H$^{13}$CN-HN$^{13}$C intensity ratio as a temperature indicator of interstellar clouds

TL;DR

This study demonstrates that the intensity ratio of H$^{13}$CN to HN$^{13}$C can serve as an effective indicator of temperature in interstellar clouds, based on radio telescope observations.

Contribution

It introduces the use of the H$^{13}$CN-HN$^{13}$C intensity ratio as a novel temperature diagnostic for interstellar clouds.

Findings

The intensity ratio correlates with kinetic temperature.

No significant correlation between gas temperature and dust temperature.

Proposes a new method for estimating interstellar cloud temperatures.

Abstract

With the 30-m IRAM radio telescope, we observed several massive star forming regions at wavelengths of 3-4 and 2 mm. The temperature of the gas in the sources was estimated from the lines of CH$_{3}$CCH and from the transitions of the NH$_3$ molecule obtained during observations at the 100-m radio telescope in Effelsberg. As a result, a correlation between the integrated intensity ratios of the $J=1-0$ transitions of H$^{13}$CN and HN$^{13}$C and the kinetic temperature has been obtained. The obtained results allow us to propose the use of the intensity ratio H$^{13}$CN-HN$^{13}$C as a possible temperature indicator of interstellar clouds. We also compared the obtained estimates of the kinetic temperature with the dust temperature $T_{dust}$. As a result, no significant correlation was found.