Herschel Far-Infrared and Sub-millimeter Photometry for the KINGFISH Sample of Nearby Galaxies

TL;DR

This paper presents Herschel far-infrared and sub-millimeter photometry for 61 nearby galaxies, revealing insights into dust properties, emission models, and the impact of including Herschel data on understanding dust heating and mass estimates.

Contribution

It provides new Herschel photometry data for the KINGFISH galaxy sample and compares dust mass estimates from different models, highlighting discrepancies and the presence of sub-millimeter excess in dwarf irregulars.

Findings

Herschel data largely consistent with previous models but show sub-millimeter excess in dwarf irregulars.

Including Herschel data increases the estimated fraction of dust heating from intense radiation fields.

Dust masses from Draine & Li models are nearly twice those from single-temperature blackbody fits.

Abstract

New far-infrared and sub-millimeter photometry from the Herschel Space Observatory is presented for 61 nearby galaxies from the Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel (KINGFISH) sample. The spatially-integrated fluxes are largely consistent with expectations based on Spitzer far-infrared photometry and extrapolations to longer wavelengths using popular dust emission models. Dwarf irregular galaxies are notable exceptions, as already noted by other authors, as their 500um emission shows evidence for a sub-millimeter excess. In addition, the fraction of dust heating attributed to intense radiation fields associated with photo-dissociation regions is found to be (21+/-4)% larger when Herschel data are included in the analysis. Dust masses obtained from the dust emission models of Draine & Li are found to be on average nearly a factor of two higher than those based on single-temperature modified blackbodies, as single blackbody curves do not capture the full range of dust temperatures inherent to any galaxy. The discrepancy is largest for galaxies exhibiting the coolest far-infrared colors.