Studying the molecular gas towards the R Coronae Australis dark cloud

TL;DR

This study uses molecular line observations to analyze the gas dynamics and chemistry in the R Coronae Australis dark cloud, revealing outflows and detecting N2H+ for the first time in this region.

Contribution

It provides new molecular line data, including the first detection of N2H+ J=4-3, and links outflow activity to chemical enhancements in the cloud.

Findings

Detection of outflow signatures in CO lines.

Enhanced HCO+ emission associated with outflows.

First detection of N2H+ J=4-3 in R CrA dark cloud.

Abstract

The R Coronae Australis dark cloud is one of the closest star-forming regions to the Sun. The cloud is known to be very active in star formation, harboring many Herbig-Haro objects (HHs) and Molecular Hydrogen emission-line Objects (MHOs). In this work we present results from molecular observations (a $5.5^{'}\times5.5^{'}$ map of $^{12}$CO J$=3-2$ and HCO$^{+}$ J$=4-3$, and a single spectrum of N$_{2}$H$^{+}$ J$=4-3$) obtained with the Atacama Submillimeter Telescope Experiment (ASTE) towards the R CrA dark cloud with an angular and spectral resolution of 22$^{"}$ and 0.11 km s$^{-1}$, respectively. From the $^{12}$CO J$=3-2$ line we found kinematical spectral features strongly suggesting the presence of outflows towards a region populated by several HHs and MHOs. Moreover, most of these objects lie within an HCO$^{+}$ maximum, suggesting that its emission arises from an increasement of its abundance due to the chemistry triggered by the outflow activity. Additionally, we are presenting the first reported detection of N$_{2}$H$^{+}$ in the J$=4-3$ line towards the R CrA dark cloud.