Census of Young Stars in Galactic Star Forming Region Sh2-88

Abstract

We present here the census and characterization of Young Stellar Objects (YSOs) associated with the active star-forming H II region Sh2-88 with multi-wavelength data situated in the Vulpecula OB1 association. To understand the extinction properties of Sh2-88 region, we generate an extinction map over 20×20 arcminutes using the neighbourhood method of Gutermuth et al. (2005) from the deep near-infrared HK band photometric archival data of UKIDSS. We find a sizable variable extinction over the region up to AV ≃11.7 mag, with a median value of AV ≃4.3 mag. The high extinction regions trace the dense filamentary structure, which was found earlier in the far-infrared and sub-mm data. Following the YSO classification scheme of Gutermuth et al. (2009), we have identified 74 YSOs in that region using Spitzer-IRAC data from four mid-infrared bands (3.6, 4.5, 5.8 and 8 μm) and 2MASS near-infrared K-band (2.16 μm) data. Among 74 YSOs, six are class I and 68 class II objects. Using IPHAS Hα, r, and i-band photometry, we have identified 41 additional YSOs. Among these 41, four sources are common with IR excess YSOs. From the spatial distribution of YSOs, it is apparent that YSOs are primarily distributed over the relatively higher extinction regions of the cloud, and star-formation activity might be ongoing in those dense parts of the cloud.