Chemical chronology of the Southern Coalsack

2007/05/22 by S. D. Rodgers, Scott Rodgers, S. B. Charnley +3
Earth and Planetary Sciences · Physics and Astronomy · #Astro and Planetary Science #Astrophysics #Astrophysics and Star Formation Studies #Atmospheric Ozone and Climate #Chemical evolution #Chronology #Galaxy #Geology #Geometry #Line (geometry) #Paleontology #Physics #astro-ph

paper · pdf · doi:10.1111/j.1365-2966.2007.11985.x

published as Mon.Not.Roy.Astron.Soc.379:807-815,2007 · 10 pages, 4 figures, in press at MNRAS

arxiv created 2007/05/22 · openalex publication_date 2007/07/05 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We demonstrate how the observed H2O ice column densities toward three dense globules in the Southern Coalsack could be used to constrain the ages of these sources. We derive ages of ∼105 yr, in agreement with dynamical studies of these objects. We have modelled the chemical evolution of the globules and showed how the molecular abundances are controlled by both the gas density and the initial chemical conditions as the globules formed. Based on our derived ages, we predict the column densities of several species of interest. These predictions should be straightforward to test by performing molecular-line observations.

Citations

• Internal structure of a cold dark molecular cloud inferred from the extinction of background starlight
• The size distribution of interstellar grains
• Star Formation in a Crossing Time
• Near-Infrared Imaging Survey of Bok Globules: Density Structure
• Observational Constraints on the Ages of Molecular Clouds and the Star Formation Timescale: Ambipolar‐Diffusion–controlled or Turbulence‐induced Star Formation?
• Star Formation in Molecular Clouds: Observation and Theory
• Rapid Formation of Molecular Clouds and Stars in the Solar Neighborhood
• Remarks on Rapid vs. Slow Star Formation