J/ApJ/745/74 Pre-maximum spectra of type Ia SNe (Folatelli+, 2012)
Unburned material in the ejecta of type Ia supernovae.
Folatelli G., Phillips M.M., Morrell N., Tanaka M., Maeda K., Nomoto K.,
Stritzinger M., Burns C.R., Hamuy M., Mazzali P., Boldt L., Campillay A.,
Contreras C., Gonzalez S., Roth M., Salgado F., Freedman W.L., Madore B.F.,
Persson S.E., Suntzeff N.B.
<Astrophys. J., 745, 74 (2012)>
=2012ApJ...745...74F 2012ApJ...745...74F
ADC_Keywords: Supernovae ; Line Profiles ; Equivalent widths
Keywords: supernovae: general - techniques: spectroscopic
Abstract:
The presence of unburned material in the ejecta of normal Type Ia
supernovae (SNe Ia) is investigated using early-time spectroscopy
obtained by the Carnegie Supernova Project. The tell-tale signature of
pristine material from a C+O white dwarf progenitor star is the
presence of carbon, as oxygen is also a product of carbon burning. The
most prominent carbon lines in optical spectra of SNe Ia are expected
to arise from CII. We find that at least 30% of the objects in the
sample show an absorption at ~6300Å which is attributed to
CIIλ6580. An alternative identification of this absorption as
Hα is considered to be unlikely. These findings imply a larger
incidence of carbon in SNe Ia ejecta than previously noted.
Description:
We base the current work on the sample of optical spectra presented by
G. Folatelli et al. (2011, in preparation). This sample consists of
588 spectra of 82 SNe Ia observed by the Carnegie Supernova Project
(CSP; Hamuy et al. 2006PASP..118....2H 2006PASP..118....2H) between 2004 and 2009.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 97 53 Sample of SNe Ia
table2.dat 70 154 List of pre-maximum spectra
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See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
J/AJ/142/156 : The CSP (DR2): photometry of SNe Ia (Stritzinger+, 2011)
J/AJ/139/519 : Carnegie supernova project. SNe Ia (Contreras+, 2010)
J/AJ/139/120 : Low-redshift Type-Ia supernovae (Folatelli+, 2010)
J/A+A/500/L17 : Spectral flux ratio of SN Ia (Bailey+, 2009)
J/MNRAS/377/1531 : Optical + IR photometry of SN 2004eo (Pastorello+, 2007)
J/ApJ/645/488 : SN type Ia luminosities (Wang+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- SN SN name (YYYYaa)
8- 12 F5.1 d Ep1 [-11.9,0.3] Epoch of the first spectroscopic
observation relative to B-band maximum light
14- 15 A2 --- C2 CII detection type (G1)
17- 22 F6.3 mag Bmag [12.241,18.447] B-band magnitude (1)
24- 28 F5.3 mag e_Bmag [0.005,0.096] Bmag uncertainty
30- 35 F6.3 mag B-Vmax [-0.157,1.196] Maximum B-V color index (2)
37- 41 F5.3 mag e_B-Vmax [0.008,0.136] B-Vmax uncertainty
43- 46 F4.2 mag Dm15 [0.59,1.97] observed decline rate Δm15(B)
48- 51 F4.2 mag e_Dm15 [0.01,0.3] Dm15 uncertainty
53- 58 F6.3 mag E(B-V) [-0.147,1.21]? host galaxy B-V color excess
60- 64 F5.3 mag e_E(B-V) [0.051,0.145]? E(B-V) uncertainty
66 A1 --- n_E(B-V) [Y/ ] Low reddening sample? (3)
68- 74 F7.5 --- zhelio [0.00488,0.07943] NED heliocentric redshift
76- 81 F6.2 mag BMag [-19.68,-15.69]? B-band absolute peak magnitude
83- 86 F4.2 mag e_BMag [0.05,0.22]? BMag uncertainty
88- 92 F5.2 mag DBMag [-0.61,0.75]? B-band Hubble residual (4)
94- 97 F4.2 mag e_DBMag [0.06,0.41]? DBMag uncertainty
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Note (1): MW-extinction-corrected, K-corrected, apparent B-band peak magnitude.
Note (2): Observed pseudo-color at maximum light, corrected for MW reddening.
Note (3): The SNe in the low-reddening sample are indicated with a "Y":
Following the criteria of Folatelli et al. (2010, Cat. J/AJ/139/120),
we picked SNe that
* occurred in E/S0 galaxies or that appeared outside the nuclei and arms
of spiral galaxies and
* which did not show any sign of interstellar Na I D absorption in their
early-time spectra.
To these we added a few objects whose observed (B-V) colors one month
past maximum light were compatible with the intrinsic-color law given
in Equation (2) of Folatelli et al. (2010, Cat. J/AJ/139/120). See
section 4.1 for further explanations.
Note (4): See Figure 18 in section 4.2.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- --- [SN]
4- 9 A6 --- SN Supernova identification (YYYYaa)
11- 20 A10 "YYYY/MM/DD" Date UT Date of the observation
22 A1 --- Flag [d] Spectrum corrected to match
photometry (1)
24- 31 F8.2 d JD Julian Date of the observation (JD-2400000)
33- 37 F5.1 d Phase Phase; days since B-band maximum light
39- 42 I4 0.1nm lam.0 Starting wavelength range; in Angstroms
44- 48 I5 0.1nm lam.1 Ending wavelength range; in Angstroms
50- 53 F4.1 0.1nm Res ? Spectral resolution; in Angstroms (2)
55- 56 A2 --- C2 [N QN F SC] Type of CII 6300Å feature (G1)
58 A1 --- l_pW The 3σ limit on pW
59- 63 F5.2 0.1nm pW ? Pseudo-equivalent width of ∼630nm
absorption; in Angstroms
65- 68 F4.2 0.1nm e_pW ? Uncertainty in pW
70 I1 --- Ref ? Reference (3)
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Note (1): See Folatelli et al. (2011, in prep.).
Note (2): As estimated from the FWHM of arc-lamp lines.
Note (3): Reference as follows:
1 = Folatelli et al. (2011, in prep.);
2 = Altavilla et al. (2007A&A...475..585A 2007A&A...475..585A);
3 = Pastorello et al. (2007, Cat. J/MNRAS/377/1531);
4 = Taubenberger et al. (2008MNRAS.385...75T 2008MNRAS.385...75T);
5 = Yamanaka et al. (2009ApJ...707L.118Y 2009ApJ...707L.118Y);
6 = Stritzinger et al. (2010AJ....140.2036S 2010AJ....140.2036S);
7 = This paper.
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Global notes:
Note (G1): CII type as follows:
N = No detection: SN which shows no apparent absorption but rather a clear
emission component of the SiII6355 line.
A = Absoption: object that does show a clear absorption feature, usually
centered at ∼6320Å.
F = Flat emission profile: intermediate case is that of SNe which show no
clear absorption but an apparently suppressed SiII6355 emission
component.
SC = We have also included SN 2009dc which is a luminous, slowly expanding
SN Ia suggested to arise from a super-Chandrasekhar mass progenitor.
See Section 2.1 for further explanations.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS] , Emmanuelle Perret [CDS] 29-Jul-2013