Formation and evolution of the local interstellar environment: combined constraints from nucleosynthetic and X-ray data. (arXiv:2007.12180v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Fujimoto_Y/0/1/0/all/0/1">Yusuke Fujimoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Krumholz_M/0/1/0/all/0/1">Mark R. Krumholz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Inutsuka_S/0/1/0/all/0/1">Shu-ichiro Inutsuka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boss_A/0/1/0/all/0/1">Alan P. Boss</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nittler_L/0/1/0/all/0/1">Larry R. Nittler</a>
Several observations suggest that the Solar system has been located in a
region affected by massive stellar feedback for at least a few Myr; these
include detection of live $^{60}text{Fe}$ in deep-sea archives and Antarctic
snow, the broad angular distribution of $^{26}{rm Al}$ around the Galactic
plane seen in all-sky $gamma$-ray maps, and the all-sky soft X-ray background.
However, our position inside the Galactic disc makes it difficult to fully
characterise this environment, and our limited time baseline provides no
information about its formation history or relation to large-scale Galactic
dynamics. We explore these questions by using an $N$-body+hydrodynamics
simulation of a Milky-Way-like galaxy to identify stars on Sun-like orbits
whose environments would produce conditions consistent with those we observe.
We find that such stars are uncommon but not exceptionally rare. These stars
are found predominantly near the edges of spiral arms, and lie inside kpc-scale
bubbles that are created by multiple generations of star formation in the arm.
We investigate the stars’ trajectories and find that the duration of the stay
in the bubble ranges from 20 Myr to 90 Myr. The duration is governed by the
crossing time of stars across the spiral arm. This is generally shorter than
the bubble lifetime, which is $sim 100$ Myr as a result of the continuous gas
supply provided by the arm environment.
Several observations suggest that the Solar system has been located in a
region affected by massive stellar feedback for at least a few Myr; these
include detection of live $^{60}text{Fe}$ in deep-sea archives and Antarctic
snow, the broad angular distribution of $^{26}{rm Al}$ around the Galactic
plane seen in all-sky $gamma$-ray maps, and the all-sky soft X-ray background.
However, our position inside the Galactic disc makes it difficult to fully
characterise this environment, and our limited time baseline provides no
information about its formation history or relation to large-scale Galactic
dynamics. We explore these questions by using an $N$-body+hydrodynamics
simulation of a Milky-Way-like galaxy to identify stars on Sun-like orbits
whose environments would produce conditions consistent with those we observe.
We find that such stars are uncommon but not exceptionally rare. These stars
are found predominantly near the edges of spiral arms, and lie inside kpc-scale
bubbles that are created by multiple generations of star formation in the arm.
We investigate the stars’ trajectories and find that the duration of the stay
in the bubble ranges from 20 Myr to 90 Myr. The duration is governed by the
crossing time of stars across the spiral arm. This is generally shorter than
the bubble lifetime, which is $sim 100$ Myr as a result of the continuous gas
supply provided by the arm environment.
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