SPECTRA AND HUBBLE SPACE TELESCOPE LIGHT CURVES OF SIX TYPE Ia SUPERNOVAE AT 0.511 < z < 1.12 AND THE UNION2 COMPILATION

By R. Amanullah, C. Lidman, David Rubin, G. Aldering, P. Astier, K. Barbary, M. Burns, A. Conley, K. Dawson, S. Deustua and 35 more. 2010

1,047 citations recorded by the source corpus.

We report on work to increase the number of well-measured Type Ia supernovae (SNe Ia) at high redshifts. Light curves, including high signal-to-noise Hubble Space Telescope data, and spectra of six SNe Ia that were discovered during 2001, are presented. Additionally, for the two SNe with z > 1, we present ground-based J-band photometry from Gemini and the Very Large Telescope. These are among the most distant SNe Ia for which ground-based near-IR observations have been obtained. We add these six SNe Ia together with other data sets that have recently become available in the literature to the Union compilation. We have made a number of refinements to the Union analysis chain, the most important ones being the refitting of all light curves with the SALT2 fitter and an improved handling of systematic errors. We call this new compilation, consisting of 557 SNe, the Union2 compilation. The flat concordance ΛCDM model remains an excellent fit to the Union2 data with the best-fit constant equation-of-state parameter w = −0.997+0.050−0.054(stat)+0.077−0.082(stat + sys together) for a flat universe, or w = −1.038+0.056−0.059(stat)+0.093−0.097(stat + sys together) with curvature. We also present improved constraints on w(z). While no significant change in w with redshift is detected, there is still considerable room for evolution in w. The strength of the constraints depends strongly on redshift. In particular, at z ≳ 1, the existence and nature of dark energy are only weakly constrained by the data.

Subfields: Astronomy and Astrophysics

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Citations in the corpus

THE EFFECT OF HOST GALAXIES ON TYPE Ia SUPERNOVAE IN THE SDSS-II SUPERNOVA SURVEY (2010, background): “…been compiled, e.g., CSP (Hamuy et al. 2006), SNLS (Astier et al. 2006), ESSENCE (Wood-Vasey et al. 2007), SDSS (Frieman et al. 2008), CfA (Hicken et al. 2009), and combined, we are approaching ∼ 1000 spectroscopicallyconfirmed SNe Ia available for cosmological analysis (Amanullah et al. 2010).”
Evidence of Environmental Dependencies of Type Ia Supernovae from the Nearby Supernova Factory indicated by Local H$\alpha$ (2013, methodology): “3 and 5 would shift the estimate of the dark energy equation of state by ∆w ≈ −0.06 (D. Rubin, private communication, as estimated using the Union machinery, Kowalski et al. 2008; Amanullah et al. 2010; Suzuki et al. 2012)”
SUPERNOVA CONSTRAINTS AND SYSTEMATIC UNCERTAINTIES FROM THE FIRST THREE YEARS OF THE SUPERNOVA LEGACY SURVEY (2011, methodology): “The analysis of Kowalski et al. (2008) was extended to a larger sample and refined to allow for more subtle redshift dependence within each sample in Amanullah et al. (2010).”
COSMOLOGICAL CONSTRAINTS FROM SUNYAEV–ZEL'DOVICH-SELECTED CLUSTERS WITH X-RAY OBSERVATIONS IN THE FIRST 178 deg2 OF THE SOUTH POLE TELESCOPE SURVEY (2011, methodology): “After adding the SPTCL data the uncertainty from SNe systematics is reduced to δw = ±0.026, a factor of ∼2.3 improvement.”
Expansion History with Decaying Vacuum: A Complete Cosmological Scenario (2012, background): “…data (supernovae type Ia, CMB, galaxy clustering, etc.) have converged towards a cosmic expansion history that involves a spatially flat geometry and a recent accelerating period of the Universe (cf. Spergel et al. 2007; Amanullah et al. 2010; Komatsu et al. 2011 and references therein).”
Observational probes of cosmic acceleration (2012, background): “Recent examples include the “Gold” sample (Riess et al., 2004, 2007), the “Union” and “Union2” samples (Kowalski et al., 2008; Amanullah et al., 2010), the “Constitution” sample (Hicken et al., 2009a), and the compilation of local, SDSS-II, SNLS3, and HST supernovae analyzed by Conley et al. (2011).”
Probing the anisotropic local Universe and beyond with SNe Ia data (2010, methodology): “We divide the Union 2 data (Amanullah et al. 2010) into five bins at z < 0.1 and seven bins at z > 0.1 so as to have sufficient number of data points in each bin (see Table 1).”
The Rh=ct universe (2011, neutral): “15 < z < 1.4 (Amanullah et al. 2010).”
Berkeley Supernova Ia Program – I. Observations, data reduction and spectroscopic sample of 582 low-redshift Type Ia supernovae (2012, background): “…Ia) have been particularly useful in recent years as a way to accurately measure cosmological parameters (Astier et al. 2006; Riess et al. 2007; Wood-Vasey et al. 2007; Hicken et al. 2009; Kessler et al. 2009; Amanullah et al. 2010; Conley et al. 2011; Sullivan et al. 2011; Suzuki et al. 2012).”