Runaway stars masquerading as star formation in galactic outskirts
(2021) In Monthly Notices of the Royal Astronomical Society: Letters 502(1). p.29-34- Abstract
In the outskirts of nearby spiral galaxies, star formation is observed in extremely low gas surface densities. Star formation in these regions, where the interstellar medium is dominated by diffuse atomic hydrogen, is difficult to explain with classic star formation theories. In this letter, we introduce runaway stars as an explanation for this observation. Runaway stars, produced by collisional dynamics in young stellar clusters, can travel kiloparsecs during their main-sequence lifetime. Using galactic-scale hydrodynamic simulations including a treatment of individual stars, we demonstrate that this mechanism enables the ejection of young massive stars into environments where the gas is not dense enough to trigger star formation. This... (More)
In the outskirts of nearby spiral galaxies, star formation is observed in extremely low gas surface densities. Star formation in these regions, where the interstellar medium is dominated by diffuse atomic hydrogen, is difficult to explain with classic star formation theories. In this letter, we introduce runaway stars as an explanation for this observation. Runaway stars, produced by collisional dynamics in young stellar clusters, can travel kiloparsecs during their main-sequence lifetime. Using galactic-scale hydrodynamic simulations including a treatment of individual stars, we demonstrate that this mechanism enables the ejection of young massive stars into environments where the gas is not dense enough to trigger star formation. This results in the appearance of star formation in regions where it ought to be impossible. We conclude that runaway stars are a contributing, if not dominant, factor to the observations of star formation in the outskirts of spiral galaxies.
(Less)
- author
- Andersson, Eric P. LU ; Renaud, Florent LU and Agertz, Oscar LU
- organization
- publishing date
- 2021
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- galaxies: star formation, ISM: evolution, stars: kinematics and dynamics
- in
- Monthly Notices of the Royal Astronomical Society: Letters
- volume
- 502
- issue
- 1
- pages
- 29 - 34
- publisher
- Oxford University Press
- external identifiers
-
- scopus:85100993903
- ISSN
- 1745-3925
- DOI
- 10.1093/mnrasl/slaa201
- language
- English
- LU publication?
- yes
- id
- df6674ca-592e-4f54-aba0-cf5291bbb123
- date added to LUP
- 2021-03-02 08:52:55
- date last changed
- 2024-04-18 02:50:06
@article{df6674ca-592e-4f54-aba0-cf5291bbb123,
abstract = {{<p>In the outskirts of nearby spiral galaxies, star formation is observed in extremely low gas surface densities. Star formation in these regions, where the interstellar medium is dominated by diffuse atomic hydrogen, is difficult to explain with classic star formation theories. In this letter, we introduce runaway stars as an explanation for this observation. Runaway stars, produced by collisional dynamics in young stellar clusters, can travel kiloparsecs during their main-sequence lifetime. Using galactic-scale hydrodynamic simulations including a treatment of individual stars, we demonstrate that this mechanism enables the ejection of young massive stars into environments where the gas is not dense enough to trigger star formation. This results in the appearance of star formation in regions where it ought to be impossible. We conclude that runaway stars are a contributing, if not dominant, factor to the observations of star formation in the outskirts of spiral galaxies.</p>}},
author = {{Andersson, Eric P. and Renaud, Florent and Agertz, Oscar}},
issn = {{1745-3925}},
keywords = {{galaxies: star formation; ISM: evolution; stars: kinematics and dynamics}},
language = {{eng}},
number = {{1}},
pages = {{29--34}},
publisher = {{Oxford University Press}},
series = {{Monthly Notices of the Royal Astronomical Society: Letters}},
title = {{Runaway stars masquerading as star formation in galactic outskirts}},
url = {{http://dx.doi.org/10.1093/mnrasl/slaa201}},
doi = {{10.1093/mnrasl/slaa201}},
volume = {{502}},
year = {{2021}},
}