Journal Article

FZJ-2020-05017

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Oumuamuas Passing through Molecular Clouds

Pfalzner, S. (Corresponding author)FZJ* ; Davies, M. B. ; Kokaia, G. ; Bannister, M. T.

2020
Institute of Physics Publ.86747 London

This record in other databases:    

Please use a persistent id in citations: http://hdl.handle.net/2128/26421  doi:10.3847/1538-4357/abb9ae

Abstract: The detections of 1I/'Oumuamua and 2I/Borisov within just two years of each other impressively demonstrate that interstellar objects (ISOs) must be common in the Milky Way. Once released from their parent system, these ISOs travel for billions of years through interstellar space. While often imagined as empty, interstellar space contains gas and dust most prominent in the form of molecular clouds. Performing numerical simulations, we test how often ISOs cross such molecular clouds (MCs). We find that the ISOs pass through MCs amazingly often. In the solar neighborhood, ISOs typically spend 0.1%-0.2% of their journey inside MCs, for relatively slow ISOs (<5 km s-1) this can increase to 1%-2%, equivalent to 10-20 Myr per Gyr. Thus the dynamically youngest ISOs spend the longest time in MCs. In other words, MCs must mainly contain relatively young ISOs (<1-2 Gyr). Thus the half-life of the seeding process by ISOs is substantially shorter than a stellar lifetime. The actual amount of time spent in MCs decreases with distance to the Galactic center. We find that ISOs pass through MCs so often that backtracing their path to find their parent star beyond 250 Myr seems pointless. Besides, we give a first estimate of the ISO density depending on the distance to the Galactic center based on the stellar distribution.

---

Contributing Institute(s):

1. Jülich Supercomputing Center (JSC)

Research Program(s):

1. 511 - Computational Science and Mathematical Methods (POF3-511) (POF3-511)

Appears in the scientific report 2020

---

Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---