Nienke van der Marel in collaboration with Paolo Cazzoletti, Paola Pinilla, Antonio Garufi

Beatrice Watson Parrent Fellow IfA, University of Hawaii

May 18 2016 *a.k.a. SAO206462

Spirals and vortices in HD135344B*

evidence for triggered planet formation?

HD135344B• F4 star, 140 pc • mm-dust cavity ~40 AU • small dust grains/gas ~ 30 AU • Proposed scenario:

Clearing by a planet + trapping of the mm-dust

• Spiral armsBrown et al. 2007, 2009

Perez et al. 2014 vd Marel et al. 2015, 2016

Pinilla et al. 2015 Muto et al. 2012 Garufi et al 2013

Stolker et al. 2016

HD135344B: SMA (335GHz)

Brown et al. 2009

0.47x0.25” S/N ~ 13

HD135344B: ALMA B9 (690GHz)

Perez et al. 2014

0.27x0.19” S/N ~ 160

van der Marel et al. 2016

0.26x0.21” S/N ~ 180

HD135344B: ALMA B7 (330GHz)

van der Marel et al. 2016

0.26x0.21” S/N ~ 180

HD135344B: ALMA B7 (330GHz)

Briggs weighting robust=0.5

van der Marel et al. in revision

0.20x0.15” S/N ~ 120

Superuniform weighting

ring + asymmetry?

HD135344B: ALMA B7 (330GHz)

Link with spiral arms?

van der Marel et al. in revision Garufi et al. 2013

PDI VLT/NACO Ks (2.2 μm)

Link with spiral arms?

mm-dust feature is coradial: does not follow spiral structure

brightest ALMA dpbrightest NACO dp

Link with spiral arms?

• Theoretical point of view: hard to explain as well!

• Spiral arms triggered by planets:

• variations in scale height, not density: invisible in (sub)mm

• Spiral arms due to gravitational instability:

• Disk mass (mm-dust, CO isotopologues) too low

Juhasz et al. 2015, Pohl et al. 2015, Lodato & Rice 2004, diPierro et al. 2015, Dong et al. 2015, Zhu et al. 2015

Alternative: ring+vortex?

• Fit ring+asymmetry (2D Gaussian, vortex description Lyra & Lin 2013)

• Primary vortex at planet gap edge triggers secondary vortex in the outer disk (Lobo-Gomes et al. 2015)

Vortex triggers spiral?

Spiral arms have launching points at planet and vortex locations

F1

F2

S2

S1

1. A planet is formed at 30 AU 2a. Inner dust trap due to planet gap

3. Secondary vortex dust trap triggered by inner ring

2b. Planet triggers spiral arm outwards

4. Vortex triggers second spiral arm inwards

Vortex+spiral?

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Problems & predictions• Problems

• Spiral arms symmetric, but moving at different speeds: likelihood of observing them at this time?

• Spiral arms cause shadowing: influence on mm emission? • Spiral density wave equation not physical

• Test predictions • Find the planet(s) • Vortex traps dust azimuthally: high-res mm/cm wavelengths • Spiral arms move at speeds launching points: re-observe

scattered light in ~5 years

Is it a spiral?