The Structure of Spiral Shocks Excited by Planetary-Mass Companions

Zhu, Zhaohuan; Dong, Ruobing; Stone, James M.; Rafikov, Roman R.

doi:10.1088/0004-637x/813/2/88

Cited by 214 publications

(282 citation statements)

References 42 publications

Supporting

Mentioning

255

Contrasting

Order By: Relevance

“…These studies have revealed spiral arms in a growing number of disks (Figure 1), both prominent near-symmetric twoarm spirals (e.g., Grady et al 2013;Benisty et al 2015) and more flocculent multiarm spirals on smaller scales and at lower contrast (e.g., Fukagawa et al 2004;Hashimoto et al 2011). Spiral arms can be produced by either gravitational instability (e.g., Rice et al 2003;Lodato & Rice 2004;Stamatellos & Whitworth 2008;Kratter et al 2010;Kratter & Lodato 2016) or the presence of massive companions (gas giant to stellar masses; e.g., Kley & Nelson 2012;Zhu et al 2015;Muñoz & Lai 2016).…”

Section: Introductionmentioning

confidence: 99%

Spiral Arms in Disks: Planets or Gravitational Instability?

Dong

Najita

Brittain

2018

ApJ

Self Cite

View full text Add to dashboard Cite

Spiral arm structures seen in scattered-light observations of protoplanetary disks can potentially serve as signposts of planetary companions. They can also lend unique insights into disk masses, which are critical in setting the mass budget for planet formation but are difficult to determine directly. A surprisingly high fraction of disks that have been well studied in scattered light have spiral arms of some kind (8/29), as do a high fraction (6/11) of wellstudied Herbig intermediate-mass stars (i.e., Herbig stars >1.5 M e ). Here we explore the origin of spiral arms in Herbig systems by studying their occurrence rates, disk properties, and stellar accretion rates. We find that two-arm spirals are more common in disks surrounding Herbig intermediate-mass stars than are directly imaged giant planet companions to mature A and B stars. If two-arm spirals are produced by such giant planets, this discrepancy suggests that giant planets are much fainter than predicted by hot-start models. In addition, the high stellar accretion rates of Herbig stars, if sustained over a reasonable fraction of their lifetimes, suggest that disk masses are much larger than inferred from their submillimeter continuum emission. As a result, gravitational instability is a possible explanation for multiarm spirals. Future observations can lend insights into the issues raised here.

show abstract

Section: Introductionmentioning

confidence: 99%

Spiral Arms in Disks: Planets or Gravitational Instability?

Dong

Najita

Brittain

2018

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…3D hydrodynamical simulations of Zhu et al (2015) and Dong et al (2015) have shown that a massive planet of a few Jupiter mass in the outer regions would produce a pair of inner spiral arms, whose brightness and large pitch angle are compatible with the near-IR observations. Recent simulations of Bae et al (2017) have also shown that, for a disk with low viscosity (i. e. α ∼ 10 −4 ), a massive planet can also produce a secondary gap in the inner regions of the planet orbit.…”

Section: Possible Scenariosmentioning

confidence: 81%

The Complex Morphology of the Young Disk MWC 758: Spirals and Dust Clumps around a Large Cavity

Boehler

Ricci

Weaver

et al. 2018

ApJ

126

View full text Add to dashboard Cite

We present Atacama Large Millimeter Array (ALMA) observations at an angular resolution of 0.1 -0.2 of the disk surrounding the young Herbig Ae star MWC 758. The data consist of images of the dust continuum emission recorded at 0.88 millimeter, as well as images of the 13 CO and C 18 O J = 3-2 emission lines. The dust continuum emission is characterized by a large cavity of roughly 40 au in radius which might contain a mildly inner warped disk. The outer disk features two bright emission clumps at radii of ∼ 47 and 82 au that present azimuthal extensions and form a double-ring structure. The comparison with radiative transfer models indicates that these two maxima of emission correspond to local increases in the dust surface density of about a factor 2.5 and 6.5 for the south and north clumps, respectively. The optically thick 13 CO peak emission, which traces the temperature, and the dust continuum emission, which probes the disk midplane, additionally reveal two spirals previously detected in near-IR at the disk surface. The spirals seen in the dust continuum emission present, however, a slight shift of a few au towards larger radii and one of the spirals crosses the south dust clump. Finally, we present different scenarios in order to explain the complex structure of the disk.

show abstract

“…Protoplanet solutions inside the scattered light cavity seem unlikely because the spiral arm pitch angles would require unphysical disk temperatures. -The surface brightness contrast and symmetry of the spiral arms indicate that a single massive protoplanet might have excited both the primary and secondary spiral arm interior of its orbit Zhu et al 2015;Fung & Dong 2015), however no gap is detected in scattered light beyond the spiral arms up to 1. 0.…”

Section: Discussionmentioning

confidence: 99%

“…Interference of different azimuthal modes results in a one-armed spiral which can be approximated with linear perturbation theory when M p /M * (H(r)/r) 3 , where M p is the mass of the protoplanet, M * the stellar mass, H(r) the pressure scale height, and r the disk radius. Higher order perturbation terms become important when M p /M * ∼ (H(r)/r) 3 which can lead to the presence of secondary spiral arm (Juhász et al 2015;Zhu et al 2015).…”

Section: Spiral Arms As Tracers Of Protoplanetsmentioning

confidence: 99%

“…However, it was assumed that each spiral arm is excited by an individual low-mass, M p /M * 10 −3 , planet. Several authors have shown, using 3D hydrodynamical and radiative transfer simulations, that a massive, M p /M * 6 × 10 −3 , protoplanet in the exterior of the disk will excite both the m = 1 and m = 2 spiral arm with a morphology, pitch angle, and surface brightness contrast similar to HD 135344B and MWC 758 Zhu et al 2015;Fung & Dong 2015). A kink is visible in the S1 spiral arm (see Fig.…”

Section: The Origin Of the Spiral Armsmentioning

confidence: 99%

See 1 more Smart Citation

Shadows cast on the transition disk of HD 135344B

Stolker

Dominik

Avenhaus

et al. 2016

A&A

162

124

View full text Add to dashboard Cite

Context. The protoplanetary disk around the F-type star HD 135344B (SAO 206462) is in a transition stage and shows many intriguing structures both in scattered light and thermal (sub-)millimeter emission which are possibly related to planet formation processes. Aims. We aim to study the morphology and surface brightness of the disk in scattered light to gain insight into the innermost disk regions, the formation of protoplanets, planet-disk interactions traced in the surface and midplane layers, and the dust grain properties of the disk surface. Methods. We have carried out high-contrast polarimetric differential imaging (PDI) observations with VLT/SPHERE and obtained polarized scattered light images with ZIMPOL in the R and I-bands and with IRDIS in the Y and J-bands. The scattered light images and surface brightness profiles are used to study in detail structures in the disk surface and brightness variations. We have constructed a 3D radiative transfer model to support the interpretation of several detected shadow features. Results. The scattered light images reveal with unprecedented angular resolution and sensitivity the spiral arms as well as the 25 au cavity of the disk. Multiple shadow features are discovered on the outer disk with one shadow only being present during the second observation epoch. A positive surface brightness gradient is observed in the stellar irradiation corrected (r 2 -scaled) images in southwest direction possibly due to an azimuthally asymmetric perturbation of the temperature and/or surface density by the passing spiral arms. The disk integrated polarized flux, normalized to the stellar flux, shows a positive trend towards longer wavelengths which we attribute to large (2πa λ) aggregate dust grains in the disk surface. Part of the non-azimuthal polarization signal in the U φ image of the J-band observation can be attributed to multiple scattering in the disk. Conclusions. The detected shadow features and their possible variability have the potential to provide insight into the structure of and processes occurring in the innermost disk regions. Possible explanations for the presence of the shadows include a 22 • misaligned inner disk, a warped disk region that connects the inner disk with the outer disk, and variable or transient phenomena such as a perturbation of the inner disk or an asymmetric accretion flow. The spiral arms are best explained by one or multiple protoplanets in the exterior of the disk although no gap is detected beyond the spiral arms up to 1. 0.

show abstract

The Structure of Spiral Shocks Excited by Planetary-Mass Companions

Cited by 214 publications

References 42 publications

Spiral Arms in Disks: Planets or Gravitational Instability?

Spiral Arms in Disks: Planets or Gravitational Instability?

The Complex Morphology of the Young Disk MWC 758: Spirals and Dust Clumps around a Large Cavity

Shadows cast on the transition disk of HD 135344B

Contact Info

Product

Resources

About