NOAO >   Observing Info >   Approved Programs >   2012A-0320

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Proposal Information for 2012A-0320


PI: Ryan Foley, Harvard-Smithsonian Center for Astrophysics, rfoley@cfa.harvard.edu
Address: 60 Garden St MS 20, Cambridge, MA 02138

CoI: Nathan Sanders, Harvard-Smithsonian Center for Astrophysics
CoI: Daniel Scolnic, Johns Hopkins University
CoI: Ryan Chornock, Harvard-Smithsonian Center for Astrophysics
CoI: Mark Huber, University of Hawaii
CoI: Robert Kirshner, Harvard-Smithsonian Center for Astrophysics
CoI: Armin Rest, Space Telescope Science Institute

Title: The Most Precise Distances to Type Ia Supernovae

Abstract: Using low-redshift Type Ia supernovae (SN Ia), we have identified a correlation between SN ejecta velocity and intrinsic color. This new result has significant implications for the precision with which we can measure SN Ia distances. Using this knowledge, we have reduced the intrinsic scatter in the peak magnitudes from 0.17 mag to 0.11 mag. Measuring the ejecta velocity also avoids several potentially large systematic biases in measuring the amount of host-galaxy extinction, which directly affects the estimated distances. We propose to test this relationship at high redshift using SN Ia discovered with Pan-STARRS and spectra from Gemini/GMOS. These data will provide the most precise distances to high-redshift SN Ia yet, which will in turn make the inferences on dark energy properties both more precise and more accurate.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2012A-0320

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