Deep VLA observations of nearby star forming regions I: Barnard 59 and Lupus

TL;DR

This study presents deep 6 GHz radio observations of Barnard 59 and Lupus 1, detecting 114 sources including young stellar objects and background extragalactic sources, with insights into their emission properties.

Contribution

First deep radio survey of Barnard 59 and Lupus 1 at 6 GHz, identifying young stellar objects and characterizing their radio emission origins.

Findings

13 sources associated with known young stellar objects

Most young stellar objects show thermal radio emission

Remaining sources are consistent with background extragalactic sources

Abstract

Barnard 59 and Lupus 1 are two nearby star-forming regions visible from the southern hemisphere. In this manuscript, we present deep ($\sigma$ $\lesssim$ 15 $ \mu$Jy) radio observations ($\nu$ = 6 GHz; $\lambda$ = 5 cm) of these regions, and report the detection of a total of 114 sources. Thirteen of these sources are associated with known young stellar objects, nine in Barnard 59 and four in Lupus 1. The properties of the radio emission (spectral index and, in some cases, polarization) suggest a thermal origin for most young stellar objects. Only for two sources (Sz~65 and Sz~67) are there indications for a possible non-thermal origin; more observations will be needed to ascertain the exact nature of the radio emission in these sources. The remaining radio detections do not have counterparts at other wavelengths, and the number of sources detected per unit solid angle is in agreement with extragalactic number counts. This suggests that all radio sources not associated with known young stellar objects are background extragalactic sources.