): Instrument as follows:
P48+ZTF = the 1.2m Samuel Oschin Telescope (P48) at Palomar Observatory
with the Zwicky Transient Facility (ZTF) wide-field camera
(407 occurrences)
SWIFT+UVOT = Swift with UVOT (92 occurrences)
P60+SEDM = the robotic 1.52m telescope at Palomar (P60) with the rainbow
camera arm of the SED Machine spectrograph (44 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 18-Jan-2022