Back from Paris
I'm back from Paris. The conference was great and long (6 days of conference, I'll try to make a summary tomorrow), the weather was lousy, but I could see the town, see talks of people I like the work and so on.As every time you come back from a conference, the first day is DEAD! Resting in the morning (I've got home late at night yesterday), trying to read all the e-mails, meeting with the group to be update of what's going on and trying to finish the paper. It will be finished tomorrow ... anyway! But I'll have to change the LaTeX macro, because we are now sending it to MNRAS and not to AJ (this one is too expencive and we have no budget for that). This will be tomorrow "science".
Today, no science :-)
A little summary of "Salvador-Sole et al, 2005 (MNRAS, 358, 901)" as asked by David Hogg.
- They've modeled Dark Matter Halos (relaxed, non-rotating, spherically symmetric, even though in Paris he showed the results for rotating DM halo and is the same kind of result).
- The model can use different cosmologies and the "typical" accretion rates lead to a NFW profile.
- There are no differences between halos formed by major mergers or by gentle accretion with the same mass and boundary conditions.
- The properties of the halo depends only on: Mass, Energy and the instantaneous accretion rates of those quantities (M, E, Mdot and Edot).
- No relation of density profile and mass agregation history (MAH) - Main conclusion.
- Some correlations found previously can still be explained on that light (mass-concentration relation, for example).
Basically that's it. On the new work presented in Paris, also the Angular Momentum (since now the halos rotate) are included in the properties which are independent of the MAH.
Today I still have to reply collaborators mails about other work of us ...
The only new about coffee ... brought some from France hehehehehe :-)))
posted by Cris Da Rocha @ 7:36 PM
4 Comments:
Thanks for that summary! It's interesting that the halo profile is so robust. This bodes ill for the age-old project of reconstructing the cosmic-time history of gravitational collapse by observations of the central densities and density profiles of halos: it looks like they eat their own histories.
Definitively the DM haloes "eat their own histories".
I don't know (and would like to) how this apply to the galaxies, fortunately galaxies seem to keep their formation history for longer!!
presumably its because halos don't have disks -- it is the accretion and destruction of disks (maybe) that gives us a handle on galaxy formation (I hope).
Disks really generate longer living structures, but elliptical/elliptical encounters also gerenerate structures as shells that can be used to trace the merger history, don't they? We want to try this with our low surface brightness detection routines.
Gas also leaves a good tracer, since it form stars, specially in globular clusters. We are trying that also.
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