Peering into the Heart of the Giant Molecular Cloud G148.24+00.41: A Deep Near-infrared View of the Newly Hatched Cluster FSR 655

TL;DR

This study provides a detailed near-infrared analysis of a very young embedded star cluster within a giant molecular cloud, revealing its age, mass, star formation rate, and potential for future growth.

Contribution

It offers the first detailed near-infrared characterization of the newly formed cluster FSR 655 in the G148.24+00.41 cloud, including age, mass, and star formation activity.

Findings

Cluster age is approximately 0.5 million years.

Current cluster mass is around 180 solar masses.

Star formation rate is about 330 solar masses per million years.

Abstract

We present a detailed near-infrared study of an embedded cluster located in the hub of the giant molecular cloud G148.24+00.41 of mass $\sim$10$^5$ $M_\odot$, with the TANSPEC instrument mounted on the 3.6 m Devasthal Optical Telescope. The hub is located near the geometric center of the cloud and represents its most massive clump. We studied the central 2 pc $\times$ 2 pc area of the hub with 5$\sigma$ limiting magnitudes of 20.5, 20.1, and 18.6 mag in the $J$, $H$, and $K_s$ bands, respectively. Using the $K_s$-band luminosity function and comparing it with the synthetic clusters, we obtained the age of the cluster as $\sim$0.5 Myr, which was found to corroborate well with the visual extinction versus the age of nearby embedded clusters. We find that the present mass of the cluster is around $\sim$180 $M_\odot$, and the cluster is currently forming stars at a rate of $\sim$330 $M_\odot$ $\rm{Myr}^{-1}$, with an efficiency of $\sim$20%. The cluster is connected to an extended gas reservoir through a filamentary network; thus, we hypothesize that the cluster has the potential to become a richer cluster in a few Myr of time.