Date: Fri, 07 Mar 2008 10:48:28 -0700 From: Craig Walker To: Barry Clark Cc: schedsoc@aoc.nrao.edu, rdickman@aoc.nrao.edu, analysts@aoc.nrao.edu Subject: Re: Request for extension of BW090. Thank you for the extension to BW090. I will submit schedules shortly. FYI, to continue the saga so far, since my request there have been two observations: BW090H Mar. 2 FD out for bearing work HN out for frozen FRM, SC high Tsys for part of run. BW090I Mar. 7 FD out for bearing work, PT out for communication problem. Snow at LA, Rain at SC. Let's hope my luck improves! Cheers, Craig Barry Clark wrote: > Yes, we will extend this as requested. > > > From cwalker@aoc.nrao.edu Mon Feb 25 13:22:05 2008 > > > > BW090 is M87 43 GHz VLBA movie project for which we are currently > > observing every 5 days. The object of the project is to study the > > dynamics of the M87 jet as close as possible to the black hole in terms > > of gravitational units. BW090 is an extension of BW088 in which we > > observed M87 every 3 weeks throughout 2007. BW090 was proposed because > > of a determination from the first half of BW088 that the motions in the > > jet were being undersampled. The movie from the first 11 observations > > of BW088 is available at > > http://www.aoc.nrao.edu/~cwalker/M87/index.html. > > > > Starting with session 12 of BW088, the resolution of both of these > > projects has been compromised. SC was not available due to the painting > > project, or lost to mechanical problems in all but one of the remaining > > BW088 epochs, including the one 5 days before the start of BW090. The > > record for BW090 so far is: > > > > 1 BW090A: Jan. 26, Storm at MK. Ts near 300K. > > 2 BW090B: Jan. 31, Some high Tsys at SC, but probably full resolution. > > 3 BW090C: Feb. 04, MK stowed in storm. KP and NL also compromised. > > 4 BW090D: Feb. 10, MK and HN stowed because of ice. > > 5 BW090E: Feb. 15, HN FRM frozen - no data. KP very bad weather. > > 6 BW090F: Feb. 20, BR lost to a combination of confusion and maintenance > > 7 BW090G: Feb. 25, Probably ok despite minor problems at many sites > > > > Based on what is seen in the BW088 movie that we have, a significant > > number of frames of a movie is needed to make sense of the motions. > > Given the loss of MK, SC, HN, and/or BR in 5 of the first 6 BW090 > > observations, we request that 4 additional observations be added to the > > BW090 sequence in the hope of obtaining a reasonable sequence of full > > resolution frames. If 4 is too many, any that can be provided would be > > much appreciated. I am making this request now because the opportunity > > to extend the existing sequence will be gone quickly once the final > > BW090 observation is done on about March 11. > > > > Cheers, > > > > Craig > > > > --------------------------------------------------------------------- > > R. Craig Walker Array Operations Center > > cwalker@nrao.edu National Radio Astronomy Observatory > > Phone 505 835 7247 P. O. Box O > > Fax 505 835 7027 Socorro NM 87801 USA > > --------------------------------------------------------------------- > >