J/A+A/630/A76 SN2016hnk photometry and spectroscopy (Galbany+, 2019)
Evidence for a Chandrasekhar-mass explosion in the Ca-strong 1991bg-like type Ia
supernova 2016hnk.
Galbany L., Ashall C., Hoeflich P., Gonzalez-Gaitan S., Taubenberger S.,
Stritzinger M., Hsiao E.Y., Mazzali P., Baron E., Blondin S., Bose S.,
Bulla M., Burke J.F., Burns C.R., Cartier R., Chen P., Della Valle M.,
Diamond T.R., Gutierrez C.P., Harmanen J., Hiramatsu D., Holoien T.W.-S,
Hosseinzadeh G., Howell D.A., Huang Y., Inserra C., de Jaeger T., Jha S.W.,
Kangas T., Kromer M., Lyman J.D., Maguire K., Howie Marion G.,
Milisavljevic D., Prentice S.J., Razza A., Reynolds T.M., Sand D.J.,
Shappee B.J., Shekhar R., Smartt S.J., Stassun K.G., Sullivan M.,
Valenti S., Villanueva S., Wang X., Craig Wheeler J., Zhai Q., Zhang J.
<Astron. Astrophys. 630, A76 (2019)>
=2019A&A...630A..76G 2019A&A...630A..76G (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Photometry, UBV ; Photometry, ugriz ;
Photometry, infrared ; Spectroscopy ; Equivalent widths
Keywords: supernovae: general - supernovae: individual: SN 2016hnk
Abstract:
We present a comprehensive dataset of optical and near-infrared
photometry and spectroscopy of type Ia supernova (SN) 2016hnk,
combined with integral field spectroscopy (IFS) of its host galaxy,
MCG -01-06-070, and nearby environment. Our goal with this complete
dataset is to understand the nature of this peculiar object. Methods:
Properties of the SN local environment are characterized by means of
single stellar population synthesis applied to IFS observations taken
two years after the SN exploded. We performed detailed analyses of SN
photometric data by studying its peculiar light and color curves. SN
2016hnk spectra were compared to other 1991bg-like SNe Ia, 2002es-like
SNe Ia, and Ca-rich transients. In addition, we used abundance
stratification modeling to identify the various spectral features in
the early phase spectral sequence and also compared the dataset to a
modified non-LTE model previously produced for the subluminous
SN1999by. Results: SN 2016hnk is consistent with being a subluminous
(MB=-16.7mag, sBV=0.43±0.03), highly reddened object. The IFS of
its host galaxy reveals both a significant amount of dust at the SN
location, residual star formation, and a high proportion of old
stellar populations in the local environment compared to other
locations in the galaxy, which favors an old progenitor for SN
2016hnk. Inspection of a nebular spectrum obtained one year after
maximum contains two narrow emission lines attributed to the forbidden
[CaII] λλ7291,7324 doublet with a Doppler shift of
700km/s. Based on various observational diagnostics, we argue that the
progenitor of SN 2016hnk was likely a near Chandrasekhar-mass (MCh)
carbon-oxygen white dwarf that produced 0.108M☉ of 56 Ni. Our
modeling suggests that the narrow [CaII] features observed in the
nebular spectrum are associated with 48 Ca from electron capture
during the explosion, which is expected to occur only in white dwarfs
that explode near or at the MCh limit.
Description:
We present ATLAS photometry in c and o bands, and ASASS-SN V-band
photometry in Tables C1 and C2, respectively. All other photometric
observations and SN magnitudes are given in Tables C3 (optical) and
C4 (NIR) in the AB system.
The full spectral log is presented in Table C5.
We highlight a few features in SN 2016hnk that we characterized in the
spectral sequence in terms of the evolution of their pseudo-equivalent
width (pEW) and velocities. We list our measurements in Tables C6
and C7.
Objects:
------------------------------------------------------------
RA (2000) DE Designation(s)
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02 13 16.63 -07 39 40.7 SN 2016hnk = NAME AT 2016hnk
------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 29 17 ASASSN V-band photometry and upper limits
tablec2.dat 39 58 ATLAS c/o-band photometry and upper limits
tablec3.dat 115 72 Photometry for SN2016hnk
tablec4.dat 62 6 Near-infrared photometry for SN2016hnk
tablec5.dat 127 30 Journal of spectroscopic observations
tablec6.dat 91 22 Measured velocities in units of 10+3km/s
tablec7.dat 103 22 Measured pseudo-equivalent widths in Å
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Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d MJD Modified Julian Day
11- 16 F6.2 d Epoch [-36.46/+08.66] Rest-frame epoch
18 A1 --- l_Vmag Limit flag on Vmag
19- 23 F5.2 mag Vmag ASASSN V-band magnitude or upper limit (AB)
25- 29 F5.3 mag e_Vmag ? V-band magnitude error
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Byte-by-byte Description of file: tablec2.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d MJD Modified Julian Day
11- 16 F6.2 d Epoch [-45.15/+93.33] Rest-frame epoch
18- 22 F5.2 mag cmag ? ATLAS c-band magnitude (AB)
24- 27 F4.2 mag e_cmag ? ATLAS c-band magnitude error
29 A1 --- l_omag Limit flag on omag
30- 34 F5.2 mag omag ? ATLAS o-band magnitude or upper limit (AB)
36- 39 F4.2 mag e_omag ? ATLAS o-band magnitude error
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Byte-by-byte Description of file: tablec3.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d MJD Modified Julian Day
11- 17 F7.2 d Epoch [+0.7/+108.6] Rest-frame epoch
19- 24 F6.3 mag Bmag ? B-band magnitude (AB)
26- 30 F5.3 mag e_Bmag ? B-band magnitude error
32- 37 F6.3 mag Vmag ? V-band magnitude (AB)
39- 43 F5.3 mag e_Vmag ? V-band magnitude error
45 A1 --- l_umag limit flag on umag
46- 51 F6.3 mag umag ? u-band upper limit (AB)
53- 58 F6.3 mag gmag ? g-band magnitude (AB)
60- 64 F5.3 mag e_gmag ? g-band magnitude error
66- 71 F6.3 mag rmag ? r-band magnitude (AB)
73- 77 F5.3 mag e_rmag ? r-band magnitude error
79- 84 F6.3 mag imag ? i-band magnitude (AB)
86- 90 F5.3 mag e_imag ? i-band magnitude error
92- 97 F6.3 mag zmag ? z-band magnitude (AB)
99-103 F5.3 mag e_zmag ? z-band magnitude error
105-115 A11 --- Inst Telescope/instrument (1)
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Note (1): Instrument as follows:
fl03 = LCOGT node at Cerro Tololo Inter-American Observatory
fl04 = LCOGT node at Cerro Tololo Inter-American Observatory
fl06 = LCOGT node at SAAO
fl11 = LCOGT node at Siding Spring Observatory
fl12 = LCOGT node at Siding Spring Observatory
fl14 = LCOGT node at SAAO
fl15 = LCOGT node at Cerro Tololo Inter-American Observatory
fl16 = LCOGT node at SAAO
FLI = DEMONEXT
IO:O = Liverpool Telescope
ALFOSC_FASU = Nordic Optical Telescope
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Byte-by-byte Description of file: tablec4.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d MJD Modified Julian Day
11- 16 F6.2 d Epoch [+5.62/+72.29] Rest-frame epoch
18- 23 F6.3 mag Jmag J-band magnitude
25- 29 F5.3 mag e_Jmag J-band magnitude error
31- 36 F6.3 mag Hmag H-band magnitude
38- 42 F5.3 mag e_Hmag H-band magnitude error
44- 49 F6.3 mag Kmag K-band magnitude
51- 55 F5.3 mag e_Kmag K-band magnitude error
57- 62 A6 --- Inst Telescope/instrument (1)
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Note (1): Telescope as follows:
SOFI = New Technology Telescope
NOTCAM = Nordic Optical Telescope
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Byte-by-byte Description of file: tablec5.dat
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Bytes Format Units Label Explanations
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1- 23 A23 "datime" UT Time of the spectrum
25- 32 F8.2 d MJD Modified Julian day
34- 40 F7.2 d Epoch B-band rest-frame epoch
42- 63 A22 s Texp Time of exposure
65- 68 F4.2 --- Airmass Airmass
70- 76 A7 --- Tel Telescope
78- 89 A12 --- Spec Spectrograph (1)
91-101 A11 --- Grism Grism
103-112 A10 --- Range Wavelength range (Å)
114-127 A14 --- Res Resolution
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Note (1): Spectrograph as follows:
HILTNER = Hiltner Telescope 2.4m
SOAR = Southern Astrophysical Research Telescope 4.1m
SALT = Southern African Large Telescope 11m
NOT = Nordic Optical telescope 2.6m
NTT = New Technology Telescope 3.58m
LT = Liverpool Telescope 2.0m
GEMINI = Gemini South Telescope 8.1m
LJT = Lijiang Telescope 2.4m
MMT = MMT Telescope 6.5m
VLT = Very Large Telescope 8.2m
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Byte-by-byte Description of file: tablec6.dat
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Bytes Format Units Label Explanations
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1- 6 F6.2 d Epoch B-band Rest-frame epoch
8- 12 F5.2 10+3km/s VCaIIHK ? CaIIHK velocity
14- 17 F4.2 10+3km/s e_VCaIIHK ? CaIIHK velocity error
19- 23 F5.2 10+3km/s VFeII ? FeII velocity
25- 28 F4.2 10+3km/s e_VFeII ? FeII velocity error
30- 33 F4.2 10+3km/s VSIIW1 ? SIIW1 velocity
35- 38 F4.2 10+3km/s e_VSIIW1 ? SIIW1 velocity error
40- 43 F4.2 10+3km/s VSIIW2 ? SIIW2 velocity
45- 48 F4.2 10+3km/s e_VSIIW2 ? SIIW2 velocity error
50- 53 F4.2 10+3km/s VSiII5972 ? SiII5972 velocity
55- 58 F4.2 10+3km/s e_VSiII5972 ? SiII5972 velocity error
60- 64 F5.2 10+3km/s VSiII6355 ? SiII6355 velocity
66- 69 F4.2 10+3km/s e_VSiII6355 ? SiII6355 velocity error
71- 75 F5.2 10+3km/s VOI ? OI velocity
77- 80 F4.2 10+3km/s e_VOI ? OI velocity error
82- 86 F5.2 10+3km/s VCaIINIR ? CaIINIR velocity
88- 91 F4.2 10+3km/s e_VCaIINIR ? CaIINIR velocity error
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Byte-by-byte Description of file: tablec7.dat
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Bytes Format Units Label Explanations
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1- 6 F6.2 d Epoch B-band rest-frame epoch
8- 13 F6.2 0.1nm WCaIIHK ? CaIIHK pseudo equivalent width
15- 19 F5.2 0.1nm e_WCaIIHK ? CaIIHK pseudo equivalent width error
21- 26 F6.2 0.1nm WFeII ? FeII pseudo equivalent width
28- 32 F5.2 0.1nm e_WFeII ? FeII pseudo equivalent width error
34- 38 F5.2 0.1nm WSIIW1 ? SIIW1 pseudo equivalent width
40- 43 F4.2 0.1nm e_WSIIW1 ? SIIW1 pseudo equivalent width error
45- 49 F5.2 0.1nm WSIIW2 ? SIIW2 pseudo equivalent width
51- 54 F4.2 0.1nm e_WSIIW2 ? SIIW2 pseudo equivalent width error
56- 60 F5.2 0.1nm WSiII5972 ? SiII5972 pseudo equivalent width
62- 65 F4.2 0.1nm e_WSiII5972 ? SiII5972 pseudo equivalent width error
67- 72 F6.2 0.1nm WSiII6355 ? SiII6355 pseudo equivalent width
74- 78 F5.2 0.1nm e_WSiII6355 ? SiII6355 pseudo equivalent width error
80- 85 F6.2 0.1nm WOI ? OI pseudo equivalent width
87- 90 F4.2 0.1nm e_WOI ? OI pseudo equivalent width error
92- 97 F6.2 0.1nm WCaIINIR ? CaIINIR pseudo equivalent width
99-103 F5.2 0.1nm e_WCaIINIR ? CaIINIR pseudo equivalent width error
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Acknowledgements:
Lluis Galbany, lluisgalbany(at)gmail.com
(End) Patricia Vannier [CDS] 30-Aug-2019