A Kim: turbulent nuclear rings are found... if angular momentum large... ring
can be very close to center
Q: Best guess for age of molecular torus in Herschel data?
A Kim: Simulations for external galaxies, didn't run for our Galaxy.
Q Morris: Asymmetry in distribution of molecular gas. No asymmetry in
stellar distribution. Implies m=1 mode / asymmetry in CMZ. Has the
asymmetry been worked into models?
A Kim: ????
[ I can barely understand this discussion ]
Q: X1/X2; Kim sees mainly X2, but dust may be X1. Does the ring form at transition?
A: No, rarely forms at transition radius.
Q: Weak bar case, lindlbad resonance is where x1/x2 change. But with strong bar,
that approximation doesn't work.
A: Don't know if X2 orbits exist outside of inner lindblad resonance
Q: Dust lane on x1, ring on x2
Q: What is the filling factor of molecular gas in the inner region?
A Bally: 10%-30% very dense, with "soup" of low-density molecular gas. H3+
indicates ionized molecular gas present.
Q Which phase dominates?
A Bally: Megakelvin plasma must fill the volume (X-ray measurements), thermal free-free emission,
plenty of ionized gas. 30-60% ionized gas filling factor
A Farhad: controversial what filling factor of mol gas is. Oka, Geballe: 1%
A Geballe: 1% along one line of sight, towards Sgr A*
A John: Area filling factor is 1, volume filling factor is open question
Q Farhad: Twisted ring. Problem with this idea. Where is Sgr B2 w.r.t. X2 orbits?
A Bally: Sgr B2 is in the x2 orbit. Not at apocenter yet, Sgr B2 not at
tangent point, still moving out.
Q Crocker: Radius for ring?
A Bally: 140, 150 pc? At least a degree
A Longmore: I'll show tomorrow inner ~100 pc
Smaller Scale
Q Longmore: What is the connection between the 100pc and 1pc ring?
A Ott: 20 km/s cloud is connected to the CND. May be where molecular gas is exchanged
A Requen-Torres: John showed work from Rodriguez-Fernandez
A Bally: Streamers connected to CND. Why's it called a disk? It's a ring!
Q: What's the origin of the cirmnuclear disk?
A Bally: Matter that's losing angular momentum. Dynamic friction, magnetic stresses, etc.
A Lacy: Suggestion of why gas drives into center....
A Kim: Collision between molecular clouds, B-fields too
A Morris: Room for controversy. Transient feature because shear timescale
is short, but the CND seems to be in some sort of dynamical equilibrium. Is
it long-lived, in which stabilities create clumps that are sheared out, or
if this is just an infalling cloud that has recently circularized.
Requen-Torres: Inclination, two different areas (disks?) inclined to each other
Q Any evidence for ring evaporation?
[ most interesting point of the conference so far ]
Q: Gas dynamics in Galactic center complicated... creates bias related to BH
mass. How worried should we be about BH mass measurements using gas?
A Lacy: If we see gas preferentially at apocenter, we will underestimate BH mass