Gaston Folatelli

Improved cosmological constraints from new, old, and combined supernova data sets

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.

New constraints on Omega(M), Omega(lambda), and w from an independent set of eleven high-redshift supernovae observed with HST

We report measurements of

Spectra and hubble space telescope light curves of six typE Ia supernovae at 0.511 < z < 1.12 and the union2 compilation

Omega_M

The Carnegie Supernova Project: The Low-Redshift Survey

,

The Peculiar SN 2005hk: Do Some Type Ia Supernovae Explode as Deflagrations?

Omega_Lambda

Measurement of Ωm, ΩΛ from a Blind Analysis of Type Ia Supernovae with CMAGIC: Using Color Information to Verify the Acceleration of the Universe

, and w from eleven supernovae at z=0.36-0.86 with high-quality lightcurves measured using WFPC-2 on the HST. This is an independent set of high-redshift supernovae that confirms previous supernova evidence for an accelerating Universe. Combined with earlier Supernova Cosmology Project data, the new supernovae yield a flat-universe measurement of the mass density

Quantitative comparison between Type Ia supernova spectra at low and high redshifts: A case study

Omega_M=0.25^{+0.07}_{-0.06}

TYPE IIb SUPERNOVA 2013df ENTERING INTO AN INTERACTION PHASE: A LINK BETWEEN THE PROGENITOR AND THE MASS LOSS

(statistical)

Nebular phase observations of the Type-Ib supernova iPTF13bvn favour a binary progenitor

pm0.04

Strong near-infrared carbon in the Type Ia supernova iPTF13ebh

(identified systematics), or equivalently, a cosmological constant of