Title:
Eccentric Tidal Disruption Event Disks around Supermassive Black Holes: 
Dynamics and Thermal Emission

Abstract:
After the Tidal Disruption Event (TDE) of a star around 
a SuperMassive Black Hole (SMBH), an accretion disk rapidly 
forms from the stellar debris on highly elliptical trajectories. 
If the newly formed accretion disk remains eccentric with 
a radial extent much larger than the tidal radius, hydrodynamic simulations 
and order-of-magnitude arguments suggest many optical 
TDE candidate effective temperatures, blackbody emission radii, 
and bolometric luminocities can be explained by thermal emission 
from the TDE disk. Using a secular theory for a hydrodynamical disk with 
non-linear eccentric disturbances mediated by pressure, 
we study the dynamics and thermal emission from highly-eccentric disks 
formed after TDEs. We calculate the properties of uniformly precessing 
apsidally-aligned non-linear eccentric modes, and find slowly-precessing 
coherent eccentric modes exist for feasible models of newly-formed TDE disks, 
even under the influence of general-relativistic apsidal precession from the SMBH. 
Taking into account the vertical structure of an accretion disk on a highly eccentric orbit, 
we find the thermal emission from eccentric TDE disks can explain 
the effective temperatures, blackbody emission radii, 
and bolometric luminocities of many optical TDE candidates. 
Our work lends support to theories which argue optical TDE emission is powered by 
energy liberated during the circularization process, rather than accretion of 
material onto the SMBH.