ar X iv : a st ro - p h / 05 01 06 5 v 1 5 J an 2 00 5 Properties of Type Ia Supernova Host Galaxies

ar X iv : a st ro - p h / 05 08 18 0 v 1 8 A ug 2 00 5 Chemistry and Star Formation in the Host Galaxies of Type

We study the effect of environment on the properties of type Ia supernovae by analyzing the integrated spectra of 57 local type Ia supernova host galaxies. We deduce from the spectra the metallicity, current star formation rate, and star formation history of the host and compare these to the supernova decline rates. Additionally, we compare the host properties to the difference between the deri...

ar X iv : a st ro - p h / 05 04 66 8 v 1 2 9 A pr 2 00 5 Classifications of the Host Galaxies of Supernovae , Set III

A homogeneous sample comprising host galaxies of 604 recent supernovae, including 212 objects discovered primarily in 2003 and 2004, has been classified on the David Dunlap Observatory system. Most SN 1991bg-like SNe Ia occur in E and E/Sa galaxies, whereas the majority of SN 1991T-like SNe Ia occur in intermediate-type galaxies. This difference is significant at the 99.9% level. As expected, a...

ar X iv : a st ro - p h / 05 07 06 6 v 1 4 J ul 2 00 5 Multiband Echo Tomography of Sco X - 1

ar X iv : a st ro - p h / 01 06 06 8 v 2 5 S ep 2 00 1 Analysis of two quintessence models with SN Ia data

The supernovae Ia data are used to analyze two general exact solutions for quintessence models. The best fit values for Ω m0 are smaller than in the Λ-term model, but still acceptable. With present-day data, it is not possible to discriminate among the various situations.

ar X iv : a st ro - p h / 05 06 12 3 v 2 1 A ug 2 00 5 To appear in ApJL GRB 050509 B : Constraints on short gamma - ray burst models 1

– 2 – We have obtained deep optical images with the Very Large Telescope at ESO of the first well-localized short-duration gamma-ray burst, GRB 050509B. From V and R imaging, initiated ∼ 2 days after the GRB trigger and lasting up to three weeks, we detect no variable object inside the small Swift/XRT X-ray error circle down to 2σ limits of V = 26.5 and R = 25.1. The X-ray error circle includes...