J/AJ/143/126 Spectroscopy of 462 nearby Type Ia supernovae (Blondin+, 2012)
The spectroscopic diversity of type Ia supernovae.
Blondin S., Matheson T., Kirshner R.P., Mandel K.S., Berlind P.,
Calkins M., Challis P., Garnavich P.M., Jha S.W., Modjaz M., Riess A.G.,
Schmidt B.P.
<Astron. J., 143, 126 (2012)>
=2012AJ....143..126B 2012AJ....143..126B
ADC_Keywords: Supernovae ; Spectroscopy ; Redshifts ; Equivalent widths ;
Photometry, UBV ; Surveys
Keywords: supernovae: general - surveys
Abstract:
We present 2603 spectra of 462 nearby Type Ia supernovae (SNe Ia),
including 2065 previously unpublished spectra, obtained during
1993-2008 through the Center for Astrophysics Supernova Program. There
are on average eight spectra for each of the 313 SNe Ia with at least
two spectra. Most of the spectra were obtained with the FAST
spectrograph at the Fred Lawrence Whipple Observatory 1.5m telescope
and reduced in a consistent manner, making this data set well suited
for studies of SN Ia spectroscopic diversity. Using additional data
from the literature, we study the spectroscopic and photometric
properties of SNe Ia as a function of spectroscopic class using the
classification schemes of Branch et al. (2006PASP..118..560B 2006PASP..118..560B) and Wang
et al. (2009, Cat. J/ApJ/699/L139). The width-luminosity relation
appears to be steeper for SNe Ia with broader lines, although the
result is not statistically significant with the present sample. Based
on the evolution of the characteristic SiIIλ6355 line, we
propose improved methods for measuring velocity gradients, revealing a
larger range than previously suspected, from ∼0 to ∼400km/s/day
considering the instantaneous velocity decline rate at maximum light.
Description:
We present the second large release of supernovae (SNe) Ia
spectra from the Harvard-Smithsonian Center for Astrophysics (CfA) SN
Program (CfA1, 1999AJ....117..707R 1999AJ....117..707R; CfA2, 2006, Cat. J/AJ/131/527;
CfA3, 2011, Cat. J/ApJ/700/331; CfA4, 2012, Cat. J/ApJS/200/12) taken
between 1993 October and 2008 August. This sample consists of 2603
spectra of 462 nearby supernovae Ia out to z∼0.12.
The majority of spectra presented here were obtained with the FAST
spectrograph mounted on the Tillinghast 1.5m telescope at the Fred
Lawrence Whipple Observatory (FLWO) on Mount Hopkins, Arizona. The
observations were carried out for the most part by two professional
observers (P. Berlind and M. L. Calkins), as well as by the
Harvard-Smithsonian Center for Astrophysics (CfA) personnel. The setup
for observations with FAST yielded a typical FWHM resolution of
6-7Å over a wavelenght range of ∼3700 to ∼7500Å. Additional
spectra were obtained during classically scheduled nights at the MMT
Observatory 6.5m telescope with the Blue Channel and Red Channel
spectrographs. A number of different spectrograph settings were used,
yielding FWHM resolutions ranging between ∼3 and ∼13Å.
Last, a few spectra were obtained with the Magellan 6.5m Clay
(+LDSS-2/LDSS-3) and Baade (+IMACS) telescopes. The FWHM resolution
varies between ∼9 and ∼18Å for LDSS-2, 9-12Å for LDSS-3, and
5-6Å for IMACS.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 122 462 Basic supernovae parameters
table3.dat 53 24 SN redshifts not taken from NED
table4.dat 50 246 Supernovae Ia classification using the schemes
of Branch et al. (2006PASP..118..560B 2006PASP..118..560B) and
Wang et al. (2009, Cat. J/ApJ/699/L139)
tablea1.dat 146 2603 Journal of observations
observer.dat 23 96 Observers
standard.dat 18 26 Standard stars
refs.dat 135 20 References
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See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
J/ApJS/200/12 : CfA4: light curves for 94 type Ia SNe (Hicken+, 2012)
J/MNRAS/410/1262 : Supernova Legacy Survey. Type Ia supernovae (Walker+, 2011)
J/ApJ/731/120 : Intrinsic SN Ia light curves (Mandel+, 2011)
J/A+A/529/L4 : Reddening law of type Ia supernovae (Chotard+, 2011)
J/ApJ/742/89 : Relations between spectra & colors of SNe Ia (Foley+, 2011)
J/AJ/142/156 : The CSP (DR2): photometry of SNe Ia (Stritzinger+, 2011)
J/MNRAS/406/782 : Type Ia supernovae luminosities (Sullivan+, 2010)
J/ApJS/190/418 : Light curves for 165 SNe (Ganeshalingam+, 2010)
J/AJ/139/120 : Low-redshift Type-Ia supernovae (Folatelli+, 2010)
J/AJ/139/519 : Carnegie supernova project. SNe Ia (Contreras+, 2010)
J/A+A/500/L17 : Spectral flux ratio of SN Ia (Bailey+, 2009)
J/ApJ/699/L139 : Spectral parameters of SNe Ia (Wang+, 2009)
J/ApJ/700/1097 : Light curve parameters of SN Ia (Hicken+, 2009)
J/ApJ/700/331 : Light curves of type Ia supernovae (CfA3) (Hicken+, 2009)
J/ApJ/689/377 : PAIRITEL SN Ia as NIR standard candles (Wood-Vasey+, 2008)
J/MNRAS/389/1577 : UBVRI absolute magnitudes of Type Ia SNe (Takanashi+, 2008)
J/AJ/136/2306 : SDSS-II Supernova survey, 2005 (Holtzman+, 2008)
J/A+A/477/717 : Spectroscopy of Type Ia supernovae (Bronder+, 2008)
J/AJ/135/1598 : Optical spectroscopy of type Ia supernovae (Matheson+, 2008)
J/ApJ/666/674 : ESSENCE supernova survey (Miknaitis+, 2007)
J/ApJ/659/122 : Improved distances to type Ia supernovae (Jha+, 2007)
J/AJ/131/1648 : Type Ia SNe at high and low redshifts (Blondin+, 2006)
J/AJ/131/527 : UBVRI light curves of 44 type Ia supernovae (Jha+, 2006)
http://www.cfa.harvard.edu/supernova/SNarchive.html : CfA SN archive
http://snfactory.lbl.gov/snf/open_access/snlist.php : SNfactory Supernova
Discoveries
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- SN SN identifier (SN YYYYaa or SNFYYYYMMDD-NNN)
17- 22 F6.4 --- z Heliocentic redshift (1)
24- 30 F7.1 d MJD ? Modified Julian Date at B-band maximum light
tmax(B)
32- 34 F3.1 d e_MJD ? The 1σ error in MJD (2)
36- 44 A9 --- Ref1 Light-curve fitter reference for MJD (3)
46- 50 A5 --- r_MJD References to estimates taken from the
literature for MJD (in refs.dat file)
52 A1 --- f_MJD [hij] Uncertain tmax (4)
54- 57 F4.2 mag Dm15B ? Decline rate in B-band Δm15(B)
(change of Bmag at tmax+15d)
59- 62 F4.2 mag e_Dm15B ? The 1σ error in Dm15B (5)
64- 65 A2 --- Ref2 Light-curve fitter reference for Dm15B (3)
67- 71 A5 --- r_Dm15B References to estimates taken from the
literature for Dm15B (in refs.dat file)
73- 78 F6.2 mag BMag ? Intrinsic absolute peak B-band magnitude (6)
80- 83 F4.2 mag e_BMag ? The 1σ error in BMag
85- 89 F5.2 mag B-V ? Intrinsic (B-V) color index at B-band maximum
light (7)
91- 94 F4.2 mag e_B-V ? The 1σ error in B-V
96-100 F5.2 mag Bm-Vm ? Intrinsic (Bmax-Vmax) pseudo-color (7)
102-105 F4.2 mag e_Bm-Vm ? The 1σ error in Bm-Vm
107-122 A16 --- r_phot References for published photometric data
(see refs.dat file)
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Note (1): As reported in NASA/IPAC Extragalactic Database (NED) (except for the
redshifts given in Table 3).
Note (2): In the case of multiple MJD estimates the error is given as the
standard deviation of the individual values. For cases where no error
information was available we assume a typical 0.5day uncertainty.
Note (3): Fitter reference as follows:
B = BayeSN (Mandel et al., 2009ApJ...704..629M 2009ApJ...704..629M);
M = Updated version of the multicolor light-curve shape method (MLCS2k2;
Jha et al. 2007, Cat. J/ApJ/659/122);
SA = SALT2 (Guy et al., 2007A&A...466...11G 2007A&A...466...11G);
SN = SNooPy (Burns et al., 2011AJ....141...19B 2011AJ....141...19B);
Note (4): Flag as follows:
h = Jha et al. (2007, Cat. J/ApJ/659/122) give tmax(B)=49288.08±1.19,
but the fit is uncertain (first photometric point>+10days past B-band
maximum).
i = Jha et al. (2007, Cat. J/ApJ/659/122) give tmax(B)=50630.25±0.98 and
Dm15B=1.02±0.10, but the fit is uncertain (first photometric
point>+10days past B-band maximum).
j = Jha et al. (2007, Cat. J/ApJ/659/122) give tmax(B)=50840.57±2.02,
but the fit is qualified by them as "poor".
Note (5): We assign a minimum 0.05mag uncertainty to Dm15B estimates with
SNooPy (Burns et al., 2011AJ....141...19B 2011AJ....141...19B) which typically yield a
formal ∼0.01mag uncertainty.
Note (6): From BayeSN (Mandel et al., 2009ApJ...704..629M 2009ApJ...704..629M; assuming
H0=72km/s/Mpc) for SN Ia with zCMB≥0.01 and AV<1mag.
Note (7): From BayeSN (Mandel et al., 2009ApJ...704..629M 2009ApJ...704..629M) for supernovae Ia
with zCMB≥0.01 and AV<1mag.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- SN SN identifier (SN YYYYaa or SNFYYYYMMDD-NNN)
17- 39 A23 --- Gal SN host galaxy
41- 46 F6.4 --- z Redshift
48 A1 --- f_z Flag on z (1)
50- 53 A4 --- r_z Reference for z (2)
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Note (1): Flag as follows:
b = NED reports a redshift z=0.049 based on the host-galaxy redshift given in
IAUC 5882 (Schmidt et al., 1993IAUC.5882....3S 1993IAUC.5882....3S). We have re-derived the
redshift using the same spectrum of the host galaxy as
Schmidt et al. (1993IAUC.5882....3S 1993IAUC.5882....3S).
c = NED reports an approximate redshift z=0.13 based on the blueshift of the
SiIIλ5972 line (assumed to be 10000km/s in IAUC 6405;
Garnavich et al., 1996IAUC.6332....1G 1996IAUC.6332....1G); Riess et al. (1999AJ....117..707R 1999AJ....117..707R)
give log(cz)=4.571, or cz=37239km/s (z=0.1242), "from (their) spectra of
the host galaxies;" last, Jha et al. (2007, Cat. J/ApJ/659/122) give
cz=37109km/s (z=0.1238). There are no obvious galaxy lines in our spectrum
of SN 1996ab nor could we find a spectrum of its host galaxy.
d = NED reports an erroneous redshift of cz=1800km/s (z=0.0060) for
MCG+07-36-33.
e = Scalzo et al. (2010ApJ...713.1073S 2010ApJ...713.1073S) report z=0.07416±0.00082 based on
[O II]λ3727 and Hα.
f = Redshift of a nearby galaxy cluster; the SN spectrum is consistent with
this redshift.
g = Bailey et al. (2009, Cat. J/A+A/500/L17) report the CMB-frame redshift for
this SN. We derived a heliocentric redshift using its coordinates as
reported on the SNfactory Supernova Discoveries Web site
(http://snfactory.lbl.gov/snf/open_access/snlist.php).
Note (2): Reference as follows:
1 = Scalzo et al. (2010ApJ...713.1073S 2010ApJ...713.1073S);
2 = Yuan et al. (2008CBET.1206....1Y 2008CBET.1206....1Y);
3 = Bailey et al. (2009, Cat. J/A+A/500/L17);
abs = absorption lines from the host galaxy in our own spectrum;
em = emission lines from the host galaxy in our own spectrum;
SNID = cross-correlation with SN Ia spectral templates using the SNID code of
Blondin & Tonry (2007ApJ...666.1024B 2007ApJ...666.1024B; typical error <0.005).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- SN SN identifier (SN YYYYaa or SNFYYYYMMDD-NNN)
17 A1 --- f_SN [dg*] Flag on SN (1)
19- 22 F4.1 0.1nm pW5972 Pseudo-equivalent width of SiII λ5972
absorption feature (2)
24- 28 F5.1 0.1nm pW6355 Pseudo-equivalent width of SiII λ6355
absorption feature (2)
30- 35 I6 km/s v6355 Absorption velocity of SiII λ6355
absorption feature (3)
37- 40 F4.1 d Phase Phase in rest-frame (days from B-band maximum)
42- 43 A2 --- Bcl Branch et al. (2006PASP..118..560B 2006PASP..118..560B) class based
on EW5972 and EW6355 (4)
45- 48 A4 --- Wcl Wang et al. (2009, Cat. J/ApJ/699/L139) class
based on vabs(λ6355) (5)
50 A1 --- f_Wcl Peculiar supernovae not classified by Wang (6)
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Note (1): Flag as follows:
g = Supernovae 2003fg is also known as SNLS-03D3bb
(Howell et al., 2006Natur.443..308H 2006Natur.443..308H).
d = Reddening and contamination by the host galaxy renders the Branch
classification uncertain.
* = Branch et al. (2006PASP..118..560B 2006PASP..118..560B) classification differs from that
reported by Branch et al. (2009PASP..121..238B 2009PASP..121..238B) indicated in
parentheses:
SN 1989B=BL (CL), SN 1999ac=CN (SS), SN 1999ee=CN (SS),
SN 1999gd=CN (BL), SN 2000E=CN (SS), SN 2002er=CN (BL),
SN 2005cg=CN (SS).
Note (2): In units of Angstroms. Formal uncertainty typically<1Å.
Note (3): Formal uncertainty typically<100km/s.
Note (4): Within 5days from maximum light. We also report a classification for
supernovae Ia with no spectra within 5days from maximum
(but within 7days) based on the overall shape of the SiII λ6355
absorption feature.
Branch et al. (2006PASP..118..560B 2006PASP..118..560B) class as follows:
CN = Core Normal;
BL = Broad Line;
SS = Shallow Silicon;
CL = Cool.
Note (5): Within 7days from maximum light (note that Figure 8 only displays
measurements within 3days from maximum). Wang et al. (2009, Cat.
J/ApJ/699/L139) class as follows:
N = Normal;
HV = High-velocity;
91T = 1991T-like;
91bg = 1991bg-like.
Note (6): Peculiar supernovae Ia (SN 2000cx, SN 2002cx, SN 2003fg, SN
2005hk, SN 2006gz, SN 2007if, SN 2008A, SN 2008ae, SN 2009dc) are
not part of the Wang classification scheme.
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- SN SN identifier (SN YYYYaa
or SNFYYYYMMDD-NNN)
17- 29 A13 "YYYY/MM/DD" ObsDate UT date at midpoint of the observation
31 A1 --- f_ObsDate [pqrs] Observation flag on Obs.date (1)
33- 42 F10.2 d HJD Heliocentric Julian date at midpoint
of observation
44 A1 --- f_Phase [@] no reliable estimate of tmax(B) (2)
45- 50 F6.1 d Phase Rest-frame phase of spectrum relative
to B-band maximum
52- 58 A7 --- Inst Telescope and instrument used (3)
60- 63 I4 0.1nm lam.0 Observed spectrum wavelength range (Å)
64 A1 --- --- [-]
65- 69 I5 0.1nm lam.1 Observed spectrum wavelength range (Å)
71- 74 F4.2 0.1nm/pix Disp Spectral dispersion; in Angstroms/pixel
76- 80 A5 0.1 Res Approximate FWHM spectral resolution (Å)
82- 87 F6.1 deg PA [-180/180]? Observed position angle
during observation
89- 92 F4.1 deg dphi Absolute difference |Δφ| (4)
94- 97 F4.2 --- AirM Airmass of observation
99-110 A12 --- spStd Spectrophotometric standard star used
(in standard.dat file)
112-117 A6 arcsec Seeing Seeing based upon estimates by the
observers.
119-121 F3.1 arcsec Slit ? Spectroscopic slit width
123-133 A11 s Exp Exposure time. Separate exposures indicated
135-146 A12 --- Obs Observer code (in observer.dat file)
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Note (1): Observation flag as follows:
p = Spectra with ∼400Å wide gaps (∼6150-6550Å) between blue and red
halves.
q = The first two standard stars were used to calibrate a spectrum taken
with our standard grating tilt, while the third was used to calibrate
a spectrum taken with a red tilt.
r = Spectra accidently omitted from
Matheson et al. (2008, Cat. J/AJ/135/1598).
s = Spectra strongly affected by dark-current problems following UV
flashing, for which we have trimmed off a portion of the spectrum.
Note (2):
@ = A supernovae Ia with no reliable estimate for the time of maximum.
Phase given is relative to the first spectrum.
Note (3): Telescope and instrument as follows:
FAST = FLWO 1.5m+FAST;
IMACS = Magellan Baade+IMACS;
LDSS2 = Magellan Clay+LDSS2;
LDSS3 = Magellan Clay+LDSS3;
MMTblue = MMT+Blue Channel;
MMTred = MMT+Red Channel.
Note (4): Between the observed position angle and the average parallactic
angle over the course of the observation.
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Byte-by-byte Description of file: observer.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Code Observer code
6- 23 A18 --- Name Observer name
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Byte-by-byte Description of file: standard.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Code Standard star code
7- 18 A12 --- Name Standard star name
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Ref Reference code
7- 25 A19 --- BibCode BibCode
27- 46 A20 --- Aut Author's name
48-135 A88 --- Com Comments
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 26-Jun-2013