Article
Astronomy & Astrophysics
Lin Qiao, Gavin A. L. Coleman, Thomas J. Haworth
Summary: We demonstrate that planet formation via pebble accretion is sensitive to external photoevaporation of the outer disc. Pebble accretion relies on the supply of pebble flux from the outer disc, but if external photoevaporation truncates the disc too fast, it can limit the availability of pebble mass for planet growth. However, cloud shielding can protect the disc and preserve the pebble reservoir, resulting in significant differences in planetary properties.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
James M. Miley, Olja Panic, Richard A. Booth, John D. Ilee, Shigeru Ida, Masanobu Kunitomo
Summary: This study investigates the impact of pre-main sequence stellar luminosity evolution on the thermal and chemical properties of disc mid-planes. It reveals that temperature profiles diverge significantly for different stellar masses beyond 2 Myr, affecting the location of the CO snowline. The research indicates a well-defined stellar mass and age range for the formation of high C/O gas giants.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Haochang Jiang, Chris W. Ormel
Summary: ALMA observations have shown that dust rings in protoplanetary discs are important for planet formation, where planetesimals can grow efficiently via pebble accretion. Type-I planet migration is crucial for the evolution of rings and planets.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Gavin A. L. Coleman
Summary: Planet formation models often skip the crucial step of planetesimal/proto-embryo formation. This study includes prescriptions for planetesimal and proto-embryo formation from trapped pebbles in pressure bumps, examining their sizes and distributions throughout the disc. Results show that planetesimal sizes increase with orbital distance and proto-embryo masses increase with orbital radius. By combining different accretion scenarios, more massive proto-embryos can form at larger distances, allowing for a better understanding of planetary system formation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
G. Andama, N. Ndugu, S. K. Anguma, E. Jurua
Summary: In the classical picture of pebble-based core growth, planetary cores grow through accretion of single pebble species, reaching a pebble isolation mass that halts core growth. Recent hydrodynamic simulations show that core growth rates and final core masses are sensitive to parameters like turbulent viscosity and pebble size. Accretion of multiple pebble species can lead to fast growth of planetary cores, potentially explaining heavy element abundance in Jupiter, massive cores of extrasolar planets, disc rings and gaps at wider orbits, and early formation of planetary bodies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
M. Fritscher, J. Teiser
Summary: The stability of planetesimals is crucial for their growth and evolution, and it depends on the stability, adhesion, and fragmentation of macroscopic agglomerates. In this study, we investigate the stability of highly porous CO2 agglomerates, which are abundant in the outer parts of protoplanetary discs. Our experiments show that the tensile strength of the agglomerates follows a power law dependence on the volume filling. The surface energy of the agglomerates is calculated to be γ = 0.060 +/- 0.022 J m(-2).
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Leandro Esteves, Andra Izidoro, Bertram Bitsch, Seth A. Jacobson, Sean N. Raymond, Rogerio Deienno, Othon C. Winter
Summary: The study suggests that perfect accretion is a suitable approximation for dynamic purposes in the scenario described. Despite common fragmentation events, only around 10% of the system mass is fragmented during a typical 'late instability phase', with most fragments being reacreted by surviving planets. The limited total mass in fragments proves insufficient to qualitatively alter the final system dynamical configuration compared to simulations where fragmentation is disregarded.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
G. Andama, N. Ndugu, S. K. Anguma, E. Jurua
Summary: This study investigates the impact of globally perturbed discs on dust evolution and core growth through simulations, focusing on the formation of planetary cores at pressure minima and maxima. The results show that pressure maxima generated by planets or other physical phenomena can hinder planet formation in the inner parts of the disc, while multiple wave-like pressure bumps can promote rapid planet formation in broad areas of the disc.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
E. Miller, S. Marino, S. M. Stammler, P. Pinilla, C. Lenz, T. Birnstiel, Th Henning
Summary: Studying the determinants of exoKuiper belt width is complex, as observations have shown a nearly fourfold increase in width in mature systems compared to narrow belts in protoplanetary discs. Research suggests that dust traps during migration may facilitate planetesimal formation, leading to a positive correlation between inward radial speed and final planetesimal belt width.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Lin Qiao, Thomas J. Haworth, Andrew D. Sellek, Ahmad A. Ali
Summary: In this study, we combined star cluster formation and feedback simulations with 1D disc evolutionary models to investigate the impact of external photoevaporation on disc populations in massive star-forming regions. Our results show that shielding effects only occur for a small fraction of discs, providing protection for less than 0.5 million years. However, this initial shielding can prevent significant gas/dust mass-loss and disc radius reduction due to external photoevaporation. Shielding is potentially significant for retaining the solid mass budget for terrestrial planet formation, but the stripping of gas when shielding ends could still affect migration and the gas reservoir for giant planet atmospheres.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Thomas J. Haworth, Jinyoung S. Kim, Lin Qiao, Andrew J. Winter, Jonathan P. Williams, Cathie J. Clarke, James E. Owen, Stefano Facchini, Megan Ansdell, Mikhel Kama, Giulia Ballabio
Summary: We searched for C I 1-0 emission towards eight proplyds in NGC 1977 using the APEX telescope, but no detections were made despite reaching sensitivities deeper than previous observations. Comparison with external photo-evaporation simulations suggests that the non-detections are consistent with very low mass proplyd discs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Jacob Cleaver, Lee Hartmann, Jaehan Bae
Summary: We investigate the role of the magnetorotational instability (MRI) in explaining the diverse range of observed accretion outbursts in protoplanetary discs. Our results suggest that short-lived, low accretion rate events are likely triggered in the inner disc and cannot be explained by MRI triggering through gravitational instability. By using time-dependent accretion disc models and comparing with observations, we find that the lag time between infrared and optical bursts in Gaia 17bpi can be explained by an outside-in propagation with an α > 0.1 in the MRI-active region. Our findings highlight the importance of near-infrared monitoring and call for more sophisticated simulations to better understand the observed phenomena.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Arturo Cevallos Soto, Jonathan C. Tan, Xiao Hu, Chia-Jung Hsu, Catherine Walsh
Summary: Inside-out planet formation theory suggests that certain types of planets are formed in situ near the inner boundary of protoplanetary discs. This study presents a model that predicts the physical and chemical evolution of these discs, showing that water-rich planets can form close to the star while the outer regions become dust-depleted. These findings provide important insights into the formation and composition of planets.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. J. Rucska, J. W. Wadsley
Summary: This article presents the first simulations of the streaming instability (SI) based on a realistic size distribution. The simulations show that kilometre-sized planetesimals can form from the gravitational collapse of pebble clouds. It also reveals a size cutoff for pebbles incorporated into asteroids and comets and warns of potential underestimations of dust mass due to dust clumping and optical depth effects.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Thomas J. Haworth
Summary: The study focuses on the effect of external massive sources on the temperature and dust mass estimates of protoplanetary discs, showing that disc masses can be overestimated, significantly altering dust mass estimates. Close proximity to massive stars can influence disc properties and lead to the disappearance of the CO snow line within a certain distance.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Apostolos Zormpas, Tilman Birnstiel, Giovanni P. Rosotti, Sean M. Andrews
Summary: Recent surveys of nearby protoplanetary disks show a strong correlation between the sizes and luminosities of the disks. Using models and calculations, researchers found that a combination of smooth and substructured disks exists in the observed sample, and factors such as particle composition and porosity also affect the evolution of the disks.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Feng Long, Sean M. Andrews, Giovanni Rosotti, Daniel Harsono, Paola Pinilla, David J. Wilner, Karin Oberg, Richard Teague, Leon Trapman, Benoit Tabone
Summary: The size of a disk encodes important information about its evolution. By analyzing data from a sample of 44 protoplanetary disks, we found that the size range can be explained by different models of viscous evolution or spread of initial conditions. Most disks' sizes are consistent with MHD wind models, but larger initial disk sizes are needed to explain the CO disks in the sample.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Richard Teague, Jaehan Bae, Myriam Benisty, Sean M. Andrews, Stefano Facchini, Jane Huang, David Wilner
Summary: This study presents new observations of the protoplanetary disk around TW Hya, analyzing the CO J = 2 - 1 emission. The emission is detected up to 240 au (4 ''), showing azimuthal variations beyond 180 au (3 ''), with the west side of the disk being brighter. The observed asymmetry correlates with the previously seen shadow in scattered light, and the temporal evolution of the shadow is better explained by an oscillatory motion rather than orbital motion. The angular offset between the dust shadow and gas shadow is attributed to the finite rate at which dust grains and gas molecules exchange heat.
ASTROPHYSICAL JOURNAL
(2022)
Correction
Astronomy & Astrophysics
Charles J. Law, Ryan A. Loomis, Richard Teague, Karin I. Oberg, Ian Czekala, Sean M. Andrews, Jane Huang, Yuri Aikawa, Felipe Alarcon, Jaehan Bae, Edwin A. Bergin, Jennifer B. Bergner, Yann Boehler, Alice S. Booth, Arthur D. Bosman, Jenny K. Calahan, Gianni Cataldi, L. Ilsedore Cleeves, Kenji Furuya, Viviana V. Guzman, John D. Ilee, Romane Le Gal, Yao Liu, Feng Long, Francois Menard, Hideko Nomura, Chunhua Qi, Kamber R. Schwarz, Anibal Sierra, Takashi Tsukagoshi, Yoshihide Yamato, Merel L. R. van 't Hoff, Catherine Walsh, David J. Wilner, Ke Zhang
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Astronomy & Astrophysics
Charles J. Law, Sage Crystian, Richard Teague, Karin Oberg, Evan A. Rich, Sean M. Andrews, Jaehan Bae, Kevin Flaherty, Viviana V. Guzman, Jane Huang, John D. Ilee, Joel H. Kastner, Ryan A. Loomis, Feng Long, Laura M. Perez, Sebastian Perez, Chunhua Qi, Giovanni P. Rosotti, Dary Ruiz-Rodriguez, Takashi Tsukagoshi, David J. Wilner
Summary: High-resolution CO observations provide insights into the emission and temperature distribution of protoplanetary disks. The asymmetry of line emission allows for a direct mapping of the emission height, and the intensity can be used as a measure of the local gas temperature. Analysis of archival data reveals emission surfaces and gas temperature distributions for multiple disks, showing a wide range of emission heights and correlations with dust structures.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Jaehan Bae, Richard Teague, Sean M. Andrews, Myriam Benisty, Stefano Facchini, Maria Galloway-Sprietsma, Ryan A. Loomis, Yuri Aikawa, Felipe Alarcon, Edwin Bergin, Jennifer B. Bergner, Alice S. Booth, Gianni Cataldi, L. Ilsedore Cleeves, Ian Czekala, Viviana V. Guzman, Jane Huang, John D. Ilee, Nicolas T. Kurtovic, Charles J. Law, Romane Le Gal, Yao Liu, Feng Long, Francois Menard, Karin Oberg, Laura M. Perez, Chunhua Qi, Kamber R. Schwarz, Anibal Sierra, Catherine Walsh, David J. Wilner, Ke Zhang
Summary: This paper reports the discovery of a candidate circumplanetary disk (CPD) in the circumstellar disk of the T Tauri star AS 209. This is the first instance of CPD detection using gaseous emission, which allows for tracing of the CPD mass. The CPD has a high gas temperature and a low dust-to-gas mass ratio.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
Evan A. Rich, John D. Monnier, Alicia Aarnio, Anna S. E. Laws, Benjamin R. Setterholm, David J. Wilner, Nuria Calvet, Tim Harries, Chris Miller, Claire L. Davies, Fred C. Adams, Sean M. Andrews, Jaehan Bae, Catherine Espaillat, Alexandra Z. Greenbaum, Sasha Hinkley, Stefan Kraus, Lee Hartmann, Andrea Isella, Melissa McClure, Rebecca Oppenheimer, Laura M. Perez, Zhaohuan Zhu
Summary: We present a complete sample of protoplanetary disks, searching for signatures of disk evolution and ongoing planet formation. Our findings show that the presence of a companion significantly reduces polarized flux levels, far-IR excess correlates with polarized flux for nonbinary systems, and systems with ring structures have low stellar masses. Additionally, we discovered several extremely young FS CMa systems.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
David Vizgan, A. Meredith Hughes, Evan S. Carter, Kevin M. Flaherty, Margaret Pan, Eugene Chiang, Hilke Schlichting, David J. Wilner, Sean M. Andrews, John M. Carpenter, Attila Moor, Meredith A. MacGregor
Summary: Debris disks, which are scaled-up analogs of the Kuiper Belt, generate dust through collisions between planetesimals. By observing the debris disk around the nearby M dwarf AU Microscopii, researchers discovered that smaller bodies are more easily disrupted by collisions, contradicting current assumptions.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Anna J. Fehr, A. Meredith Hughes, Rebekah Dawson, Rachel E. Marino, Matan Ackelsberg, Jamar Kittling, Kevin M. Flaherty, Erika Nesvold, John Carpenter, Sean M. Andrews, Brenda Matthews, Katie Crotts, Paul Kalas
Summary: Debris disks are dusty structures around main-sequence stars, and HD 106906AB is a stellar binary system with a wide-separation planet and a debris disk. By studying the edge-on, highly asymmetric structure of the debris disk using ALMA, it is found that a broad, axisymmetric disk captures the observations well. The observations support in-situ formation via gravitational instability for the planet HD 106906b, although a scattering event origin cannot be ruled out.
ASTROPHYSICAL JOURNAL
(2022)
Correction
Astronomy & Astrophysics
Jaehan Bae, Richard Teague, Sean M. Andrews, Myriam Benisty, Stefano Facchini, Maria Galloway-Sprietsma, Ryan A. Loomis, Yuri Aikawa, Felipe Alarcon, Edwin Bergin, Jennifer B. Bergner, Alice S. Booth, Gianni Cataldi, L. Ilsedore Cleeves, Ian Czekala, Viviana V. Guzman, Jane Huang, John D. Ilee, Nicolas T. Kurtovic, Charles J. Law, Romane Le Gal, Yao Liu, Feng Long, Franccois Menard, Karin I. Oberg, Laura M. Perez, Chunhua Qi, Kamber R. Schwarz, Anibal Sierra, Catherine Walsh, David J. Wilner, Ke Zhang
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
Feng Long, Sean M. Andrews, Shangjia Zhang, Chunhua Qi, Myriam Benisty, Stefano Facchini, Andrea Isella, David J. Wilner, Jaehan Bae, Jane Huang, Ryan A. Loomis, Karin Oberg, Zhaohuan Zhu
Summary: We present deep ALMA observations of the LkCa 15 disk, revealing emission morphology of an inner cavity and three dust rings. The faint ring at 42 au shows excess emission features that resemble a horseshoe orbit produced by planet-disk interaction models. The coincidence of the horseshoe ring with a gap in near-IR scattered light suggests planet sculpting, with the planet likely having a mass between Neptune and Saturn.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
Zhaohuan Zhu, Avery Bailey, Enrique Macias, Takayuki Muto, Sean M. Andrews
Summary: Despite difficulties in detecting low-mass planets embedded in protoplanetary discs, a large population of such planets at the Kelvin-Helmholtz contraction phase is suggested by the core-accretion theory. This study uses 1D models and 3D simulations to calculate the envelopes around low-mass cores and derives their thermal fluxes at radio wavelengths. The results show that radio observations can probe the denser envelope within a planet's Hill sphere when the background disc is optically thin.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jane Huang, Edwin A. Bergin, Jaehan Bae, Myriam Benisty, Sean M. Andrews
Summary: DR Tau is known for its high variability compared to other T Tauri stars. Millimeter interferometry observations reveal the distribution of CO and other substances, showing the presence of a protoplanetary disk, gas envelope, asymmetrical outflow, and spiral arm with clumps. The CO arm is much larger than spiral arms seen in scattered light, highlighting the importance of sensitive molecular imaging for understanding the disk environment. Kinematics and compact emission distribution suggest that (CO)-O-18, SO, DCO+, and H2CO primarily originate from the circumstellar disk. The asymmetry in SO emission may be due to interaction with infalling material or unresolved substructure, indicating a complex environment similar to outbursting FUor and EXor sources, suggesting a link between DR Tau's extreme stellar activity and disk instabilities caused by large-scale infall.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Jamila Pegues, Karin Oberg, Chunhua Qi, Sean M. Andrews, Jane Huang, Charles J. Law, Romane Le Gal, Luca Matra, David J. Wilner
Summary: Protoplanetary disks around Herbig AeBe stars are exciting targets for studying the chemical environments where giant planets form. We conducted a pilot survey of millimeter continuum CO isotopologs and other small molecules in disks around five Herbig AeBe stars and detected or tentatively detected various molecular emissions. The flux ratios between CO 2-1 isotopologs were closest to unity for the Herbig AeBe/F disks, suggesting emitting layers with similar temperatures and more abundant CO relative to the disk dust mass. However, lower detection rates and flux ratios for certain molecules suggest smaller regimes of cold chemistry around the luminous Herbig AeBe/F stars.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Charles J. J. Law, Richard Teague, Karin I. I. Oberg, Evan A. A. Rich, Sean M. M. Andrews, Jaehan Bae, Myriam Benisty, Stefano Facchini, Kevin Flaherty, Andrea Isella, Sheng Jin, Jun Hashimoto, Jane Huang, Ryan A. A. Loomis, Feng Long, Carlos E. E. Munoz-Romero, Teresa Paneque-Carreno, Laura M. M. Perez, Chunhua Qi, Kamber R. R. Schwarz, Jochen Stadler, Takashi Tsukagoshi, David J. J. Wilner, Gerrit van der Plas
Summary: High-spatial-resolution observations of CO isotopologue line emission in protoplanetary disks reveal detailed gas structure, including radial and vertical substructures, emission surface heights, and temperature profiles. Observations of CO, (CO)-C-13, and (CO)-O-18 in transition disks provide insights into disk structure and temperature distributions. The derived emission surfaces and temperature models show potential correlations with source characteristics, suggesting the influence of stellar host mass, gas temperature, and disk size on the emitting heights.
ASTROPHYSICAL JOURNAL
(2023)