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Nice work! A long time ago I was doing analysis of X-ray data of Coma and Perseus to infer dark matter distribution, using the temperature and density variatio
by martinpw 7y ago
Nice work!
A long time ago I was doing analysis of X-ray data of Coma and Perseus to infer dark matter distribution, using the temperature and density variation of the gas to derive the shape of the gravitational well. Among other things, that assumes things are in hydrostatic equilibrium. How much do you feel the bulk motion you are detecting will affect dark matter estimates derived from such X-ray measurements of clusters?
BTW one thing I think is underappreciated in this kind of analysis is the sheer amount of work you need to do to get believable results. I am guessing you probably spent more time on data reduction and correcting for the endless variety of sources of noise and uncertainty than you did on the actual science.
- xioxox 7y agoThanks! The motions detected are pretty subsonic, so probably aren't expected to affect the hydrostatic equilibrium assumption significantly. We're measuring bulk flows, however, and not the turbulent width. There are some other recent observational results suggesting that the hydrostatic assumption isn't too bad: https://arxiv.org/abs/1805.00034 https://arxiv.org/abs/1805.00034 Yes - there was a lot of work behind this paper, and most of it was on trying to get the calibration procedures we developed to work. It was a long process of trying things and seeing what worked and testing the results for consistency. Initially I thought it would be a lot simpler, but real detectors in space are complex things.