1 / 1

Well mixed

CATP funded by. Dead Zones & the Diversity of Exoplanetary Systems. Yasuhiro Hasegawa & Ralph E Pudritz Dept. of Physics & Astronomy, McMaster University, Canada. Dust distribution Dead Zone. 1. Introduction: the Diversity of Exoplanetary System

baker-orr
Download Presentation

Well mixed

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CATP funded by Dead Zones & the Diversity of Exoplanetary Systems Yasuhiro Hasegawa & Ralph E Pudritz Dept. of Physics & Astronomy, McMaster University, Canada Dust distribution Dead Zone • 1. Introduction: the Diversity of Exoplanetary System • 2. The Problem: Dust Settling & Rapid Planetary Migration (NEW RESULTS!!) • a) Disk Structures b) Type I Migration c) Type II Migration • 3. Possible Solutions: Thermal Barriers Induced by Dead Zones • a) Disk Structures b) Temperature at the mid-plane c) Migration Time & Rate • 4. Next Step: Combination of Our Barriers with Density Barriers Gas + Dust distribution • the Mass-Period relation: all detected exoplanetary systems are consolidated • Many Hot Jupiters: gas giants with < 3day orbital periods (called Hot Jupiters)are piled up • the diversity: planetary masses & orbital periods days • (Udry & Santos 2007; http://exoplanet.eu) Well mixed Planetary Migration Potentially Explains Such Diversity Dust settling: ubiquitous for disks around any type of stars • Rapid planetary migration: • In standard disk models, the migration • timescale is times faster than • the disk life time ( years) • More rapid migration with dust settling: • Dust settling results in even more rapid • migration by up to a factor of about 2, • as a consequence of flatter disk structures • (Hasegawa & Pudritz, 2010c, submitted) • Two-layer disk structures: • Hasegawa & Pudritz, 2010a performed • Monte Carlo simulations, and showed • the hot surface and cool mid-plane • regions [1] • Flatter structures: • dust settling results in the hotter • surface &the cooler mid-plane • reducing the gap-opening mass • Dust settling decreases the gap- • opening mass by a factor of 2 • Even slower type II migration • Dust settling slows type II • migration by a factor of 2 • a dusty wall: (Hasegawa & Pudritz 2010a) • it is left at the boundary due to the • enhanced dust settling in the dead zone • a positive temperature gradient: • it is produced by the back heating of • the dead zone by such a hot wall • planets trapping: (Hasegawa & Pudritz 2010b) • such a temperature structure reverses the torque balance • Density Barriers: dead zones also provide density barriers at their outer boundary by piling up gas, as a result of • the viscous evolution (Matsumura, Pudritz, & Thommes 2009) • Expectations: these two barriers can play a significant role for planets with longer periods ( days ) References : [1] Chiang, E. I., & Goldreich, P. 1997, ApJ, 490, 368, Matsumura, S., Pudritz, R. E., & Thommes, E. W. 2009, ApJ, 691, 1764, Hasegawa, Y., & Pudritz, R. E. 2010a, MNRAS, 401, 143, Hasegawa, Y., & Pudritz, R. E. 2010b, ApJ, 710, L167, Hasegawa, Y., & Pudritz, R. E. 2010c, submitted

More Related