Journal article
The Molecular Cloud Life Cycle. II. Formation and Destruction of Molecular Clouds Diagnosed via H2 Fluorescent Emission
The Astrophysical journal, Vol.975(2), 269
11/01/2024
DOI: 10.3847/1538-4357/ad75f8
Abstract
Molecular hydrogen (H2) formation and dissociation are key processes that drive the gas life cycle in galaxies. Using the SImulating the LifeCycle of Molecular Clouds zoom-in simulation suite, we explore the utility of future observations of H2 dissociation and formation for tracking the life cycle of molecular clouds. The simulations used in this work include nonequilibrium H2 formation, stellar radiation, sink particles, and turbulence. We find that at early times in the cloud evolution H2 formation rapidly outpaces dissociation and molecular clouds build their mass from the atomic reservoir in their environment. Rapid H2 formation is also associated with a higher early star formation rate. For the clouds studied here, H2 is strongly out of chemical equilibrium during the early stages of cloud formation but settles into a bursty chemical steady state about 2 Myr after the first stars form. At the latest stage of cloud evolution, dissociation outweighs formation and the clouds enter a dispersal phase. We discuss how theories of the molecular cloud life cycle and star formation efficiency may be distinguished with observational measurements of H2 fluorescence with a space-based high-resolution far-UV spectrometer, such as the proposed Hyperion and Eos NASA Explorer missions. Such missions would enable measurements of the H2 dissociation and formation rates, which we demonstrate can be connected to different phases in a molecular cloud’s star-forming life, including cloud building, rapidly star forming, H2 chemical equilibrium, and cloud destruction.
Details
- Title: Subtitle
- The Molecular Cloud Life Cycle. II. Formation and Destruction of Molecular Clouds Diagnosed via H2 Fluorescent Emission
- Creators
- Blakesley Burkhart - Rutgers, The State University of New JerseyShmuel Bialy - Technion – Israel Institute of TechnologyDaniel Seifried - University of CologneStefanie Walch - University of CologneErika Hamden - University of ArizonaThomas Haworth - Queen Mary University of LondonKeri Hoadley - University of IowaShuo Kong - University of ArizonaMadisen Johnson - Rutgers University–NewarkSarah Jeffreson - Center for Astrophysics Harvard & SmithsonianMark Krumholz - Australian National UniversityLee Min-Young - Korea Astronomy and Space Science InstituteAmiel Sternberg - Tel Aviv UniversityNeal Turner - Jet Propulsion Laboratory
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.975(2), 269
- Publisher
- IOP Publishing
- DOI
- 10.3847/1538-4357/ad75f8
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Grant note
- Simons Foundation (SF)https://doi.org/10.13039/100000893: AST-2009679 NSF: 80NSSC20K0500 NASADavid and Lucile Packard FoundationAlfred P. Sloan Foundation: Sonderforschungsbereich (SFB) 956 Deutsche Forschungsgemeinschaft (DFG)Ministry of Culture and Science of the State of Northrhine Westphalia - Royal Society Dorothy Hodgkin Fellowship: EP/Y024710/1 Horizon Europe ERCCenter for Computational Astrophysics (CCA) of the Flatiron InstituteMathematics and Physical Sciences (MPS) division of the Simons Foundation: FL220100020, 80NM0018D0004 Australian Research Council through the Laureate Fellowship programNational Aeronautics and Space Administration
B.B. acknowledges support from NSF grant AST-2009679 and NASA grant No. 80NSSC20K0500. B.B. is grateful for generous support by the David and Lucile Packard Foundation and Alfred P. Sloan Foundation. D.S. and S.W. acknowledge funding support from the Deutsche Forschungsgemeinschaft (DFG) via the Sonderforschungsbereich (SFB) 956, Conditions and Impact of Star Formation (projects C5 and C6). Furthermore, the project is supported by the B3D project, a program within "Profilbildung 2020," an initiative of the Ministry of Culture and Science of the State of Northrhine Westphalia. The sole responsibility for the content of this publication lies with the authors. T.J.H. is funded by a Royal Society Dorothy Hodgkin Fellowship and UKRI guaranteed funding for a Horizon Europe ERC consolidator grant (EP/Y024710/1). A.S. and B.B. thank the Center for Computational Astrophysics (CCA) of the Flatiron Institute and the Mathematics and Physical Sciences (MPS) division of the Simons Foundation for support. M.R.K. acknowledges support from the Australian Research Council through the Laureate Fellowship program, award FL220100020. The research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under contract 80NM0018D0004 with the National Aeronautics and Space Administration.
- Language
- English
- Date published
- 11/01/2024
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984745457102771
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