Arcadian Functor

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Marni D. Sheppeard

Tuesday, May 15, 2007

NASA News

NASA have announced a press conference for the discovery of a ring of Dark Matter. It is scheduled for 1 p.m. EDT on Tuesday May 15. For the Kiwis, that's 5am tomorrow morning (sigh, why can't the Americans get up in the middle of the night sometimes?).

It is said that the Hubble space telescope has observed a ghostly ring of dark matter in the cluster CL0024+17. Sounds interesting! An earlier paper on this cluster may be found here. There is a noteworthy remark on page 6: compared to the weak lensing mass ... and the virial mass ... the mass deduced here from the X-ray observations is lower by a factor of 4. Matti Pitkanen says, "Rings puts bells ringing!."

In other news, the Cassini mission has been observing organic molecules in the atmosphere of Titan.

Update: Here is the dark ring image from NASA: Observe that this is a LARGE scale image. The weak lensing circle is barely visible at the inner edge of the dark ring. That means a LOT of 'dark matter'.

6 Comments:

Blogger Matti Pitkanen said...

The early bird finds the worm but you were still earlier! Before visit here I had just written my own comment on the finding which is really fascinating!

Rotationally symmetry structures with Z_n symmetry with very very large n of "field body" of system (in particular rings) are just what dark matter as large Planck constant phase predicts!

May 15, 2007 3:58 PM  
Blogger Kea said...

Oooh. This article looks interesting.... that factor of "3 to 5" again ...

May 15, 2007 4:24 PM  
Blogger Kea said...

OK, so following Bohringer et al: ignoring the weak lensing mass, which is measured over a much larger scale, and correcting by a factor of 3 for the tripled statistics, we could predict a ring mass of 1/12 of the stated cluster mass. That is, a ring mass of about 5 x 10^13 h^(-1)Msol (the units used by Bohringer et al). Note that this is significantly less than the enormous mass attributed to the ring in the standard picture. Does this make sense?

Hmmm. They are going to show pictures. This prediction would suggest a smallish ring near the compact core of the cluster. Should be pretty.

May 15, 2007 4:48 PM  
Blogger Matti Pitkanen said...

Could one understand the discrepancy if dark matter flows to towards the center with a slower speed than ordinary matter so that dark matter is concentrated more strongly in the halo of the cluster? If dark matter contributes more to the lensing this might make sense.

The underlying reason for different radial distributions of visible and dark matter would be lower dissipation of dark matter (large hbar) implying that the motion transforms to a radial inward motion with a slower rate. This would explain also the apparent failure of Equivalence Principle which we discussed earlier.


This would also conform with the observation of dark matter rings in periphery at Bohr orbits. It would be interesting to look whether the distance of the dark matter ring corresponds to Bohr orbit. The distance would be r= n^2 r_0, where r_0 is Bohr radius and n is integer. If I remember correctly Bohr radius is r_0=GM/v_0, 1/v_0= k*2^11, k small integer, M the total mass inside the ring: about 2000 times Schwartschild radius. The model also predicts the rotational velocity assignable to the ring as v_0/n. The observation of several rings corresponding to different values of n would be a victory for the model.

May 15, 2007 11:55 PM  
Blogger Kea said...

OK, so I was wrong in my guess that it would be a small scale image. This applies to the large scale weak lensing mass of 4 x 10^15 h^(-1)Msol.

May 16, 2007 11:23 AM  
Blogger Kea said...

The underlying reason for different radial distributions of visible and dark matter would be lower dissipation of dark matter (large hbar) implying that the motion transforms to a radial inward motion with a slower rate.

OK, Matti, I think this was a good predictive statement, since it describes the image well. What do you think of the 'collision' interpretation?

May 16, 2007 1:56 PM  

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