disk of O/WR stars
+ distinct from S stars: circular-ish orbits
binary disruption formation of S-stars
+ hypervelocity ejected star
+ other star has eccentricity > 0.98
further stars?
+ "memory" of initial eccentricity "stored" at large radii
+ relaxation times increase
+ can't measure eccentricity directly because of long orbital timescales
Simulations of young stars orbiting
+ initial high eccentricity (disruption formation)
+ initial low eccentricity (disk formation)
Depending on the stellar mass, both origins are possible.
+ lower masses better fit for disruption mechanism
IMF in disk
+ different formation mechanism would imply they should not be included in IMF measurements
start in eccentric, relax into circular
+ depends on density profile
+ can infer density profile
"h-statistic"
+ angular momentum vector = ±1 if circular orbit, 0 on plunging "orbit"
+ degeneracy between inclination and eccentricity
"special purpose" n-body code
+ high-mass stars consistent with disk
+ low-mass stars more like binary disruption
implies top-heavier IMF
Questions
Q Cuadra: What tells you about the cuspiness? Precession?
A: Yes. Orbits closer to black hole have long precession scales. Leads to
more rapid change in eccentricity (and less precession).
Q: What is timescale for thermalization to eccentricity?
