10:45 AM - 12:15 PM
[PPS07-P25] Hyper-volatile Element Transport to the Inner Region of Protoplanetary Disks and Jupiter Formation
Keywords:Protoplanetary Disk, Jupiter Formation, Volatile Elements
Jupiter's atmosphere has the remarkable feature of being uniformly enriched in hyper-volatile elements such as O, C, N, and noble gases compared to the Sun (e.g., Wong et al., 2004; Bolton et al., 2017). This feature is key to elucidating the formation process of Jupiter.
Jupiter's volatile element enrichment has been explained by the accretion of hyper-volatiles frozen on dust in cryogenic regions (< 30 K), such as the distant part or shadow regions of the disk (e.g. Bosman et al. 2019, Ohno & Ueda 2021). However, there are difficulties with the distant formation theory. For example, the orbital migration from distant regions where the disk becomes < 30 K is rare, and the planetary core formed in distant regions grows fast and exceeds current Jupiter’s mass (e.g. Bitsch et al. 2019, Tanaka et al. 2020). The shadow region theory also has the issue that it is not clear whether the stability of the shadow region is compatible with the formation of Jupiter.
Trapping hyper-volatiles in amorphous ice and transporting them to the inner disk with inward drifting dust is an elemental enrichment mechanism that does not require Jupiter formation in a cryogenic environment (Monga & Desch 2015). Mousis et al. (2019) theoretically calculated disk element abundances accounting for volatile emissions associated with phase transitions in amorphous ice and showed that uniform element enrichment occurs in the vicinity of Jupiter's orbit, while they have not considered the trapping efficiency of individual elements in the amorphous ice. Since the nitrogen capture efficiency of amorphous ice is an order of magnitude lower than other materials (Bar-Nun et al. 2007), this mechanism has difficulties in Jupiter's nitrogen enrichment.
This study examines the possibility that Jupiter's uniform elemental enrichment, including nitrogen, was achieved by elemental transport with amorphous ice and semi-volatile salts. In recent years, several observations of Comet 67P by the Rosetta spacecraft have indicated that the comet may contain semi-volatile ammonium salts that are much more abundant than NH3, traditionally considered the most dominant nitrogen carrier in the inner disk (Altwegg et al. 2020; Poch et al. 2020). Interstellar ice observations also indicate that 20-30% of the total nitrogen is refractory components (Öberg & Bergin 2021), and abundant nitrogen was likely transported to the inner disk in the form of salts and other low-volatile products.
We assumed ammonium salts as the nitrogen carriers and vapors trapped in amorphous ice as the other volatile element carriers and calculated the time evolution of dust, gas, and vapors emitted by icy dust in a planet-bearing disk. In this poster presentation, we will show the effects of the position and time of planet formation and the dust composition on planetary elemental abundances, and discuss the possibility that Jupiter formed in the inner part of the disk.
Jupiter's volatile element enrichment has been explained by the accretion of hyper-volatiles frozen on dust in cryogenic regions (< 30 K), such as the distant part or shadow regions of the disk (e.g. Bosman et al. 2019, Ohno & Ueda 2021). However, there are difficulties with the distant formation theory. For example, the orbital migration from distant regions where the disk becomes < 30 K is rare, and the planetary core formed in distant regions grows fast and exceeds current Jupiter’s mass (e.g. Bitsch et al. 2019, Tanaka et al. 2020). The shadow region theory also has the issue that it is not clear whether the stability of the shadow region is compatible with the formation of Jupiter.
Trapping hyper-volatiles in amorphous ice and transporting them to the inner disk with inward drifting dust is an elemental enrichment mechanism that does not require Jupiter formation in a cryogenic environment (Monga & Desch 2015). Mousis et al. (2019) theoretically calculated disk element abundances accounting for volatile emissions associated with phase transitions in amorphous ice and showed that uniform element enrichment occurs in the vicinity of Jupiter's orbit, while they have not considered the trapping efficiency of individual elements in the amorphous ice. Since the nitrogen capture efficiency of amorphous ice is an order of magnitude lower than other materials (Bar-Nun et al. 2007), this mechanism has difficulties in Jupiter's nitrogen enrichment.
This study examines the possibility that Jupiter's uniform elemental enrichment, including nitrogen, was achieved by elemental transport with amorphous ice and semi-volatile salts. In recent years, several observations of Comet 67P by the Rosetta spacecraft have indicated that the comet may contain semi-volatile ammonium salts that are much more abundant than NH3, traditionally considered the most dominant nitrogen carrier in the inner disk (Altwegg et al. 2020; Poch et al. 2020). Interstellar ice observations also indicate that 20-30% of the total nitrogen is refractory components (Öberg & Bergin 2021), and abundant nitrogen was likely transported to the inner disk in the form of salts and other low-volatile products.
We assumed ammonium salts as the nitrogen carriers and vapors trapped in amorphous ice as the other volatile element carriers and calculated the time evolution of dust, gas, and vapors emitted by icy dust in a planet-bearing disk. In this poster presentation, we will show the effects of the position and time of planet formation and the dust composition on planetary elemental abundances, and discuss the possibility that Jupiter formed in the inner part of the disk.