J/ApJ/738/162 SN Ia candidates from the SDSS-II SN Survey (Sako+, 2011)
Photometric type Ia supernova candidates from the three-year SDSS-II SN Survey
data.
Sako M., Bassett B., Connolly B., Dilday B., Cambell H., Frieman J.A.,
Gladney L., Kessler R., Lampeitl H., Marriner J., Miquel R., Nichol R.C.,
Schneider D.P., Smith M., Sollerman J.
<Astrophys. J., 738, 162 (2011)>
=2011ApJ...738..162S 2011ApJ...738..162S
ADC_Keywords: Extinction ; Redshifts ; Supernovae ; Photometry ; Surveys
Keywords: cosmology: observations - supernovae: general - surveys
Abstract:
We analyze the three-year Sloan Digital Sky Survey II (SDSS-II)
Supernova (SN) Survey data and identify a sample of 1070 photometric
Type Ia supernova (SN Ia) candidates based on their multiband light
curve data. This sample consists of SN candidates with no
spectroscopic confirmation, with a subset of 210 candidates having
spectroscopic redshifts of their host galaxies measured while the
remaining 860 candidates are purely photometric in their
identification. We describe a method for estimating the efficiency and
purity of photometric SN Ia classification when spectroscopic
confirmation of only a limited sample is available, and demonstrate
that SN Ia candidates from SDSS-II can be identified photometrically
with ∼91% efficiency and with a contamination of ∼6%. Although this is
the largest uniform sample of SN candidates to date for studying
photometric identification, we find that a larger spectroscopic sample
of contaminating sources is required to obtain a better
characterization of the background events. A Hubble diagram using SN
candidates with no spectroscopic confirmation, but with host galaxy
spectroscopic redshifts, yields a distance modulus dispersion that is
only ∼20%-40% larger than that of the spectroscopically confirmed SN
Ia sample alone with no significant bias. A Hubble diagram with purely
photometric classification and redshift-distance measurements,
however, exhibits biases that require further investigation for
precision cosmology.
Description:
The SDSS-II SN Survey was conducted during the September-November
months of 2005-2007. A 300deg2 region along the celestial equator
was observed using the SDSS 2.5m telescope with an average cadence of
four days.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 89 210 SDSS-II zhost-Ia Candidates
table4.dat 92 860 SDSS-II Photo-Ia Candidates
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See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
J/A+A/526/A28 : SDSS-II supernovae NTT and NOT spectroscopy (Oestman+, 2011)
J/ApJ/713/1026 : SN Ia rate at redshift ≲0.3 from SDSS-II (Dilday+, 2010)
J/ApJ/722/566 : Host galaxies of SNIa in SDSS-II SN survey (Lampeitl+, 2010)
J/AJ/139/519 : Carnegie supernova project. SNe Ia (Contreras+, 2010)
J/MNRAS/406/782 : Type Ia supernovae luminosities (Sullivan+, 2010)
J/ApJ/700/331 : Light curves of type Ia supernovae (CfA3) (Hicken+, 2009)
J/ApJS/185/32 : First-year SDSS-II SN results (Kessler+, 2009)
J/AJ/136/2306 : SDSS-II Supernova survey, 2005 (Holtzman+, 2008)
J/AJ/135/1766 : Sloan Digital Sky Survey-II supernova survey (Zheng+, 2008)
J/AJ/135/348 : SDSS-II SNe survey: search and follow-up (Sako+, 2008)
J/MNRAS/389/1871 : Type Ia supernovae candidates from SDSS (Horesh+, 2008)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- CID [703/22006] Internal SDSS-II SN candidate
designation
7- 16 F10.6 deg RAdeg [-53/58.7] Right ascension (J2000)
18- 26 F9.6 deg DEdeg [-1.3/1.3] Declination (J2000)
28- 33 F6.4 --- z [0.10/0.50] Spectroscopic redshift
35- 40 F6.4 --- e_z [0/0.01] Uncertainty in z
42- 46 F5.2 mag AV [-0.68/2.37] V-band extinction
48- 52 F5.2 mag B_AV The 1σ upper V-band extinction limit
54- 58 F5.2 mag b_AV The 1σ lower V-band extinction limit
60- 63 F4.2 mag dm15 [0.61/1.74] Phillips Δm15(B) (G1)
65- 69 F5.2 mag B_dm15 The 1σ upper Phillips Δm15(B) limit
71- 75 F5.2 mag b_dm15 The 1σ lower Phillips Δm15(B) limit
77- 81 F5.3 --- PzIa Bayesian SN Ia probability (1)
83- 86 F4.2 --- chi2 [0.74/1.8] Best-fit reduced chi-squared
87- 89 A3 --- --- [000]
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Note (1): With spectroscopic redshift prior.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- CID [822/21890] Internal SDSS-II SN candidate
designation
7- 16 F10.6 deg RAdeg [-58.2/58.8] Right Ascension (J2000)
18- 26 F9.6 deg DEdeg [-1.3/1.3] Declination (J2000)
28- 32 F5.3 --- zph [0.01/0.7] Photometric redshift
34- 39 F6.3 --- B_zph The 1σ upper photometric redshift
41- 46 F6.3 --- b_zph The 1σ lower photometric redshift
48- 52 F5.2 mag AV [-0.94/5] V-band extinction
54- 58 F5.2 mag B_AV The 1σ upper V-band extinction limit
60- 64 F5.2 mag b_AV The 1σ lower V-band extinction limit
66- 69 F4.2 mag dm15 [0.6/1.77] Phillips Δm15(B) (G1)
71- 75 F5.2 mag B_dm15 The 1σ upper Phillips Δm15(B) limit
77- 81 F5.2 mag b_dm15 The 1σ lower Phillips Δm15(B) limit
83- 87 F5.3 --- PIa Bayesian SN Ia probability (1)
89- 92 F4.2 --- chi2 [0.51/1.6] Best-fit reduced chi-squared
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Note (1): With flat redshift prior.
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Golbal Notes:
Note (G1): Decline rate parameter defined by Philips (1999AJ....118.1766P 1999AJ....118.1766P):
Δm15(B)=B(+15days)-B(max)
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 23-Jan-2013