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SUMMARY:Supermassive black hole feeding / Capture of interstellar asteroid
 s and comets - Prof. Walter Dehnen (University of Leicester)
DTSTART:20200217T140000Z
DTEND:20200217T150000Z
UID:TALK136468@talks.cam.ac.uk
CONTACT:Chris Hamilton
DESCRIPTION:SUPERMASSIVE BLACK HOLE FEEDING\n\nSupermassive black holes (S
 MBHs) form predominantly by accreting gas from an accretion disc\, which i
 s efficient only at radii  <  0.001 pc. As this is well inside the region 
 where the SMBHs gravity dominates\, it remains unclear how material to be 
 accreted can lose its angular momentum to reach these scales. Here\, I wil
 l detail a possible solution to this problem\, which is based on the cance
 llation of angular momenta of different inflows onto the innermost neighbo
 urhood of the SMBH.\n\nCAPTURE OF INTERSTELLAR ASTEROIDS AND COMETS\n\nThe
  recent by fly-bys of 'Oumuamua and Borisov suggest a large space density 
 of such interstellar asteroids and comets. I investigate the possibility o
 f capturing such objects into the Solar system via a fly-by of Jupiter or 
 Saturn\, presenting analytical arguments and estimates as well as results 
 of various numerical simulations. The most likely captures occur for an in
 coming speed of around 0.6 km/s and populate orbits akin to those occupied
  by long-period comets. We estimate that the Solar system may contain arou
 nd 10000 captured Oumuamua-like asteroids and 100 captured comets
LOCATION:MR14\,  Centre for Mathematical Sciences\, Wilberforce Road\, Cam
 bridge
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