ESSENCE Supernova Survey - Data Release 1

2007 January 3 - Initial Release
2007 January 18 - Preliminary global SN Ia distance modulus compilation of Davis07
2007 March 27 - Addition of sample distribution plot from simulations that led to glosz prior. 2007 October 3 - Fixed misdirected link for ESSENCE+SNLSnearby MLCS2k2 fit data file. Added ADS links.


We present here the SN Ia light curves, luminosity distance moduli, and cosmological results from the first results papers from the ESSENCE supernova survey. These papers detailed the first four years ESSENCE supernova survey and presented an analysis of the luminosity distance moduli to 60 Type Ia supernovae from this first phase of the project. These data are consistent with the now-standard LCDM cosmological constant model of the Universe.

For the convenience of those interested in replicating and analyzing our results, we here provide the lightcurves and observed passbands for the 119 supernovae discussed in Miknaitis07, of which the 60 highest-quality SNe Ia were used for the first cosmological results above. We also give the luminosity distance moduli and other parameters from the fits to the supernova light curves with both the MLCS2k2 (Jha06) and SALT (Guy05 ; 2005, A&A, 443, 781) fitters.

ESSENCE Data

Please note that the absolute scale of the distance moduli presented above is arbitrary. The useful cosmological information is in the relative luminosity distance evolution as a function of redshift.

Please contact Michael Wood-Vasey or Gajus Miknaitis if you have any questions about this work or the data and analysis presented on this page.


Preliminary joint Riess07+Wood-Vasey07 list from Davis07

Davis07_R07_WV07.dat

This is a hybrid list from two different fitters where the distance moduli have been normalized by the mean of the nearby SNe Ia in common. Riess and Wood-Vasey will soon provide a proper list of consistently-fit distance to all SNeIa in the Riess07 and Wood-Vasey07 set. Note that as with all SN Ia distance moduli these are relative distances. The absolute scale, which is dependent on a combination of the Hubble parameter and absolute luminosity of a fiducial SN Ia, is not known. Please cite all three papers, Davis07 (astro-ph/0701510), Wood-Vasey07 (astro-ph/0701041), and Riess07 (astro-ph/0611572) when referring to this table.


Detailed and Derived Data Products

If you would like to reproduce our cosmological results using the same cosmological fitter we provide the formatted data and parameter files as expected for this fitter. Generically, the distance modulus/fit parameter files from above, in combination with the BAO results of Eisenstein05 (2005, AJ, 633, 650) and Percival06 (astro-ph/0608635), will provide all of the information you need.

Cosmology Fitter

The cosmological results presented in Wood-Vasey07 were generated using the "simple_cosfitter" package written by Alex Conley (2006, ApJ, 644, 1) and available at http://qold.astro.utoronto.ca/conley/simple_cosfitter/.

SNLS Data

The SNLS lightcurves used in the Astier06 (2006, A&A, 447, 31) cosmological results paper and the SALT light-curve fitter (Guy05) and accompanying cosmology fitter are available at http://snls.in2p3.fr/conf/release/.

Cosmological Constraints

ESSENCE+nearby SNeIa

ESSENCE Omega_Matter, Omega_Lambda probability surfaces and plots

ESSENCE Omega_Matter, w probability surfaces and plots

ESSENCE+SNLS+nearby SNe Ia

[2007/10/03: MWV] Please note that the following link was to the wrong file (one that had a redshift range restricted from z=[0.015,0.67] as done for the ESSENCE+nearby online above) until 2007/10/03. Thanks to Alex Conley for finding this mistake.

ESSENCE+SNLS Omega_Matter, Omega_Lambda probability surfaces and plots

ESSENCE+SNLS Omega_Matter, w probability surfaces and plots

Note that the BAO-only probabilities above are the same for each of the fits.


File-Naming Conventions

For the files we provide above we have retained the full filenames we use internally for the analysis files. This may make the filenames seem a bit unwieldy but our goal it to be completely clear and open about what we've done. In addition, this currently-execessive naming detail will smooth the way for future updates to be clearly distinguished from previous versions. For example, here's an explanation of the source of the MLCS2k2 fit parameter filename above: "SN.v025.nn2.SNLS.nearby.MLCS2k2.v004.nearby_Astier__tweaked__prior_glosz__RV_3.1.z_0.015.pureIa.fitparams"


Sample detail of glosz redshift simulation

We provide here a postscript plot showing a typical distribution of distance errors from the simulations done for the glosz prior for a particular redshift. Marked are the mean and medians of the distribution. There are sufficient simulated events so that the mean and median are well-defined and the slight skew that leads to the use of the median for these simulations purposes.
Michael Wood-Vasey

Last modified: Tue Mar 27 22:57:08 EDT 2007

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