Misaligned disks induced by infall
Michael Küffmeier
C. P. Dullemond, F. Goicovic, S. Reißl
Stars are born and embedded in large assemblies of gas
Star-disk systems form and are located in different environments provided by Giant Molecular Clouds (Size: 10 - 100 pc)
Credit: ALMA (ESO/NAOJ/NRAO)
Heterogeneous accretion implies late infall
Küffmeier et al.
2017
Observational indication: luminosity bursts
Late infall
AB Aurigae
HD 100546
Credit: Grady+ 1999, Fukagawa+ 2004
Can (late) infall cause misalignment of inner and outer disk?
Credit: Ardila+ 2007
200 au
HD 142527
Credit: Avenhaus+ 2014
Extended arc-like structures can be induced by late infall
(Dullemond, Küffmeier, Goicovic+ 2019, Küffmeier, Goicovic & Dullemond 2020)
Possibility of "second-generation" disk
Shadows due to misaligned inner and outer disk
Credit: Marino+ 2015
Simulate cloudlet infall onto disk
AREPO, pure hydrodynamical
R_{\rm i,d}=50\, \rm au
\Sigma(r) = 170 \left(\frac{\rm g}{\rm cm}\right)^{2} \left( \frac{r}{1 \rm au} \right)^{-3/2}
M_{\rm cloudlet}(R_{\rm cloudlet}) = 0.01 {\rm M}_{\odot} \left( \frac{R_{\rm cloudlet}}{5000 \rm au}\right)^{2.3}
R_{\rm cloudlet} = 887\, \rm au
isothermal gas
vary infalling angle
\alpha = 0^{\circ} (35^{\circ}, 60^{\circ}, 90^{\circ})
b = 1774\, \rm au
vary rotation (prograde, retrograde)
Küffmeier, Dullemond, Reißl, Goicovic submitted
M_{*}=2.5\, \mathrm{M}_{\odot}
Outer disk forms around inner disk
Küffmeier+ subm
consistent with star formation simulations by Bate '18
Prograde vs. retrograde infall
Retrograde infall causes:
- counter-rotating inner and outer disk
- shrinking of inner disk
- enhanced accretion
- larger and deeper gap between disks
see also Vorobyov+ 2016
Effect of infall angle on disk
Formation of misaligned configuration
Observable as shadows in outer disk
Take-away points
In infall-induced misaligned systems, the outer disk is expected to have higher eccentricity than the inner disk.
Retrograde infall can cause counter-rotating disks, shrinking of inner disk, formation of gaps (>10 AU) and enhanced accretion.
TBC: zoom-in simulations to consistently account for replenishment of disks through streamers
WIP: study synthetic observations of infall-induced shadows
RGB image of misaligned system forming from infall with 60°
blue (1.66 micron), green (53 micron), red (870 micron); Credit: S. Reißl
AAS237
By kuffmeier
