J/ApJ/857/51 Measuring dark energy properties with PS1 SNe. II. (Jones+, 2018)
Measuring dark energy properties with photometrically classified Pan-STARRS
supernovae.
II. Cosmological parameters.
Jones D.O., Scolnic D.M., Riess A.G., Rest A., Kirshner R.P., Berger E.,
Kessler R., Pan Y.-C., Foley R.J., Chornock R., Ortega C.A., Challis P.J.,
Burgett W.S., Chambers K.C., Draper P.W., Flewelling H., Huber M.E.,
Kaiser N., Kudritzki R.-P., Metcalfe N., Tonry J., Wainscoat R.J.,
Waters C., Gall E.E.E., Kotak R., McCrum M., Smartt S.J., Smith K.W.
<Astrophys. J., 857, 51 (2018)>
=2018ApJ...857...51J 2018ApJ...857...51J
ADC_Keywords: Supernovae; Surveys; Redshifts; Photometry; Optical
Keywords: cosmology: observations ; dark energy ; supernovae: general
Abstract:
We use 1169 Pan-STARRS supernovae (SNe) and 195 low-z (z<0.1) SNe Ia
to measure cosmological parameters. Though most Pan-STARRS SNe lack
spectroscopic classifications, in a previous paper we demonstrated
that photometrically classified SNe can be used to infer unbiased
cosmological parameters by using a Bayesian methodology that
marginalizes over core-collapse (CC) SN contamination. Our sample
contains nearly twice as many SNe as the largest previous SN Ia
compilation. Combining SNe with cosmic microwave background (CMB)
constraints from Planck, we measure the dark energy equation-of-state
parameter w to be -0.989±0.057 (stat+sys). If w evolves with
redshift as w(a)=w0+wa(1-a), we find w0=-0.912±0.149 and
wa=-0.513±0.826. These results are consistent with cosmological
parameters from the Joint Light-curve Analysis and the Pantheon
sample. We try four different photometric classification priors for
Pan-STARRS SNe and two alternate ways of modeling CC SN contamination,
finding that no variant gives a w differing by more than 2% from the
baseline measurement. The systematic uncertainty on w due to
marginalizing over CC SN contamination, σwCC=0.012, is the
third-smallest source of systematic uncertainty in this work. We find
limited (1.6σ) evidence for evolution of the SN color-luminosity
relation with redshift, a possible systematic that could constitute a
significant uncertainty in future high-z analyses. Our data provide
one of the best current constraints on w, demonstrating that samples
with ∼5% CC SN contamination can give competitive cosmological
constraints when the contaminating distribution is marginalized over
in a Bayesian framework.
Description:
The PS1 Medium Deep Survey covers 10 7deg2 fields in five filters,
with typical observing cadences in a given field of six observations
per 10 days. Over its 4yr of operation, PS1 flagged ∼5200 likely SNe.
Spectroscopic follow-up was triggered for ∼10% of SNe, typically those
with r≲22mag, on a wide variety of spectroscopic instruments.
During the last year of PS1, we began a survey to obtain spectroscopic
host galaxy redshifts for the majority of the sample, both those with
SN spectra and those without. This survey primarily used the Hectospec
multifiber instrument on the MMT. We also measured redshifts with the
Apache Point Observatory (APO) 3.5m telescope, the WIYN telescope,
and, for two of the most southern medium-deep fields, the
Anglo-Australian Telescope (AAT). An additional ∼600 of our redshifts
came from SDSS or other public redshift surveys. We chose targets
independent of SN type in order to build a sample without any color or
shape selection bias. Of 3930 targets, the host galaxies of 3261 SN
candidates had strong enough spectral features and high enough S/N to
yield reliable spectroscopic redshifts. These data are discussed in
detail in Paper I, Jones+ 2017ApJ...843....6J 2017ApJ...843....6J
After SN discovery and redshift follow-up, the PS1 light curves were
reprocessed. See section 2.1 for further details.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 174 1169 PS1 coordinates and light curve parameters
table3.dat 75 1169 PS1 host galaxies
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See also:
III/250 : The VIMOS VLT deep survey (VVDS-DEEP) (Le Fevre+ 2005)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
VII/259 : 6dF galaxy survey final redshift release (Jones+, 2009)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/ApJ/607/665 : Type Ia supernovae at z>1 discovered by HST (Riess+, 2004)
J/AJ/131/527 : UBVRI light curves of 44 type Ia supernovae (Jha+, 2006)
J/ApJS/172/70 : zCOSMOS-bright catalog (Lilly+, 2007)
J/ApJ/700/331 : Light curves of type Ia supernovae (CfA3) (Hicken+, 2009)
J/ApJ/700/1097 : Light curve parameters of SN Ia (Hicken+, 2009)
J/ApJS/185/32 : First-year SDSS-II SN results (Kessler+, 2009)
J/AJ/139/519 : Carnegie supernova project. SNe Ia (Contreras+, 2010)
J/AJ/139/120 : Low-redshift Type-Ia supernovae (Folatelli+, 2010)
J/A+A/523/A7 : Light curves of type Ia supernovae in SNLS (Guy+, 2010)
J/ApJ/722/566 : Host galaxies of SNIa in SDSS-II SN survey (Lampeitl+, 2010)
J/MNRAS/406/782 : Type Ia supernovae luminosities (Sullivan+, 2010)
J/A+A/529/L4 : Reddening law of type Ia supernovae (Chotard+, 2011)
J/ApJS/192/1 : Light-curve parameters from the SNLS (Conley+, 2011)
J/MNRAS/416/2840 : The 2M++ galaxy redshift catalogue (Lavaux+, 2011)
J/ApJ/738/162 : SN Ia candidates from the SDSS-II SN Survey (Sako+, 2011)
J/AJ/142/156 : The CSP (DR2): photometry of SNe Ia (Stritzinger+, 2011)
J/ApJS/200/12 : CfA4: light curves for 94 type Ia SNe (Hicken+, 2012)
J/ApJ/746/85 : THe HST Cluster Supernova Survey. V. (Suzuki+, 2012)
J/A+A/552/A124 : SNLS & SDSS SN surveys phot. calibration (Betoule+, 2013)
J/ApJ/763/88 : SDSS-II SNe Ia cosmological analysis (Campbell+, 2013)
J/A+A/568/A22 : Joint analysis of SDSS-II and SNLS SNe Ia (Betoule+, 2014)
J/MNRAS/438/1391 : Host galaxies of Type Ia SN from PTF (Pan+, 2014)
J/ApJ/795/44 : PS1 SNe Ia (0.02<z<0.7) griz light curves (Rest+, 2014)
J/ApJ/812/31 : Local Star Formation effects on type Ia SNe (Jones+, 2015)
J/MNRAS/457/3470 : SN Ia host-galaxy/cosmological parameters (Campbell+, 2016)
J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)
J/ApJ/821/115 : SDSS-II SN Survey: host-galaxy spectral data (Wolf+, 2016)
J/MNRAS/465/4914 : R-band light curves of HE 0435-1223 (Bonvin+, 2017)
J/ApJ/848/56 : Relationships between SNe Ia & host galaxies (Uddin+, 2017)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- ID Supernova identifier
11- 12 I2 h RAh [2/23] Hour of Right Ascension (J2000)
14- 15 I2 min RAm Minute of Right Ascension (J2000)
17- 22 F6.3 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- Sign of the Declination (J2000)
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 35 F5.2 arcsec DEs Arcsecond of Declination (J2000)
37- 45 F9.4 --- zSN [0.02/0.7]?=-999 Supernova redshift
relative to the CMB
47- 56 F10.5 --- zHost [0.03/1]?=-999 Host redshift
relative to the CMB
58- 64 F7.1 --- tpeak [55076.5/56683.2] Modified Julian Date
of peak
66- 68 F3.1 --- e_tpeak [0/2.7] Uncertainty in tpeak
70- 76 F7.4 --- x1 [-3/3] SALT2 light curve shape parameter
78- 83 F6.4 --- e_x1 [0.04/1] Uncertainty in x1
85- 91 F7.4 --- c [-0.3/0.3] SALT light curve color parameter
93- 98 F6.4 --- e_c [0.007/0.6] Uncertainty in c
100-106 F7.4 mag Bmag [15.8/23.9] Apparent B band AB magnitude
108-113 F6.4 mag e_Bmag [0.02/0.3] Uncertainty in Bmag
115-122 F8.3 [Msun] logM [6.5/12.1]?=-999 Log host mass
124-131 F8.3 [Msun] e_logM [0.003/58.8]?=-999 Uncertainty in logM
133-138 F6.3 mag dcorr [-0.04/0.1] Distance correction (1)
140-147 F8.4 --- P(PSNID) [-99/1] Probability of SNe Ia (2)
149-156 F8.4 --- P(NN) [-99/1] Probability of SNe Ia (3)
158-165 F8.4 --- P(Fit) [-99/1] Probability of SNe Ia (4)
167-174 F8.4 --- P(Gal) [-99/1] Probability of SNe Ia (5)
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Note (1): Add to the SN distance to correct for biases.
Note (2): Probability given by the PSNID classifier (Sako+ 2011, J/ApJ/738/162).
Set to 1 for spectroscopically classified SNe Ia and to the
probability given for photometrically classified SNe. SNe equal to -99
were unable to be classified.
Note (3): Probability given by the nearest neighbor classifier
(Sako+ 2018PASP..130f4002S 2018PASP..130f4002S) and Kessler & Scolnic (2017ApJ...836...56K 2017ApJ...836...56K).
Set to 1 for spectroscopically classified SNe Ia and to the
probability for photometrically classified SNe. SNe equal to -99 were
unable to be classified.
Note (4): Probability that the data match the SALT2 model (inferred from the
χ2 and degrees of freedom when fitting to SALT2). Set to 1 for
spectroscopically classified SNe Ia and to the probability for
photometrically classified SNe. SNe equal to -99 were unable to be
classified.
Note (5): Probability that each SN is Type Ia inferred from the host galaxy
properties of each SN. Set to 1 for spectroscopically classified SNe
Ia and to the probability for photometrically classified SNe. SNe
equal to -99 were unable to be classified.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ID Supernova identifier
11- 12 I2 h RAh [2/23] Hour of Right Ascension (J2000)
14- 15 I2 min RAm Minute of Right Ascension (J2000)
17- 22 F6.3 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- Sign of the Declination (J2000)
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 35 F5.2 arcsec DEs Arcsecond of Declination (J2000)
37- 46 F10.5 --- zHost [0.003/1.1]?=-999 Host redshift relative
to the CMB
48- 55 F8.3 --- NSep [0.02/18.7]?=-999 Normalized separation (2)
57- 63 F7.2 --- R [2.8/32.1]?=-999 Cross-correlation parameter (3)
65- 75 A11 --- r_zHost Reference for zHost (1)
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Note (1): A -999 indicates the host could not be identified.
For the instruments, see the "Description" section above.
Note (2): Of the SN from the center of its host galaxy, normalized by the size
and orientation of the host (the R parameter; Sullivan+ 2006ApJ...648..868S 2006ApJ...648..868S).
The isophotal radius of a galaxy corresponds to R∼3.
Note (3): Computed by comparing the host galaxy spectrum to a template spectrum
to determine the host redshift. Redshifts with R>4 are treated as
reliable in this work, though 1.4% of all redshifts are expected to be
spurious as discussed in Jones+ 2017ApJ...843....6J 2017ApJ...843....6J
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History:
From electronic version of the journal
References:
Jones et al. Paper I. 2017ApJ...843....6J 2017ApJ...843....6J
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 18-Feb-2019