Hubble space telescope observations of nine high-redshift essence supernovae

Kevin Krisciunas, Peter M. Garnavich, Peter Challis, Jose Luis Prieto, Adam G. Riess, Brian Barris, Claudio Aguilera, Andrew C. Becker, Stephane Blondin, Ryan Chornock, Alejandro Clocchiatti, Ricardo Covarrubias, Alexei V. Filippenko, Ryan J. Foley, Malcolm Hicken, Saurabh Jha, Robert P. Kirshner, Bruno Leibundgut, Weidong Li, Thomas MathesonAnthony Miceli, Gajus Miknaitis, Armin Rest, Maria Elena Salvo, Brian P. Schmidt, R. Chris Smith, Jesper Sollerman, Jason Spyromilio, Christopher W. Stubbs, Nicholas B. Suntzeff, John L. Tonry, W. Michael Wood-Vasey

Research output: Contribution to journalArticlepeer-review


We present broadband light curves of nine supernovae ranging in redshift from 0.5 to 0.8. The supernovae were discovered as part of the ESSENCE project, and the light curves are a combination of Cerro Tololo 4 m and Hubble Space Telescope (HST) photometry. On the basis of spectra and/or light-curve fitting, eight of these objects are definitely Type la supernovae, while the classification of one is problematic. The ESSENCE project is a 5 yr endeavor to discover about 200 high-redshift Type la supernovae, with the goal of tightly constraining the time average of the equation-of-state parameter [w = p/(ρc 2)] of the "dark energy." To help minimize our systematic errors, all of our ground-based photometry is obtained with the same telescope and instrument. In 2003 the highest redshift subset of ESSENCE supernovae was selected for detailed study with HST. Here we present the first photometric results of the survey. We find that all but one of the ESSENCE supernovae have slowly declining light curves and that the sample is not representative of the low-redshift set of ESSENCE Type la supernovae. This is unlikely to be a sign of evolution in the population. We attribute the decline-rate distribution of HST events to a selection bias at the high-redshift edge of our sample and find that such a bias will infect other magnitude-limited Type la supernova searches unless appropriate precautions are taken.

Original languageEnglish (US)
Pages (from-to)2453-2472
Number of pages20
JournalAstronomical Journal
Issue number6
StatePublished - Dec 2005


  • Distance scale
  • Galaxies: distances and redshifts
  • Supernovae: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Hubble space telescope observations of nine high-redshift essence supernovae'. Together they form a unique fingerprint.

Cite this