Year: 2010
Type: article
Abstract: Aims. In this work we explore the possibility of using the fast expansion of a type Ia supernova photosphere to detect extra-galactic ISM column density variations on spatial scales of ~100 AU on time scales of a few months.Methods. We constructed a simple model which describes the expansion of the photodisk and the effects of a patchy interstellar cloud on the observed equivalent width of D lines. Using this model we derived the behavior of the equivalent width as a function of time, spatial scale and amplitude of the column density fluctuations.Results. The calculations show that isolated, small (≤100 AU) clouds with column densities exceeding a few 1011 cm-2 would be easily detected. In contrast, the effects of a more realistic, patchy ISM become measurable in a fraction of cases, and for peak-to-peak variations larger than ~1012 cm-2 on a scale of 1000 AU.Conclusions. The proposed technique provides a unique way to probe the extra-galactic small scale structure, which is out of reach for any of the methods used so far. The same tool can also be applied to study the sub-AU Galactic ISM structure.
Source: Astronomy and Astrophysics
Authors: F. Patat, N. L. J. Cox, J. Parrent, D. Branch
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2139552470