We present a plausible and coherent view of the evolution of the protosolar disk that is consistent with the cosmochemical constraints and compatible with observations of other protoplanetary disks and sophisticated numerical simulations. The evidence that high-temperature condensates, CAIs and AOAs, formed near the protosun before being transported to the outer disk can be explained by either an early phase of vigorous radial spreading of the disk, or fast transport of these condensates from the vicinity of the protosun towards large disk radii via the protostellar outflow. The assumption that the material accreted towards the end of the infall phase was isotopically distinct allows us to explain the observed dichotomy in nucleosynthetic isotopic anomalies of meteorites and leads to intriguing predictions on the isotopic composition of refractory elements in comets. When the infall of material waned, the disk started to evolve as an accretion disk. Initially, dust drifted inwards, shrinking the radius of the dust component to ~ 45 au, probably about 1/2 of the width of the gas component. Then structures must have emerged, producing a series of pressure maxima in the disk which trapped the dust on My timescales. This allowed planetesimals to form at radically distinct times without changing significantly of isotopic properties. There was no late accretion of material onto the disk via streamers. The disk disappeared in ~5 Myr, as indicated by paleomagnetic data in meteorites. In conclusion, the evolution of the protosolar disk seems to have been quite typical in terms of size, lifetime, and dust behavior, suggesting that the peculiarities of the Solar system with respect to extrasolar planetary system probably originate from the chaotic nature of planet formation and not at the level of the parental disk.
Chondrule formation remains one of the most elusive early Solar System events. Here, we take the novel approach of employing numerical simulations to investigate chondrule origin beyond purely cosmochemical methods. We model the transport of generically-produced chondrules and dust in a 1D viscous protoplanetary disk model, in order to constrain the chondrule formation events. For a single formation event we are able to match analytical predictions of the memory chondrule and dust populations retain of each other (complementarity), finding that a large mass accretion rate ($\gtrsim 10^{-7}$~M$…
I summarize recent surveys of protoplanetary disks at millimeter wavelengths and show that the distribution of luminosity, equivalent to the mass in small dust grains, declines rapidly. This contrasts with statistics on the lifetime of disks from infrared observations and the high occurrence of planets from radial velocity and transit surveys. I suggest that these disparate results can be reconciled if most of the dust in a disk is locked up in millimeter and larger sized particles within about 2 Myr. This statistical result on disk evolution agrees with detailed modeling of a small number of …
Meteoritical and astrophysical models of planet formation make contradictory predictions for dust concentration factors in chondrule forming regions of the solar nebula. Meteoritical and cosmochemical models strongly suggest that chondrules, a key component of the meteoritical record, formed in regions with solids-to-gas mass ratios orders of magnitude above background. However, models of dust grain dynamics in protoplanetary disks struggle to surpass factors of a few outside of very brief windows in the lifetime of the dust grains. Worse, those models do not predict significant concentration …
The gas-phase CO abundance (relative to hydrogen) in protoplanetary disks decreases by up to 2 orders of magnitude from its ISM value ${\sim}10^{-4}$, even after accounting for freeze-out and photo-dissociation. Previous studies have shown that while local chemical processing of CO and the sequestration of CO ice on solids in the midplane can both contribute, neither of these processes appears capable of consistently reaching the observed depletion factors on the relevant timescale of $1{-}3\mathrm{~Myr}$. In this study, we model these processes simultaneously by including a compact chemical n…
The similar orbital distances and detection rates of debris disks and the prominent rings observed in protoplanetary disks suggest a potential connection between these structures. We explore this connection with new calculations that follow the evolution of rings of pebbles and planetesimals as they grow into planets and generate dusty debris. Depending on the initial solid mass and planetesimal formation efficiency, the calculations predict diverse outcomes for the resulting planet masses and accompanying debris signature. When compared with debris disk incidence rates as a function of lumino…
Measuring the properties of protoplanetary disks around brown dwarfs is central to understanding the formation of brown dwarfs and their planetary companions. We present modeling of CFHT Tau 4 and 2M0444, two brown dwarfs with protoplanetary disks in the Taurus Molecular Cloud. By combining modeling of the spectral energy distributions and ALMA images, we obtain disk radii and masses for these objects; these parameters can be used to constrain brown dwarf formation and planet formation, respectively. We find that the disk around CFHT Tau 4 has a mass of 0.42 M$_{Jup}$ and a radius of 80 au; we…
Measuring the amount of gas and dust in protoplanetary disks is a key challenge in planet formation studies. Here we provide a new set of dust depletion factors and relative mass surface densities of gas and dust for the innermost regions of a sample of protoplanetary disks. We do this by combining stellar theory with observed refractory element abundances in both disk hosts and open cluster stars. Our results are independent of, and complementary to, those obtained from spatially resolved disk observations.
The gas surface density profile of protoplanetary disks is one of the most fundamental physical properties to understand planet formation. However, it is challenging to determine the surface density profile observationally, because the H$_2$ emission cannot be observed in low-temperature regions. We analyzed the Atacama Large Millimeter/submillimeter Array (ALMA) archival data of the \co line toward the protoplanetary disk around TW Hya and discovered extremely broad line wings due to the pressure broadening. In conjunction with a previously reported optically thin CO isotopologue line, the pr…
Numerical Insights into Disk Accretion, Eccentricity, and Kinematics in the Class 0 phase
ENS de Lyon, CRAL UMR5574, Universite Claude Bernard Lyon 1, CNRS（里昂高等师范学院，CRAL UMR5574，里昂第一大学，法国国家科学研究中心）；Université Paris Cité, Institut de Physique du Globe de Paris, CNRS（巴黎西岱大学，巴黎地球物理研究所，法国国家科学研究中心）；International Space Science Institute（国际空间科学研究所）；Collège de France, CNRS, PSL Univ., Sorbonne Univ.（法兰西公学院，法国国家科学研究中心，巴黎文理研究大学，索邦大学）；Observatoire de la Côte d’Azur, Université Cote d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸天文台，蔚蓝海岸大学，法国国家科学研究中心，拉格朗日实验室）
Combining 3D smoothed-particle hydrodynamics and Monte Carlo radiative transfer calculations, we examine the morphology of spiral density waves induced by gravitational instability (GI) in protoplanetary disks, as they would appear in direct images at near-infrared (NIR) wavelengths. We find that systems with disk-to-star-mass ratios q=M_disk/M_star that are ~0.25 or more may produce prominent spiral arms in NIR imaging, remarkably resembling features observed in the MWC 758 and SAO 206462 systems. The contrast of GI-induced arms at NIR wavelengths can reach a factor of ~3, and their pitch ang…
As the earliest stage of planet formation, massive, optically thick, and gas rich protoplanetary disks provide key insights into the physics of star and planet formation. When viewed edge-on, high resolution images offer a unique opportunity to study both the radial and vertical structures of these disks and relate this to vertical settling, radial drift, grain growth, and changes in the midplane temperatures. In this work, we present multi-epoch HST and Keck scattered light images, and an ALMA 1.3 mm continuum map for the remarkably flat edge-on protoplanetary disk SSTC2DJ163131.2-242627, a y…
Azimuthally asymmetric structures have been discovered in millimeter continuum emission from many protoplanetary disks. One hypothesis is that they are vortices produced by the Rossby wave instability, for example at edges of planet-opened gaps or deadzones. Confirming the vortex nature of these structures will have profound implications to planet formation. One way to test the hypothesis is to compare the observed morphology of vortex candidates in near-infrared scattered light with theoretical expectations. To this end, we synthesize the appearance of vortices in H-band polarized light by co…
The vertical shear instability (VSI) is a hydrodynamical instability that requires rapid gas cooling and has been suggested to operate in outer regions of protoplanetary disks. The VSI drives turbulence with strong vertical motions, which could regulate the dust growth and settling. However, dust growth and settling can regulate the VSI because dust depletion makes gas cooling inefficient in outer disk regions that are optically thin to their own thermal emission. In this study, we quantify this potentially stabilizing effects of dust evolution on the VSI based on the linear analysis. We const…
European Southern Observatory (ESO)（欧洲南方天文台）；Boston University（波士顿大学）；Joint ALMA Observatory（阿塔卡马大型毫米波/亚毫米波阵列联合天文台）；UNED（西班牙国家远程教育大学）
We model the spectral energy distributions (SEDs) of 23 protoplanetary disks in the Taurus-Auriga star-forming region using detailed disk models and a Bayesian approach. This is made possible by combining these models with artificial neural networks to drastically speed up their performance. Such a setup allows us to confront $α$-disk models with observations while accounting for several uncertainties and degeneracies. Our results yield high viscosities and accretion rates for many sources, which is not consistent with recent measurements of low turbulence levels in disks. This inconsistency c…
We present Herschel Space Observatory PACS spectra of T Tauri stars, in which we detect amorphous and crystalline water ice features. Using irradiated accretion disk models, we determine the disk structure and ice abundance in each of the systems. Combining a model-independent comparison of the ice feature strength and disk size with a detailed analysis of the model ice location, we estimate that the ice emitting region is at disk radii >30AU, consistent with a proto-Kuiper belt. Vertically, the ice emits most below the photodesorption zone, consistent with Herschel observations of cold water …
Investigating Variability in Long-lived Protoplanetary Disks (>10 Myr) using NEOWISE
Indian Institute of Science Education and Research Tirupati（印度科学教育研究所提鲁帕蒂分校）；Instituto de Astronomía, Universidad Nacional Autónoma de México（墨西哥国立自治大学天文学研究所）
We present a high-resolution (2.5 au) multiband analysis of the protoplanetary disk around TW Hya using ALMA long baseline data at Bands 3, 4, 6, and 7. We aim to reconstruct a high-sensitivity millimeter continuum image and revisit the spectral index distribution. The imaging is performed by combining new ALMA data at Bands 4 and 6 with available archive data. Two methods are employed to reconstruct the images; multi-frequency synthesis (MFS) and the fiducial image-oriented method, where each band is imaged separately and the frequency dependence is fitted pixel by pixel. We find that the MFS…
It is still unclear whether the evolution of protoplanetary disks, a key ingredient in the theory of planet formation, is driven by viscous turbulence or magnetic disk winds. As viscously evolving disks expand outward over time, the evolution of disk sizes is a discriminant test for studying disk evolution. However, it is unclear how the observed disk size changes over time if disk evolution is driven by magnetic disk winds. Combining the thermochemical code DALI with the analytical wind-driven disk evolution model presented in Tabone et al. (2021a), we study the time evolution of the observed…
We present deep Herschel-PACS spectroscopy of far-infrared water lines from a sample of four protoplanetary disks around solar-mass stars, selected to have strong water emission at mid-infrared wavelengths. By combining the new Herschel spectra with archival Spitzer-IRS spectroscopy, we retrieve a parameterized radial surface water vapor distribution from 0.1-100 AU using two-dimensional dust and line radiative transfer modeling. The surface water distribution is modeled with a step model comprising of a constant inner and outer relative water abundance and a critical radius at which the surfa…
The radial extent of millimetre dust in protoplanetary discs is often far smaller than that of their gas, mostly due to processes such as dust growth and radial drift. However, it has been suggested that current millimetre continuum observations of discs do not trace their full extent due to limited sensitivity. In this Letter, we present deep (19 $μ$Jy beam$^{-1}$) moderate resolution (0.37") ALMA observations at 1 mm of the nearest protoplanetary disc, TW Hya. Using the visibility analysis tool `frank', we reveal a structured millimetre intensity distribution out to 100 au, well beyond previ…
We conduct simulations of the inner regions of protoplanetary disks (PPDs) to investigate the effects of protostellar magnetic fields on their long-term evolution. We use an inner boundary model that incorporates the influence of a stellar magnetic field. The position of the inner disk is dependent on the mass accretion rate as well as the magnetic field strength. We use this model to study the response of a magnetically truncated inner disk to an episodic accretion event. Additionally, we vary the protostellar magnetic field strength and investigate the consequences of the magnetic field on t…
JWST Imaging of Edge-on Protoplanetary Disks. V. Flux Ratio Reversal and Disk-edge Structure in the Flying Saucer
Univ. Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；Department of Astronomy, University of California, Berkeley（加州大学伯克利分校天文学系）；Department of Earth Science and Astronomy, The University of Tokyo（东京大学地球系统行星科学科）
Combining hydrodynamic planet-disk interaction simulations with dust evolution models, we show that protoplanetary disks having a giant planet can reveal diverse morphology in (sub-)millimeter continuum, including a full disk without significant radial structure, a transition disk with an inner cavity, a disk with a single gap and a central continuum peak, and a disk with multiple rings and gaps. Such a diversity originates from (1) the level of viscous transport in the disk which determines the number of gaps a planet can open; (2) the size and spatial distributions of grains determined by th…
Direct imaging observations of protoplanetary disks at near-infrared (NIR) wavelengths have revealed structures of potentially planetary origin. Investigations of observational signatures from planet-induced features have so far focused on disks viewed face-on. Combining 3D hydrodynamics and radiative transfer simulations, we study how the appearance of the spiral arms and the gap produced in a disk by a companion varies with inclination and position angle in NIR scattered light. We compare the cases of a $3M_{\rm J}$ and a $0.1M_{\odot}$ companion, and make predictions suitable for testing wi…
Short-lived radioisotopes (SLRI) such as $^{60}$Fe and $^{26}$Al were likely injected into the solar nebula in a spatially and temporally heterogeneous manner. Marginally gravitationally unstable (MGU) disks, of the type required to form gas giant planets, are capable of rapid homogenization of isotopic heterogeneity as well as of rapid radial transport of dust grains and gases throughout a protoplanetary disk. Two different types of new models of a MGU disk in orbit around a solar-mass protostar are presented. The first set has variations in the number of terms in the spherical harmonic solut…
We present the sub-mm/mm SED for a sample of eight young circumstellar disks in the outer regions of the Orion Nebula Cluster. New observations were carried out at 2.9 mm with the CARMA array and for one disk, 216-0939, at 3.3 and 6.8 mm with ATCA. By combining these new millimeter data with literature measurements at sub-millimeter wavelengths we investigate grain growth and measure the dust mass in protoplanetary disks in the Orion Nebula Cluster. These data provide evidence for dust grain growth to at least millimeter-sizes for the first time in a high-mass star forming region. The obtained…
Recent ALMA molecular line observations have revealed 3-D gas velocity structure in protoplanetary disks, shedding light on mechanisms of disk accretion and structure formation. 1) By carrying out viscous simulations, we confirm that the disk's velocity structure differs dramatically using vertical stress profiles from different accretion mechanisms. Thus, kinematic observations tracing flows at different disk heights can potentially distinguish different accretion mechanisms. On the other hand, the disk surface density evolution is mostly determined by the vertically integrated stress. The sh…
The composition of planets may be largely determined by the chemical processing and accretion of icy pebbles in protoplanetary disks. Recent observations of protoplanetary disks hint at wide-spread depletion of gaseous carbon. The missing volatile carbon is likely frozen in CO and/or CO$_2$ ice on grains and locked into the disk through pebble trapping in pressure bumps or planetesimals. We present the results of the first successful ACA (Atacama Compact Array) [C I] $J$ = 1-0 mini-survey of seven protoplanetary disks. Using tailored azimuthally symmetric DALI (Dust And LInes) thermo-chemical …
Recent observations of protoplanetary disk have reported spiral structures that are potential signatures of embedded planets, and modeling efforts have shown that a single planet can excite multiple spiral arms, in contrast to conventional disk-planet interaction theory. Using two and three-dimensional hydrodynamics simulations to perform a systematic parameter survey, we confirm the existence of multiple spiral arms in disks with a single planet, and discover a scaling relation between the azimuthal separation of the primary and secondary arm, $ϕ_{\rm sep}$, and the planet-to-star mass ratio …
We present a study of the evolution of the inner few astronomical units of protoplanetary disks around low-mass stars. We consider nearby stellar groups with ages spanning from 1 to 11 Myr, distributed into four age bins. Combining PANSTARSS photometry with spectral types, we derive the reddening consistently for each star, which we use (1) to measure the excess emission above the photosphere with a new indicator of IR excess and (2) to estimate the mass accretion rate ($\dot{M}$) from the equivalent width of the H$α$ line. Using the observed decay of $\dot{M}$ as a constrain to fix the initia…
An SMA Molecular Inventory of the Edge-on Protoplanetary Disk Gomez's Hamburger
Massachusetts Institute of Technology（麻省理工学院）；Boston University（波士顿大学）；Queen Mary University of London（伦敦玛丽女王大学）；University of Leeds（利兹大学）；University of Belgrade（贝尔格莱德大学）；University of Virginia（弗吉尼亚大学）；Université Grenoble Alpes（格勒诺布尔阿尔卑斯大学）；CNRS（法国国家科学研究中心）；Institut de Radioastronomie Millimétrique（毫米波射电天文研究所）
We present high resolution H-band polarized intensity (PI; FWHM = 0."1: 14 AU) and L'-band imaging data (FWHM = 0."11: 15 AU) of the circumstellar disk around the weak-lined T Tauri star PDS 70 in Centaurus at a radial distance of 28 AU (0."2) up to 210 AU (1."5). In both images, a giant inner gap is clearly resolved for the first time, and the radius of the gap is ~70 AU. Our data show that the geometric center of the disk shifts by ~6 AU toward the minor axis. We confirm that the brown dwarf companion candidate to the north of PDS 70 is a background star based on its proper motion. As a resu…
Class III stars are those in star forming regions without large non-photospheric infrared emission, suggesting recent dispersal of their protoplanetary disks. We observed 30 class III stars in the 1-3 Myr Lupus region with ALMA at ${\sim}856μ$m, resulting in 4 detections that we attribute to circumstellar dust. Inferred dust masses are $0.036{-}0.093M_\oplus$, ${\sim}1$ order of magnitude lower than any previous measurements; one disk is resolved with radius ${\sim}80$ au. Two class II sources in the field of view were also detected, and 11 other sources, consistent with sub-mm galaxy number c…
Coordinated Space and Ground-Based Monitoring of Accretion Bursts in a Protoplanetary Disk: Establishing Mid-Infrared Hydrogen Lines as Accretion Diagnostics for JWST-MIRI
本文利用 JWST-MIRI 对 DQ Tau 双星系统三个轨道周期的协调监测，首次确立并校准了中红外氢复合线作为原行星盘吸积光度诊断指标，并据此为 38 个已发表的原行星盘 MRS 光谱档案样本提供了吸积光度。
We investigate the kinematic evolution of planetesimals in self-gravitating discs, combining Smoothed Particle Hydrodynamical (SPH) simulations of the disc gas with a gravitationally coupled population of test particle planetesimals. We find that at radii of 10s of au (which is where we expect planetesimals to be possibly formed in such discs) the planetesimals' eccentricities are rapidly pumped to values $>$ 0.1 within the timescales for which the disc is in the self-gravitating regime. The high resulting velocity dispersion and the lack of planetesimal concentration in the spiral arms means …
We present ALMA Band 6 observations of a complete sample of protoplanetary disks in the young (1-3 Myr) Lupus star-forming region, covering the 1.33 mm continuum and the 12CO, 13CO, and C18O J=2-1 lines. The spatial resolution is 0.25 arcsec with a medium 3-sigma continuum sensitivity of 0.30 mJy, corresponding to M_dust ~ 0.2 M_earth. We apply "Keplerian masking" to enhance the signal-to-noise ratios of our 12CO zero-moment maps, enabling measurements of gas disk radii for 22 Lupus disks; we find that gas disks are universally larger than mm dust disks by a factor of two on average, likely du…
Ortho-Para Chemistry of H2CO in the Protoplanetary Disk TW Hya
Université Grenoble Alpes（格勒诺布尔阿尔卑斯大学）；CNRS（法国国家科学研究中心）；Korea Astronomy and Space Science Institute（韩国天文学与空间科学研究院）；National Astronomical Observatory of Japan（日本国立天文台）；RIKEN Pioneering Research Institute（理化学研究所前沿研究机构）
High spatial resolution CO observations of mid-inclination (30-75°) protoplanetary disks offer an opportunity to study the vertical distribution of CO emission and temperature. The asymmetry of line emission relative to the disk major axis allows for a direct mapping of the emission height above the midplane, and for optically-thick, spatially-resolved emission in LTE, the intensity is a measure of the local gas temperature. Our analysis of ALMA archival data yields CO emission surfaces, dynamically-constrained stellar host masses, and disk atmosphere gas temperatures for the disks around: HD …
Theories of planet formation predict the birth of giant planets in the inner, dense, and gas-rich regions of the circumstellar disks around young stars. These are the regions from which strong CO emission is expected. Observations have so far been unable to confirm the presence of planets caught in formation. We have developed a novel method to detect a giant planet still embedded in a circumstellar disk by the distortions of the CO molecular line profiles emerging from the protoplanetary disk's surface. The method is based on the fact that a giant planet significantly perturbs the gas velocit…
Observations of protoplanetary disks provide information on planet formation and the reasons for the diversity of planetary systems. The key to understanding planet formation is the study of dust evolution from small grains to pebbles. Smaller grains are well-coupled to the gas dynamics, and their distribution is significantly extended above the disk midplane. Larger grains settle much faster and are efficiently formed only in the midplane. By combining near-infrared polarized light and millimeter observations, it is possible to constrain the spatial distribution of both the small and large gr…
