J/ApJ/926/L25 New LBT/MODS spectra of type Ia SN 2011fe (Tucker+, 2022)
A rapid ionization change in the nebular-phase spectra of the type Ia SN 2011fe.
Tucker M.A., Ashall C., Shappee B.J., Kochanek C.S., Stanek K.Z.,
Garnavich P.
<Astrophys. J., 926, L25 (2022)>
=2022ApJ...926L..25T 2022ApJ...926L..25T
ADC_Keywords: Supernovae; Spectra, optical
Keywords: Type Ia supernovae ; Supernovae ; White dwarf stars
Abstract:
We present three new spectra of the nearby Type Ia supernova (SNIa)
2011fe covering ∼480-850days after maximum light and show that the
ejecta undergoes a rapid ionization shift at ∼500days after explosion.
The prominent FeIII emission lines at ∼4600Å are replaced with
FeI+FeII blends at ∼4400Å and ∼5400Å. The ∼7300Å feature,
which is produced by [FeII]+[NiII] at ≲400days after explosion, is
replaced by broad (~±15000km/s) symmetric [CaII] emission. Models
predict this ionization transition occurring ∼100 days later than what
is observed, which we attribute to clumping in the ejecta. Finally, we
use the nebular-phase spectra to test several proposed progenitor
scenarios for SN 2011fe. Nondetections of H and He exclude nearby
nondegenerate companions, [OI] nondetections disfavor the violent
merger of two white dwarfs, and the symmetric emission-line profiles
favor a symmetric explosion.
Description:
We obtained new spectroscopic observations of SN 2011fe ∼480-850days
after maximum light with the Multi-Object Double Spectrograph (MODS)
on the Large Binocular Telescope (LBT). Table 1 summarizes the
observations.
Objects:
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RA (ICRS) DE Designation(s)
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14 03 05.71 +54 16 25.2 SN 2011fe = PTF 11kly
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 57 3 New LBT MODS spectroscopy
sp/* . 3 The 3 new LBT MODS spectra in ASCII format
(Data behind Figure 1)
fig6.dat 27 7 Line luminosity limits for H-alpha, HeI5876A,
and [OI]6300A (Data behind Figure 6)
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See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
J/ApJ/733/124 : Cepheids in M101 observed with HST (Shappee+, 2011)
J/MNRAS/425/1789 : Berkeley supernova Ia program. I. (Silverman+, 2012)
J/other/NewA/20.30 : BVRI light curves of 3 SN (Munari+, 2013)
J/A+A/554/A27 : 2011fe spectrophotometric time series (Pereira+, 2013)
J/MNRAS/446/3895 : The rising LCs of Type Ia supernovae (Firth+, 2015)
J/ApJ/841/48 : UBVR and IR photometry of SN 2011fe (Ia) (Shappee+, 2017)
J/A+A/630/A76 : SN2016hnk photometry and spectroscopy (Galbany+, 2019)
J/MNRAS/491/2902 : Sub-Chandrasekhar progenitors for Ia SNe (Flors+, 2020)
J/MNRAS/493/1044 : Nebular spectra of 111 Type Ia supernovae (Tucker+, 2020)
J/ApJ/914/50 : Opt. phot. & GMOS & NIRES sp. of SN2019yvq (Tucker+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "Y/M/D" Date Date of observation (UT)
12- 16 F5.1 d Phase [482.6/848.2] Phase relative to tmax
18- 22 I5 s Exp [10800/14650] Exposure time
24- 36 F13.5 d JD Julian Date
38- 57 A20 --- File Name of the ASCII file in subdirectory "sp"
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
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1- 6 F6.1 0.1nm lambda [3247.9/9692.2] Wavelength, Angstroms
8- 20 E13.8 cW/m2/nm Flux [3.4e-24/1.6e-16] Flux, erg/s/cm2/Å
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Byte-by-byte Description of file: fig6.dat
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Bytes Format Units Label Explanations
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1- 6 F6.1 d Phase [229.6/1016] Phase, rest-frame days
8- 13 F6.3 10-28W Ha [0.59/20] Line luminosity limit, H-alpha,
10+35erg/s (1)
15- 20 F6.3 10-28W HeI [0.6/27] Line luminosity limit, HeI5876Å,
10+35erg/s (1)
22- 27 F6.3 10-28W OI [0.7/13.6] Line luminosity limit, [OI]6300Å,
10+35erg/s (1)
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Note (1): Assuming a line width of 1000km/s and including uncertainties
from the broadband flux calibration (see Sec. 2). The distance is
assumed to be 6.4Mpc (Shappe and Stanek 2011, J/ApJ/733/124) and the
distance uncertainty is not included when computing the line limits.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Nov-2023