J/A+A/477/717 Spectroscopy of Type Ia supernovae (Bronder+, 2008)
SNLS spectroscopy: testing for evolution in type Ia supernovae.
Bronder T.J., Hook I.M., Astier P., Balam D., Balland C., Basa S.,
Carlberg R.G., Conley A., Fouchez D., Guy J., Howell D.A., Neill J.D.,
Pain R., Perrett K., Pritchet C.J., Regnault N., Sullivan M., Baumont S.,
Fabbro S., Filliol M., Perlmutter S., Ripoche P.
<Astron. Astrophys., 477, 717-734 (2008)>
=2008A&A...477..717B 2008A&A...477..717B
ADC_Keywords: Supernovae ; Photometry ; Equivalent widths
Keywords: Supernovae: general - cosmology: observations - surveys
Abstract:
We present a quantitative study of a new data set of high redshift
Type Ia supernovae spectra, observed at the Gemini telescopes during
the first 34 months of the Supernova Legacy Survey. During this time
123 supernovae candidates were observed, of which 87 have been
identified as SNe Ia at a median redshift of z=0.720. Spectra from the
entire second year of the survey and part of the third year (59 total
SNe candidates with 46 confirmed SNe Ia) are published here for the
first time. The spectroscopic measurements made on this data set are
used determine if these distant SNe comprise a population similar to
those observed locally.
Rest-frame equivalent width and ejection velocity measurements are
made on four spectroscopic features. Corresponding measurements are
presented for a set of 167 spectra from 24 low-z SNe Ia from the
literature.
Description:
Full details of the methods used for CFHT Supernova Legacy Survey
(SNLS) SN candidate selection and observation can be found in Sullivan
et al. (2006AJ....131..960S 2006AJ....131..960S) and Howell et al. (2005ApJ...634.1190H 2005ApJ...634.1190H),
respectively. In summary, the Canada-France-Hawaii Telescope Legacy
Survey (CFHTLS), using the Megacam wide field imager, acquires real
time light-curves of possible SNe by repeatedly imaging four, one
square-degree fields approximately every four days (observers' frame)
in several filters (a combination of g', r', i', and z') as part of
the Deep component of the CFHTLS. Spectroscopic observations are then
made at 8m-class telescopes in order to identify the SN-type and
redshift of these candidates.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 76 61 Observed properties and instrument settings for
SNLS SNe candidates observed from November 2004
to May 2006
table7.dat 71 59 SNLS identifications and derived properties for SNe
candidates observed from Nov. 2004 to May 2006
tablea1.dat 65 55 *Equivalent width and ejection velocity results
for the published high redshift SNe Ia observed
by the SNLS at the Gemini telescopes
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Note on tablea1.dat: This set includes all of the SNLS objects (reduced by
the author) that were confirmed as Type Ia SNe (a confidence index of
3 or higher) and were subject to less than 65% contamination from
their host galaxies.
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See also:
B/sn : Asiago Supernova Catalogue
II/189 : Magnitude Observations of Type I Supernovae (Cadonau+ 1990)
J/AJ/112/2408 : Light Curves of 29 SNe (Hamuy+ 1996)
J/A+A/437/789 : Restframe I-band light curves of SN Ia (Nobili+, 2005)
J/AJ/131/527 : UBVRI light curves of 44 type Ia supernovae (Jha+, 2006)
J/AJ/131/1648 : Type Ia supernovae at high and low redshifts (Blondin+, 2006)
J/ApJ/645/488 : SN type Ia luminosities (Wang+, 2006)
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- SNLS SN name
8- 9 I2 h RAh Right ascension (J2000)
11- 12 I2 min RAm Right ascension (J2000)
14- 19 F6.3 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 32 F5.2 arcsec DEs Declination (J2000)
34- 43 A10 "YYYY-MM-DD" ObsDate Observation date
45- 48 I4 s ExpTime Exposure time
50- 52 A3 --- Mode Observing mode (1)
54- 56 I3 nm lambdac ? Central wavelength
58- 61 F4.2 arcsec Seeing Seeing
63- 67 F5.2 mag i'mag i' magnitude (2)
69 A1 --- l_Inc Limit flag on Inc
70- 74 I5 % Inc Percentage increase (2) (3)
76 A1 --- EW [*] For SN having equivalent width data
in tablea1
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Note (1): Observing mode as follows:
C = classical
N+S = nod-and-shuffle
Note (2): Estimated from the light-curves and correspond to the date of
spectroscopy.
Note (3): Percentage increase relative to the host galaxy (interpolated to
the date of spectroscopy)
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- SNLS SN name
8- 12 F5.3 --- z ?=- Redshift (1)
14- 18 F5.3 --- e_z ?=- rms uncertainty on z
20 I1 --- CI Confidence index
22- 27 A6 --- SNType Final object identification
29- 34 A6 --- Temp Template name of best low-z spectral fit
36- 38 I3 d TempDay ? Days past maximum of best low-z spectral fit
40- 71 A32 --- r_z Host features used to estimate z
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Note (1): Redshifts identified with host galaxy features are accurate to
~±0.001. Redshifts identified with template matches are accurate to
~±0.01.
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- SNLS SN name
8- 12 F5.2 --- Day Rest-frame day, relative to B'max
14- 17 F4.2 --- e_Day rms uncertainty on Day
20- 24 F5.1 0.1nm EW(CaII) ?=- CaII equivalent width (1)
26- 29 F4.1 0.1nm e_EW(CaII) ?=- rms uncertainty in EW(CaII) (2)
33- 36 F4.1 0.1nm EW(SiII) ?=- SiII equivalent width (1)
38- 41 F4.1 0.1nm e_EW(SiII) ?=- rms uncertainty in EW(SiII) (2)
44- 48 F5.1 0.1nm EW(MgII) ?=- MgII equivalent width (1)
50- 53 F4.1 0.1nm e_EW(MgII) ?=- rms uncertainty in EW(MgII) (2)
56- 60 F5.2 10+4km/s Vej ?=- Ejection velocity (1)
62- 65 F4.2 10+4km/s e_Vej ?=- rms uncertainty on Vej
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Note (1): The blank spaces (---) indicate where a measurement had to be
removed due to inadequate wavelength coverage.
Note (2): The uncertainties in the EW results include measurement errors,
errors from any possible variance in the pseudo-continuum, and the
uncertainty from the host galaxy contamination correction.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 29-Feb-2008