A multiwavelength study of the star forming H II region Sh2-82

TL;DR

This multiwavelength study investigates the interstellar medium and young stellar objects around HII region Sh2-82, revealing star formation likely triggered by expansion but not solely through the collect and collapse process.

Contribution

It provides a detailed multiwavelength analysis of Sh2-82, identifying molecular clumps, embedded clusters, and evaluating star formation mechanisms with spectral energy distribution fitting.

Findings

Identified two molecular clumps and associated young clusters.

Confirmed star formation activity within the molecular clumps.

Disproved the collect and collapse process as the primary trigger.

Abstract

Based on a multiwavelength study, the interstellar medium and young stellar objects (YSOs) around the HII region Sh2-82 have been analyzed. Two molecular clumps were found from the archival data of the Galactic Ring Survey, and using the Two Micron All-Sky Survey catalog, we found two corresponding young clusters embedded in the molecular clumps. The very good relations between CO emission, infrared shells and YSOs suggest that it is probably a triggered star formation region from the expansion of Sh2-82. We further used the data from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire from Spitzer to study the YSOs within the two clumps, confirming star formation in this region. By spectral energy distribution fits to each YSO candidate with infrared excess, we derived the slope of the initial mass function. Finally, comparing the HII region's dynamical age and the fragmentation time of the molecular shell, we discard the "collect and collapse" process as being the triggering mechanism for YSO formation. Sh2-82 can be a mixture of other processes such as radiative-driven implosion and/or collisions with pre-existing clumps.