J/MNRAS/433/2240 SALT2 parameters and distances for SNe (Ganeshalingam+, 2013)
Constraints on dark energy with the LOSS SN Ia sample.
Ganeshalingam M., Li W., Filippenko A.V.
<Mon. Not. R. Astron. Soc., 433, 2240-2258 (2013)>
=2013MNRAS.433.2240G 2013MNRAS.433.2240G
ADC_Keywords: Supernovae ; Stars, distances
Keywords: supernovae: general - cosmological parameters -
cosmology: observations - distance scale
Abstract:
We present a cosmological analysis of the Lick Observatory Supernova
Search (LOSS) Type Ia supernova (SN Ia) photometry sample introduced
by Ganeshalingam et al. (2010ApJS..190..418G 2010ApJS..190..418G, Cat. J/ApJS/190/418).
These supernovae (SNe) provide an effective anchor point to estimate
cosmological parameters when combined with data sets at higher
redshift. The data presented by Ganeshalingam et al. have been
rereduced in the natural system of the Katzman Automatic Imaging
Telescope (KAIT) and Nickel telescopes to minimize systematic
uncertainties. We have run the light-curve-fitting software SALT2 on
our natural-system light curves to measure light-curve parameters for
LOSS light curves and available SN Ia data sets in the literature. We
present a Hubble diagram of 586 SNe in the redshift range z=0.01-1.4
with a residual scatter of 0.176mag. Of the 226 low-z SNe Ia in our
sample, 91 objects are from LOSS, including 45 without previously
published distances. Assuming a flat Universe, we find that the best
fit for the dark energy equation-of-state parameter
w=-0.86+0.13-0.16(stat)±0.11(sys) from SNe alone, consistent
with a cosmological constant. Our data prefer a Universe with an
accelerating rate of expansion with 99.999% confidence. When looking
at Hubble residuals as a function of host-galaxy morphology, we do not
see evidence for a significant trend, although we find a somewhat
reduced scatter in Hubble residuals from SNe residing within a
projected distance <10kpc of the host-galaxy nucleus
(σ=0.156mag). Similar to the results of Blondin, Mandel and
Kirshner and Silverman et al. (2012AJ....143..126B 2012AJ....143..126B, Cat.
J/AJ/143/126), we find that Hubble residuals do not correlate with the
expansion velocity of SiIIλ6355 measured in optical spectra
near maximum light. Our data are consistent with no presence of a
local "Hubble bubble". Improvements in cosmological analyses within
low-z samples can be achieved by better constraining calibration
uncertainties in the zero-points of photometric systems.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 87 586 SALT2 parameters and distances for SNe
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See also:
J/AJ/143/126 : Spectroscopy of 462 nearby Type Ia supernovae (Blondin+, 2012)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- SN SN name
13- 17 F5.3 --- zCMB Redshift in CMB frame
19- 24 F6.3 mag Bmag B magnitude
27- 31 F5.3 mag e_Bmag 1-σ uncertainty on Bmag
34- 39 F6.3 mag x1 SALT2 light-curve width
42- 46 F5.3 mag e_x1 1-σ uncertainty on x1
49- 54 F6.3 mag c SALT2 colour (related to (B-V)max)
57- 61 F5.3 mag e_c 1-σ uncertainty on c
64- 69 F6.3 mag mu Distance modulus
72- 76 F5.3 mag e_mu 1-σ uncertainty on mu
79- 83 A5 --- Sample Sample name (1)
86- 87 I2 --- Ref Reference (2)
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Note (1): Summary of SN samples:
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Sample Redshift range NSN Npts
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Low-z 0.01-0.13 226 43
SDSS 0.04-0.42 122 42
SNLS 0.12-1.03 230 37
HST 0.84-1.34 8 13
Low-z
LOSS 0.01-0.10 91 51
CfA3 0.01-0.07 55 32
CSP 0.01-0.08 22 77
Lit 0.01-0.13 58 31
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Note: Npts = Median number of photometry epochs used in SALT2.
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Note (2): References as follows:
1 = Jha et al. (2006AJ....131..527J 2006AJ....131..527J, Cat. J/AJ/131/527)
2 = Ganeshalingam et al. (2010ApJS..190..418G 2010ApJS..190..418G, Cat. J/ApJS/190/418)
3 = Contreras et al. (2010AJ....139..519C 2010AJ....139..519C, Cat. J/AJ/139/519)
4 = Stritzinger et al. (2002AJ....124.2100S 2002AJ....124.2100S)
5 = Hicken et al. (2009ApJ...700..331H 2009ApJ...700..331H, Cat. J/ApJ/700/331)
6 = Hamuy et al. (1996AJ....112.2398H 1996AJ....112.2398H)
7 = Krisciunas et al. (2004AJ....128.3034K 2004AJ....128.3034K)
8 = Riess et al. (1999AJ....117..707R 1999AJ....117..707R)
9 = Krisciunas et al. (2004AJ....127.1664K 2004AJ....127.1664K)
10 = Krisciunas et al. (2001AJ....122.1616K 2001AJ....122.1616K)
11 = Holtzman et al. (2008AJ....136.2306H 2008AJ....136.2306H, Cat. J/AJ/136/2306)
12 = Guy et al. (2010A&A...523A...7G 2010A&A...523A...7G, Cat. J/A+A/523/A7)
13 = Riess et al. (2007ApJ...659...98R 2007ApJ...659...98R)
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(End) Patricia Vannier [CDS] 18-Jul-2014