J/ApJ/870/L1 K2 observations of type Ia supernova SN 2018oh (Dimitriadis+, 2019)
K2 observations of SN2018oh reveal a two-component rising light curve for a
type Ia supernova.
Dimitriadis G., Foley R.J., Rest A., Kasen D., Piro A.L., Polin A.,
Jones D.O., Villar A., Narayan G., Coulter D. A, Kilpatrick C.D.,
Pan Y.-C., Rojas-Bravo C., Fox O.D., Jha S.W., Nugent P.E., Riess A.G.,
Scolnic D., Drout M.R., Barentsen G., Dotson J., Gully-Santiago M.,
Hedges C., Cody A.M., Barclay T., Howell S., Garnavich P.,
Tucker B.E., Shaya E., Mushotzky R., Olling R.P., Margheim S., Zenteno A.,
Coughlin J., Van Cleve J.E., Vinicius de Miranda Cardoso J., Larson K.A.,
McCalmont-Everton K.M., Peterson C.A., Ross S.E., Reedy L.H.,
Osborne D., McGinn C., Kohnert L., Migliorini L., Wheaton A., Spencer B.,
Labonde C., Castillo G., Beerman G., Steward K., Hanley M., Larsen R.,
Gangopadhyay R., Kloetzel R., Weschler T., Nystrom V., Moffatt J.,
Redick M., Griest K., Packard M., Muszynski M., Kampmeier J., Bjella R.,
Flynn S., Elsaesser B., Chambers K.C., Flewelling H.A., Huber M.E.,
Magnier E.A., Waters C.Z., Schultz A.S.B., Bulger J., Lowe T.B.,
Willman M., Smartt S.J., Smith K.W., Points S., Strampelli G.M.,
Brimacombe J., Chen P., Munoz J.A., Mutel R.L., Shields J., Vallely P.J.,
Villanueva S., Li W., Wang X., Zhang J., Lin H., Mo J., Zhao X.,
Sai H., Zhang X., Zhang K., Zhang T., Wang L., Zhang J., Baron E.,
DerKacy J.M., Li L., Chen Z., Xiang D., Rui L., Wang L., Huang F.,
Li X., Hosseinzadeh G., Howell D.A., Arcavi I., Hiramatsu D., Burke J.,
Valenti S., Tonry J.L., Denneau L., Heinze A.N., Weiland H., Stalder B.,
Vinko J., Sarneczky K., Pal A., Bodi A., Bognar Z., Csak B., Cseh B.,
Csornyei G., Hanyecz O., Ignacz B., Kalup C., Konyves-Toth R.,
Kriskovics L., Ordasi A., Rajmon I., Sodor A., Szabo R., Szakats R.,
Zsidi G., Williams S.C., Nordin J., Cartier R., Frohmaier C., Galbany L.,
Gutierrez C.P., Hook I., Inserra C., Smith M., Sand D.J., Andrews J.E.,
Smith N., Bilinski C.
<Astrophys. J., 870, L1 (2019)>
=2019ApJ...870L...1D 2019ApJ...870L...1D
ADC_Keywords: Supernovae; Optical; Photometry
Keywords: supernovae: general ; supernovae: individual (SN 2018oh)
Abstract:
We present an exquisite 30minute cadence Kepler (K2) light curve of
the Type Ia supernova (SNIa) 2018oh All-Sky Automated Survey for
Supernovae (ASASSN-18bt), starting weeks before explosion, covering
the moment of explosion and the subsequent rise, and continuing past
peak brightness. These data are supplemented by multi-color Panoramic
Survey Telescope (Pan-STARRS1) and Rapid Response System 1 and Cerro
Tololo Inter-American Observatory 4m Dark Energy Camera (CTIO 4-m
DECam) observations obtained within hours of explosion. The K2 light
curve has an unusual two-component shape, where the flux rises with a
steep linear gradient for the first few days, followed by a quadratic
rise as seen for typical supernovae (SNe) Ia. This "flux excess"
relative to canonical SNIa behavior is confirmed in our i-band light
curve, and furthermore, SN2018oh is especially blue during the early
epochs. The flux excess peaks 2.14±0.04 days after explosion, has
a full width at half maximum (FWHM) of 3.12±0.04 days, a blackbody
temperature of T=17500-9000+11500K, a peak luminosity of
4.3±0.2x1037erg/s, and a total integrated energy of
1.27±0.01x1043erg. We compare SN2018oh to several models that
may provide additional heating at early times, including collision
with a companion and a shallow concentration of radioactive nickel.
While all of these models generally reproduce the early K2 light curve
shape, we slightly favor a companion interaction, at a distance of
∼2x1012cm based on our early color measurements, although the exact
distance depends on the uncertain viewing angle. Additional
confirmation of a companion interaction in future modeling and
observations of SN2018oh would provide strong support for a
single-degenerate progenitor system.
Description:
SN 2018oh was discovered by the All Sky Automated Survey for
SuperNovae (ASAS-SN) in images obtained on 2018 February 4.41 UT.
The supernova is located 7.8" north and 2.0" east of the center of
UGC 4780, an Sdm star-forming galaxy, with a redshift of z=0.010981
and a distance of 49.4Mpc. UGC 4780 was included as a Campaign 16
target through "The K2 ExtraGalactic Survey (KEGS) for Transients"
(PI: A. Rest) and the "Multi-Observatory Monitoring of K2 Supernovae"
(PI: R. J. Foley) programs as part of the K2 SCE (internal Kepler
ID 228682548). The UGC 4780 data were retrieved from MAST.
We also observed the K2 field with both the Panoramic Survey
Telescope and Rapid Response System 1 (Pan-STARRS1) telescope and the
Cerro Tololo Inter-American Observatory (CTIO) 4m Mayall telescope
with the Dark Energy Camera (DECam) during Campaign 16.
Objects:
------------------------------------------------------
RA (ICRS) DE Designation(s)
------------------------------------------------------
09 06 39.59 +19 20 17.5 SN 2018oh = ASASSN -18bt
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 50 3520 SN 2018oh K2 photometry
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See also:
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
J/AJ/133/403 : Light curve of 11 type Ia supernovae (Garg+, 2007)
J/AJ/135/1598 : Optical spectroscopy of type Ia supernovae (Matheson+, 2008)
J/MNRAS/389/1577 : UBVRI absolute magnitudes of Type Ia SNe (Takanashi+, 2008)
J/A+A/523/A7 : Light curves of type Ia supernovae in SNLS (Guy+, 2010)
J/ApJ/716/712 : HST light curves of six SNe and Union2 (Amanullah+, 2010)
J/ApJ/722/566 : Host galaxies of SNeIa in SDSS-II SN survey (Lampeitl+,2010)
J/MNRAS/406/782 : Type Ia supernovae luminosities (Sullivan+, 2010)
J/ApJ/749/18 : Swift/UVOT observations of 12 nearby SN-Ia (Brown+, 2012)
J/ApJS/200/12 : CfA4: light curves for 94 type Ia SNe (Hicken+, 2012)
J/A+A/554/A27 : 2011fe spectrophotometric time series (Pereira+, 2013)
J/A+A/568/A22 : Joint analysis of the SDSS-II & SNLS SNe Ia (Betoule+, 2014)
J/ApJ/795/44 : PS1 SNe Ia (0.02<z<0.7) griz light curves (Rest+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/ApJ/813/30 : UV-Optical light curves of SNIa iPTF14bdn (Smitka+, 2015)
J/ApJS/220/9 : CfAIR2: NIR light curves of Type Ia SNe (Friedman+, 2015)
J/MNRAS/446/3895 : The rising light curves of Type Ia supernovae (Firth+, 2015)
J/ApJ/826/144 : Follow-up observations of SNIa ASASSN-14lp (Shappee+, 2016)
J/MNRAS/456/2260 : K2 Variability Catalogue II (Armstrong+, 2016)
J/ApJ/854/24 : Environmental dependence of SN Ia luminosities (Kim+, 2018)
J/ApJ/857/51 : Measuring dark energy data with PS1 SNe. II. (Jones+,2018)
J/A+A/627/A174 : Early light curve of SN 2013gy (Holmbo+, 2019)
J/ApJ/870/13 : K2 LC alternative analysis of ASASSN-18bt (Shappee+, 2019)
http://archive.stsci.edu/missions-and-data/k2 : K2 mission data on MAST
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 yr Obs.Y Year of the observation
5 A1 --- --- [-]
6- 7 I2 "month" Obs.M Month of the observation
8 A1 --- --- [-]
9- 13 F5.2 d Obs.D Day of the observation in decimal days
15- 22 F8.2 d MJD [58094/58174] Modified julian date of
observation
24- 29 F6.2 d Phase [-67/12] Rest-frame phase relative
to MJDpeakK2=58162.1
31- 36 F6.2 d Time [-49/30] Time from detection relative
to MJDK2detection=58144.39
38 A1 --- l_Kpmag 3σ upper limit flag on Kpmag
39- 44 F6.3 mag Kpmag [14/22] Apparent Kepler magnitude
46- 50 F5.3 mag e_Kpmag [0.001/0.36]? Uncertainty in Kpmag
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix 12-Feb-2020