I started to put together the image test-bed for the astrometry.net pre-alpha testing. I will be contacting the alpha users (no doubt my most loyal readers) soon for example images.
At coffee we discussed a recent paper on cluster gas fractions which claims that x-ray observations of clusters were in (weak) disagreement with WMAP results on cosmological parameters. The odd thing is, they find that the discrepancy is a strong function of the radius at which you do the measurement, and that the discrepancy gets small at large radius; perhaps there is no discrepancy at all when extrapolated to the cosmic mean density?
I had correspondence with the authors, and they say that there are good physical arguments it can't vary much with radius.
ReplyDeleteOf course my position is that such variation is observed!