Related papers: Beta, Local SNIa data and the Great Attractor
We present Hubble Space Telescope measurements of surface brightness fluctuations (SBF) distances to early-type galaxies that have hosted Type Ia supernovae (SNIa). The agreement in the relative SBF and SNIa multicolor light curve shape and…
While many studies have shown a correlation between properties of the light curves of Type Ia SN (SNe Ia) and properties of their host galaxies, it remains unclear what is driving these correlations. We introduce a new direct method to…
Type Ia supernovae (SNe Ia) were instrumental in establishing the acceleration of the universe's expansion. By virtue of their combination of distance reach, precision, and prevalence, they continue to provide key cosmological constraints,…
Recently, Chornock and co-workers announced the Pan-STARRS discovery of a transient source reaching an apparent peak luminosity of ~4x10^44 erg s^-1. We show that the spectra of this transient source are well fit by normal Type Ia supernova…
We develop a novel approach to constrain the Hubble parameter $H_0$ and the primordial power spectrum amplitude $A_\mathrm{s}$ using type Ia supernovae (SNIa) data. By considering SNIa as tracers of the peculiar velocity field, we can model…
The properties of the highest velocity ejecta of normal Type Ia supernovae (SNe Ia) are studied via models of very early optical spectra of 6 SNe. At epochs earlier than 1 week before maximum, SNe with a rapidly evolving Si II 6355 line…
We present an analysis of 15 Type Ia supernovae (SNe Ia) at redshift z > 1 (9 at 1.5 < z < 2.3) recently discovered in the CANDELS and CLASH Multi-Cycle Treasury programs using WFC3 on the Hubble Space Telescope. We combine these SNe Ia…
We explore the implications of type Ia supernovae (SNIa) observations on flat cosmological models whose matter content is an exotic fluid with equation of state, p=-M^(4(a+1))/rho^a. In this scenario, a single fluid component may drive the…
Type Ia supernovae provide direct evidence for an accelerating universe, and for the existence of "dark energy" driving this expansion. The Supernova Legacy Survey (SNLS) will deliver many hundreds of SNIa detections, and well-sampled…
We describe our ongoing program designed to measure the SN-Ia rate in a sample of massive z=0.5-0.9 galaxy clusters. The SN-Ia rate is a poorly known observable, especially at high z, and in cluster environments. The SN rate and its…
We present 139 spectra of 124 Type Ia supernovae (SNeIa) that were observed at the ESO/VLT during the first three years of the Canada-France-Hawai Telescope (CFHT) Supernova Legacy Survey (SNLS). This homogeneous data set is used to test…
The peculiar velocity field offers a unique way to probe dark matter density field on large scales at low redshifts. In this work, we have compiled a new sample of 465 peculiar velocities from low redshift $(z < 0.067)$ Type Ia supernovae.…
Observations show that Type Ia Supernovae (SNe Ia) form a homogeneous class of objects. They share similar spectroscopic evolution, light-curve shapes, and peak absolute magnitudes. The slight departures from homogeneity that are observed…
The velocities and equivalent widths (EWs) of a set of absorption features are measured for a sample of 28 well-observed Type Ia supernovae (SN Ia) covering a wide range of properties. The values of these quantities at maximum are obtained…
We present the first application of a spherical collapse model to a supercluster of galaxies. Positions and redshifts of $\sim 3000$ galaxies in the Shapley Supercluster (SSC) are used to define velocity caustics that limit the…
We present the results of a galaxy redshift survey in the central region of the Shapley Concentration. Our total sample contains ~2000 radial velocities of galaxies both in the clusters and in the intercluster field. We reconstruct the…
We re-analyze the detectability of large scale dark flow (or local bulk flow) with respect to the CMB background based upon the redshift-distance relation for Type Ia supernovae (SN Ia). We made two independent analyses: one based upon…
We used the GMBCG galaxy cluster catalogue and SDSS-II supernovae data with redshifts measured by the BOSS project to identify 48 SNe Ia residing in rich galaxy clusters and compare their properties with 1015 SNe Ia in the field. Their…
The luminosities of Type Ia supernovae (SNe), the thermonuclear explosions of white-dwarf stars, vary systematically with their intrinsic color and the rate at which they fade. From images taken with the Galaxy Evolution Explorer (GALEX),…
Type Ia supernovae (SNe Ia) are thermonuclear explosions of white dwarf stars in close binary systems. They play an important role as cosmological distance indicators and have led to the discovery of the accelerated expansion of the…