The Spitzer survey of interstellar clouds in the Gould Belt. II. The Cepheus Flare observed with IRAC and MIPS

TL;DR

This study uses Spitzer IRAC and MIPS observations to identify and analyze young stellar objects in the Cepheus Flare, revealing disk properties, clustering, and star formation efficiency in this Gould Belt region.

Contribution

First comprehensive infrared survey of Cepheus Flare with detailed YSO identification, SED modeling, and clustering analysis, providing new insights into star formation in this region.

Findings

Most disks are optically thick and actively accreting.

Identified four small protostellar groups and a larger association.

Star formation efficiency varies between clustered and isolated cores.

Abstract

We present Spitzer IRAC (~2 deg^2) and MIPS (~8 deg^2) observations of the Cepheus Flare which is associated with the Gould Belt, at an approximate distance of ~300 pc. Around 6500 sources are detected in all four IRAC bands, of which ~900 have MIPS 24 micron detections. We identify 133 YSO candidates using color-magnitude diagram techniques, a large number of the YSO candidates are associated with the NGC 7023 reflection nebula. Cross identifications were made with the Guide Star Catalog II and the IRAS Faint Source Catalog, and spectral energy distributions (SED) were constructed. SED modeling was conducted to estimate the degree of infrared excess. It was found that a large majority of disks were optically thick accreting disks, suggesting that there has been little disk evolution in these sources. Nearest-neighbor clustering analysis identified four small protostellar groups (L1228, L1228N, L1251A, and L1251B) with 5-15 members each and the larger NGC 7023 association with 32 YSO members. The star formation efficiency for cores with clusters of protostars and for those without clusters was found to be ~8% and ~1% respectively. The cores L1155, L1241, and L1247 are confirmed to be starless down to our luminosity limit of L_bol=0.06 L_sol.