J/AJ/135/1766 Sloan Digital Sky Survey-II supernova survey (Zheng+, 2008)
First-year spectroscopy for the Sloan Digital Sky Survey-II supernova survey.
Zheng C., Romani R.W., Sako M., Marriner J., Bassett B., Becker A.,
Choi C., Cinabro D., Dejongh F., Depoy D.L., Dilday B., Doi M.,
Frieman J.A., Garnavich P.M., Hogan C.J., Holtzman J., Im M., Jha S.,
Kessler R., Konishi K., Lampeitl H., Marshall J.L., McGinnis D.,
Miknaitis G., Nichol R.C., Prieto J.L., Riess A.G., Richmond M.W.,
Schneider D.P., Smith M., Takanashi N., Tokita K., Van Der Heyden K.,
Yasuda N., Assef R.J., Barentine J., Bender R., Blandford R.D., Bremer M.,
Brewington H., Collins C.A., Crotts A., Dembicky J., Eastman J., Edge A.,
Elson E., Eyler M.E., Filippenko A.V., Foley R.J., Frank S., Goobar A.,
Harvanek M., Hopp U., Ihara Y., Kahn S., Ketzeback W., Kleinman S.J.,
Kollatschny W., Krzesinski J., Leloudas G., Long D.C., Lucey J.,
Malanushenko E., Malanushenko V., Mcmillan R.J., Morgan C.W., Morokuma T.,
Nitta A., Ostman L., Pan K., Romer A.K., Saurage G., Schlesinger K.,
Snedden S.A., Sollerman J., Stritzinger M., Watson L.C., Watters S.,
Wheeler J.C., York D.
<Astron. J., 135, 1766-1784 (2008)>
=2008AJ....135.1766Z 2008AJ....135.1766Z
ADC_Keywords: Surveys ; Supernovae
Keywords: cosmology: observations - methods: data analysis -
supernovae: general - surveys - techniques: spectroscopic
Abstract:
This paper presents spectroscopy of supernovae (SNe) discovered in
the first season of the Sloan Digital Sky Survey-II SN Survey. This
program searches for and measures multi-band light curves of SNe in
the redshift range z=0.05-0.4, complementing existing surveys at
lower and higher redshifts. Our goal is to better characterize the SN
population, with a particular focus on SNe Ia, improving their utility
as cosmological distance indicators and as probes of dark energy.
Our SN spectroscopy program features rapid-response observations
using telescopes of a range of apertures, and provides confirmation
of the SN and host-galaxy types as well as precise redshifts. We
describe here the target identification and prioritization, data
reduction, redshift measurement, and classification of 129 SNe Ia,
16 spectroscopically probable SNe Ia, 7 SNe Ib/c, and 11 SNe II from
the first season. We also describe our efforts to measure and remove
the substantial host-galaxy contamination existing in the majority of
our SN spectra.
Description:
During fall 2005, three telescopes were routinely available for
SDSS-II SN spectroscopy: MDM 2.4m (49 shared nights), ARC 3.5m (31
half-nights), and HET 9.2m (64.5h of queue time). Several additional
dedicated campaigns helped greatly, with six nights on the 4.2m WHT,
six shared nights on Subaru, and one target-of-opportunity night on
Keck. A handful of additional spectra were obtained at other
facilities based on the SDSS-II SN candidate announcements. In total,
259 useful spectra were obtained which yielded 129 spectroscopically
confirmed SNe Ia, 16 probable SNe Ia, 7 SNe Ib/c, and 11 SNe II.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 58 260 SDSS-II SN spectroscopic follow-up observations
table3.dat 69 260 SDSS-II SN redshift cross-correlation and type
analysis
table4.dat 69 96 SDSS-II SNe spectral decomposition and host
analysis results
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See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
J/ApJ/659/122 : Improved distances to type Ia supernovae (Jha+, 2007)
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 Official IAU name (YYYYAA), when assigned
8 A1 --- n_SN Note on SN (G1)
10- 14 I5 --- SNID SDSS Internal SN candidate ID,
<SDSS-II SN NNNNN> in Simbad
16- 17 I2 h RAh Right ascension (J2000)
19- 20 I2 min RAm Right ascension (J2000)
22- 26 F5.2 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 38 F4.1 arcsec DEs Declination (J2000)
40- 47 A8 --- Tel Telescope
49- 58 A10 "YYYY/MM/DD" ObsDate Observation date (UT)
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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- 6 A6 --- SN Official IAU name (YYYYAA), when assigned
8 A1 --- n_SN Note on SN (G1)
10- 14 I5 --- SNID SDSS Internal SN candidate ID
16- 18 I3 d Ep.p ? Spectrum day (in observer frame) relative to
epoch of maximum brightness from the
photometric typing
20- 22 I3 d Ep.s ? Spectrum day (in observer frame) relative to
epoch of maximum brightness from the
spectroscopic cross-correlation analysis
24- 30 A7 --- SNtype Best-fitted type of the SN (2)
32- 37 F6.4 --- zSN ? SN redshift (3)
40- 45 A6 --- SNtemp Template spectrum (4)
47- 50 F4.1 --- rSN ? r value of the rvsao.xcsao comparison with
SN templates (5)
52- 57 F6.4 --- zG ? Redshift from cross-correlation against
galaxy templates (6)
59- 64 A6 --- GType Best-fit morphological type of the host galaxy
66- 69 F4.1 --- rG ? r value for rvsao.xcsao correlation against
host-galaxy templates (7)
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Note (2): peculiar types:
* "Ia?" indicates a best match to an SN Ia template, although some
features are not detected.
* "II?" indicates a general match to the SN II template, although
expected SN II features are not all detected.
* "Ia-pec" indicates peculiar SN Ia.
Note (3): Redshift measured from cross-correlation against SN templates.
This value has been corrected for the systematic offset 0.003.
The expected redshift error is 0.005.
Note (4): Template spectrum providing the best match to the observed spectrum.
If blank, then the best-fitted template belongs to the Nugent SN Ia set.
SN templates from Pun et al. (1995ApJS...99..223P 1995ApJS...99..223P),
Turatto et al. (1996MNRAS.283....1T 1996MNRAS.283....1T),
Hamuy et al. (2002AJ....124..417H 2002AJ....124..417H),
Gal-Yam et al. (2002MNRAS.332L..73G 2002MNRAS.332L..73G),
Leonard et al. (2002PASP..114...35L 2002PASP..114...35L),
Elmhamdi et al. (2004A&A...426..963E 2004A&A...426..963E),
and Nugent et al. (2002PASP..114..803N 2002PASP..114..803N)
Note (5): Ratio of peak height h to the root-mean square (rms).
r{SN}>3 is a criterion for a "good" fit. See text for details.
Note (6): The expected redshift error is 0.0005.
Note (7): Ratio of peak height h to the root-mean square (rms).
rg>3 is a criterion for a "good" fit. See text for details.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
-------------------------------------------------------------------------------
1 A1 --- Flag [AB] Flag about extinction (1)
3- 7 I5 --- SNID SDSS Internal SN candidate ID
9- 15 A7 --- Tel Spectroscopic follow-up telescope
16- 18 I3 d Ep.p Observation date of the SN relative to B-band
maximum brightness estimated from light-curve fits
20- 34 A15 --- SNs The best and second-best SN type from
cross-correlation analysis (2)
35- 37 I3 d Ep.sh Age of the SN relative to B-band maximum
brightness estimated from spectrum
decomposition
39- 45 A7 --- Gal.sh Host-galaxy morphological type from spectral
decomposition (3)
47- 51 F5.3 --- SNfrac Estimate of the SN light fraction in the
observed spectrum
53- 57 F5.3 --- e_SNfrac Statistical error on SNFrac (the maximum value
of the asymmetric errors obtained from the
PCA code)
59- 63 F5.2 --- chi2 Reduced χ2 value
65- 69 F5.1 --- Q Quality factor (4)
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Note (1): Flag as follows:
A = SNe have extinction estimates from MCLS2k2 analysis (Jha et al.
2007, Cat. J/ApJ/659/122)
B = SNe have A_V from light-curve fitting using the frame difference
photometry
Note (2): "Ia?" indicates best fit to an SN Ia template, but a reasonable
fit to the next-best type.
Note (3): Unknown indicates too little host light for type ID.
Note (4): Quality factor Q=Δ(χ2ν)sqrt(ν)/χ2ν,
which estimates the significance of the χ2 differentiation between
the best two SN types. Negative values indicate a selected type
differing from that determined by the cross-correlation analysis.
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Global Notes:
Note (G1): Notes as follows:
c = Spectroscopically confirmed by another group using the HET
(CBET 266; Quimby et al. 2007ApJ...666.1083Q 2007ApJ...666.1083Q). The spectrum is
not available.
d = Spectroscopically confirmed by the ESSENCE group
m = Initially identified as a normal SN Ia by cross-correlation
analysis. Later, determined to be a peculiar SN Ia
(SN 2002ic-like) based on detailed spectroscopic analysis
n = This SN was confirmed by another group using the HET (CBET 266;
Quimby et al. 2007ApJ...666.1083Q 2007ApJ...666.1083Q). The spectrum is
not available
o = Initially identified as a normal SN Ia by cross-correlation
analysis. Later, determined to be a peculiar SN Ia
(SN 1991T-like), based on detailed spectroscopic analysis
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 06-Nov-2010