J/ApJS/219/13 SNe Ia light curves for the LSQ-CSP sample (Walker+, 2015)
First results from the La Silla-QUEST supernova survey and
the Carnegie Supernova Project.
Walker E.S., Baltay C., Campillay A., Citrenbaum C., Contreras C.,
Ellman N., Feindt U., Gonzalez C., Graham M.L., Hadjiyska E., Hsiao E.Y.,
Krisciunas K., McKinnon R., Ment K., Morrell N., Nugent P., Phillips M.M.,
Rabinowitz D., Rostami S., Seron J., Stritzinger M., Sullivan M.,
Tucker B.E.
<Astrophys. J. Suppl. Ser., 219, 13 (2015)>
=2015ApJS..219...13W 2015ApJS..219...13W
ADC_Keywords: Photometry, UBV; Photometry, SDSS ; Supernovae ; Redshifts ;
Surveys
Keywords: dark energy; supernovae: general; surveys
Abstract:
The La Silla/QUEST Variability Survey (LSQ) and the Carnegie Supernova
Project (CSP II) are collaborating to discover and obtain photometric
light curves for a large sample of low-redshift (z<0.1) Type Ia
supernovae (SNe Ia). The supernovae are discovered in the LSQ survey
using the 1m ESO Schmidt telescope at the La Silla Observatory with
the 10 square degree QUEST camera. The follow-up photometric
observations are carried out using the 1m Swope telescope and the 2.5m
du Pont telescopes at the Las Campanas Observatory. This paper
describes the survey, discusses the methods of analyzing the data, and
presents the light curves for the first 31 SNe Ia obtained in the
survey. The SALT 2.4 supernova light-curve fitter was used to analyze
the photometric data, and the Hubble diagram for this first sample is
presented. The measurement errors for these supernovae averaged 4%,
and their intrinsic spread was 14%.
Description:
All of the supernovae described in this paper were discovered in the
La Silla/QUEST Southern Hemisphere Variability Survey and were
classified spectroscopically as SNe Ia by a variety of larger
telescopes. The spectra are available on the WISEREP database (Yaron &
Gal-Yam 2012PASP..124..668Y 2012PASP..124..668Y). The supernovae published here were
followed photometrically in multiple filter bands using the Swope
telescope at the Las Campanas Observatory to construct the light
curves covering the period around maximum light.
The La Silla/QUEST survey started the Low Redshift Supernova Search in
2011 December (Baltay et al. 2013PASP..125..683B 2013PASP..125..683B). The survey uses the
1m ESO Schmidt telescope at the La Silla Observatory in Chile.
The spectroscopy used to classify the supernova candidates was carried
out using five different telescopes. The spectra taken for this sample
of supernovae that had peak brightness before 2013 May are:
------------------------------------------------------------------
Source Telescope Spectrometer No. of SNe
------------------------------------------------------------------
PESSTO 3.5m NTT EFOSC-II 12
CSP II 2.5m du Pont WFCCD 10
SNfactory 2.2m UHT SNIFS 8
LCOGT 2.0m Faulkes FLOYDS 2
PTF/CalTech 5.0m Palomar DBSP 1
------------------------------------------------------------------
PESSTO = Public ESO Spectroscopic Survey for Transient Objects.
CSP II = the second Carnegie Supernova Survey.
SNfactory = Supernova Factory.
LCOGT = Las CumbrasOptical Global Telescopes.
PTF = Palomar Transient Factory.
NTT = New Technology Telescope.
UHT = University of Hawaii Telescope.
EFOSC-II = ESO Faint Object Spectrograph and Camera.
WFCCD = wide Field CCD Camera.
SNIFS = Supernova Integral Field Spectrometer.
FLOYDS = Faulkes Low Resolution Spectrograph.
DBSP = Double Spectrograph on the 200 Telescope.
------------------------------------------------------------------
The 1m Swope telescope at the Las Campanas Observatory was used to
follow the SNe Ia with optical imaging to obtain their light curves.
Exposure times were typically 5-10 minutes near peak, longer for
fainter supernovae and for supernovae long past peak, with nominally
each of six filters, the B,V (Bessell 1990PASP..102.1181B 1990PASP..102.1181B), and the
SDSS u, g, r and i.
The 2.5m du Pont telescope, also located at the Las Campanas
Observatory in Chile, has been used both to take spectra to classify
supernova candidates and to take the final template images of the host
galaxy after the supernova has faded to allow the subtraction of the
host galaxy light from the measured light curve.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 37 2680 Supernova photometric observations
table3.dat 97 31 Parameters for the La Silla/QUEST Variability
Survey-Carnegie Supernova Project (LSQ-CSP)
supernova sample
--------------------------------------------------------------------------------
See also:
J/A+A/568/A22 : Joint analysis of the SDSS-II & SNLS SNe Ia (Betoule+, 2014)
J/MNRAS/444/3258 : Velocities and pEW of PTF SNe Ia (Maguire+, 2014)
J/MNRAS/433/2240 : SALT2 parameters & distances for SNe (Ganeshalingam+, 2013)
J/ApJ/763/88 : SDSS-II SNe Ia cosmological analysis (Campbell+, 2013)
J/ApJ/746/85 : THe HST Cluster Supernova Survey. V. (Suzuki+, 2012)
J/ApJS/200/12 : CfA4: light curves for 94 type Ia SNe (Hicken+, 2012)
J/ApJ/731/120 : Intrinsic SN Ia light curves (Mandel+, 2011)
J/AJ/142/156 : The CSP (DR2): photometry of SNe Ia (Stritzinger+, 2011)
J/ApJS/192/1 : Light-curve parameters from the SNLS (Conley+, 2011)
J/MNRAS/406/782 : Type Ia supernovae luminosities (Sullivan+, 2010)
J/A+A/523/A7 : Light curves of type Ia supernovae in SNLS (Guy+, 2010)
J/ApJ/716/712 : HST light curves of six SNe and Union2 (Amanullah+, 2010)
J/AJ/139/519 : Carnegie supernova project. SNe Ia (Contreras+, 2010)
J/ApJ/700/1097 : Light curve parameters of SN Ia (Hicken+, 2009)
J/MNRAS/389/1577 : UBVRI absolute magnitudes of Type Ia SNe (Takanashi+, 2008)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [LSQ]
4- 8 A5 --- LSQ SN Ia identifier
10- 22 F13.5 d JD Julian Date of observation start
24 A1 --- Filt Filter used in the observation
(B, V, u, g, r or i)
26- 31 F6.3 mag mag [13.9/23] Observed magnitude in Filter (1)
33- 37 F5.3 mag e_mag [0.004/0.6] Error in mag (2)
--------------------------------------------------------------------------------
Note (1): Calibrated in the Swope natural system.
Note (2): The quoted error is the combination of the measurement error on the
magnitude and the statistical error which incorporates errors on the
mean zero point and the extinction coefficient.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [LSQ]
4- 8 A5 --- LSQ SN Ia identifier
10- 11 I2 h RAh Hour of right ascension (J2000)
13- 14 I2 min RAm Minute of right ascension (J2000)
16- 20 F5.2 s RAs Second of right ascension (J2000)
22 A1 --- DE- Sign of declination (J2000)
23- 24 I2 deg DEd Degree of declination (J2000)
26- 27 I2 arcmin DEm Arcminute of declination (J2000)
29- 33 F5.2 arcsec DEs Arcsecond of declination (J2000)
35- 39 F5.3 --- z [0.009/0.2] Heliocentric redshift
41- 46 F6.4 --- e_z [0.0001/0.005] z uncertainty
48- 52 F5.3 --- zCMB [0.009/0.2] CMB frame redshift
54- 59 F6.3 mag mB [13.7/19.8] Rest-frame blue magnitude mB (1)
61- 65 F5.3 mag e_mB [0.01/0.03] mB uncertainty (1)
67- 72 F6.3 --- c [-0.3/0.4] Supernova SALT2 color parameter c (1)
74- 78 F5.3 --- e_c [0.01/0.03] c uncertainty (1)
80- 85 F6.3 --- x1 [-3.2/2.4] SALT2 shape (stretch) factor x1 (1)
87- 91 F5.3 --- e_x1 [0.02/0.4] x1 uncertainty (1)
93- 97 F5.3 --- E(B-V) [0.01/0.2] Milky Way extinction color parameter
--------------------------------------------------------------------------------
Note (1): Values output by SALT2.4 (see Guy et al. 2007A&A...466...11G 2007A&A...466...11G;
Betoule et al. 2014, Cat. J/A+A/568/A22): the distance modulus is
given by µSN=mB-M+αx1-βc
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 31-Aug-2015