Synthetic observations of H$_2$D$^+$ towards high-mass starless cores (1812.01191v3)

Abstract: Young massive stars are usually found embedded in dense and massive molecular clumps and are known for being highly obscured and distant. During their formation process, deuteration is regarded as a potentially good indicator of the formation stage. Therefore, proper observations of such deuterated molecules are crucial, but still, hard to perform. In this work, we test the observability of the transition o-H$2$D$^+(1{10}$-$1_{11})$, using a synthetic source, to understand how the physical characteristics are reflected in observations through interferometers and single-dish telescopes. In order to perform such tests, we post-processed a magneto-hydrodynamic simulation of a collapsing magnetized core using the radiative transfer code POLARIS. Using the resulting intensity distributions as input, we performed single-dish (APEX) and interferometric (ALMA) synthetic observations at different evolutionary times, always mimicking realistic configurations. Finally, column densities were derived to compare our simulations with real observations previously performed. Our derivations for o-H$_2$D$^+$ are in agreement with values reported in the literature, in the range of 10$^{!10-11}$cm$^{!-2}$ and 10$^{!12-13}$cm$^{!-2}$ for single-dish and interferometric measurements, respectively.