Ruobing Dong
A5007809754- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Molecular Spectroscopy and Structure
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Thermodynamic properties of mixtures
- Advanced Thermodynamic Systems and Engines
- Spectroscopy and Laser Applications
- Space Exploration and Technology
- Solar and Space Plasma Dynamics
- High-pressure geophysics and materials
- Spacecraft and Cryogenic Technologies
- Calibration and Measurement Techniques
- Atmospheric Ozone and Climate
- Astrophysics and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Planetary Science and Exploration
- Particle Accelerators and Free-Electron Lasers
- Phase Equilibria and Thermodynamics
- Medical Imaging Techniques and Applications
- Geography and Environmental Studies in Latin America
University of Victoria
2018-2024
Kavli Institute for Theoretical Sciences
2010-2024
Peking University
2007-2024
University of California, Berkeley
2014-2023
Kean University
2023
Wake Forest University
2023
Institute of Astronomy and Astrophysics, Academia Sinica
2016-2023
Shanghai Jiao Tong University
2023
University of Arizona
2017-2021
Center for Excellence in Molecular Cell Science
2019
An exoplanet extracted from the bright Direct imaging of Jupiter-like exoplanets around young stars provides a glimpse into how our solar system formed. The brightness requires use next-generation devices such as Gemini Planet Imager (GPI). Using GPI, Macintosh et al. discovered planet orbiting star, 51 Eridani (see Perspective by Mawet). planet, Eri b, has methane signature and is probably smallest that been directly imaged. These findings open door to understanding origins herald dawn new...
We present high-resolution, H-band, imaging observations, collected with Subaru/HiCIAO, of the scattered light from transitional disk around SAO 206462 (HD 135344B). Although previous sub-mm imagery suggested existence dust-depleted cavity at r~46AU, our observations reveal presence components as close 0.2" (~28AU) star. Moreover, we have discovered two small-scale spiral structures lying within 0.5" (~70AU). models for using density wave theory, and derive a aspect ratio h~0.1, which is...
By carrying out two-dimensional two-fluid global simulations, we have studied the response of dust to gap formation by a single planet in gaseous component protoplanetary disk—the so-called filtration mechanism. We found that opened giant at 20 AU an α = 0.01, disk can effectively stop particles larger than 0.1 mm drifting inward, leaving submillimeter (submm) cavity/hole. However, smaller are difficult filter induced several MJ due (1) diffusion and (2) high gas accretion velocity edge....
We present the first near-IR scattered light detection of transitional disk associated with Herbig Ae star MWC 758 using data obtained as part Strategic Exploration Exoplanets and Disks Subaru, 1.1 micron HST/NICMOS data. While sub-millimeter studies suggested there is a dust-depleted cavity r=0.35, we find close 0.1 (20-28 AU) from star, no visible at H, K', or Ks. two small-scaled spiral structures which asymmetrically shadow outer disk. model one spirals density wave theory, derive aspect...
Using 3D global hydro simulations coupled with radiative transfer calculations, we study the appearance of density waves induced by giant planets in direct imaging observations at near infrared wavelengths. We find that a 6 MJ planet typical disk around 1 M_sun star can produce prominent and detectable spiral arms both interior exterior to its orbit. The inner have (1) two well separated roughly m=2 symmetry, (2) exhibit ~10-15 degrees pitch angles, (3) ~180-270 extension azimuthal...
We investigate the observational signatures of super-Earths (i.e., Earth-to-Neptune mass planets) in their natal disks gas and dust. Combining two-fluid global hydrodynamics simulations with a radiative transfer code, we calculate distributions sub-mm-sized dust disk perturbed by super-Earth, synthesizing images near-infrared scattered light mm-wave thermal continuum for direct comparison observations. In low viscosity ($\alpha\lesssim10^{-4}$), super-Earth opens two annular gaps to either...
It has been suggested that the gaps and cavities recently discovered in transitional disks are opened by planets. To explore this scenario, we combine two-dimensional two fluid (gas + particle) hydrodynamical calculations with three-dimensional Monte Carlo Radiative Transfer simulations, study observational signatures of one or several planets, making qualitative comparisons observations. We find a single planet as small 0.2 MJ can produce deep gap at millimeter (mm) wavelengths almost no...
We present high resolution H-band polarized intensity (PI; FWHM = 0."1: 14 AU) and L'-band imaging data (FWHM 0."11: 15 of the circumstellar disk around weak-lined T Tauri star PDS 70 in Centaurus at a radial distance 28 AU (0."2) up to 210 (1."5). In both images, giant inner gap is clearly resolved for first time, radius ~70 AU. Our show that geometric center shifts by ~6 toward minor axis. confirm brown dwarf companion candidate north background based on its proper motion. As result SED...
Abstract Spatially resolved structures in protoplanetary disks hint at unseen planets. Previous imaging observations of the transitional disk around MWC 758 revealed an inner cavity, a ring-like outer disk, emission clumps, and spiral arms, all possibly generated by companions. We present ALMA dust continuum 0.87 mm wavelength with 43 × 39 mas angular resolution (6.9 6.2 au) 20 μ Jy beam −1 rms. The central submillimeter cavity is to be eccentric; once deprojected, its edge can well fitted...
Transitional circumstellar disks around young stellar objects have a distinctive infrared deficit 10 μm in their spectral energy distributions, recently measured by the Spitzer Infrared Spectrograph (IRS), suggesting dust depletion inner regions. These been confirmed to giant central cavities imaging of submillimeter continuum emission using Submillimeter Array (SMA). However, polarized near-infrared scattered light images for most systematic IRS/SMA cross sample, obtained HiCIAO on Subaru...
We present optical and near-infrared high contrast images of the transitional disk HD 100546 taken with Magellan Adaptive Optics system (MagAO) Gemini Planet Imager (GPI). GPI data include both polarized intensity total imagery, MagAO are in Simultaneous Differential Imaging mode at H{\alpha}. The new H -band represent a significant enhancement sensitivity field rotation compared to previous sets enable detailed exploration substructure disk. processed variety differential imaging techniques...
Direct imaging observations have revealed spiral structures in protoplanetary disks. Previous studies suggested that planet-induced arms cannot explain some of these patterns, due to the large pitch angle and high contrast observations. We carried out three-dimensional (3D) hydrodynamical simulations study wakes/shocks excited by young planets. find that, with linear theory, does depend on planet mass, which can be explained nonlinear density wave theory. A secondary (or even a tertiary)...
ALMA has found multiple dust gaps and rings in a number of protoplanetary disks continuum emission at millimeter wavelengths. The origin such structures is debate. Recently, we documented how one super-Earth planet can open (up to five) disk with low viscosity ($\alpha\lesssim10^{-4}$). In this paper, examine the positions, depths, total opened by depend on input parameters, apply our results real systems. Gap locations (equivalently, spacings) are easiest metric use when making comparisons...
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 direct images at near-infrared (NIR) wavelengths. We find that systems with disk-to-star-mass ratios q=M_disk/M_star are ~0.25 or more may produce prominent arms NIR imaging, remarkably resembling features observed MWC 758 SAO 206462 systems. The contrast...
We present the first scattered light detections of HD 106906 debris disk using Gemini/Gemini Planet Imager in infrared and Hubble Space Telescope (HST)/Advanced Camera for Surveys optical. is a 13 Myr old F5V star Sco–Cen association, with previously detected planet-mass candidate 106906b projected 650 AU from host star. Our observations reveal near edge-on that has central cleared region radius ∼50 AU, an outer extent >500 AU. The HST data show regions are highly asymmetric, resembling...
Two studies utilizing sparse aperture masking (SAM) interferometry and $H_{\rm \alpha}$ differential imaging have reported multiple jovian companions around the young solar-mass star, LkCa 15 (LkCa bcd): first claimed direct detection of infant, newly-formed planets ("protoplanets"). We present new near-infrared imaging/spectroscopy from SCExAO system coupled with CHARIS integral field spectrograph multi-epoch thermal infrared Keck/NIRC2 at high Strehl ratios. These data provide look same...
ABSTRACT Direct imaging observations of protoplanetary disks at near-infrared (NIR) wavelengths have revealed structures potentially planetary origin. Investigations observational signatures from planet-induced features so far focused on viewed face-on. Combining 3D hydrodynamics and radiative transfer simulations, we study how the appearance spiral arms gap produced in a disk by companion varies with inclination position angle NIR scattered light. We compare cases 3 M J 0.1 ⊙ companion,...
Abstract We report the results of a ∼4 yr direct imaging survey 104 stars to resolve and characterize circumstellar debris disks in scattered light as part Gemini Planet Imager (GPI) Exoplanet Survey. targeted nearby (≲150 pc), young (≲500 Myr) with high infrared (IR) excesses ( L IR / ⋆ > 10 −5 ), including 38 previously resolved disks. Observations were made using GPI high-contrast integral field spectrograph H -band (1.6 μ m) coronagraphic polarimetry mode measure both polarized total...
Abstract Since the discovery of multiring structure HL Tau disk, ALMA data suggest that dust continuum emission many, if not all, protoplanetary disks consists rings and gaps, no matter their spectral type or age. The origin these gaps so far remains unclear. We present a sample study 16 with multiple ring-like structures in continuum, using published archival data, to compare morphologies gap locations systematic way. targets range from early- late-type stars, <0.5 Myr >10 ∼0.2 40 L ⊙...
In recent years, the disk populations in a number of young star-forming regions have been surveyed with ALMA. Understanding properties and their correlation those central star is critical to understand planet formation. particular, decrease average measured dust mass age region has observed. We conducted high-sensitivity continuum ALMA observations 43 Class II stellar objects CrA at 1.3 mm (230 GHz). The typical spatial resolution 0.3". fluxes are used estimate masses disks, survival...
We have updated our publicly available dust radiative transfer code (HOCHUNK3D) to include new emission processes and various 3-D geometries appropriate for forming stars. The warps spirals in disks, accretion hotspots on the central star, fractal clumping density enhancements, misaligned inner disks. Additional axisymmetric (2-D) features gaps disks envelopes, "puffed-up rims" multiple bipolar cavity walls, iteration of disk vertical structure assuming hydrostatic equilibrium. option simple...
Through detailed radiative transfer modeling, we present a disk+cavity model to simultaneously explain both the spectral energy distribution (SED) and Subaru H-band polarized light imaging for pre-transitional protoplanetary disk PDS 70. In particular, are able match not only radial dependence but also absolute scale of surface brightness scattered light. Our has cavity 65 AU in radius, which is heavily depleted sub-micron-sized dust grains, small residual inner that produces weak still...
We report high-resolution (0.07 arcsec) near-infrared polarized intensity images of the circumstellar disk around star 2MASS J16042165-2130284 obtained with HiCIAO mounted on Subaru 8.2 m telescope. present our $H$-band data, which clearly exhibits a resolved, face-on large inner hole for first time at infrared wavelengths. detect centrosymmetric polarization pattern in material as has been observed other disks. Elliptical fitting gives semimajor axis, semiminor and position angle (P.A.) 63...