arXiv - PHYS - Earth and Planetary Astrophysics最新文献_第6页

Polar Neptunes are Stable to Tides 极地海王星对潮汐稳定

arXiv - PHYS - Earth and Planetary Astrophysics Pub Date : 2024-09-05 DOI: arxiv-2409.03679

Emma Louden, Sarah Millholland

{"title":"Polar Neptunes are Stable to Tides","authors":"Emma Louden, Sarah Millholland","doi":"arxiv-2409.03679","DOIUrl":"https://doi.org/arxiv-2409.03679","url":null,"abstract":"There is an intriguing and growing population of Neptune-sized planets with\u0000stellar obliquities near $sim90^{circ}$. One previously proposed formation\u0000pathway is a disk-driven resonance, which can take place at the end stages of\u0000planet formation in a system containing an inner Neptune, outer cold Jupiter,\u0000and protoplanetary disk. This mechanism occurs within the first $sim10$ Myr,\u0000but most of the polar Neptunes we see today are $sim$Gyrs old. Up until now,\u0000there has not been an extensive analysis of whether the polar orbits are stable\u0000over $sim$Gyr timescales. Tidal realignment mechanisms are known to operate in\u0000other systems, and if they are active here, this would cause theoretical\u0000tension with a primordial misalignment story. In this paper, we explore the\u0000effects of tidal evolution on the disk-driven resonance theory. We use both\u0000$N$-body and secular simulations to study tidal effects on both the initial\u0000resonant encounter and long-term evolution. We find that the polar orbits are\u0000remarkably stable on $sim$Gyr timescales. Inclination damping does not occur\u0000for the polar cases, although we do identify sub-polar cases where it is\u0000important. We consider two case study polar Neptunes, WASP-107 b and HAT-P-11\u0000b, and study them in the context of this theory, finding consistency with\u0000present-day properties if their tidal quality factors are $Q gtrsim 10^4$ and\u0000$Q gtrsim 10^5$, respectively.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Retrieval of Thermally-Resolved Water Vapor Distributions in Disks Observed with JWST-MIRI 用 JWST-MIRI 观测的盘中热解水蒸汽分布的检索

arXiv - PHYS - Earth and Planetary Astrophysics Pub Date : 2024-09-05 DOI: arxiv-2409.03831

Carlos E. Muñoz-Romero, Andrea Banzatti, Karin I. Öberg, Klaus M. Pontoppidan, Colette Salyk, Joan Najita, Geoffrey A. Blake, Sebastiaan Krijt, Nicole Arulanantham, Paola Pinilla, Feng Long, Giovanni Rosotti, Sean M. Andrews, David J. Wilner, Jenny Calahan, The JDISCS Collaboration

{"title":"Retrieval of Thermally-Resolved Water Vapor Distributions in Disks Observed with JWST-MIRI","authors":"Carlos E. Muñoz-Romero, Andrea Banzatti, Karin I. Öberg, Klaus M. Pontoppidan, Colette Salyk, Joan Najita, Geoffrey A. Blake, Sebastiaan Krijt, Nicole Arulanantham, Paola Pinilla, Feng Long, Giovanni Rosotti, Sean M. Andrews, David J. Wilner, Jenny Calahan, The JDISCS Collaboration","doi":"arxiv-2409.03831","DOIUrl":"https://doi.org/arxiv-2409.03831","url":null,"abstract":"The mid-infrared water vapor emission spectrum provides a novel way to\u0000characterize the delivery of icy pebbles towards the innermost ($<5$ au)\u0000regions of planet-forming disks. Recently, JWST MIRI-MRS showed that compact\u0000disks exhibit an excess of low-energy water vapor emission relative to extended\u0000multi-gapped disks, suggesting that icy pebble drift is more efficient in the\u0000former. We carry out detailed emission line modeling to retrieve the excitation\u0000conditions of rotational water vapor emission in a sample of four compact and\u0000three extended disks within the JDISC Survey. We present two-temperature H$_2$O\u0000slab model retrievals and, for the first time, constrain the spatial\u0000distribution of water vapor by fitting parametric radial temperature and column\u0000density profiles. Such models statistically outperform the two-temperature slab\u0000fits. We find a correlation between the observable hot water vapor mass and\u0000stellar mass accretion rate, as well as an anti-correlation between cold water\u0000vapor mass and sub-mm dust disk radius, confirming previously reported water\u0000line flux trends. We find that the mid-IR spectrum traces H$_2$O with\u0000temperatures down to 180-300 K, but the coldest 150-170 K gas remains\u0000undetected. Furthermore the H$_2$O temperature profiles are generally steeper\u0000and cooler than the expected `super-heated' dust temperature in passive\u0000irradiated disks. The column density profiles are used to estimate icy pebble\u0000mass fluxes, which suggest that compact and extended disks may produce markedly\u0000distinct inner-disk exoplanet populations if local feeding mechanisms dominate\u0000their assembly.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cavitating bubbles in condensing gas as a means of forming clumps, chondrites, and planetesimals 冷凝气体中的空化气泡是形成团块、软玉和行星的一种手段

arXiv - PHYS - Earth and Planetary Astrophysics Pub Date : 2024-09-04 DOI: arxiv-2409.02978

Eugene Chiang

{"title":"Cavitating bubbles in condensing gas as a means of forming clumps, chondrites, and planetesimals","authors":"Eugene Chiang","doi":"arxiv-2409.02978","DOIUrl":"https://doi.org/arxiv-2409.02978","url":null,"abstract":"Vaporized metal, silicates, and ices on the verge of re-condensing into solid\u0000or liquid particles appear in many contexts: behind shocks, in impact ejecta,\u0000and within the atmospheres and outflows of stars, disks, planets, and minor\u0000bodies. We speculate that a condensing gas might fragment, forming\u0000overdensities within relative voids, from a radiation-condensation instability.\u0000Seeded with small thermal fluctuations, a condensible gas will exhibit spatial\u0000variations in the density of particle condensates. Regions of higher particle\u0000density may radiate more, cooling faster. Faster cooling leads to still more\u0000condensation, lowering the local pressure. Regions undergoing runaway\u0000condensation may collapse under the pressure of their less condensed\u0000surroundings. Particle condensates will compactify with collapsing regions,\u0000into overdense clumps or macroscopic solids (planetesimals). As a first step\u0000toward realizing this hypothetical instability, we calculate the evolution of a\u0000small volume of condensing silicate vapor -- a spherical test \"bubble\" embedded\u0000in a background medium whose pressure and radiation field are assumed fixed for\u0000simplicity. Such a bubble condenses and collapses upon radiating its latent\u0000heat to the background, assuming its energy loss is not stopped by background\u0000irradiation. Collapse speeds can range up to sonic, similar to cavitation in\u0000terrestrial settings. Adding a non-condensible gas like hydrogen to the bubble\u0000stalls the collapse. We discuss whether cavitation can provide a way for\u0000mm-sized chondrules and refractory solids to assemble into meteorite parent\u0000bodies, focusing on CB/CH chondrites whose constituents likely condensed from\u0000silicate/metal vapor released from the most energetic asteroid collisions.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design and Performance of the Upgraded Mid-InfraRed Spectrometer and Imager (MIRSI) on the NASA Infrared Telescope Facility 美国国家航空航天局红外望远镜设施上的升级版中红外分光计和成像仪（MIRSI）的设计与性能

arXiv - PHYS - Earth and Planetary Astrophysics Pub Date : 2024-09-04 DOI: arxiv-2409.02752

Joseph L. Hora, David E. Trilling, Andy J. Lopez-Oquendo, Howard A. Smith, Michael Mommert, Nicholas Moskovitz, Chris Foster, Michael S. Connelley, Charles Lockhart, John T. Rayner, Schelte J. Bus, Darryl Watanabe, Lars Bergknut, Morgan Bonnet, Alan Tokunaga

{"title":"Design and Performance of the Upgraded Mid-InfraRed Spectrometer and Imager (MIRSI) on the NASA Infrared Telescope Facility","authors":"Joseph L. Hora, David E. Trilling, Andy J. Lopez-Oquendo, Howard A. Smith, Michael Mommert, Nicholas Moskovitz, Chris Foster, Michael S. Connelley, Charles Lockhart, John T. Rayner, Schelte J. Bus, Darryl Watanabe, Lars Bergknut, Morgan Bonnet, Alan Tokunaga","doi":"arxiv-2409.02752","DOIUrl":"https://doi.org/arxiv-2409.02752","url":null,"abstract":"We describe the new design and current performance of the Mid-InfraRed\u0000Spectrometer and Imager (MIRSI) on the NASA Infrared Telescope Facility (IRTF).\u0000The system has been converted from a liquid nitrogen/liquid helium cryogen\u0000system to one that uses a closed-cycle cooler, which allows it to be kept on\u0000the telescope at operating temperature and available for observing on short\u0000notice, requiring less effort by the telescope operators and day crew to\u0000maintain operating temperature. Several other enhancements have been completed,\u0000including new detector readout electronics, an IRTF-style standard instrument\u0000user interface, new stepper motor driver electronics, and an optical camera\u0000that views the same field as the mid-IR instrument using a cold dichroic\u0000mirror, allowing for guiding and/or simultaneous optical imaging. The\u0000instrument performance is presented, both with an engineering-grade array used\u0000from 2021-2023, and a science-grade array installed in the fall of 2023. Some\u0000sample astronomical results are also shown. The upgraded MIRSI is a facility\u0000instrument at the IRTF available to all users.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Oxygen Isotope Exchange Between Dust Aggregates and Ambient Nebular Gas 尘埃聚合体与环境星云气体之间的氧同位素交换

arXiv - PHYS - Earth and Planetary Astrophysics Pub Date : 2024-09-04 DOI: arxiv-2409.02736

Sota Arakawa, Daiki Yamamoto, Lily Ishizaki, Tamami Okamoto, Noriyuki Kawasaki

{"title":"Oxygen Isotope Exchange Between Dust Aggregates and Ambient Nebular Gas","authors":"Sota Arakawa, Daiki Yamamoto, Lily Ishizaki, Tamami Okamoto, Noriyuki Kawasaki","doi":"arxiv-2409.02736","DOIUrl":"https://doi.org/arxiv-2409.02736","url":null,"abstract":"Meteorites and their components exhibit a diverse range of oxygen isotope\u0000compositions, and the isotopic exchange timescale between dust grains and\u0000ambient gas is a key parameter for understanding the spatiotemporal evolution\u0000of the solar nebula. As dust grains existed as macroscopic aggregates in the\u0000solar nebula, it is necessary to consider the isotopic exchange timescales for\u0000these aggregates. Here, we theoretically estimate the isotope exchange\u0000timescales between dust aggregates and ambient vapor. The isotope exchange\u0000process between aggregates and ambient vapor is divided into four processes:\u0000(i) supply of gas molecules to the aggregate surface, (ii) diffusion of\u0000molecules within the aggregate, (iii) isotope exchange on the surface of\u0000constituent particles, and (iv) isotope diffusion within the particles. We\u0000evaluate these timescales and assess which one becomes the rate-determining\u0000step. We reveal that the isotope exchange timescale is approximately the same\u0000as that of the constituent particles when the aggregate radius is smaller than\u0000the critical value, which is a few centimeters when considering the exchange\u0000reaction between amorphous forsterite aggregates and water vapor.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

New gravity field of comet 67P/C-G based on Rosetta's Doppler and optical data 基于 "罗塞塔 "多普勒和光学数据的 67P/C-G 彗星新重力场

arXiv - PHYS - Earth and Planetary Astrophysics Pub Date : 2024-09-04 DOI: arxiv-2409.02692

Julien Laurent-Varin, Théo James, Jean-Charles Marty, Laurent Jorda, Sebastien Le Maistre, Robert Gaskell

引用次数: 0

Horseshoes and spiral waves: capturing the 3D flow induced by a low-mass planet analytically 马蹄形和螺旋波：通过分析捕捉低质量行星引发的三维流动

arXiv - PHYS - Earth and Planetary Astrophysics Pub Date : 2024-09-04 DOI: arxiv-2409.02687

Joshua J. Brown, Gordon I. Ogilvie

{"title":"Horseshoes and spiral waves: capturing the 3D flow induced by a low-mass planet analytically","authors":"Joshua J. Brown, Gordon I. Ogilvie","doi":"arxiv-2409.02687","DOIUrl":"https://doi.org/arxiv-2409.02687","url":null,"abstract":"The key difficulty faced by 2D models for planet-disc interaction is in\u0000appropriately accounting for the impact of the disc's vertical structure on the\u0000dynamics. 3D effects are often mimicked via softening of the planet's\u0000potential; however, the planet-induced flow and torques often depend strongly\u0000on the choice of softening length. We show that for a linear adiabatic flow\u0000perturbing a vertically isothermal disc, there is a particular vertical average\u0000of the 3D equations of motion which exactly reproduces 2D fluid equations for\u0000arbitrary adiabatic index. There is a strong connection here with the\u0000Lubow-Pringle 2D mode of the disc. Correspondingly, we find a simple, general\u0000prescription for the consistent treatment of planetary potentials embedded\u0000within '2D' discs. The flow induced by a low-mass planet involves large-scale\u0000excited spiral density waves which transport angular momentum radially away\u0000from the planet, and 'horseshoe streamlines' within the co-orbital region. We\u0000derive simple linear equations governing the flow which locally capture both\u0000effects faithfully simultaneously. We present an accurate co-orbital flow\u0000solution allowing for inexpensive future study of corotation torques, and\u0000predict the vertical structure of the co-orbital flow and horseshoe region\u0000width for different values of adiabatic index, as well as the vertical\u0000dependence of the initial shock location. We find strong agreement with the\u0000flow computed in 3D numerical simulations, and with 3D one-sided Lindblad\u0000torque estimates, which are a factor of 2 to 3 times lower than values from\u0000previous 2D simulations.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Systematic Survey of Moon-Forming Giant Impacts. II. Rotating bodies 月球形成巨型撞击的系统调查。II.旋转体

arXiv - PHYS - Earth and Planetary Astrophysics Pub Date : 2024-09-04 DOI: arxiv-2409.02746

Thomas Meier, Christian Reinhardt, Miles Timpe, Joachim Stadel, Ben Moore

{"title":"A Systematic Survey of Moon-Forming Giant Impacts. II. Rotating bodies","authors":"Thomas Meier, Christian Reinhardt, Miles Timpe, Joachim Stadel, Ben Moore","doi":"arxiv-2409.02746","DOIUrl":"https://doi.org/arxiv-2409.02746","url":null,"abstract":"In the leading theory of lunar formation, known as the giant impact\u0000hypothesis, a collision between two planet-size objects resulted in a young\u0000Earth surrounded by a circumplanetary debris disk from which the Moon later\u0000accreted. The range of giant impacts that could conceivably explain the\u0000Earth-Moon system is limited by the set of known physical and geochemical\u0000constraints. However, while several distinct Moon-forming impact scenarios have\u0000been proposed -- from small, high-velocity impactors to low-velocity mergers\u0000between equal-mass objects -- none of these scenarios have been successful at\u0000explaining the full set of known constraints, especially without invoking one\u0000or more controversial post-impact processes. Allowing for pre-impact rotation\u0000of the colliding bodies has been suggested as an avenue which may produce more\u0000promising collision outcomes. However, to date, only limited studies of\u0000pre-impact rotation have been conducted. Therefore, in the second paper of this\u0000series, we focus on pairwise impacts between rotating bodies. Using\u0000non-rotating collisions as a baseline, we systematically study the effects of\u0000rotation on collision outcomes. We consider nine distinct rotation\u0000configurations and a range of rotation rates up to the rotational stability\u0000limit. Notably, we identify a population of collisions that can produce low\u0000post-impact angular momentum budgets and massive, iron-poor protolunar disks.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Up, Up, and Away: Winds and Dynamical Structure as a Function of Altitude in the Ultra-Hot Jupiter WASP-76b 上升，上升，远离：超热木星 WASP-76b 的风和动力学结构与高度的函数关系

arXiv - PHYS - Earth and Planetary Astrophysics Pub Date : 2024-09-04 DOI: arxiv-2409.03124

Aurora Y. Kesseli, Hayley Beltz, Emily Rauscher, I. A. G. Snellen

{"title":"Up, Up, and Away: Winds and Dynamical Structure as a Function of Altitude in the Ultra-Hot Jupiter WASP-76b","authors":"Aurora Y. Kesseli, Hayley Beltz, Emily Rauscher, I. A. G. Snellen","doi":"arxiv-2409.03124","DOIUrl":"https://doi.org/arxiv-2409.03124","url":null,"abstract":"Due to the unprecedented signal strengths offered by the newest\u0000high-resolution spectrographs on 10-m class telescopes, exploring the 3D nature\u0000of exoplanets is possible with an unprecedented level of precision. In this\u0000paper, we present a new technique to probe the vertical structure of\u0000exoplanetary winds and dynamics using ensembles of planet absorption lines of\u0000varying opacity, and apply it to the well-studied ultra-hot Jupiter WASP-76b.\u0000We then compare these results to state-of-the-art global circulation models\u0000(GCMs) with varying magnetic drag prescriptions. We find that the known\u0000asymmetric velocity shift in Fe I absorption during transit persists at all\u0000altitudes, and observe tentative trends for stronger blueshifts and more narrow\u0000line profiles deeper in the atmosphere. By comparing three different model\u0000prescriptions (a hydrodynamical model with no drag, a magnetic drag model, and\u0000a uniform drag model) we are able to rule out the uniform drag model due to\u0000inconsistencies with observed trends in the data. We find that the magnetic\u0000model is slightly favored over the the hydrodynamic model, and note that this\u00003-Gauss kinematic magnetohydrodynamical GCM is also favored when compared to\u0000low-resolution data. Future generation high-resolution spectrographs on\u0000Extremely large telescopes (ELTs) will greatly increase signals and make\u0000methods like these possible with higher precision and for a wider range of\u0000objects.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gravitational instability in a planet-forming disk 行星形成盘中的引力不稳定性

arXiv - PHYS - Earth and Planetary Astrophysics Pub Date : 2024-09-03 DOI: arxiv-2409.02196

Jessica Speedie, Ruobing Dong, Cassandra Hall, Cristiano Longarini, Benedetta Veronesi, Teresa Paneque-Carreño, Giuseppe Lodato, Ya-Wen Tang, Richard Teague, Jun Hashimoto

{"title":"Gravitational instability in a planet-forming disk","authors":"Jessica Speedie, Ruobing Dong, Cassandra Hall, Cristiano Longarini, Benedetta Veronesi, Teresa Paneque-Carreño, Giuseppe Lodato, Ya-Wen Tang, Richard Teague, Jun Hashimoto","doi":"arxiv-2409.02196","DOIUrl":"https://doi.org/arxiv-2409.02196","url":null,"abstract":"The canonical theory for planet formation in circumstellar disks proposes\u0000that planets are grown from initially much smaller seeds. The long-considered\u0000alternative theory proposes that giant protoplanets can be formed directly from\u0000collapsing fragments of vast spiral arms induced by gravitational instability\u0000-- if the disk is gravitationally unstable. For this to be possible, the disk\u0000must be massive compared to the central star: a disk-to-star mass ratio of 1/10\u0000is widely held as the rough threshold for triggering gravitational instability,\u0000inciting significant non-Keplerian dynamics and generating prominent spiral\u0000arms. While estimating disk masses has historically been challenging, the\u0000motion of the gas can reveal the presence of gravitational instability through\u0000its effect on the disk velocity structure. Here we present kinematic evidence\u0000of gravitational instability in the disk around AB Aurigae, using deep\u0000observations of 13CO and C18O line emission with the Atacama Large\u0000Millimeter/submillimeter Array (ALMA). The observed kinematic signals strongly\u0000resemble predictions from simulations and analytic modelling. From quantitative\u0000comparisons, we infer a disk mass of up to 1/3 the stellar mass enclosed within\u00001\" to 5\" on the sky.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0