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Saul Perlmutter, Robert Knop,
Greg Aldering, and Peter Nugent,
Lawrence Berkeley National Laboratory
Alex Conely and Michael Wood-Vasey,
University of California, Berkeley
Research Objectives
Several supernova search
and asteroid search groups formed an alliance to find a large batch of
nearby supernovae. The key element of the alliance was to run all of the
supernova searches simultaneously so that the follow-up resources were
used in a concentrated and complementary fashion. This provided us with
the well-sampled photometric (multiple times a week) and spectroscopic
(weekly) follow-up required to yield the greatest scientific return.
Computational Approach
Data reduction, analysis,
and storage are being performed using NERSC facilities. We are using a
multiple instruction/multiple data (MIMD) approach utilizing Fortran 90,
C, and MPI.
Accomplishments
In total, the alliance
discovered 35 supernovae during March 1999. Twenty Type Ia supernovae
were caught before or at maximum light and were followed with UBVRI (ultraviolet,
blue, visual, red, infrared) photometry and spectroscopy. These nearby
supernovae will become the calibrators for high-redshift supernovae and
will help us determine the fundamental cosmological parameters which describe
our universe. This is the largest and most successful search for and follow-up
of nearby supernovae in history.
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| By
subtracting two charge-coupled device (CCD) images, obtained with
the Cerro Tololo Inter-American Observatory's 4.0-meter telescope
with a one month spacing, the Supernova Cosmology Project was able
to detect SN 1998ba exploding in its host galaxy over 3 billion light-years
away. One week after the discovery, SN 1998ba was observed by the
Hubble Space Telescope. The dramatic improvement in resolution from
the space-based image is readily apparent. The Supernova Cosmology
Project has been using NERSC resources to determine the best way to
reduce these types of images and improve upon our detection capabilities. |
Significance
In order to draw any
scientific conclusions from the high-redshift supernovae research, we need
to be able to fully understand Type Ia supernovae. This is accomplished
through careful analysis of several nearby supernovae in order to calibrate
the high-redshift supernovae and ascertain possible systematic biases.
Publications
S. Perlmutter, G. Aldering,
G. Goldhaber, R. A. Knop, P. Nugent, P. G. Castro, S. Deustua, S. Fabbro,
A. Goobar, D. E. Groom, I. M. Hook, A. G. Kim, M. Y. Kim, J. C. Lee, N.
J. Nunes, R. Pain, C. R. Pennypacker, R. Quimby, C. Lidman, R. S. Ellis,
M. Irwin, R. G. McMahon, P. Ruiz-Lapuente, N. Walton, B. Schaefer, B.
J. Boyle, A. V. Filippenko, T. Matheson, A. S. Fruchter, N. Panagia, H.
J. M. Newberg, W. J. Couch, and the Supernova Cosmology Project, "Measurements
of [Omega]and [^] from 42 high-redshift supernovae," Astophys. J. 517,
565 (1999).
S. Perlmutter, G. Aldering,
M. Della Valle, S. Deustua, R. S. Ellis, S. Fabbro, A. Fruchter, G. Goldhaber,
D. E. Groom, I. M. Hook, A. G. Kim, M. Y. Kim, R. A. Knop, C. Lidman,
R. G. McMahon, P. Nugent, R. Pain, N. Panagia, C. R. Pennypacker, P. Ruiz-Lapuente,
B. Schaefer, and N. Walton, "Discovery of a supernova explosion at half
the age of the Universe," Nature 391, 51 (1998).
S. Perlmutter, B. Boyle, P.
Bunclark, D. Carter, W. Couch, S. Deustua, M. Dopita, R. Ellis, A.V. Filippenko,
S. Gabi, K. Glazebrook, G. Goldhaber, A. Goobar, D. Groom, I. Hook, M.
Irwin, A. Kim, M. Kim, J. Lee, T. Matheson, R. McMahon, H. Newberg, R.
Pain, C. Pennypacker, and I. Small, "High-redshift supernova discoveries
on demand: First results from a new tool for cosmology and bounds on q0,"
Nucl. Phys. B Proc. Suppl. (in press).
http://panisse.lbl.gov:80/nearsearch/
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