Developing A Chemical Evolutionary Sequence for Low-mass Starless Cores

TL;DR

This paper reviews processes for establishing a chemical evolutionary sequence in low-mass starless cores, supported by observational data from a survey of 25 nearby cores using multiple radio telescopes and molecular line observations.

Contribution

It introduces a framework for understanding chemical evolution in starless cores based on new observational data and radiative transfer modeling.

Findings

Identified chemical signatures indicative of evolutionary stages.

Provided observational constraints for chemical models.

Mapped molecular distributions in low-mass starless cores.

Abstract

I review the basic processes that may be used to develop a chemical evolutionary sequence for low-mass starless cores. I highlight observational results from the Arizona Radio Observatory-Green Bank Survey. Observations were performed with the SMT 10-m, ARO 12-m, and GBT 100-m toward a sample of 25 nearby (D < 400 pc) low-mass starless cores which have radiative transfer models of the 850 $\mu$m emission and observed SED (160 - 1300 um). The cores were observed in the lines of NH3 (1,1) and (2,2), o-NH2D 1_{11} - 1_{01}, C2S 1_2 - 2_1, C3S 4 - 3, HCN 1 - 0, HC5N 9 - 8, HC7N 21 - 20, C18O and C17O 2 - 1, and p-H2CO 1_{01} - 0_{00}.