J/ApJ/873/L3 NUV to NIR photometry of type IIP ASASSN-16at (Bose+, 2019)
Strongly bipolar inner ejecta of the normal type IIP supernova ASASSN-16at.
Bose S., Dong S., Elias-Rosa N., Shappee B.J., Bersier D., Benetti S.,
Stritzinger M.D., Grupe D., Kochanek C.S., Prieto J.L., Chen P.,
Kuncarayakti H., Mattila S., Morales-Garoffolo A., Morrell N., Onori F.,
Reynolds T.M., Siviero A., Somero A., Stanek K.Z., Terreran G.,
Thompson T.A., Tomasella L., Ashall C., Gall C., Gromadzki M.,
Holoien T.W.-S.
<Astrophys. J., 873, L3 (2019)>
=2019ApJ...873L...3B 2019ApJ...873L...3B
ADC_Keywords: Supernovae; Photometry, ultraviolet; Photometry, ugriz
Keywords: galaxies: individual (UGC 08041) ; supernovae: general ;
supernovae: individual (ASASSN-16at, SN 2016X)
Abstract:
We report distinctly double-peaked Hα and Hβ emission lines
in the late-time, nebular-phase spectra (≳200 days) of the otherwise
normal at early phases (≲100 days) type IIP supernova ASASSN-16at
(SN2016X). Such distinctly double-peaked nebular Balmer lines have
never been observed for a type II SN. The nebular-phase Balmer
emission is driven by the radioactive 56Co decay, so the observed
line profile bifurcation suggests a strong bipolarity in the 56Ni
distribution or in the line-forming region of the inner ejecta. The
strongly bifurcated blueshifted and redshifted peaks are separated by
∼3x103km/s and are roughly symmetrically positioned with respect to
the host-galaxy rest frame, implying that the inner ejecta are
composed of two almost-detached blobs. The red peak progressively
weakens relative to the blue peak, and disappears in the 740 days
spectrum. One possible reason for the line-ratio evolution is
increasing differential extinction from continuous formation of dust
within the envelope, which is also supported by the near-infrared flux
excess that develops after ∼100 days.
Description:
ASASSN-16at was discovered in the host galaxy UGC 8041 by the All-Sky
Automated Survey for Supernovae (ASAS-SN; Shappee+ 2014, J/ApJ/788/48)
on UT 2016 January 20.59 using the "Brutus" telescope in Haleakala,
Hawaii.
The host galaxy distance is 15.2±3.0Mpc according to
Sorce+ (2014, J/MNRAS/444/527).
We adopt the explosion epoch of 2016 January 18.92
(JD 2457406.42±0.57) and use this as the reference epoch.
We obtained NUV through near-IR (NIR) photometry and optical
spectroscopy of ASASSN-16at from 0.6 to 881 days.
The NUV observations were obtained with the
Neil-Gehrels-Swift-Observatory Ultraviolet/Optical Telescope (UVOT).
Optical photometric observations were obtained using the ASAS-SN
quadruple 14cm "Brutus" telescopes, the 2.0m Liverpool telescope (LT),
the Las Cumbres Observatory 1.0m telescope network.
NIR observations were obtained with the 2.6m Nordic Optical Telescope
(NOT).
Spectroscopic observations were done using the ALFOSC the 2.6m NOT,
the B&C spectrograph on the 1.2m Galileo Telescope, the AFOSC
spectrograph on the 1.8m Copernico telescope in Asiago (Italy), the
SPRAT spectrograph mounted on LT, the B&C Spectrograph on the 2.5m
Irenee du Pont, LDSS on the 6.5m Magellan Baade telescope, LRS on the
3.6m Telescopio Nazionale Galileo and the OSIRIS spectrograph on 10.4m
Gran Telescopio Canarias (GTC) between 2016 Jan 21 and 2018 Jan 28.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
12 55 15.50 +00 05 59.7 ASASSN-16at = SN 2016X
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 146 152 *Optical and NIR photometry of ASASSN-16at
table2b.dat 115 23 *NUV photometry of ASASSN-16at
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Note on table2.dat and table2b.dat: Data observed within 5hr are represented
under a single-epoch observation.
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
B/eso : ESO Science Archive Catalog (ESO, 1991-2020)
VIII/76 : Leiden/Argentine/Bonn (LAB) Survey of Galactic HI (Kalberla+ 2005)
J/ApJ/756/173 : Photom. of type IIn SNe 2005ip & 2006jd (Stritzinger+, 2012)
J/MNRAS/433/1871 : UBVRI griz light curves of SN 2012aw (Bose+, 2013)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/MNRAS/444/527 : Tully-Fisher distances for Spitzer galaxies (Sorce+, 2014)
J/MNRAS/448/2608 : UV and opt. photometric data for SN 2013by (Valenti+, 2015)
J/ApJ/799/208 : Type IIP supernovae from Pan-STARRS1 (Sanders+, 2015)
J/A+A/580/A142 : SN 2011dh. The first two years (Ergon+, 2015)
J/MNRAS/471/4966 : ASAS-SN bright supernova catalogue 2016 (Holoien+, 2017)
J/ApJ/861/63 : Type IIP SN 2016bkv LCs and spectra (Hosseinzadeh+, 2018)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Set "Opt" or "NIR"
5- 18 A14 "Y/M/D" Date UT date of observation
20- 26 F7.2 d JD [7406.99/8533.62] Julian date of observation;
JD-2450000
28- 34 F7.2 d Phase [0.57/1127.2] Days since the explosion
epoch JD 2457406.42
36- 41 F6.3 mag Bmag [14.2/18.8]? B-band magnitude
43- 47 F5.3 mag e_Bmag [0.017/1.3]? Bmag uncertainty
49- 54 F6.3 mag Vmag [14/19.1]? V-band magnitude
56- 60 F5.3 mag e_Vmag [0.02/1.8]? Vmag uncertainty
62- 67 F6.3 mag umag [13.9/20.9]? u-band magnitude
69- 73 F5.3 mag e_umag [0.06/0.3]? umag uncertainty
75- 80 F6.3 mag gmag [14/22.1]? g-band magnitude
82- 86 F5.3 mag e_gmag [0.02/0.5]? gmag uncertainty
88- 93 F6.3 mag rmag [14/21.8]? r-band magnitude
95- 99 F5.3 mag e_rmag [0.012/0.3]? rmag uncertainty
101-106 F6.3 mag imag [14.1/22.7]? i-band magnitude
108-112 F5.3 mag e_imag [0.011/0.7]? imag uncertainty
114-119 F6.3 mag zmag [14.3/22.1]? z-band magnitude
121-125 F5.3 mag e_zmag [0.013/0.5]? zmag uncertainty
127-131 F5.2 mag Kmag [14.8/19]? K-band magnitude
133-136 F4.2 mag e_Kmag [0.05/0.6]? Kmag uncertainty
138-146 A9 --- Tel Telescope and instrument (1)
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Note (1): The abbreviations of telescope/instrument used are as follows:
ASASSN = ASAS-SN quadruple 14cm telescopes;
LCOGT = Las Cumbres Observatory 1m telescope network;
LT = 2m Liverpool Telescope;
NC = NOTCam mounted on 2.0m NOT
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Byte-by-byte Description of file: table2b.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Set "NUV"
5- 18 A14 "Y/M/D" Date UT date of observation
20- 26 F7.2 d JD [7408.58/7452.83] Julian date of observation;
JD-2450000
28- 32 F5.2 d Phase [2.16/46.41] Days since the explosion
epoch JD 2457406.42
34- 39 F6.3 mag UVW2mag [12.7/18.9]? Swift/UVOT UVW2 magnitude
41- 45 F5.3 mag e_UVW2mag [0.03/0.3]? UVW2mag uncertainty
47- 52 F6.3 mag UVM2mag [12.6/19.5]? Swift/UVOT UVM2 magnitude
54- 58 F5.3 mag e_UVM2mag [0.03/0.4]? UVM2mag uncertainty
60- 65 F6.3 mag UVW1mag [12.7/17.8]? Swift/UVOT UVW1 magnitude
67- 71 F5.3 mag e_UVW1mag [0.03/0.2]? UVW1mag uncertainty
73- 78 F6.3 mag Umag [12.9/16.4]? Swift/UVOT U magnitude
80- 84 F5.3 mag e_Umag [0.03/0.08]? Umag uncertainty
86- 91 F6.3 mag Bmag [14.2/15.7]? Swift/UVOT B magnitude
93- 97 F5.3 mag e_Bmag [0.03/0.05]? Bmag uncertainty
99-104 F6.3 mag Vmag [14.1/14.9]? Swift/UVOT V magnitude
106-110 F5.3 mag e_Vmag [0.03/0.06]? Vmag uncertainty
112-115 A4 --- Tel Telescope and instrument (always "UVOT")
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 14-Aug-2020