Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO₂ Ice Abundance in Exocomets and Solar System Comets
Recent Atacama Large Millimeter/submillimeter Array observations present mounting evidence for the presence of exocometary gas released within Kuiper Belt analogs around nearby main-sequence stars. This represents a unique opportunity to study their ice reservoir at the younger ages when volatile de...
| Main Authors: | , , , , , , , , , , , , , , , |
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| Other Authors: | |
| Format: | Article |
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IOP Publishing
2017
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| Online Access: | http://hdl.handle.net/1721.1/112147 |
| _version_ | 1826216873976397824 |
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| author | Matrà, L. MacGregor, M. A. Kalas, P. Wyatt, M. C. Kennedy, G. M. Wilner, D. J. Duchene, G. Hughes, A. M. Shannon, A. Clampin, M. Fitzgerald, M. P. Graham, J. R. Holland, W. S. Panić, O. Su, K. Y. L. Pan, Margaret |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Matrà, L. MacGregor, M. A. Kalas, P. Wyatt, M. C. Kennedy, G. M. Wilner, D. J. Duchene, G. Hughes, A. M. Shannon, A. Clampin, M. Fitzgerald, M. P. Graham, J. R. Holland, W. S. Panić, O. Su, K. Y. L. Pan, Margaret |
| author_sort | Matrà, L. |
| collection | MIT |
| description | Recent Atacama Large Millimeter/submillimeter Array observations present mounting evidence for the presence of exocometary gas released within Kuiper Belt analogs around nearby main-sequence stars. This represents a unique opportunity to study their ice reservoir at the younger ages when volatile delivery to planets is most likely to occur. We here present the detection of CO J = 2-1 emission colocated with dust emission from the cometary belt in the 440 Myr old Fomalhaut system. Through spectrospatial filtering, we achieve a 5.4σ detection and determine that the ring's sky-projected rotation axis matches that of the star. The CO mass derived ((0.65-42) × 10⁻⁷ M[subscript ⊕]) is the lowest of any circumstellar disk detected to date and must be of exocometary origin. Using a steady-state model, we estimate the CO+CO₂ mass fraction of exocomets around Fomalhaut to be between 4.6% and 76%, consistent with solar system comets and the two other belts known to host exocometary gas. This is the first indication of a similarity in cometary compositions across planetary systems that may be linked to their formation scenario and is consistent with direct interstellar medium inheritance. In addition, we find tentative evidence that (49 ± 27)% of the detected flux originates from a region near the eccentric belt's pericenter. If confirmed, the latter may be explained through a recent impact event or CO pericenter glow due to exocometary release within a steady-state collisional cascade. In the latter scenario, we show how the azimuthal dependence of the CO release rate leads to asymmetries in gas observations of eccentric exocometary belts. |
| first_indexed | 2024-09-23T16:54:30Z |
| format | Article |
| id | mit-1721.1/112147 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T16:54:30Z |
| publishDate | 2017 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1121472022-09-29T22:22:15Z Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO₂ Ice Abundance in Exocomets and Solar System Comets Matrà, L. MacGregor, M. A. Kalas, P. Wyatt, M. C. Kennedy, G. M. Wilner, D. J. Duchene, G. Hughes, A. M. Shannon, A. Clampin, M. Fitzgerald, M. P. Graham, J. R. Holland, W. S. Panić, O. Su, K. Y. L. Pan, Margaret Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Massachusetts Institute of Technology. Department of Physics Pan, Margaret Recent Atacama Large Millimeter/submillimeter Array observations present mounting evidence for the presence of exocometary gas released within Kuiper Belt analogs around nearby main-sequence stars. This represents a unique opportunity to study their ice reservoir at the younger ages when volatile delivery to planets is most likely to occur. We here present the detection of CO J = 2-1 emission colocated with dust emission from the cometary belt in the 440 Myr old Fomalhaut system. Through spectrospatial filtering, we achieve a 5.4σ detection and determine that the ring's sky-projected rotation axis matches that of the star. The CO mass derived ((0.65-42) × 10⁻⁷ M[subscript ⊕]) is the lowest of any circumstellar disk detected to date and must be of exocometary origin. Using a steady-state model, we estimate the CO+CO₂ mass fraction of exocomets around Fomalhaut to be between 4.6% and 76%, consistent with solar system comets and the two other belts known to host exocometary gas. This is the first indication of a similarity in cometary compositions across planetary systems that may be linked to their formation scenario and is consistent with direct interstellar medium inheritance. In addition, we find tentative evidence that (49 ± 27)% of the detected flux originates from a region near the eccentric belt's pericenter. If confirmed, the latter may be explained through a recent impact event or CO pericenter glow due to exocometary release within a steady-state collisional cascade. In the latter scenario, we show how the azimuthal dependence of the CO release rate leads to asymmetries in gas observations of eccentric exocometary belts. United States. National Aeronautics and Space Administration (Grant NNX15AK23G) United States. National Aeronautics and Space Administration (Grant NNX15AM35G) 2017-11-08T18:37:28Z 2017-11-08T18:37:28Z 2017-06 2017-05 2017-11-08T13:38:10Z Article http://purl.org/eprint/type/JournalArticle 1538-4357 0004-637X http://hdl.handle.net/1721.1/112147 Matrà, L. et al. “Detection of Exocometary CO Within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO₂ Ice Abundance in Exocomets and Solar System Comets.” The Astrophysical Journal 842, 1 (June 2017): 9 © 2017 The American Astronomical Society http://dx.doi.org/10.3847/1538-4357/aa71b4 Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing IOP Publishing |
| spellingShingle | Matrà, L. MacGregor, M. A. Kalas, P. Wyatt, M. C. Kennedy, G. M. Wilner, D. J. Duchene, G. Hughes, A. M. Shannon, A. Clampin, M. Fitzgerald, M. P. Graham, J. R. Holland, W. S. Panić, O. Su, K. Y. L. Pan, Margaret Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO₂ Ice Abundance in Exocomets and Solar System Comets |
| title | Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO₂ Ice Abundance in Exocomets and Solar System Comets |
| title_full | Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO₂ Ice Abundance in Exocomets and Solar System Comets |
| title_fullStr | Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO₂ Ice Abundance in Exocomets and Solar System Comets |
| title_full_unstemmed | Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO₂ Ice Abundance in Exocomets and Solar System Comets |
| title_short | Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO₂ Ice Abundance in Exocomets and Solar System Comets |
| title_sort | detection of exocometary co within the 440 myr old fomalhaut belt a similar co co₂ ice abundance in exocomets and solar system comets |
| url | http://hdl.handle.net/1721.1/112147 |
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