J/ApJ/898/166 UV to NIR obs. of SN 2019ehk (Jacobson-Galan+, 2020)
SN 2019ehk: a double-peaked Ca-rich transient with luminous X-ray emission and
shock-ionized spectral features.
Jacobson-Galan W.V., Margutti R., Kilpatrick C.D., Hiramatsu D., Perets H.,
Khatami D., Foley R.J., Raymond J., Yoon S.-C., Bobrick A., Zenati Y.,
Galbany L., Andrews J., Brown P.J., Cartier R., Coppejans D.L.,
Dimitriadis G., Dobson M., Hajela A., Howell D.A., Kuncarayakti H.,
Milisavljevic D., Rahman M., Rojas-Bravo C., Sand D.J., Shepherd J.,
Smartt S.J., Stacey H., Stroh M., Swift J.J., Terreran G., Vinko J.,
Wang X., Anderson J.P., Baron E.A., Berger E., Blanchard P.K., Burke J.,
Coulter D.A., DeMarchi L., DerKacy J.M., Fremling C., Gomez S.,
Gromadzki M., Hosseinzadeh G., Kasen D., Kriskovics L., McCully C.,
Muller-Bravo T.E., Nicholl M., Ordasi A., Pellegrino C., Piro A.L., Pal A.,
Ren J., Rest A., Rich R.M., Sai H., Sarneczky K., Shen K.J., Short P.,
Siebert M.R., Stauffer C., Szakats R., Zhang X., Zhang J., Zhang K.
<Astrophys. J., 898, 166 (2020)>
=2020ApJ...898..166J 2020ApJ...898..166J
ADC_Keywords: Supernovae; Spectra, infrared; Photometry, UBVRI
Keywords: Supernovae ; White dwarf stars ; Core-collapse supernovae ;
X-ray telescopes ; Stellar mass loss ; Stellar phenomena ;
Transient sources
Abstract:
We present panchromatic observations and modeling of the Calcium-rich
supernova (SN) 2019ehk in the star-forming galaxy M100 (d∼16.2Mpc)
starting 10hr after explosion and continuing for ∼300days. SN 2019ehk
shows a double-peaked optical light curve peaking at t=3 and 15days.
The first peak is coincident with luminous, rapidly decaying
Swift-XRT-discovered X-ray emission (Lx∼1041erg/s at 3days;
Lx∝t-3), and a Shane/Kast spectral detection of narrow
Hα and HeII emission lines (v∼500km/s) originating from
pre-existent circumstellar material (CSM). We attribute this
phenomenology to radiation from shock interaction with extended, dense
material surrounding the progenitor star at r<1015cm and the
resulting cooling emission. We calculate a total CSM mass of
∼7x10-3M☉ (MHe/MH∼6) with particle density n∼109cm-3.
Radio observations indicate a significantly lower density
n<104cm-3 at larger radii r>(0.1-1)x1017cm. The photometric and
spectroscopic properties during the second light-curve peak are
consistent with those of Ca-rich transients (rise-time of
tr=13.4!±0.210days and a peak B-band magnitude of
MB=-15.1±0.200mag). We find that SN 2019ehk synthesized
(3.1±0.11)x10-2M☉ of 56Ni and ejected
Mej=(0.72±0.040)M☉ total with a kinetic energy
Ek=(1.8±0.10)x1050erg. Finally, deep HST pre-explosion imaging
at the SN site constrains the parameter space of viable stellar
progenitors to massive stars in the lowest mass bin (∼10M☉) in
binaries that lost most of their He envelope or white dwarfs (WDs).
The explosion and environment properties of SN 2019ehk further
restrict the potential WD progenitor systems to low-mass hybrid HeCO
WD+CO WD binaries.
Description:
In this paper, we present, analyze, and model multiwavelength
observations (X-ray to radio) of a new CaST, SN 2019ehk, discovered by
astronomer Joel Shepherd on 2019 April 29 (MJD 58602.24) using a TEC
140mm APO refracting telescope and Atik 460 EX Mono camera with an
SDSS g filter.
We started observing SN 2019ehk with the Ultraviolet Optical Telescope
(UVOT) on board the Neil Gehrels Swift Observatory on 2019 May 1 until
2019 May 26 (δt=2.8-27.3days since explosion).
SN 2019ehk was imaged between 2019 April 30 and 2019 August 1
(δt=1.2-94.2days since explosion) with the Direct camera on the
Swope 1m telescope at Las Campanas Observatory, Chile and the
PlaneWave CDK-700 0.7m telescope at Thacher Observatory in Ojai,
California. Observations were performed in Johnson BV and Sloan ugriz
filters.
Las Cumbres Observatory (LCO) UBVgri-band data of SN 2019ehk were
obtained with the Sinistro cameras on the 1m telescopes at Sutherland
(South Africa), CTIO (Chile), Siding Spring (Australia), and McDonald
(USA), through the Global Supernova Project.
SN 2019ehk was also observed with ATLAS, 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.
Additional follow-up photometry on SN 2019ehk was gathered at the
Konkoly Observatory, Hungary, using the 0.8m RC80 telescope equipped
with a CCD camera and BVg'r'i'z' filters.
SN 2019ehk was observed with Shane/Kast, SOAR/Goodman, and Keck/LRIS
between -12 days and +257 days relative to the second light-curve
peak. SN 2019ehk was observed using EFOSC2 at the 3.58m ESO New
Technology Telescope (NTT) on 2019 May 13. LCO optical spectra were
taken with the FLOYDS spectrographs mounted on the 2m Faulkes
Telescope North and South at Haleakala (USA) and Siding Spring
(Australia), respectively, through the Global Supernova Project. One
low-resolution optical spectrum was taken with the 300l/mm grating on
the Boller & Chivens (B&C) spectrograph mounted on the 2.3m Bok
telescope on Kitt Peak on 2019 June 5. Additionally, one
moderate-resolution spectrum was taken with the Binospec spectrograph
on the MMT using the 600l/mm grating on 2019 June 3. The spectroscopic
observations of SN 2019ehk were also collected using the Xinglong
2.16m telescope (+BFOSC), and the Lijiang 2.4m telescope (+YFOSC) in
China. On 2019 June 22 (MJD 58656.0), we used the Triple-Spec
instrument at SOAR to obtain a set of three ABBA observations of
SN2019ehk.
A full log of spectroscopic observations is presented in Table A9.
Objects:
-----------------------------------------------------
RA (ICRS) DE Designation(s)
-----------------------------------------------------
12 22 56.15 +15 49 34.2 SN 2019ehk = SN 2019ehk
-----------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea9.dat 62 27 Optical spectroscopy of SN 2019ehk
tablea10.dat 45 382 Optical photometry of SN 2019ehk
fig34.dat 39 78995 Spectral observations of SN 2019ehk
fig5.dat 19 6329 SOAR Triple Spec NIR spectrum of SN 2019ehk on
MJD 58655.9 or +38d relative to second B-band peak
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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/ApJ/692/L84 : Photometry of SN 2008D (Malesani+, 2009)
J/ApJ/702/226 : Swift/UVOT panchromatic obs. of SN 2008D (Modjaz+, 2009)
J/AJ/139/120 : Low-redshift Type-Ia supernovae (Folatelli+, 2010)
J/ApJ/742/L18 : Follow-up photometry of the SN IIb PTF 11eon (Arcavi+, 2011)
J/ApJ/749/177 : Yellow and red supergiants in the LMC (Neugent+, 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/MNRAS/438/L101 : First month on SN 2013ej (Valenti+, 2014)
J/A+A/579/A40 : PESSTO catalog (Smartt+, 2015)
J/ApJ/821/57 : Photometry of the Type Ib/c SN2013ge (Drout+, 2016)
J/A+A/593/A68 : PTF12os and iPTF13bvn spectra & LCs (Fremling+, 2016)
J/ApJ/836/60 : Bgri light curves of PTF11kmb and PTF12bho (Lunnan+, 2017)
J/ApJ/855/107 : PMAS Integral-field SN hosts COmpilation (Galbany+, 2018)
J/ApJ/867/105 : ATLAS all-sky stellar ref. cat. ATLAS-REFCAT2 (Tonry+, 2018)
J/A+A/630/A76 : SN2016hnk photometry and spectroscopy (Galbany+, 2019)
J/ApJ/887/169 : UV-Opt light curves of the type Ic SN 2018gep (Ho+, 2019)
J/ApJ/896/165 : Optical light curves of SN 2016hnk (Jacobson-Galan+, 2020)
Byte-by-byte Description of file: tablea9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "Y/M/D" Date UT date of observation
12- 18 F7.1 d MJD [58603.3/58872.1] Modified Julian Date
20- 25 F6.1 d Phase [-12/257] Phase relative to second B-band
maximum (MJD 58615.156)
27- 39 A13 --- Tel Telescope (1)
41- 51 A11 --- Inst Instrument
53- 56 I4 0.1nm lam1 Lower wavelength range
57 A1 --- --- [-]
58- 62 I5 0.1nm lam2 Upper wavelength range
--------------------------------------------------------------------------------
Note (1): Telescope as follows:
Shane = The 3m Shane telescope (+Kast)
Xinglong = The Xinglong 2.16m telescope (+BFOSC), China
Faulkes North = The 2m Faulkes Telescope North at Haleakala (USA) (+FLOYDS)
Keck I = Keck I (+LRIS)
SOAR = The Southern Astrophysical Research telescope
Bok = The Boller & Chivens (B&C) spectrograph mounted on the 2.3m
Bok telescope on Kitt Peak
LJT = The Lijiang 2.4m telescope (+YFOSC), China
MMT = The Multiple Mirror Telescope Observatory (+Binospec)
NTT = The 3.58m ESO New Technology Telescope (+EFOSC2) through the
ePESSTO+ program (Smartt+ 2015, J/A+A/579/A40 ;
Nicholl+ 2019ATel12697....1N 2019ATel12697....1N)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.2 d MJD [58573.46/58699.26] Modified Julian Date
10- 15 F6.2 --- Phase [-41.7/84.11] Phase (1)
17- 18 A2 --- Filt Filter used (ugriz, M2W1W2UBV, c, o)
20- 20 A1 --- l_mag Limit flag on mag
22- 26 F5.2 mag mag [15.41/24.0]? Apparent magnitude in Filt
28- 31 F4.2 mag e_mag [0.0/1.96]? Uncertainty in mag
33- 45 A13 --- Inst Instrument (2)
--------------------------------------------------------------------------------
Note (1): Relative to second B-band maximum (MJD 58615.156).
Note (2): Instrument as follows:
Swope = The Swope Telescope at Las Campanas Observatory, Chile
(84 occurrences)
Thacher = Thacher Observatory in Ojai, California (81 occurrences)
LCO = Las Cumbres Observatory (LCO) UBVgri-band data obtained with
the Sinistro cameras on the 1m telescopes at
Sutherland (South Africa), CTIO (Chile),
Siding Spring (Australia), and McDonald (USA), through
the Global Supernova Project (73 occurrences)
Swift = Swift/UVOT (42 occurrences)
ATLAS = The Asteroid Terrestrial-impact Last Alert System, Hawaii
(41 occurrences)
Konkoly = The 0.8m RC80 telescope at the Konkoly observatory, Hungary
(27 occurrences)
ZTF = The Zwicky Transient Facility public data (27 occurrences)
Joel Shepherd = Discovery with a TEC 140mm APO refracting telescope
(7 occurrences)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig34.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Date Observation date; UT
12- 19 A8 --- Inst Instrument (1)
21- 28 F8.2 0.1nm lambda [3150/11300] Wavelength; Angstroms
30- 39 E10.3 cW/m2/nm Flux Flux density in erg/s/cm2/Å units
--------------------------------------------------------------------------------
Note (1): Instrument as follows:
Kast = Shane/Kast (28215 occurrences)
BFOSC = the Xinglong 2.16m telescope (+BFOSC) (10105 occurrences)
FLOYDS = the FLOYDS spectrographs mounted on the 2m Faulkes Telescope North
and South at Haleakala (USA) and Siding Spring (Australia)
(17903 occurrences)
Goodman = SOAR/Goodman (2520 occurrences)
YFOSC = The Lijiang 2.4m telescope +YFOSC (1861 occurrences)
APO-Red = (1501 occurrences)
APO-Blue = (1201 occurrences)
EFOSC2 = the ePESSTO+ program (Smartt+ 2015, J/A+A/579/A40 ;
Nicholl+ 2019ATel12697....1N 2019ATel12697....1N) with Grism #13 on EFOSC2 at
the 3.58m New Technology Telescope (NTT) (1013 occurrences)
B&C = the Boller & Chivens spectrograph mounted on the 2.3m Bok telescope
on Kitt Peak (1098 occurrences)
Binospec = the Binospec spectrograph on the MMT (4023 occurrences)
LRIS = Keck I (+LRIS) (9555 occurrences)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.6 um lambda [0.94/2.5] Wavelength
10- 19 E10.3 cW/m2/nm Flux [-7.9e-16/1.2e-15] Flux density
in erg/s/cm2/Å units
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-Nov-2021