Daniel J. Beeler

TL;DR: It is shown that the velocity structure of absorbing material along the line of sight to 35 type Ia supernovae tends to be blueshifted, and these structures are likely signatures of gas outflows from the supernova progenitor systems.

TL;DR: In this article, the first results from a survey of SDSS quasars selected for strong H I damped Lyα (DLA) absorption with corresponding low equivalent width absorption from strong low-ion transitions were presented.

TL;DR: In this paper, the authors present high-resolution spectroscopy of the bright SN Ia 2007af at three epochs and search for variability in any of the Na D absorption components, finding that the host-galaxy Na D lines appear to be of interstellar rather than circumstellar origin and do not vary down to the level of 18 mA (column density of 2 × 10^(11) cm^(-2)).

TL;DR: In this article, the authors present high-resolution spectroscopy of the bright SN Ia 2007af at three epochs and search for variability in any of the Na D absorption components, finding that the host-galaxy Na D lines appear to be of interstellar rather than circumstellar origin and do not vary down to the level of 18 mA (column density of 2 x 10^11 cm^-2).