J/A+A/629/A57 Supernova ASASSN-14jb light curves and spectra (Meza+, 2019)
The extraplanar type II supernova ASASSN-14jb in the nearby edge-on galaxy
ESO 467-G051.
Meza N., Prieto J.L., Clocchiatti A., Galbany L., Anderson J.P., Falco E.,
Kochanek C.S., Kuncarayakti H., Sanchez S.F., Brimacombe J.,
Holoien T.W.-S., Shappee B.J., Stanek K.Z., Thompson T.A.
<Astron. Astrophys. 629, A57 (2019)>
=2019A&A...629A..57M 2019A&A...629A..57M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Supernovae ; Photometry ; Radial velocities ;
Spectroscopy
Keywords: supernovae: individual: ASASSN-14jb -
galaxies: individual: ESO 467-G051 - HII regions -
galaxies: abundances - supernovae: general -
galaxies: distances and redshifts
Abstract:
We present optical photometry and spectroscopy of the Type II
supernova ASASSN-14jb, together with very large telescope (VLT) multi
unit spectroscopic explorer (MUSE) integral field observations of its
host galaxy and a nebular-phase spectrum. This supernova, in the
nearby galaxy ESO 467-G051 (z=0.006), was discovered and followed-up
by the all-sky automated survey for supernovae (ASAS-SN). We obtained
well-sampled las cumbres network (LCOGTN) BVgri and Swift w2m1w1ubv
optical, near-UV/optical light curves, and several optical spectra in
the early photospheric phases. The transient ASASSN-14jb exploded
∼2kpc above the star-forming disk of ESO 467-G051, an edge-on disk
galaxy. The large projected distance from the disk of the supernova
position and the non-detection of any HII region in a 1.4kpc radius in
projection are in conflict with the standard environment of
core-collapse supernova progenitors and suggests the possible scenario
that the progenitor received a kick in a binary interaction. We
present analysis of the optical light curves and spectra, from which
we derived a distance of 25±2Mpc using state-of-the-art empirical
methods for Type II SNe, physical properties of the SN explosion
(56Ni mass, explosion energy, and ejected mass), and properties of
the progenitor; namely the progenitor radius, mass, and metallicity.
Our analysis yields a 56Ni mass of 0.0210±0.0025M☉, an
explosion energy of ∼0.25x1051ergs, and an ejected mass of
∼6M☉. We also constrained the progenitor radius to be
R*=580±28R☉ which seems to be consistent with the sub-Solar
metallicity of 0.3±0.1Z☉ derived from the supernova FeII
λ 5018 line. The nebular spectrum constrains strongly the
progenitor mass to be in the range 10-12M☉. From the Spitzer
data archive we detect ASASSN-14jb ∼330-days past explosion and we
derived a total dust mass of 10-4M☉ from the 3.6um and 4.5um
photometry. Using the FUV, NUV, BVgri,Ks, 3.6um, and 4.5u total
magnitudes for the host galaxy, we fit stellar population synthesis
models, which give an estimate of M*∼1x109M☉ , an age of
3.2Gyr, and a SFR∼0.07M☉/yr. We also discuss the low oxygen
abundance of the host galaxy derived from the MUSE data, having an
average of 12+log(O/H)=8.27+0.16-0.20 using the O3N2 diagnostic
with strong line methods. We compared it with the supernova spectra,
which is also consistent with a sub-Solar metallicity progenitor.
Following recent observations of extraplanar H II regions in nearby
edge-on galaxies, we derived the metallicity offset from the disk,
being positive, but consistent with zero at 2σ, suggesting
enrichment from disk outflows. We finally discuss the possible
scenarios for the unusual environment for ASASSN-14jb and conclude
that either the in-situ star formation or runaway scenario would imply
a low-mass progenitor, agreeing with our estimate from the supernova
nebular spectrum. Regardless of the true origin of ASASSN-14jb, we
show that the detailed study of the environment roughly agree with the
stronger constraints from the observation of the transient.
Description:
Optical photometric observations of ASASSN-14jb were obtained with the
ASAS-SN unit "Cassius" at CTIO in the V-band and the LCOGTN 1-meter
telescopes at CTIO, the Siding Spring Observatory (SSO), the South
African Astronomical Observatory (SAAO), and the McDonald Observatory
(MDO) in the BV and the Sloan Digital Sky Survey (SDSS) gri filters.
ASASSN-14jb was recorded with high signal-to-noise ratio (S/N) in the
images of LCOGTN. This, together with the negligible background from
the host galaxy at the SN site, prompted us to measure the SN flux
using aperture photometry. As our observations extended only up to
80-days after explosion, we searched for public images of the field
which could have recorded ASASSN-14jb at later times. We found some
images in the european southern observatory (ESO) archive. We
retrieved ESO/NTT EFOSC images in BV filters that contained
ASASSN-14jb's explosion site at three different epochs during 2015,
obtained by the public ESO spectroscopic survey of transient objects
(ESO program ID 191.D-0935). Since the SN is fainter in these
late-time images, we measured the SN brightness using PSF fitting
photometry as implemented in IRAF DAOPHOT package. We calibrated the
magnitudes using local standards from Pastorello et al.
(2013ApJ...767....1P 2013ApJ...767....1P).
We estimated expansion velocities from the P-Cygni profiles of the
Balmer lines Hβ and Hα, together with the FeII 5018 and
5169 lines. The spectra were first normalized to a global continuum
fitting a black body or a local power law. Then, when possible, low
degree polynomials were fit to the P-Cygni profile absorptions and the
minimum was taken as a proxy for the expansion velocity. We did not
applied corrections for reddening or peculiar velocities.
The host galaxy of ASASSN-14jb, ESO 467-G051, is an edge-on, Scd
galaxy. Our observations, together with extensive data in the
literature, make it possible to measure integrated fluxes from the UV
up to the IR. To do so, we (1) used co-added LCGOTN images with good
seeing and measured the total BVgri magnitudes using a large
elliptical aperture in ds9; (2) used a near-infrared K_s-band image of
the field from the ESO data archive (PESSTO program ID 191.D-0935) to
measure the magnitude of the host within an elliptical aperture
calibrated to 2MASS stars in the field; (3) obtained archival
ultraviolet magnitudes from GALEX and mid-infrared magnitudes from
Spitzer's S4G survey.
Objects:
----------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------
22 23 16.12 -28 58 30.8 ASASSN-14jb = SN 2014dq
----------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 115 32 Early BVgri LCOGT and late BV EFOSC photometry
of ASASSN-14jb
table2.dat 71 10 Balmer lines and FeII expansion velocities of
ASASSN-14jb
table3.dat 41 10 Integrated magnitudes of the host galaxy,
ESO 467-G051
listsp.dat 46 10 List of spectra
sp/* . 10 Individual spectra
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Date UT date
13- 21 F9.3 d MJD Modified Julian date
25- 31 F7.3 d Epoch Time since explosion
33- 38 F6.3 mag Bmag ?=99 B magnitude (1)
40- 44 F5.3 mag e_Bmag ?=9 B magnitude error
47- 52 F6.3 mag Vmag ?=99 V magnitude (1)
54- 58 F5.3 mag e_Vmag ?=9 V magnitude error
61- 66 F6.3 mag gmag ?=99 g magnitude
68- 72 F5.3 mag e_gmag ?=9 g magnitude error
75- 80 F6.3 mag rmag ?=99 r magnitude
82- 86 F5.3 mag e_rmag ?=9 r magnitude error
89- 94 F6.3 mag imag ?=99 i magnitude
96-100 F5.3 mag e_imag ?=9 i magnitude error
103-115 A13 mag Tel Telescope/Instrument
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Note (1): LCOGT photometry was calibrated using standard stars from the APASS
catalogue.
ESO-NTT photometry was calibrated using the standard stars from
Pastorello et al. (2013ApJ...767....1P 2013ApJ...767....1P).
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 "datime" Obs.date UT date
21- 28 F8.2 d MJD Modified Julian date
30- 34 F5.2 d Epoch time since explosion
36- 39 I4 km/s VHbeta Hβ velocity
41- 43 I3 km/s e_VHbeta Hβ velocity error
45- 48 I4 km/s VFe5018 ?=- FeII5018 velocity
50- 52 I3 km/s e_VFe5018 ?=- FeII5018 velocity error
54- 57 I4 km/s VFe5169 ?=- FeII5169 velocity
59- 61 I3 km/s e_VFe5169 ?=- FeII5169 velocity error
63- 67 I5 km/s VHalpha ?=- Hα velocity
69- 71 I3 km/s e_VHalpha ?=- Hα velocity error
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Filt Filter/Band
16- 20 F5.2 mag mag Magnitude in filter
22- 25 F4.2 mag e_mag Magnitude error
28- 31 A4 -- Sys Magnitude system (AB or Vega)
33- 41 A9 -- Ref Reference (1)
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Note (1): References as follows:
1 = Morrissey et al. (2007ApJS..173..682M 2007ApJS..173..682M)
2 = Sheth et al. (2010PASP..122.1397S 2010PASP..122.1397S, Cat. J/PASP/122/1397)
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Byte-by-byte Description of file: listsp.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Inst Instrument
7- 16 A10 "date" Obs.date Observation date
18- 46 A29 --- FileName Name of tue spectrum file in subdirectory sp
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Byte-by-byte Description of file: sp/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 F16.11 0.1nm lambda Wavelength
20- 32 E13.8 10-2W/m2/nm Flux Flux density (in erg/s/cm2/Å)
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Acknowledgements:
Nicolas Meza, nicomezare(at)gmail.com
(End) Patricia Vannier [CDS] 21-Aug-2019