UA Science

You are here

Understanding the Spiral Structure in HD100453A's Protoplanetary Disk

In a new paper Kevin Wagner et al. report on the disk structure and evolution in a spiral protoplanetary disk hosting binary. (Steward astronomers on this paper are Wagner, Ruobing Dong, Patrick Sheehan, Dániel Apai, Katie Morzinski, Laird Close, Jared Males, and Phil Hinz.)This disk represents one of only a few “grand-design” (two-armed) spiral protoplanetary disks, the only one in which a low-mass companion has also been detected. Wagner et al. present the first constraints on the companion’s orbit, utilizing data from VLT/NACO, VLT/SPHERE, and Magellan/MagAO. They also constrain the disk inclination from ALMA observations and gas kinematic modeling: the companion’s orbital semi-major axis (105±15 au) is 3-4 times greater than the observed extent of the disk; the companion orbits in the same plane of the disk to within measurable limits (±10º) on a low eccentricity orbit (e<0.3), in accordance with a classical disk truncation scenario. Utilizing these constraints on the system geometry in combined hydrodynamic and radiative transfer simulations, they find in all cases that the companion generates a prominent two-armed spiral pattern in the simulated disk imaging that is in good agreement with the observed spiral disk structure. This system represents a benchmark in understanding the formation of spiral arms in protoplanetary disks, and has implications for on-going planet searches in the other similar disks that do not host binary companions, but nevertheless host similar spiral features. The figure (with an enlarged version in the linked press release) shows observations on the left and the model on the right.

A summary of this paper (ApJ, 854, 130 (2018) can be found on AAS NOVA and on Astrobites.

(Thanks to Kevin Wagner for text.) 

For the public
For Public

Public events include our Monday Night Lecture Series, world-reknowned Astronomy Camp and Mt Lemmon Sky Center.

For Students

A good place to start if you want to become an undergrad major or grad student, or need to find our schedule of classes.

 

For Scientists
For Scientists

Find telescopes and instruments, telescope time applications, staff and mountain contacts, and faculty and staff scientific interests.