A Herschel study of the properties of starless cores in the Polaris Flare dark cloud region using PACS and SPIRE

TL;DR

This study uses Herschel's PACS and SPIRE instruments to analyze the properties of starless cores in the Polaris Flare, revealing their structure, temperature, and mass, and assessing their potential to be prestellar cores.

Contribution

First detailed Herschel-based analysis of starless cores in the Polaris Flare, identifying dense cores and evaluating their gravitational stability.

Findings

Identified five dense cores with filamentary structures.

Observed core masses close to the lower virial mass estimates.

Cores are potential prestellar candidates but not definitively gravitationally bound.

Abstract

The Polaris Flare cloud region contains a great deal of extended emission. It is at high declination and high Galactic latitude. It was previously seen strongly in IRAS Cirrus emission at 100 microns. We have detected it with both PACS and SPIRE on Herschel. We see filamentary and low-level structure. We identify the five densest cores within this structure. We present the results of a temperature, mass and density analysis of these cores. We compare their observed masses to their virial masses, and see that in all cases the observed masses lie close to the lower end of the range of estimated virial masses. Therefore, we cannot say whether they are gravitationally bound prestellar cores. Nevertheless, these are the best candidates to be potentialprestellar cores in the Polaris cloud region.