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Improved Cosmological Constraints from New, Old, and Combined Supernova Data Sets

Kowalski, M. and Rubin, D. and Aldering, G. and Agostinho, R. J. and Amadon, A. and Amanullah, R. and Balland, C. and Barbary, K. and Blanc, G. and Challis, P. J. and Conley, A. and Connolly, N. V. and Covarrubias, R. and Dawson, K. S. and Deustua, S. E. and Ellis, R. and Fabbro, S. and Fadeyev, V. and Fan, X. and Farris, B. and Folatelli, G. and Frye, B. L. and Garavini, G. and Gates, E. L. and Germany, L. and Goldhaber, G. and Goldman, B. and Goobar, A. and Groom, D. E. and Haissinski, J. and Hardin, D. and Hook, I. and Kent, S. and Kim, A. G. and Knop, R. A. and Lidman, C. and Linder, E. V. and Mendez, J. and Meyers, J. and Miller, G. J. and Moniez, M. and Mourão, A. M. and Newberg, H. and Nobili, S. and Nugent, P. E. and Pain, R. and Perdereau, O. and Perlmutter, S. and Phillips, M. M. and Prasad, V. and Quimby, R. and Regnault, N. and Rich, J. and Rubenstein, E. P. and Ruiz-Lapuente, P. and Santos, F. D. and Schaefer, B. E. and Schommer, R. A. and Smith, R. C. and Soderberg, A. M. and Spadafora, A. L. and Strolger, L. G. and Strovink, M. and Suntzeff, N. B. and Suzuki, N. and Thomas, R. C. and Walton, N. A. and Wang, L. and Wood-Vasey, W. M. and Yun, J. L. (2008) Improved Cosmological Constraints from New, Old, and Combined Supernova Data Sets. Astrophysical Journal, 686 (2). pp. 749-778. ISSN 0004-637X. doi:10.1086/589937.

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We present a new compilation of Type Ia supernovae (SNe Ia), a new data set of low-redshift nearby-Hubble-flow SNe, and new analysis procedures to work with these heterogeneous compilations. This "Union" compilation of 414 SNe Ia, which reduces to 307 SNe after selection cuts, includes the recent large samples of SNe Ia from the Supernova Legacy Survey and ESSENCE Survey, the older data sets, as well as the recently extended data set of distant supernovae observed with the Hubble Space Telescope (HST). A single, consistent, and blind analysis procedure is used for all the various SN Ia subsamples, and a new procedure is implemented that consistently weights the heterogeneous data sets and rejects outliers. We present the latest results from this Union compilation and discuss the cosmological constraints from this new compilation and its combination with other cosmological measurements (CMB and BAO). The constraint we obtain from supernovae on the dark energy density is Ω_Λ = 0.713^(+0.027)_(−0.029)(stat)^(+ 0.036)_(−0.039)(sys), for a flat, ΛCDM universe. Assuming a constant equation of state parameter, w, the combined constraints from SNe, BAO, and CMB give w = − 0.969^(+ 0.059)_(−0.063)(stat)^(+ 0.063)_(−0.066)(sys) . While our results are consistent with a cosmological constant, we obtain only relatively weak constraints on a w that varies with redshift. In particular, the current SN data do not yet significantly constrain w at z > 1. With the addition of our new nearby Hubble-flow SNe Ia, these resulting cosmological constraints are currently the tightest available.

Item Type:Article
Related URLs:
URLURL TypeDescription
Amanullah, R.0000-0002-5559-9351
Dawson, K. S.0000-0002-0553-3805
Ellis, R.0000-0001-7782-7071
Fan, X.0000-0003-3310-0131
Gates, E. L.0000-0002-3739-0423
Goobar, A.0000-0002-4163-4996
Hook, I.0000-0002-2960-978X
Lidman, C.0000-0003-1731-0497
Nugent, P. E.0000-0002-3389-0586
Phillips, M. M.0000-0003-2734-0796
Quimby, R.0000-0001-9171-5236
Wang, L.0000-0002-9803-166X
Additional Information:© 2008 American Astronomical Society. Received 2007 October 25, accepted for publication 2008 April 2. This work is based on observations made with: the Lick and Keck Observatories; the Cerro Tololo Inter-American Observatory 4m Blanco Telescope; the Yale/AURA/Lisbon/OSU(YALO) 1 m Telescope at Cerro Tololo Inter-American Observatory; the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium; the WIYN Observatory, owned and operated by the WIYN Consortium, which consists of the University of Wisconsin, Indiana University, Yale University, and the National Optical Astronomy Observatory (NOAO); the Isaac Newton Telescope, which is operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofısica Canarias; the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias; and the MDM Observatory 2.4m Hiltner Telescope. The authors wish to thank the telescope allocation committees and the observatory staffs for their support for the extensive supernova search campaign and follow-up observations that contributed to the results reported here. In particular, we wish to thank C. Bailyn and S. Tourtellotte for assistance with YALO observations, D. Harner for obtaining WIYN data, and D. Folha and S. Smartt for the INT 2.5 m service observing. For their efforts in the coordinated supernova search, we wish to acknowledge the NEAT search team (E.Helin, S. Pravdo, D. Rabinowitz, and K. Lawrence) at JPL and the Spacewatch program at the University of Arizona (which includes R. S. McMillan, T. Gehrels, J.A. Larsen, J. L. Montani, J. V. Scotti, N. Danzl, and A. Gleason). We also wish to thank B. Schmidt, A. Filippenko, M. Schwartz, A. Gal-Yam, and D. Maoz for providing us with early announcements of supernova candidates. This work was supported in part by the Director, Office of Science, Office of High Energy and Nuclear Physics, US Department of Energy, through contract DE-AC02-05CH11231. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the US Department of Energy under contract DEAC02- 05CH11231. The use of Portuguese time for the YALO telescope was supported by Fundacao para a Ciencia e Tecnologia, Portugal, and by Project PESO/ESO/P/PRO/1257/98. M. K. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG). P. E. N. acknowledges support from the US Department of Energy Scientific Discovery through Advanced Computing program under contract DE-FG02-06ER06-04. A. M. M. acknowledges financial support from Fundacao para a Ciencia e Tecnologia (FCT), Portugal, through project PESO/P/PRO/ 15139/99.
Funding AgencyGrant Number
Department of Energy (DOE)DE-AC02-05CH11231
Deutsche Forschungsgemeinschaft (DFG)UNSPECIFIED
Department of Energy (DOE)DE-FG02-06ER06-04
Fundação para a Ciência e Tecnologia (FCT)PESO/P/PRO/15139/99
Subject Keywords:cosmological parameters; cosmology: observations; supernovae: general
Issue or Number:2
Record Number:CaltechAUTHORS:20090617-204752748
Persistent URL:
Official Citation:Improved Cosmological Constraints from New, Old, and Combined Supernova Data Sets M. Kowalski, D. Rubin, G. Aldering, R. J. Agostinho, A. Amadon, R. Amanullah, C. Balland, K. Barbary, G. Blanc, P. J. Challis, A. Conley, N. V. Connolly, R. Covarrubias, K. S. Dawson, S. E. Deustua, R. Ellis, S. Fabbro, V. Fadeyev, X. Fan, B. Farris, G. Folatelli, B. L. Frye, G. Garavini, E. L. Gates, L. Germany, G. Goldhaber, B. Goldman, A. Goobar, D. E. Groom, J. Haissinski, D. Hardin, I. Hook, S. Kent, A. G. Kim, R. A. Knop, C. Lidman, E. V. Linder, J. Mendez, J. Meyers, G. J. Miller, M. Moniez, A. M. Mourão, H. Newberg, S. Nobili, P. E. Nugent, R. Pain, O. Perdereau, S. Perlmutter, M. M. Phillips, V. Prasad, R. Quimby, N. Regnault, J. Rich, E. P. Rubenstein, P. Ruiz-Lapuente, F. D. Santos, B. E. Schaefer, R. A. Schommer, R. C. Smith, A. M. Soderberg, A. L. Spadafora, L.-G. Strolger, M. Strovink, N. B. Suntzeff, N. Suzuki, R. C. Thomas, N. A. Walton, L. Wang, W. M. Wood-Vasey, and J. L. Yun 2008 ApJ 686 749-778 doi: 10.1086/589937
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14409
Deposited By: Joy Painter
Deposited On:29 Aug 2009 00:26
Last Modified:08 Nov 2021 23:11

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