Rho max: 40

Z min/max: -+40

grid resolution: 128x256

initial coordinate separation of peaks of scalar field: 20

initial proper distance between peaks: 97

initial proper distance between excised regions: 84

proper distance between excised regions just prior to merging: 53

initial single BH mass estimates: 10.1 each

initial merged mass estimate: 17.3

final mass estimate(t=542, run time on maci ~ 40 hours): 13.2

(mass estimates based upon area of outermost trapped surface detected).

psi X 5, colour scale [0.85,2.0]: psi_5.mpg
(1 MB)

beta_z X 75, variable colour scale: beta_z_75.mpg
(1 MB)

phi X 100, variable colour scale (hence the occasional 'jitter') :
phi_100.mpg (1.9 MB)

(the frames are distributed uniformly in time till t=542)

The following animations show a merger of black holes created from boosted scalar field collapse (boosted towards each other with v=0.05), where the pulses are initially at a coordinate separation of 40 (twice as far as above). In this case we actually loose track of the trapped region before the merger, but extrapolate the motion to 'force' a merger --- see the outward null expansion animation. id file: id_bh

alpha: alpha_768x576.mpg
(4.5 MB)

phi*r (with adjusting scale): boost_phir.mpg
(7.9 MB)

outgoing null expansion (I can't changed the colormap with the data-vault yet,
so excuse the rather horrible color contrast between positive/negative expansion) :
boost_exp.mpg (2.9 MB)

I recently added a grid function to output Psi4, one of the Newmann-Penrose scalars (with the null tetrad constructed to measure outgoing radiation in the r-direction). The following is from a run for the same boosted initial data as above, but with outer boundary twice as far away: boostf_psi4.mpg (1.3 MB) The run actually went till t=340 in the 60 hours I asked for on Maci, but there was a bug in the merger code that didn't stopped the extrapolated merger at z=0, so the 'holes' moved through and away from each other, and the excised region just kept growing after t=200. This problem didn't crop up in the earlier example where the outer boundary was closer in, as for some reason in that case a single trapped region was found soon enough. I'm re-running the job with the bug (hopefully) fixed.

As another example of Psi4, I ran a simulation of an initially spherical black hole, perturbed by a brill wave --- id file: id_bh :

sigmabar : sph_brill_sig.mpg (1.5 MB)

[Psi4*r]^2, variable scales: sph_brill_psi4r2.mpg (2.5 MB)

d/dt([Psi4*r]^2), and with a fixed color-scale, to highlight behaviour near the hole: sph_brill_ddt_psi4r2.mpg (6.7 MB) (this animation doesn't decode properly on my pc at home --- if it gives problems for you too, let me know and I'll remake it).