Dust Emission from the Perseus Molecular Cloud

TL;DR

This study combines infrared and near-infrared data to create detailed dust temperature and density maps of the Perseus molecular cloud, revealing variable dust emissivity linked to grain growth in denser regions.

Contribution

It introduces a method to account for variable dust emissivity and VSG emission, improving the accuracy of dust property maps in molecular clouds.

Findings

Dust emissivity varies with extinction and temperature.

Grain growth occurs in denser, colder regions.

Enhanced mapping accuracy of dust temperature and density.

Abstract

Using far-infrared emission maps taken by IRAS and Spitzer and a near-infrared extinction map derived from 2MASS data, we have made dust temperature and column density maps of the Perseus molecular cloud. We show that the emission from transiently heated very small grains and the big grain dust emissivity vary as a function of extinction and dust temperature, with higher dust emissivities for colder grains. This variable emissivity can not be explained by temperature gradients along the line of sight or by noise in the emission maps, but is consistent with grain growth in the higher density and lower temperature regions. By accounting for the variations in the dust emissivity and VSG emission, we are able to map the temperature and column density of a nearby molecular cloud with better accuracy than has previously been possible.