Astrochemistry And Compositions Of Planetary Systems

By Keith Cowing
Press Release
October 8, 2020
Filed under
Astrochemistry And Compositions Of Planetary Systems
Illustrations of characteristic chemical structures associated with the different stages and scales of star and planet formation. A. The Orion Molecular Cloud (OMC) as seen in CO emission (Image credit & copyright J. Pety, the ORION-B Collaboration & IRAM). a. The OMC in HCN 1-0 emission (data from Pety et al. (2017)). B. The Horsehead photondominated region (PDR) (Image credit: Robert Gendler; ESO, VISTA, HLA, Hubble Heritage Team (STScI/AURA)). B. CN 1 − 0 towards the Horsehead PDR (data from Guzm´an et al. (2015b)). C. The B68 prestellar core (Credit: ESO). c. B68 in N<sub>2</sub>H<sup>+</sup> 1 − 0 emission (data from Bergin et al. (2001)). D. The outflow L1157 in infrared emission (Image credit: NASA/JPL/Spitzer). d. The same outflow in H<sub>2</sub>O 179 µm line emission (Nisini et al. 2010). E. The binary protostar IRAS 16293-2422 in dust emission at 1 mm, and in e. in emission from a strong CH<sub>3</sub>OCHO line from Jørgensen et al. (2016). F. Protoplanetary disk TW Hya from Andrews et al. (2016). The same disk in H<sub>2</sub>CO line emission from Oberg et al. (2017).

Planets form and obtain their compositions in disks of gas and dust around young stars. The chemical compositions of these planet-forming disks regulate all aspects of planetary compositions from bulk elemental inventories to access to water and reactive organics, i.e. a planet’s hospitality to life and its chemical origins.

Disk chemical structures are in their turn governed by a combination of {in situ} chemical processes, and inheritance of molecules from the preceding evolutionary stages of the star formation process. In this review we present our current understanding of the chemical processes active in pre- and protostellar environments that set the initial conditions for disks, and the disk chemical processes that evolve the chemical conditions during the first million years of planet formation. We review recent observational, laboratory and theoretical discoveries that have led to the present view of the chemical environment within which planets form, and their effects on the compositions of nascent planetary systems. We also discuss the many unknowns that remain and outline some possible pathways to addressing them.

Karin I. Oberg, Edwin A. Bergin
Comments: Authors’ version of review to appear in Physics Reports. 47 pages, 20 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2010.03529 [astro-ph.EP] (or arXiv:2010.03529v1 [astro-ph.EP] for this version)
Submission history
From: Karin Oberg
[v1] Wed, 7 Oct 2020 17:18:44 UTC (33,840 KB)
Astrobiology, Astrochemistry

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