The Origin of the Young Stars in the Nucleus of M31
Phil Chang


 The triple nucleus of M31 consists of a population of old red stars
 in an eccentric disk (P1 and P2) and another population of younger A
 stars in a circular disk (P3) around M31's central supermassive
 black hole (SMBH).  We argue that P1 and P2 determine the maximal
 radial extent of the younger A star population and provide the gas
 that fueled the starburst that generated P3.  The eccentric stellar
 disk creates an $m=1$ non-axisymmetric perturbation to the
 potential.  This perturbed potential drives gas into the inner
 parsec around the SMBH, if the pattern speed of the eccentric
 stellar disk is $\Omega_p \lesssim 3-10\,{\rm km\,s^{-1}\,pc^{-1}}$.
 We show that stellar mass loss from P1 and P2 is sufficient to
 create a gravitationally unstable gaseous disk of $\sim 105\Msun$
 every $0.1-1$ Gyrs, consistent with the 200 Myr age of P3. Similar
 processes may act in other systems to produce very compact nuclear
 starbursts.