Linear decomposition of Planck dust maps using PMO CO and EBHIS HI surveys attributes 20-40% of dust to CO gas, negligible amounts to broad warm HI, and significant fractions to narrow cold HI and CO-dark molecular gas at boundaries.
HI Narrow Self-Absorption in Dark Clouds: Correlations with Molecular Gas and Implications for Cloud Evolution and Star Formation
3 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
We present the results of a comparative study of HI narrow self-absorption (HINSA), OH, 13CO, and C18O in five dark clouds. The HINSA follows the distribution of the emission of the carbon monoxide isotopologues, and has a characteristic size close to that of 13CO. This confirms that the HINSA is produced by cold HI which is well mixed with molecular gas in well-shielded regions. The ratio of the atomic hydrogen density to total proton density for these sources is 5 to 27 x 10^{-4}. Using cloud temperatures and the density of HI, we set an upper limit to the cosmic ray ionization rate of 10^{-16} s^{-1}. Comparison of observed and modeled fractional HI abundances indicates ages for these clouds to be 10^{6.5} to 10^{7} yr. The low values of the HI density we have determined make it certain that the time scale for evolution from an atomic to an almost entirely molecular phase, must be a minimum of several million years. This clearly sets a lower limit to the overall time scale for star formation and the lifetime of molecular clouds.
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astro-ph.GA 3years
2026 3verdicts
UNVERDICTED 3representative citing papers
HINSA observations show CRIR decreasing with H2 column density in both clouds, with IC 348 values an order of magnitude above NGC 1333, modeled as an order-of-magnitude difference in low-energy CR populations from local acceleration sources.
The paper presents predictions and observational plans for Zeeman effect measurements with SKA to provide statistical data on magnetic field strengths across scales in molecular clouds.
citing papers explorer
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PMO Polaris CO survey. II. Where is the dust?
Linear decomposition of Planck dust maps using PMO CO and EBHIS HI surveys attributes 20-40% of dust to CO gas, negligible amounts to broad warm HI, and significant fractions to narrow cold HI and CO-dark molecular gas at boundaries.
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A HINSA view of cosmic-ray ionization in IC 348 and NGC 1333: evidence for a strong low-energy cosmic-ray disparity
HINSA observations show CRIR decreasing with H2 column density in both clouds, with IC 348 values an order of magnitude above NGC 1333, modeled as an order-of-magnitude difference in low-energy CR populations from local acceleration sources.
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Measuring Magnetic Field Strengths in Galactic Star-forming Regions via the Zeeman Effect with the SKA
The paper presents predictions and observational plans for Zeeman effect measurements with SKA to provide statistical data on magnetic field strengths across scales in molecular clouds.