Journal article
A nearby dark molecular cloud in the Local Bubble revealed via H2 fluorescence
Nature astronomy, Vol.9(7), pp.1064-1072
07/2025
DOI: 10.1038/s41550-025-02541-7
Abstract
A longstanding prediction in interstellar theory posits that significant quantities of molecular gas, crucial for star formation, may be undetected due to being ’dark’ in commonly used molecular gas tracers, such as carbon monoxide. We report the discovery of Eos, a dark molecular cloud located just 94 pc from the Sun. This cloud is identified using H 2 far-ultraviolet fluorescent line emission, which traces molecular gas at the boundary layers of star-forming and supernova remnant regions. The cloud edge is outlined along the high-latitude side of the North Polar Spur, a prominent X-ray/radio structure. Our distance estimate utilizes three-dimensional dust maps, the absorption of the soft-X-ray background, and hot gas tracers such as O vi; these place the cloud at a distance consistent with the Local Bubble’s surface. Using high-latitude CO maps we note a small amount (MH2 ≈ 20–40 M⊙) of CO-bright cold molecular gas, in contrast with the much larger estimate of the cloud’s true molecular mass (MH2 ≈ 3.4 × 10 3 M⊙), indicating that most of the cloud is CO dark. Combining observational data with novel analytical models and simulations, we predict that this cloud will photoevaporate in 5.7 Myr, placing key constraints on the role of stellar feedback in shaping the closest star-forming regions to the Sun.
Details
- Title: Subtitle
- A nearby dark molecular cloud in the Local Bubble revealed via H2 fluorescence
- Creators
- Blakesley BurkhartThavisha E. DharmawardenaShmuel BialyThomas J. HaworthFernando Cruz AguirreYoung-Soo JoB-G AnderssonHaeun ChungJerry EdelsteinIsabelle GrenierErika T. HamdenWonyong HanKeri HoadleyMin-Young LeeKyoung-Wook MinThomas MüllerKate PattleJ. E. G. PeekGeoff PleissDavid SchiminovichKwang-Il SeonAndrew Gordon WilsonCatherine Zucker
- Resource Type
- Journal article
- Publication Details
- Nature astronomy, Vol.9(7), pp.1064-1072
- DOI
- 10.1038/s41550-025-02541-7
- ISSN
- 2397-3366
- eISSN
- 2397-3366
- Publisher
- NATURE PORTFOLIO
- Grant note
- National Aeronautics and Space Administration (NASA): AST-2407877 NSF: NAS 5-26555 NASA: NSF PHY-1748958 National Science FoundationDavid and Lucile Packard FoundationAlfred P. Sloan Foundation - Simons Foundation: HST-HF2-51529 NASA through the NASA Hubble Fellowship Program: NAS 5-26555 Space Telescope Science InstituteUniversity of Arizona, Research Innovation: 2071540 ISF grantIsrael Science Foundation: 2023 Alon Fellowship: EP/Y024710/1, URF\R1\211322 Israeli Council for Higher Education - Royal Society Dorothy Hodgkin Fellowship: 80NSSC24K0471 NASA Roman Technology Fellowship: 2019R1F1A1061102 Basic Science Research Program of the National Research Foundation of Korea (NRF) - Ministry of Education: 2020R1A2C1005788 NRF - Korean government (MSIT)Korea Advanced Institute of Science and Technology (KAIST)Korea Astronomy and Space Institute (KASI)University of California, Berkeley - Korean Ministry of Science and Technology
B.B. acknowledges support from NSF grant AST-2407877 and NASA grant 80NSSC20K0500. This research was also supported in part by the National Science Foundation under grant NSF PHY-1748958. B.B. is grateful for support from the David and Lucile Packard Foundation, the Alfred P. Sloan Foundation and the Flatiron Institute, which is funded by the Simons Foundation. B.B. is grateful for conversations with C. McKee, A. Lazarian, A. Sternberg and B. Benjamin. B.B. and T.E.D. are grateful to J. Dalcanton for discussions. T.E.D. acknowledges support for this work provided by NASA through the NASA Hubble Fellowship Program grant HST-HF2-51529 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. E.T.H. was supported by internal funding from the University of Arizona, Research Innovation, and Impact. S.B. acknowledges support from ISF grant 2071540, awarded by the Israel Science Foundation, and the Alon Fellowship (2023), awarded by the Israeli Council for Higher Education. We acknowledge Interstellar Institute programmes and Paris-Saclay University's Institut Pascal for hosting discussions that nourished the development of the ideas behind this work. T.J.H. is funded by a Royal Society Dorothy Hodgkin Fellowship and UKRI ERC guarantee funding (EP/Y024710/1). K.P. is a Royal Society University Research Fellow supported by grant number URF\R1\211322. K.H acknowledges support through the NASA Roman Technology Fellowship (80NSSC24K0471). Y.-S.J. was supported by the Basic Science Research Program of the National Research Foundation of Korea (NRF), funded by the Ministry of Education (2019R1F1A1061102). K.-I.S. was supported by an NRF grant funded by the Korean government (MSIT) (2020R1A2C1005788). This research is based in part on observations made with the FIMS/SPEAR mission, a joint project of the Korea Advanced Institute of Science and Technology (KAIST), the Korea Astronomy and Space Institute (KASI) and the University of California, Berkeley. FIMS/SPEAR was funded by the Korean Ministry of Science and Technology and NASA grant NAG5-5355. The data reduction for FIMS/SPEAR was funded by grant NRF-2012M1A3A4A01056418. Data from FIMS/SPEAR were obtained from the MAST data archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.
- Language
- English
- Electronic publication date
- 04/28/2025
- Date published
- 07/2025
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984820567702771
Metrics
4 Record Views