A deep optical/near-infrared catalog of Serpens

TL;DR

This paper presents a deep optical/near-infrared catalog of the Serpens molecular cloud, complementing the Spitzer c2d survey, with detailed data on sources, completeness limits, and astrometry for studying star and disk formation.

Contribution

It provides a comprehensive optical/near-infrared catalog of Serpens, including new data on disk-less young stellar objects, enhancing previous surveys and enabling detailed star formation studies.

Findings

Catalog contains 26,524 sources with magnitudes down to R=24.5 and Z=23.

Completeness limit corresponds to 0.04 solar masses without extinction, 0.1 with typical extinction.

Data has been used to identify disk-less young stellar objects in Serpens.

Abstract

We present a deep optical/near-infrared imaging survey of the Serpens molecular cloud. This survey constitutes the complementary optical data to the Spitzer "Core To Disk" (c2d) Legacy survey in this cloud. The survey was conducted using the Wide Field Camera at the Isaac Newton Telescope. About 0.96 square degrees were imaged in the R and Z filters, covering the entire region where most of the young stellar objects identified by the c2d survey are located. 26524 point-like sources were detected in both R and Z bands down to R=24.5 mag and Z=23 mag with a signal-to-noise ratio better than 3. The 95% completeness limit of our catalog corresponds to 0.04 solar masses for members of the Serpens star forming region (age 2 Myr and distance 260 pc) in the absence of extinction. Adopting the typical extinction of the observed area (Av=7 mag), we estimate a 95% completeness level down to 0.1 solar masses. The astrometric accuracy of our catalog is 0.4 arcsec with respect to the 2MASS catalog. Our final catalog contains J2000 celestial coordinates, magnitudes in the R and Z bands calibrated to the SDSS photometric system and, where possible, JHK magnitudes from 2MASS for sources in 0.96 square degrees in the direction of Serpens. This data product has been already used within the frame of the c2d Spitzer Legacy Project analysis in Serpens to study the star/disk formation and evolution in this cloud; here we use it to obtain new indications of the disk-less population in Serpens.