J/A+A/691/A156 SN 2018jmt and SN 2019cj opt and NIR obs. mag. (Wang+, 2024)
Massive stars exploding in a He-rich circumstellar medium.
X. Flash spectral features in the Type Ibn SN 2019cj and observations of
SN 2018jmt.
Wang Z.-Y., Pastorello A., Maeda K., Reguitti A., Cai Y.-Z., Howell D.A.,
Benetti S., Buckley D., Cappellaro E., Carini R., Cartier R., Chen T.-W.,
Elias-Rosa N., Fang Q.-L., Gal-Yam A., Gangopadhyay A., Gromadzki M.,
Gan W.-P., Hiramatsu D., Hu M.-K., Inserra C., McCully C., Nicholl M.,
Olivares F.E., Pignata G., Pineda-Garcia J., Pursiainen M., Ragosta F.,
Rau A., Roy R., Sollerman J., Tartaglia L., Terreran G., Valerin G.,
Wang Q., Wang S.-Q., Young D.R., Aryan A., Bronikowski M., Concepcion E.,
Galbany L., Lin H., Melandri A., Petrushevska T., Ramirez M., Shi D.-D,
Warwick B., Zhang J.-J., Wang B., Wang X.-F., Zhu X.-J.
<Astron. Astrophys. 691, A156 (2024)>
=2024A&A...691A.156W 2024A&A...691A.156W (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Photometry, infrared ; Optical
Keywords: circumstellar matter - supernovae: general -
supernovae: individual: SN 2018jmt - supernovae: individual: SN 2019cj
Abstract:
We present optical and near-infrared observations of two Type Ibn
supernovae (SNe), SN 2018jmt and SN 2019cj. Their light curves have
rise times of about 10 days, reaching an absolute peak magnitude of
Mg(SN 2018jmt)=-19.07±0.37 and MV(SN 2019cj)=-18.94±0.19mag,
respectively. The early-time spectra of SN 2018jmt are dominated by a
blue continuum, accompanied by narrow (600-1000km/s) HeI lines with
P-Cygni profile. At later epochs, the spectra become more similar to
those of the prototypical SN Ibn 2006jc. At early phases, the spectra
of SN 2019cj show flash ionisation emission lines of CIII, NIII and
HeII superposed on a blue continuum. These features disappear after a
few days, and then the spectra of SN 2019cj evolve similarly to those
of SN 2018jmt. The spectra indicate that the two SNe exploded within a
He-rich circumstellar medium (CSM) lost by the progenitors a short
time before the explosion. We model the light curves of the two SNe
Ibn to constrain the progenitor and the explosion parameters. The
ejecta masses are consistent with either that expected for a canonical
SN Ib (∼2M☉) or those from a massive WR star (≳4M☉), with
the kinetic energy on the order of 1051 erg. The lower limit on the
ejecta mass (≳2M☉) argues against a scenario involving a
relatively low-mass progenitor (e.g., MZAMS∼10M☉). We set a
conservative upper limit of ∼0.1M☉ for the 56Ni masses in both
SNe. From the light curve modelling, we determine a two-zone CSM
distribution, with an inner, flat CSM component, and an outer CSM with
a steeper density profile. The physical properties of SN 2018jmt and
SN 2019cj are consistent with those expected from the core collapse of
relatively massive, stripped-envelope (SE) stars.
Description:
We conducted multi-band optical (Sloan griz, Johnson-Cousins
UBV) and near-infrared (NIR; JHK) follow-up campaigns of SNe 2018jmt
and 2019cj starting shortly after their classification.
Photometry tables for two Ibn supernovae (SN 2018jmt, SN 2019cj).
Objects:
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RA (2000) DE Designation(s)
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06 54 47.09 -59 30 10.8 SN 2018jmt = MASTER OT J065447.10-593010.8
04 56 22.92 -46 02 11.1 SN 2019cj = ASASSN -19af
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
18jmt.dat 55 138 Light curves of SN 2018jmt (BVgri)
19cj.dat 55 188 Light curves of SN 2019cj (BVgri)
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Byte-by-byte Description of file: 18jmt.dat 19cj.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "date" Date Date of observation (YYYY/MM/DD)
12- 20 F9.3 d MJD Modified Julian Date
22- 27 F6.2 d Phase Phase relative maximum light (1)
29- 33 A5 --- Filter Filter (2)
35 A1 --- l_mag Limit flag on mag
36- 41 F6.3 mag mag Apparent magnitude in Filter
43- 47 F5.3 mag e_mag ?=- Error on apparent magnitude
49- 55 A7 --- Inst/Source Instrument or Source
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Note (1): for SN 2018jmt: phases are relative to g-band maximum light
(MJD=58465.66±1.20; 2018-12-13) in observer frame.
For SN 2019cj: phases are relative to V-band maximum light
(MJD=58492.44±0.23; 2019-01-09) in observer frame.
Note (2): Filters are U, B, V, J, H, K, g, r, i, z and Clear for SN 2018jmt,
U, B, V, J, H, K, g, r, i, z, o and r for SN 2019cj.
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Acknowledgements:
Yongzhi Cai, yzcai789(at)163.com
(End) Patricia Vannier [CDS] 28-Aug-2024