The dust mass in Cassiopeia A from infrared and optical line flux differences

TL;DR

This paper introduces a new method to measure the dust mass in Cassiopeia A by comparing infrared and optical emission line fluxes, confirming a high dust mass consistent with previous estimates.

Contribution

It presents an independent technique for estimating supernova remnant dust mass using emission line flux ratios, enhancing the reliability of such measurements.

Findings

Dust mass in Cas A is at least 0.99 solar masses.

The new method agrees with previous estimates from other techniques.

Supports the idea that supernovae can produce large dust quantities.

Abstract

The large quantities of dust that have been found in a number of high redshift galaxies have led to suggestions that core-collapse supernovae (CCSNe) are the main sources of their dust and have motivated the measurement of the dust masses formed by local CCSNe. For Cassiopeia~A, an oxygen-rich remnant of a Type~IIb CCSN, a dust mass of 0.6-1.1~M$_\odot$ has already been determined by two different methods, namely (a) from its far-infrared spectral energy distribution and (b) from analysis of the red-blue emission line asymmetries in its integrated optical spectrum. We present a third, independent, method for determining the mass of dust contained within Cas~A. This compares the relative fluxes measured in similar apertures from [O~{\sc iii}] far-infrared and visual-region emission lines, taking into account foreground dust extinction, in order to determine internal dust optical depths, from which corresponding dust masses can be obtained. Using this method we determine a dust mass within Cas~A of at least 0.99$^{+0.10}_{-0.09}$~M$_\odot$.