Accounting for the foreground contribution to the dust emission towards Kepler's supernova remnant

• Published in: Monthly notices of the Royal Astronomical Society 2009-08, Vol.397 (3), p.1621-1632
• Main Authors: Gomez, H. L., Dunne, L., Ivison, R. J., Reynoso, E. M., Thompson, M. A., Sibthorpe, B., Eales, S. A., DeLaney, T. M., Maddox, S., Isaak, K.
• Format: Article
• Language: English
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; Galaxies: abundances; ISM: submillimetre dust; Radio astronomy; radio lines: ISM; Red shift; Stars & galaxies; submillimetre; Supernovae; Supernovae: Kepler
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2009.15061.x

Whether or not supernovae contribute significantly to the overall dust budget is a controversial subject. Submillimetre (sub-mm) observations, sensitive to cold dust, have shown an excess at 450 and 850 μm in young remnants Cassiopeia A (Cas A) and Kepler. Some of the sub-mm 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 sub-mm continuum imaging and spectroscopic observations of atomic and molecular gas, via H i, 12CO(J= 2–1) and 13CO(J= 2–1). We detect weak CO emission (peak T*A= 0.2–1 K, 1–2 km s−1 full width at half-maximum) from diffuse, optically thin gas at the locations of some of the sub-mm clumps. The contribution to the sub-mm emission from foreground molecular and atomic clouds is negligible. The revised dust mass for Kepler's remnant is 0.1–1.2 M⊙, about half of the quoted values in the original study by Morgan et al., but still sufficient to explain the origin of dust at high redshifts.