J/ApJ/874/150 The first 3yrs of DES-SN (DES-SN3YR) (Brout+, 2019)
First cosmology results using SNe Ia from the Dark Energy Survey: analysis,
systematic uncertainties, and validation.
Brout D., Scolnic D., Kessler R., D'Andrea C.B., Davis T.M., Gupta R.R.,
Hinton S.R., Kim A.G., Lasker J., Lidman C., Macaulay E., Moller A.,
Nichol R.C., Sako M., Smith M., Sullivan M., Zhang B., Andersen P.,
Asorey J., Avelino A., Bassett B.A., Brown P., Calcino J., Carollo D.,
Challis P., Childress M., Clocchiatti A., Filippenko A.V., Foley R.J.,
Galbany L., Glazebrook K., Hoormann J.K., Kasai E., Kirshner R.P., Kuehn K.,
Kuhlmann S., Lewis G.F., Mandel K.S., March M., Miranda V., Morganson E.,
Muthukrishna D., Nugent P., Palmese A., Pan Y.-C., Sharp R., Sommer N.E.,
Swann E., Thomas R.C., Tucker B.E., Uddin S.A., Wester W., Abbott T.M.C.,
Allam S., Annis J., Avila S., Bechtol K., Bernstein G.M., Bertin E.,
Brooks D., Burke D.L., Carnero Rosell A., Carrasco Kind M., Carretero J.,
Castander F.J., Cunha C.E., da Costa L.N., Davis C., De Vicente J.,
DePoy D.L., Desai S., Diehl H.T., Doel P., Drlica-Wagner A., Eifler T.F.,
Estrada J., Fernandez E., Flaugher B., Fosalba P., Frieman J.,
Garcia-Bellido J., Gruen D., Gruendl R.A., Gutierrez G., Hartley W.G.,
Hollowood D.L., Honscheid K., Hoyle B., James D.J., Jarvis M., Jeltema T.,
Krause E., Lahav O., Li T.S., Lima M., Maia M.A.G., Marriner J.,
Marshall J.L., Martini P., Menanteau F., Miller C.J., Miquel R.,
Ogando R.L.C., Plazas A.A., Romer A.K., Roodman A., Rykoff E.S., Sanchez E.,
Santiago B., Scarpine V., Schubnell M., Serrano S., Sevilla-Noarbe I.,
Smith R.C., Soares-Santos M., Sobreira F., Suchyta E., Swanson M.E.C.,
Tarle G., Thomas D., Troxel M.A., Tucker D.L., Vikram V., Walker A.R.,
Zhang Y.
<Astrophys. J., 874, 150 (2019)>
=2019ApJ...874..150B 2019ApJ...874..150B
ADC_Keywords: Supernovae; Surveys; Redshifts; Photometry, RI
Keywords: cosmological parameters ; dark energy ; supernovae: general
Abstract:
We present the analysis underpinning the measurement of cosmological
parameters from 207 spectroscopically classified SNe Ia from the first
3 years of the Dark Energy Survey Supernova Program (DES-SN), spanning
a redshift range of 0.017<z<0.849. We combine the DES-SN sample with
an external sample of 122 low-redshift (z<0.1) SNe Ia, resulting in a
"DES-SN3YR" sample of 329 SNe Ia. Our cosmological analyses are
blinded: after combining our DES-SN3YR distances with constraints from
the Cosmic Microwave Background, our uncertainties in the measurement
of the dark energy equation-of-state parameter, w, are 0.042 (stat)
and 0.059 (stat+syst) at 68% confidence. We provide a detailed
systematic uncertainty budget, which has nearly equal contributions
from photometric calibration, astrophysical bias corrections, and
instrumental bias corrections. We also include several new sources of
systematic uncertainty. While our sample is less than one-third the
size of the Pantheon sample, our constraints on w are only larger by
1.4x, showing the impact of the DES-SN Ia light-curve quality. We find
that the traditional stretch and color standardization parameters of
the DES-SNe Ia are in agreement with earlier SN Ia samples such as
Pan-STARRS1 and the Supernova Legacy Survey. However, we find smaller
intrinsic scatter about the Hubble diagram (0.077mag). Interestingly,
we find no evidence for a Hubble residual step (0.007±0.018mag) as a
function of host-galaxy mass for the DES subset, in 2.4σ tension
with previous measurements. We also present novel validation methods
of our sample using simulated SNe Ia inserted in DECam images and
using large catalog-level simulations to test for biases in our
analysis pipelines.
Description:
The Dark Energy Survey Supernova Program (DES-SN) performed a deep,
time-domain survey in four optical bands (g, r, i, z) covering
∼27deg2 over five seasons (2013-2018) using the DECam mounted on the
4m Blanco telescope at the Cerro Tololo Inter-American Observatory (CTIO).
A detailed overview of the spectroscopic follow-up program as well as
a general overview of the DES-SN program and observing strategy can be
found in D'Andrea et al. (2018, arXiv:1811.09565).
Over the first 3 years of DES-SN, from 2013 September to 2016
February, we discovered roughly ∼12000 candidates of which ∼2000 are
likely SNe Ia. In this first analysis we analyze only the
spectroscopically confirmed SN Ia subset of the data. The majority of
spectra come from the Anglo-Australian Telescope (AAT) as part of the
OzDES program (Yuan+ 2015MNRAS.452.3047Y 2015MNRAS.452.3047Y &
Childress+ 2017, J/MNRAS/472/273).
We also utilize four publicly available low-redshift surveys ("LOWz"
subset): CfA3S (CfA3 Shooter), CfA3K (CfA3 KeplerCam), CfA4, and
CSP-1 (Jha+ 2006, J/AJ/131/527; Hicken+ 2009, J/ApJ/700/1097 and
2012, J/ApJS/200/12; Contreras+ 2010, J/AJ/139/519), consisting of 303
spectroscopically confirmed SNe Ia in the redshift range 0.01<z<0.1.
See Section 2.2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table12.dat 550 658 Light curve fit parameters for the 329 SNe Ia
for G10 (Guy+ 2010A&A...523A...7G 2010A&A...523A...7G) &
C11 (Chotard+ 2011A&A...529L...4C 2011A&A...529L...4C) intrinsic
scatter models
lcs/* . 329 Individual light curves in ASCII format
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See also:
II/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/AJ/131/527 : UBVRI light curves of 44 type Ia supernovae (Jha+, 2006)
J/AJ/136/2306 : SDSS-II Supernova survey, 2005 (Holtzman+, 2008)
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/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/ApJ/740/92 : SN.Ia host galaxies properties (Gupta+, 2011)
J/AJ/143/126 : Spectrosc. of 462 nearby Type Ia supernovae (Blondin+, 2012)
J/ApJS/200/12 : CfA4: light curves for 94 type Ia SNe (Hicken+, 2012)
J/ApJ/755/61 : SN Ia host galaxies SFR from SDSS-II (Smith+, 2012)
J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)
J/ApJ/770/107 : Host galaxies of SNIa from SNfactory (Childress+, 2013)
J/A+A/568/A22 : Joint analysis of the SDSS-II & SNLS SNIa (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/ApJS/220/9 : CfAIR2: NIR light curves of Type Ia SNe (Friedman+, 2015)
J/ApJS/224/3 : ESSENCE 6yr spectroscopic follow-up (Narayan+, 2016)
J/ApJ/821/115 : SDSS-II SN Survey: host-galaxy spectral data (Wolf+, 2016)
J/MNRAS/472/273 : OzDES DR1 (Childress+, 2017)
J/ApJ/857/51 : Measuring dark energy data with PS1 SNe. II. (Jones+, 2018)
http://des.ncsa.illinois.edu/releases/sn : DES-SN3YR data products
Byte-by-byte Description of file: table12.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Mod Model identifier (1)
5- 7 A3 --- --- [SN:]
9- 15 A7 --- SN Supernova identifier
17- 23 I7 --- CIDint [1/2008051] Integer identifier
25- 26 I2 --- Survey [5/66] Integer SURVEY ID (2)
28- 30 I3 --- Type [0/101]? SN type (3)
32- 36 A5 --- Field NULL for "LOWz" subset, set to SN
field name for DES subset
38 I1 --- Cut [1] SNANA cut flag (always "1" since all
events here pass cuts)
40- 46 F7.5 --- zHel [0.01/0.85] Heliocentric redshift
48- 54 F7.5 --- e_zHel [0/0.01] Uncertainty in zHel
56- 62 F7.5 --- zCMB [0.01/0.85] Cosmic Microwave Background
redshift
64- 70 F7.5 --- e_zCMB [0/0.01] Uncertainty in zCMB
72- 78 F7.5 --- zHD [0.01/0.85] Hubble diagram redshift
(zCMB with Vpec correction)
80- 86 F7.5 --- e_zHD [0.0005/0.01] Uncertainty in zHD
88- 99 E12.5 km/s Vpec [-741/699]?=0 Peculiar velocity
101-103 I3 km/s e_Vpec [250]?=0 Uncertainty in Vpec
105-111 F7.4 [Msun] logMh [2/12] log host stellar mass
113-123 E11.5 [Msun] e_logMh [0/10] Uncertainty in logMh
125-132 F8.4 --- SNRMax1 [6.5/898] Max SNR among all observations
134-141 F8.4 --- SNRMax2 [5.8/321] Max SNR after removing band
with SNRMax1
143-150 F8.4 --- SNRMax3 [/250]?=-99 Max SNR after removing bands
with SNRMax1 and SNRMax2
152-160 F9.3 d PKMJD [51931/57413] Best fit peak modified julian
date; rest-frame B band (from SALT2
light curve fit)
162-166 F5.3 d e_PKMJD [0.016/4.4] Uncertainty in PKMJD
168-179 E12.5 --- x1 [-2.8/2] The x1 light curve fit parameter
181-191 E11.5 --- e_x1 [0.02/1.8] Uncertainty in x1
193-204 E12.5 --- c [-0.3/0.3] The c light curve fit parameter
206-216 E11.5 --- e_c [0.016/0.13] Uncertainty in c
218-224 F7.4 mag mB [14/24.16] The -2.5log10(x0), where x0 is
best fit SALT2 amplitude
226-236 E11.5 mag e_mB [0.0017/0.23] Uncertainty in Bmag
238-248 E11.5 --- x0 [3.8e-6/0.042] Best fit SALT2 amplitude
250-260 E11.5 --- e_x0 [3.9e-8/0.002] Uncertainty in x0
262-273 E12.5 --- C-x1c [-0.007/0.11] Fitted covariance between x1
and c
275-286 E12.5 --- C-x1x0 [-0.0002/4.8e-5] Fitted covariance between
x1 and x0
288-299 E12.5 --- C-cx0 [-0.00012/5.1e-9] Fitted covariance between
c and x0
301-303 I3 --- dof [1/175] Degrees of Freedom
in light curve fit
305-312 F8.4 --- chi2 [0.28/185] χ2 of the light curve fit
314-324 E11.5 --- Prob [0.012/1] Fit probability given chi2 and dof
326-335 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
337-346 F10.6 deg DEdeg [-66.5/79.1] Declination (J2000)
348-354 F7.4 --- TGAPmax [1.96/32.4] Rest frame duration of gap in
light curve coverage near peak
356-367 E12.5 --- Trestmin [-15.1/9.5] Time of earliest observation
used in fit
369-375 F7.4 --- Trestmax [5.19/45] Time of latest observation
used in fit
377-387 E11.5 mag MWEBV [0.004/0.22] The E(B-V) of the Milky Way
used
389-395 F7.4 mag imag [15.3/23.6]?=0 Peak i-band mag computed (4)
397-403 F7.4 mag rmag [14.6/24.4]?=0 Peak r-band mag computed (4)
405-415 E11.5 mag e_imag [0.01/0.14]?=0 Uncertainty in imag
417-427 E11.5 mag e_rmag [0.01/0.12]?=0 Uncertainty in rmag
429-435 F7.4 mas/yr mu [33.3/43.8] Distance modulus (5)
437-443 F7.4 mas/yr muMODEL [33.2/43.7] Reference model distance
modulus (6)
445-450 F6.4 mas/yr e_mu [0.08/0.3] The 1σ uncertainty
in mu (measurement error and sigma_int)
452-457 F6.4 mas/yr s_mu [0.05/0.4] The 1σ measurement error
in mu (no sigma_int term)
459-465 F7.4 --- muRES [-0.5/0.6] MU-(MUMODEL+M0DIF)
467-472 F6.3 --- muPULL [-2.92/3.32] MURES/MUERR-1
474-480 F7.4 --- M0DIF [-0.22/0.1] z-binned MU-offset
482 I1 --- Error [0] Error code; always zero
484-489 F6.3 --- bCor-mu [-0.4/0.6] Bias correction already
applied to mu
491-495 F5.3 --- e_bCor-mu [0.002/0.08] The 1σ uncertainty in
bCor-mu; not used
497-502 F6.3 --- bCor-mB [-0.09/0.07] Bias correction on mB
504-509 F6.3 --- bCor-x1 [-0.94/0.9] Bias correction on x1
511-516 F6.3 --- bCor-c [-0.17/0.09] Bias correction on c
518-522 F5.3 --- bCor-muCOV [0.26/0.97] The R_σ value (7)
524 I1 --- Set [0/1]? Sample identifier (1=DES-SN) (8)
526-550 A25 --- File FileName in subdirectory "lcs";
column added by CDS
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Note (1): Model as follows:
G10 = simulation based on Guy+ (2010A&A...523A...7G 2010A&A...523A...7G).
C11 = simulation based on Chotard+ (2011A&A...529L...4C 2011A&A...529L...4C).
Note (2): Survey code as follows:
10 = DES (414 occurrences)
5 = CSP-1 (Contreras+, 2010, J/AJ/139/519 ; 22 occurrences)
63 = CfA3 (52 occurrences)
64 = CfA3 (88 occurrences)
65 = CfA4 (64 occurrences)
66 = CfA4 (18 occurrences)
Note (3): Code as follows:
1 = DES-SN3YR simulations (474 occurrences).
0 = (140 occurrences)
101 = (44 occurrences)
Note (4): From best fit SALT2 model.
Note (5): From Tripp formula (Tripp 1998A&A...331..815T 1998A&A...331..815T) using BEAMS with
Bias Corrections ("BBC" fitting method; Kessler & Scolnic
2017ApJ...836...56K 2017ApJ...836...56K) fitted α, β, γ.
As in Eq 5: µ=mB-M+αx1-βc+δµhost+δµbias
α and β are the correlation coefficients of x1 and c with
luminosity, respectively, and M is the absolute magnitude of a fiducial
SN Ia with x1=0 and c=0. See Section 3.8.1.
Note (6): w_DE:-1, Omega_M:0.3, Omega_k=0
Note (7): In Equation 13 of arXiv:1610.04677:
Rσ=rms(with bCor)/σsimµ
Note (8): Subset as follows:
1 = subset of SNe Ia from DES-SN (414 occurrences);
0 = subset of low-z SNe Ia from CfA3, CfA4, and CSP-1 (CfA3-4;
Hicken+ 2009, J/ApJ/700/1097 and 2012, J/ApJS/200/12;
Contreras+ 2010, J/AJ/139/519 -- 244 occurrences).
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History:
From electronic version of the journal for Table 12
LCs downloaded at: http://des.ncsa.illinois.edu/releases/sn
(from 02-DATA_PHOTOMETRY)
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 31-Aug-2020