| Title: |
Improved Cosmological Constraints from New, Old, and Combined Supernova Data Sets |
| Authors: |
Kowalski, M.; Rubin, D.; Aldering, G.; Agostinho, R. J.; Amadon, A.; Amanullah, R.; Balland, C.; Barbary, K.; Blanc, G.; Challis, P. J.; Conley, A.; Connolly, N. V.; Covarrubias, R.; Dawson, K. S.; Deustua, S. E.; Ellis, R.; Fabbro, S.; Fadeyev, V.; Fan, X.; Farris, B.; Folatelli, G.; Frye, B. L.; Garavini, G.; Gates, E. L.; Germany, L.; Goldhaber, G.; Goldman, B.; Goobar, A.; Groom, D. E.; Haissinski, J.; Hardin, D.; Hook, I.; Kent, S.; Kim, A. G.; Knop, R. A.; Lidman, C.; Linder, E. V.; Mendez, J.; Meyers, J.; Miller, G. J.; Moniez, M.; Mourão, A. M.; Newberg, H.; Nobili, S.; Nugent, P. E.; Pain, R.; Perdereau, O.; Perlmutter, S.; Phillips, M. M.; Prasad, V.; Quimby, R.; Regnault, N.; Rich, J.; Rubenstein, E. P.; Ruiz-Lapuente, P.; Santos, F. D.; Schaefer, B. E.; Schommer, R. A.; Smith, R. C.; Soderberg, A. M.; Spadafora, A. L.; Strolger, L. G.; Strovink, M.; Suntzeff, N. B.; Suzuki, N.; Thomas, R. C.; Walton, N. A.; Wang, L.; Wood-Vasey, W. M.; Yun, J. L. |
| Source: |
Astrophysical Journal, 686(2), 749-778, (2008-10-20) |
| Publisher Information: |
American Astronomical Society |
| Publication Year: |
2008 |
| Collection: |
Caltech Authors (California Institute of Technology) |
| Subject Terms: |
cosmological parameters; cosmology: observations; supernovae: general |
| Description: |
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. ; © 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 ... |
| Document Type: |
article in journal/newspaper |
| Language: |
unknown |
| Relation: |
https://authors.library.caltech.edu/communities/caltechauthors/; https://doi.org/10.1086/589937; eprintid:14409 |
| DOI: |
10.1086/589937 |
| Availability: |
https://doi.org/10.1086/589937 |
| Rights: |
info:eu-repo/semantics/openAccess ; Other |
| Accession Number: |
edsbas.2D9B76FC |
| Database: |
BASE |