Accounting for the Foreground Contribution to the Dust Emission towards Kepler's Supernova Remnant

TL;DR

This study investigates the dust emission in Kepler's supernova remnant, finding that foreground material contributes minimally, and revises the dust mass estimate to be sufficient for explaining high-redshift dust origins.

Contribution

It provides a detailed analysis of foreground contamination in submm observations of Kepler's remnant, refining dust mass estimates and clarifying supernovae's role in dust production.

Findings

Foreground molecular and atomic clouds have negligible contribution to submm emission.

Revised dust mass for Kepler's remnant is 0.1--1.2 solar masses.

Dust mass remains sufficient to explain high-redshift dust origins.

Abstract

Whether or not supernovae contribute significantly to the overall dust budget is a controversial subject. Submillimetre (submm) observations, sensitive to cold dust, have shown an excess at 450 and 850 microns in young remnants Cassiopeia A (Cas A) and Kepler. Some of the submm emission from Cas A has been shown to be contaminated by unrelated material along the line of sight. In this paper we explore the emission from material towards Kepler using submm continuum imaging and spectroscopic observations of atomic and molecular gas, via HI, 12CO (J=2-1) and 13CO (J=2-1). We detect weak CO emission (peak TA* = 0.2-1K, 1-2km/s fwhm) from diffuse, optically thin gas at the locations of some of the submm clumps. The contribution to the submm emission from foreground molecular and atomic clouds is negligible. The revised dust mass for Kepler's remnant is 0.1--1.2 solar masses, about half of the quoted values in the original study by Morgan et al. (2003), but still sufficient to explain the origin of dust at high redshifts.