A Pathway for Collisional Planetesimal Growth in the Ice-dominant Regions of Protoplanetary Disks
We present a semi-analytic model for the growth, drift, desorption, and fragmentation of millimeter- to meter-sized particles in protoplanetary disks. Fragmentation occurs where particle collision velocities exceed critical fragmentation velocities. Using this criterion, we produce fragmentation reg...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad05b9 |
| _version_ | 1827383743439962112 |
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| author | Elizabeth Yunerman Diana Powell Ruth Murray-Clay |
| author_facet | Elizabeth Yunerman Diana Powell Ruth Murray-Clay |
| author_sort | Elizabeth Yunerman |
| collection | DOAJ |
| description | We present a semi-analytic model for the growth, drift, desorption, and fragmentation of millimeter- to meter-sized particles in protoplanetary disks. Fragmentation occurs where particle collision velocities exceed critical fragmentation velocities. Using this criterion, we produce fragmentation regions in disk orbital radius–particle size phase space for particles with a range of material properties, structures, and compositions (including SiO _2 , Mg _2 SiO _4 , H _2 O, CO _2 , and CO). For reasonable disk conditions, compact aggregate H _2 O, CO _2 , and CO ice particles do not reach destructive relative velocities and are thus not likely to undergo collisional fragmentation. Uncoated silicate particles are more susceptible to collisional destruction and are expected to fragment in the inner disk, consistent with previous work. We then calculate the growth, drift, and sublimation of small particles, initially located in the outer disk. We find that ice-coated particles can avoid fragmentation as they grow and drift inward under a substantial range of disk conditions, as long as the particles are aggregates composed of 0.1 μ m-sized monomers. Such particles may undergo runaway growth in disk regions abundant in H _2 O or CO _2 ice, depending on the assumed disk temperature structure. These results indicate that icy collisional growth to planetesimally relevant sizes may happen efficiently throughout a disk’s lifetime, and is particularly robust at early times when the disk’s dust-to-gas ratio is comparable to that of the interstellar medium. |
| first_indexed | 2024-03-08T14:45:40Z |
| format | Article |
| id | doaj.art-185f35b4a0274a40a937091f1a6ec54c |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T14:45:40Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-185f35b4a0274a40a937091f1a6ec54c2024-01-11T09:50:41ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-0196113310.3847/1538-4357/ad05b9A Pathway for Collisional Planetesimal Growth in the Ice-dominant Regions of Protoplanetary DisksElizabeth Yunerman0https://orcid.org/0009-0008-4937-3314Diana Powell1https://orcid.org/0000-0002-4250-0957Ruth Murray-Clay2https://orcid.org/0000-0001-5061-0462Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USADepartment of Astronomy & Astrophysics, University of Chicago , 5640 S. Ellis Avenue, Chicago, IL 60637, USADepartment of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USAWe present a semi-analytic model for the growth, drift, desorption, and fragmentation of millimeter- to meter-sized particles in protoplanetary disks. Fragmentation occurs where particle collision velocities exceed critical fragmentation velocities. Using this criterion, we produce fragmentation regions in disk orbital radius–particle size phase space for particles with a range of material properties, structures, and compositions (including SiO _2 , Mg _2 SiO _4 , H _2 O, CO _2 , and CO). For reasonable disk conditions, compact aggregate H _2 O, CO _2 , and CO ice particles do not reach destructive relative velocities and are thus not likely to undergo collisional fragmentation. Uncoated silicate particles are more susceptible to collisional destruction and are expected to fragment in the inner disk, consistent with previous work. We then calculate the growth, drift, and sublimation of small particles, initially located in the outer disk. We find that ice-coated particles can avoid fragmentation as they grow and drift inward under a substantial range of disk conditions, as long as the particles are aggregates composed of 0.1 μ m-sized monomers. Such particles may undergo runaway growth in disk regions abundant in H _2 O or CO _2 ice, depending on the assumed disk temperature structure. These results indicate that icy collisional growth to planetesimally relevant sizes may happen efficiently throughout a disk’s lifetime, and is particularly robust at early times when the disk’s dust-to-gas ratio is comparable to that of the interstellar medium.https://doi.org/10.3847/1538-4357/ad05b9Planet formationProtoplanetary disksPlanetesimalsCollision physicsIce physicsIce composition |
| spellingShingle | Elizabeth Yunerman Diana Powell Ruth Murray-Clay A Pathway for Collisional Planetesimal Growth in the Ice-dominant Regions of Protoplanetary Disks The Astrophysical Journal Planet formation Protoplanetary disks Planetesimals Collision physics Ice physics Ice composition |
| title | A Pathway for Collisional Planetesimal Growth in the Ice-dominant Regions of Protoplanetary Disks |
| title_full | A Pathway for Collisional Planetesimal Growth in the Ice-dominant Regions of Protoplanetary Disks |
| title_fullStr | A Pathway for Collisional Planetesimal Growth in the Ice-dominant Regions of Protoplanetary Disks |
| title_full_unstemmed | A Pathway for Collisional Planetesimal Growth in the Ice-dominant Regions of Protoplanetary Disks |
| title_short | A Pathway for Collisional Planetesimal Growth in the Ice-dominant Regions of Protoplanetary Disks |
| title_sort | pathway for collisional planetesimal growth in the ice dominant regions of protoplanetary disks |
| topic | Planet formation Protoplanetary disks Planetesimals Collision physics Ice physics Ice composition |
| url | https://doi.org/10.3847/1538-4357/ad05b9 |
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