A5062528291- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Molecular Spectroscopy and Structure
- Stellar, planetary, and galactic studies
- Atmospheric Ozone and Climate
- Astronomy and Astrophysical Research
- Advanced Chemical Physics Studies
- Spectroscopy and Laser Applications
- Spacecraft and Cryogenic Technologies
- Astrophysical Phenomena and Observations
- Phase Equilibria and Thermodynamics
- Calibration and Measurement Techniques
- Statistical and numerical algorithms
- Astrophysics and Cosmic Phenomena
- Space Exploration and Technology
- Inertial Sensor and Navigation
- High-pressure geophysics and materials
- Atmospheric and Environmental Gas Dynamics
- Advanced Sensor and Energy Harvesting Materials
- Pain Management and Placebo Effect
- Semiconductor materials and devices
- Geophysics and Gravity Measurements
- E-commerce and Technology Innovations
- Astronomical Observations and Instrumentation
- Innovative Educational Techniques
University of Michigan
1982-2024
South University
2021-2024
Columbia University
2023-2024
Center for Astrophysics Harvard & Smithsonian
2015-2022
National Center for Complementary and Integrative Health
2020
University of Virginia
2020
Guangzhou University
2019
Harvard University Press
2018
Institute of High Energy Physics
2018
Chinese Academy of Sciences
2018
We introduce the Disk Substructures at High Angular Resolution Project (DSHARP), one of initial Large Programs conducted with Atacama Millimeter/submillimeter Array (ALMA). The primary goal DSHARP is to find and characterize substructures in spatial distributions solid particles for a sample 20 nearby protoplanetary disks, using very high resolution (0.035 arcsec, or 5 au FWHM) observations their 240 GHz (1.25 mm) continuum emission. These data provide first homogeneous look small-scale...
Abstract The Disk Substructures at High Angular Resolution Project (DSHARP) used ALMA to map the 1.25 mm continuum of protoplanetary disks a spatial resolution ∼5 au. We present systematic analysis annular substructures in 18 single-disk systems targeted this survey. No dominant architecture emerges from sample; instead, remarkably diverse morphologies are observed. Annular can occur virtually any radius where millimeter emission is detected and range widths few astronomical units tens...
Abstract The Disk Substructures at High Angular Resolution Project (DSHARP) provides a large sample of protoplanetary disks with substructures that could be induced by young forming planets. To explore the properties planets may responsible for these substructures, we systematically carry out grid 2D hydrodynamical simulations, including both gas and dust components. We present resulting structures, relationship between planet mass, as well (1) gaseous gap depth/width (2) sub/super-Keplerian...
A large fraction of the protoplanetary disks observed with ALMA display multiple well-defined and nearly perfectly circular rings in continuum, many cases substantial peak-to-valley contrast. The DSHARP campaign shows that several these are very narrow radial extent. In this paper we test hypothesis dust caused by trapping pressure bumps, if confirmed, put constraints on physics mechanism. We model process analytically 1D, assuming axisymmetry. By comparing to data, find all consistent...
Planets form and obtain their compositions in dust gas-rich disks around young stars, the outcome of this process is intimately linked to disk chemical properties. The distributions molecules across regulate elemental planets, including C/N/O/S ratios metallicity (O/H C/H), as well access water prebiotically relevant organics. Emission from also encodes information on ionization levels, temperature structures, kinematics, gas surface densities, which are all key ingredients evolution planet...
Abstract Atacama Large Millimeter Array (ALMA) surveys have suggested that the dust in Class II disks may not be enough to explain averaged solid mass exoplanets, under assumption mm disk continuum emission is optically thin. This thin seems supported by recent Disk Substructures at High Angular Resolution Project (DSHARP) observations where measured optical depths are mostly less than one. However, we point out scattering can considerably reduce from an thick region. If ignored, with...
We present evidence for localised deviations from Keplerian rotation, i.e., velocity "kinks", in 8 of 18 circumstellar disks observed by the DSHARP program: DoAr 25, Elias 2-27, GW Lup, HD 143006, 163296, IM Sz 129 and WaOph 6. Most kinks are detected over a small range both radial extent velocity, suggesting planetary origin, but some them foreground contamination prevents us measuring their spatial extent. Because limited spectral resolution signal-to-noise 12CO J=2-1 line, as well cloud...
Here we present high resolution (15-24 au) observations of CO isotopologue lines from the Molecules with ALMA on Planet-forming Scales (MAPS) Large Program. Our analysis employs $^{13}$CO and C$^{18}$O ($J$=2-1), (1-0), C$^{17}$O (1-0) line five protoplanetary disks. We retrieve gas density distributions, using three independent methods: (1) a thermo-chemical modeling framework based data, broadband spectral energy distribution, mm-continuum emission; (2) an empirical temperature...
Abstract We analyze high angular resolution ALMA observations of the TW Hya disk to place constraints on CO and dust properties. present new, sensitive 12 J = 3 − 2 line at a spatial 8 au (0.″14). The emission exhibits bright inner core, shoulder r ≈ 70 au, prominent break in slope 90 au. Radiative transfer modeling is used demonstrate that morphology can be reasonably reproduced with column density profile featuring steep decrease 15 secondary bump peaking Similar features have been...
The deuterium enrichment of molecules is sensitive to their formation environment. Constraining patterns chemistry in protoplanetary disks therefore useful for probing how material inherited or reprocessed throughout the stages star and planet formation. We present ALMA observations at $\sim0.6"$ resolution DCO$^+$, H$^{13}$CO$^+$, DCN, H$^{13}$CN full around T Tauri stars AS 209 IM Lup, transition V4046 Sgr LkCa 15, Herbig Ae MWC 480 HD 163296. also HCN Lup disk. H$^{13}$CO$^+$ are detected...
ABSTRACT The spatial distribution of gas and solids in protoplanetary disks determines the composition formation efficiency planetary systems. A number show starkly different distributions for small grains compared to millimeter–centimeter-sized dust. We present new Atacama Large Millimeter/Submillimeter Array observations dust continuum, CO, 13 C 18 O IM Lup disk, one first systems where this dust–gas dichotomy was clearly seen. 12 CO is detected out a radius 970 au, while millimeter...
Abstract The Molecules with ALMA at Planet-forming Scales Large Program (MAPS LP) surveyed the chemical structures of five protoplanetary disks across more than 40 different spectral lines high angular resolution (0.″15 and 0.″30 beams for Bands 6 3, respectively) sensitivity (spanning 0.3–1.3 mJy beam −1 0.4–1.9 respectively). In this article, we describe multistage workflow—built around CASA tclean image deconvolution procedure—that used to generate core data product MAPS LP:...
The Molecules with ALMA at Planet-forming Scales (MAPS) Large Program provides a unique opportunity to study the vertical distribution of gas, chemistry, and temperature in protoplanetary disks around IM Lup, GM Aur, AS 209, HD 163296, MWC 480. By using asymmetry molecular line emission relative disk major axis, we infer height ($z$) above midplane as function radius ($r$). Using this method, measure emitting surfaces for suite CO isotopologues, HCN, C$_2$H. We find that $^{12}$CO traces...
The Disk Substructures at High Angular Resolution Project (DSHARP) is the largest homogeneous high-resolution ($\sim 0.035$ arcsec, or $\sim$ 5 au) disk continuum imaging survey with ALMA so far. In coming years, many more disks will be mapped similar resolution. Interpreting results in terms of properties and quantities emitting dusty material is, however, a very non-trivial task. This part due to uncertainty dust opacities, an which not likely resolved any time soon. It also partly fact...
The Molecules with ALMA at Planet-forming Scales (MAPS) Large Program provides a detailed, high resolution (${\sim}$10-20 au) view of molecular line emission in five protoplanetary disks spatial scales relevant for planet formation. Here, we present systematic analysis chemical substructures 18 lines toward the MAPS sources: IM Lup, GM Aur, AS 209, HD 163296, and MWC 480. We identify more than 200 substructures, which are found nearly all radii where is detected. A wide diversity radial...
Constraining dust properties of planet-forming disks via high angular resolution observations is fundamental to understanding how solids are trapped in substructures and growth may be favored or accelerated therein. We use ALMA continuum the Molecules with at Planet-forming Scales (MAPS) explore a large parameter space constrain radial distribution solid mass maximum grain size each disk, including excluding scattering. In nonscattering model, surface density profiles decrease from inner...
The protoplanetary disk around the T Tauri star GM Aur was one of first hypothesized to be in midst being cleared out by a forming planet. As result, has had an outsized influence on our understanding structure and evolution. We present 1.1 2.1 mm ALMA continuum observations at resolution ~50 mas (~8 au), as well HCO$^+$ $J=3-2$ ~100 mas. dust shows least three rings atop faint, extended emission. Unresolved emission is detected center cavity both wavelengths, likely due combination...
Abstract We explore the dynamical structure of protoplanetary disks surrounding HD 163296 and MWC 480 as part Molecules with ALMA at Planet-forming Scales (MAPS) large program. Using J = 2–1 transitions 12 CO, 13 C 18 O imaged spatial resolutions ∼0.″15 a channel spacing 200 m s −1 , we find perturbations from Keplerian rotation in projected velocity fields both (≲5% local velocity), suggestive large-scale (tens astronomical units size), coherent flows. By accounting for azimuthal dependence...
Abstract Gas-rich circumstellar disks are the cradles of planet formation. As such, their evolution will strongly influence resulting population. In ESO DESTINYS large program, we study these within first 10 Myr development with near-infrared scattered-light imaging. Here present VLT/SPHERE polarimetric observations nearby class II system SU Aur in which resolve disk down to scales ∼7 au. addition new SPHERE observations, utilize VLT/NACO, HST/STIS, and ALMA archival data. The data show...
The elemental composition of the gas and dust in a protoplanetary disk influences compositions planets that form it. We use Molecules with ALMA at Planet-forming Scales (MAPS) data to constrain locations potentially forming planets. abundances are inferred by comparing source-specific gas-grain thermochemical models, variable C/O ratios small-grain abundances, from DALI code CO C2H column densities derived high-resolution observations disks AS 209, HD 163296, MWC 480. Elevated (~2.0), even...
Abstract We report the discovery of a circumplanetary disk (CPD) candidate embedded in circumstellar T Tauri star AS 209 at radial distance about 200 au (on-sky separation 1.″4 from position angle 161°), isolated via 13 CO J = 2−1 emission. This is first instance CPD detection gaseous emission capable tracing overall mass. The spatially unresolved with 117 × 82 mas beam and manifests as point source CO, indicating that its diameter ≲14 au. within an annular gap previously identified using 12...
The sample of planet-forming disks observed by high-contrast imaging campaigns over the last decade is mature enough to enable demographical analysis individual star-forming regions. We present full census Taurus sources with VLT/SPHERE polarimetric images available. whole sums up 43 targets (of which 31 have not been previously published) corresponding one-fifth Class II population in and about half such objects that are observable. A large fraction apparently made isolated faint (equally...
Abstract We present MIRI Medium-resolution Spectrograph observations of the large, multi-gapped protoplanetary disk around T Tauri star AS 209. The reveal hundreds water vapor lines from 4.9–25.5 μ m toward inner ∼1 au in disk, including first detection rovibrational emission this disk. spectrum is dominated by hot (∼800 K) and OH gas, with only marginal detections CO 2 , HCN, a possible colder component. Using slab models detailed treatment opacities line overlap, we retrieve column...
Abstract We present an analysis of Atacama Large Millimeter/submillimeter Array 1.25 mm continuum observations spiral structures in three protoplanetary disks from the Disk Substructures at High Angular Resolution Project. The around Elias 27, IM Lup, and WaOph 6 were observed a resolution ∼40–60 mas (∼6–7 au). All feature m = 2 patterns conjunction with annular substructures. Gas kinematics established by 12 CO J 2−1 indicate that arms are trailing. arm–interarm intensity contrasts modest,...
We present a detailed analysis of new ALMA observations the disk around T-Tauri star HD 143006, which at 46 mas (7.6 au) resolution reveal substructures in 1.25 mm continuum emission. The resolves into series concentric rings and gaps together with bright arc exterior to that resembles hydrodynamics simulations vortex, bridge-like feature connecting two innermost rings. Although our $^{12}$CO similar spatial do not show obvious substructure, they an inner depleted CO From emission velocity...