J/ApJ/924/15 Final moments. I. Type II SN 2020tlf (Jacobson-Galan+, 2022)
Final moments.
I. Precursor emission, envelope inflation, and enhanced mass loss preceding the
luminous type II supernova 2020tlf.
Jacobson-Galan W.V., Dessart L., Jones D.O., Margutti R., Coppejans D.L.,
Dimitriadis G., Foley R.J., Kilpatrick C.D., Matthews D.J., Rest S.,
Terreran G., Aleo P.D., Auchettl K., Blanchard P.K., Coulter D.A.,
Davis K.W., de Boer T.J.L., DeMarchi L., Drout M.R., Earl N., Gagliano A.,
Gall C., Hjorth J., Huber M.E., Ibik A.L., Milisavljevic D., Pan Y.-C.,
Rest A., Ridden-Harper R., Rojas-Bravo C., Siebert M.R., Smith K.W.,
Taggart K., Tinyanont S., Wang Q., Zenati Y.
<Astrophys. J., 924, 15 (2022)>
=2022ApJ...924...15J 2022ApJ...924...15J
ADC_Keywords: Supernovae; Spectra, optical; Photometry, ugriz;
Photometry, ultraviolet
Keywords: Core-collapse supernovae ; Type II supernovae ; Supernovae ;
Massive stars ; Stellar mass loss
Abstract:
We present panchromatic observations and modeling of supernova (SN)
2020tlf, the first normal Type II-P/L SN with confirmed precursor
emission, as detected by the Young Supernova Experiment transient
survey. Pre-SN activity was detected in riz-bands at -130 days and
persisted at relatively constant flux until first light. Soon after
discovery, "flash" spectroscopy of SN 2020tlf revealed narrow,
symmetric emission lines that resulted from the photoionization of
circumstellar material (CSM) shed in progenitor mass-loss episodes
before explosion. Surprisingly, this novel display of pre-SN emission
and associated mass loss occurred in a red supergiant (RSG) progenitor
with zero-age main-sequence mass of only 10-12M☉, as inferred
from nebular spectra. Modeling of the light curve and multi-epoch
spectra with the non-LTE radiative-transfer code CMFGEN and
radiation-hydrodynamical code HERACLES suggests a dense CSM limited to
r∼1015cm, and mass-loss rate of 10-2M☉/yr. The luminous
light-curve plateau and persistent blue excess indicates an extended
progenitor, compatible with an RSG model with R*=1100R☉.
Limits on the shock-powered X-ray and radio luminosity are consistent
with model conclusions and suggest a CSM density of
ρ<2x10-16g/cm3 for distances from the progenitor star of
r∼5x1015cm, as well as a mass-loss rate of
dM/dt<1.3x10-5M☉/yr at larger distances. A promising power
source for the observed precursor emission is the ejection of stellar
material following energy disposition into the stellar envelope as a
result of gravity waves emitted during either neon/oxygen burning or a
nuclear flash from silicon combustion.
Description:
SN 2020tlf was first reported to the Transient Name Server by the
Asteroid Terrestrial-impact Last Alert System (ATLAS;
Tonry+ 2018PASP..130f4505T 2018PASP..130f4505T) on 2020 September 16, but the earliest
detections of the SN are from the Young Supernova Experiment (YSE;
Jones+ 2021ApJ...908..143J 2021ApJ...908..143J) with the PS1 telescope on 2020-Sept-5.
See Section 2.1.
Pre-explosion imaging of SN 2020tlf was also acquired by the Zwicky
Transient Facility (ZTF) and ATLAS. See Section 2.2.
We started observing SN 2020tlf with the Ultraviolet Optical Telescope
(UVOT) on board the Neil Gehrels Swift Observatory on 2020-September-9
until 2021-February-18 (δt=11.0-165.2days since first light).
Additional griz-band imaging of SN 2020tlf was obtained through the
YSE sky survey with the Pan-STARRS telescope (PS1) between 2020-Sept-8
and 2021-Jun-26 (δt=1.5-292.3days since first light).
SN 2020tlf was observed with ATLAS (δt=-9.40-157.8days since
first light), 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.
We also observed SN 2020tlf with the Las Cumbres Observatory (LCO)
Global Telescope Network 1m telescopes and Las Cumbres Observatory
imagers from 2020-Sept-21 to 2021-Mar-29 (δt=14.34-203.5days
since first light) in ugri-bands.
Observations of SN 2020tlf were obtained with the 1m Lulin telescope
located at Lulin Observatory on 2020-Oct-9 (δt=32.71days since
first light) in BVgr bands.
The complete light curve of SN 2020tlf is presented in Figure 4, and
all photometric observations are listed in Appendix Table A4. In
addition to our observations, we include g/r-band photometry from the
ZTF forced-photometry service, which span from 2020-Nov-27 to
2021-Jun-28 (δt=81.81-294.5days since first light).
In Figure 5, we present the complete series of optical spectroscopic
observations of SN 2020tlf from -9 to +257days relative to the B-band
maximum (δt=10-270days relative to first light). A full log of
spectroscopic observations is presented in Appendix Table A1.
SN 2020tlf was observed with Shane/Kast and Keck/LRIS between -9 and
+257days relative to the B-band maximum. Spectra of SN 2020tlf were
also obtained with Keck NIRES and DEIMOS, as well as Binospec on MMT
and the Dual Imaging Spectrograph (DIS) on the Astrophysical Research
Consortium (ARC) 3.5-m telescope at Apache Point Observatory (APO).
The X-Ray Telescope (XRT) on board the Swift spacecraft started
observing the field of SN 2020tlf on 2020-Sept-9 until 2021-Feb-18
(δt=11.0-165.2days since first light) with a total exposure time
of 35.2ks, (Source IDs 11337 and 11339). We find no evidence for
significant X-ray emission in any of the individual Swift-XRT epochs,
nor in merged images near optical/UV peak and at all observed phases.
See Section 3.3.
We acquired deep radio observations of SN 2020tlf with the Karl G.
Jansky Very Large Array (VLA) at δt=146-320days since first
light through project SD1096 (PI Margutti). All observations have been
obtained at 10GHz (X band). SN 2020tlf is not detected in our
observations. See Section 3.4.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
14 40 10.03 +42 46 39.6 SN 2020tlf = ATLAS 20bbft
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea4.dat 38 463 Optical photometry of SN 2020tlf
tablea1.dat 54 9 Optical spectroscopy of SN 2020tlf
fig5.dat 46 47118 Spectral observations of SN 2020tlf
--------------------------------------------------------------------------------
See also:
VIII/76 : Leiden/Argentine/Bonn (LAB) Survey of Galactic HI (Kalberla+ 2005)
J/MNRAS/383/1485 : BVRI light curves of SN 2003jd (Valenti+, 2008)
J/MNRAS/394/21 : Multi-epoch spectroscopy of SN 1994W (Dessart+, 2009)
J/ApJ/721/1608 : Absolute UV magnitudes of type Ia SNe (Brown+, 2010)
J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)
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/ApJ/768/47 : Swift/XRT 0.2-10keV obs. of SN2009ip (Ofek+, 2013)
J/other/Nat/494.65 : SN 2010mc outburst before explosion (Ofek+, 2013)
J/ApJ/789/104 : SNe IIn observations and properties (Ofek+, 2014)
J/ApJ/795/44 : PS1 SNe Ia (0.02<z<0.7) griz light curves (Rest+, 2014)
J/MNRAS/449/1921 : UV/optical/NIR phot. for Type Ibn SNe (Pastorello+, 2015)
J/A+A/589/A110 : SN II in host HII regions (Anderson+, 2016)
J/ApJ/824/6 : PTF obs. of SNHunt275 2015 May event (Ofek+, 2016)
J/A+A/605/A6 : Photometry of supernova iPTF13z (Nyholm+, 2017)
J/MNRAS/475/193 : Foundation SN Survey first data release (Foley+, 2018)
J/ApJ/867/108 : Stellar masses & rest-frame u-g of SNIa (Jones+, 2018)
J/ApJ/864/L20 : SN 2017eaw NIR spectroscopy (Rho+, 2018)
J/ApJ/859/101 : The supernovae Ia Pantheon sample (Scolnic+, 2018)
J/ApJ/867/105 : ATLAS all-sky stellar ref. cat. (Tonry+, 2018)
J/ApJ/875/136 : BVRI, sp. & IR obs. of SN2017eaw (Van Dyk+, 2019)
J/ApJ/898/166 : UV to NIR obs. of SN 2019ehk (Jacobson-Galan+, 2020)
J/ApJ/912/46 : ZTF Type II supernovae with follow-up obs. (Bruch+, 2021)
J/ApJ/907/99 : Pre-explosion LC of 227 Supernovae (Strotjohann+, 2021)
Byte-by-byte Description of file: tablea4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.2 d MJD [58970.39/59398.3] Modified Julian Date
10- 16 F7.2 --- Phase [-147.3/280.7] Phase relative to B-band maximum
(MJD 59117.6)
18- 19 A2 --- Filt Filter used
21 A1 --- l_mag Limit flag on mag
23- 27 F5.2 mag mag [14.3/21.87] Apparent magnitude in Filter
29- 32 F4.2 mag e_mag [0.01/0.35]? Uncertainty in mag
34- 38 A5 --- Inst Instrument used (1)
--------------------------------------------------------------------------------
Note (1): Instrument as follows:
Swift = the Ultraviolet Optical Telescope (UVOT) on board the Neil Gehrels
Swift Observatory (227 occurrences)
ZTF = the Zwicky Transient Facility (113 occurrences)
PS1 = the Pan-STARRS1 telescope (60 occurrences)
LCO = the Las Cumbres Observatory (43 occurrences)
ATLAS = the Asteroid Terrestrial-impact Last Alert System (16 occurrences)
Lulin = the 1m Lulin telescope located at Lulin Observatory (4 occurrences)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "Y/M/D" Date Date of observation (UT)
12- 18 F7.1 d MJD [59109/59375] Modified Julian Date
20- 25 F6.1 d Phase [-8.6/257.4] Phase relative to B-band
maximum (MJD 59117.6)
27- 34 A8 --- Tel Telescope
36- 43 A8 --- Inst Instrument
45- 48 I4 0.1nm lam1 [3200/9500] Lower range of wavelength in Å
49 A1 --- --- [-]
50- 54 I5 0.1nm lam2 [9200/24500] Upper range of wavelength in Å
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 d MJD [59109/59375] Modified Julian Date of
the observation
7- 14 A8 --- Inst Instrument identifier (1)
16- 27 E12.6 0.1nm lambda [3162.18/24660.3] Wavelength; Angstroms
29- 37 E9.2 --- Flux [-48.6/34.1] Observed flux (2)
39- 46 E8.2 --- e_Flux [0.003/0.4]? Uncertainty in Flux
--------------------------------------------------------------------------------
Note (1): Instrument as follows:
LRIS = the Keck Low-Resolution Imaging Spectrometer (11797 occurrences)
NIRES = the Keck Near-Infrared Echellette Spectrometer (10961 occurrences)
DEIMOS = the Keck DEep Imaging Multi-Object Spectrograph (8192 occurrences)
Binospec = Binospec on MMT (8108 occurrences)
Kast = the Kast spectrograph on the Shane 3m telescope at Lick
Observatory (5205 occurrences)
DIS = the Dual Imaging Spectrograph on the Astrophysical Research
Consortium (ARC) 3.5-m telescope at Apache Point Observatory (APO)
(2855 occurrences)
Note (2): The LRIS, DEIMOS, and Kast spectra are normalized. The Binospec
and NIRES spectra have units of erg/s/cm^2/Angstroms.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 25-Jul-2023