The Galactic NH - AV Relation and its Application to Historical Galactic SNRs

TL;DR

This paper refines the NH-AV relation using data from 39 Galactic SNRs and demonstrates its application in constraining distances or magnitudes of historical SNRs, improving our understanding of their properties.

Contribution

It provides a more accurate NH-AV relation based on a larger sample of SNRs and applies it to estimate distances or magnitudes of historical SNRs.

Findings

Refined NH-AV relation: NH = (1.69+/-0.07)*10^21 Av cm^(-2) mag^(-1)

Application to historical SNRs constrains their distances or magnitudes

Enhanced understanding of Galactic SNR properties

Abstract

We refine a classic relation between the hydrogen column density (NH) and optical extinction (Av) by employing 39 Galactic Supernova Remnants (SNRs) with X-rays, optical and/or infra-red data available. We find NH = (1.69+/-0.07)*10^21 Av cm^(-2) mag^(-1) . Applying this relation to three Galactic SNRs with good historical records allows us to further constrain either their progenitor's distances or magnitudes, which is independent access to their distances.