An Ice Age JWST inventory of dense molecular cloud ices
Abstract
Icy grain mantles are the main reservoir of the volatile elements that link chemical processes in dark, interstellar clouds with the formation of planets and composition of their atmospheres. The initial ice composition is set in the cold, dense parts of molecular clouds, prior to the onset of star formation. With the exquisite sensitivity of JWST, this critical stage of ice evolution is now accessible for detailed study. Here we show the first results of the Early Release Science program "Ice Age" that reveal the rich composition of these dense cloud ices. Weak ices, including, CO, OCN, CO, OCS, and COMs functional groups are now detected along two pre-stellar lines of sight. The CO ice profile indicates modest growth of the icy grains. Column densities of the major and minor ice species indicate that ices contribute between 2 and 19% of the bulk budgets of the key C, O, N, and S elements. Our results suggest that the formation of simple and complex molecules could begin early in a water-ice rich environment.
Keywords
Cite
@article{arxiv.2301.09140,
title = {An Ice Age JWST inventory of dense molecular cloud ices},
author = {M. K. McClure and W. R. M. Rocha and K. M. Pontoppidan and N. Crouzet and L. E. U. Chu and E. Dartois and T. Lamberts and J. A. Noble and Y. J. Pendleton and G. Perotti and D. Qasim and M. G. Rachid and Z. L. Smith and Fengwu Sun and Tracy L Beck and A. C. A. Boogert and W. A. Brown and P. Caselli and S. B. Charnley and Herma M. Cuppen and H. Dickinson and M. N. Drozdovskaya and E. Egami and J. Erkal and H. Fraser and R. T. Garrod and D. Harsono and S. Ioppolo and I. Jimenez-Serra and M. Jin and J. K. Jørgensen and L. E. Kristensen and D. C. Lis and M. R. S. McCoustra and Brett A. McGuire and G. J. Melnick and Karin I. Oberg and M. E. Palumbo and T. Shimonishi and J. A. Sturm and E. F. van Dishoeck and H. Linnartz},
journal= {arXiv preprint arXiv:2301.09140},
year = {2023}
}
Comments
To appear in Nature Astronomy on January 23rd, 2023. 33 pages, 16 figures, 3 tables; includes extended and supplemental data sections. Part of the JWST Ice Age Early Release Science program's science enabling products. Enhanced spectra downloadable on Zenodo at the following DOI: 10.5281/zenodo.7501239