FUNA Lunch Talk:

Craig Walker


A VLBA Movie of the Jet Launch Region in M87

June 27

12:10PM, Room 230, NRAO, Edgemont Road


M87 provides the best opportunity to observe a jet close to the region in which it is launched. Structures in that region are expected to scale with the gravitational radius of the black hole and M87 has the largest angular-size black hole of objects with bright jets. We are making a movie of the base of the jet with a resolution of about 60 Schwartzschild radii using the VLBA at 43 GHz. Observations were made every three weeks throughout 2007 and every 5 days for 14 epochs in early 2008. Preliminary movies, one based on the first 11 epochs and the other based on some of the fast-sampling data, show rapid structural changes and motions of about 2c, in contrast to previous results on larger scales showing subluminal motions. In the movie, the jet looks something like a smoke plume. It is strongly edge brightened suggesting that something like a sheath is being seen. A TeV flare was seen by VERITAS during the period of the fast sampling data and new results suggesting there was a corresponding event in the radio will be shown.

After the science talk, photos and movies from a 21-day private raft trip in the Grand Canyon will be shown for those who wish to stay.