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Uclock
2012-Apr-02, 08:53 PM
Hi

Does this (http://arxiv.org/pdf/1203.4219.pdf) mean they potentially, possibly, have the ability to accurately detect the speed of any distant massive object?

Tensor
2012-Apr-02, 10:12 PM
Hi

Does this (http://arxiv.org/pdf/1203.4219.pdf) mean they potentially, possibly, have the ability to accurately detect the speed of any distant massive object?

No. The paper is quite specific as to the mass limits, of the objects, that they are able to use to measure the kinematic Sunyaev-Zel’dovich effect. Which is what is used to determine an objects (basically a low-mass cluster) velocity.

Uclock
2012-Apr-03, 06:13 PM
Thanks Tensor

If I read the paper correctly, the distance of the object will make no difference to the accuracy of the velocity measurment?

Tensor
2012-Apr-03, 10:02 PM
Thanks Tensor

If I read the paper correctly, the distance of the object will make no difference to the accuracy of the velocity measurment?

Yep, distance isn't a factor in the Sunyaev-Zel’dovich effect. There are other constraining parameters, such as mass for the kinematic effect, others are listed in the paper. But the beauty of the Sunyaev-Zel’dovich effect, is its independence of distance.

George
2012-Apr-04, 03:07 AM
Yep, distance isn't a factor in the Sunyaev-Zel’dovich effect. There are other constraining parameters, such as mass for the kinematic effect, others are listed in the paper. But the beauty of the Sunyaev-Zel’dovich effect, is its independence of distance.
I don't recall looking at this effect. Is it any different to an analogy of a Jupiter boost for satellites, but for light?

Tensor
2012-Apr-04, 05:57 AM
I don't recall looking at this effect. Is it any different to an analogy of a Jupiter boost for satellites, but for light?

Well, technically, it's an effect on the CMB (I make that distinction, only because the CMB is EM radiation, which light is also, but the SZ effect isn't technically on optical light). As for the analogy, it's sorta, kinda like that, but, since it's an inelastic collision, I really don't like to have it thought of that way, since a satellite and Jupiter don't actually collide . Compton scattering is a photon losing energy when it collides with an electron. The Sunyaev-Zel’dovich effect is an inverse Compton effect where the photons of the CMB pick up energy when they collide with the hot gas surrounding a galactic cluster. It's easier to pick up the Thermal effect, as it's the energy of electrons due to temperature effects. The Kinematic effect is tougher as it's the energy of the electrons due to their velocity. Wikipedia (http://en.wikipedia.org/wiki/Sunyaev–Zel'dovich_effect) has a decent intro to it. This link (http://ned.ipac.caltech.edu/level5/Birkinshaw/Birk_contents.html) is a bit more in-depth and math intensive.

George
2012-Apr-04, 06:04 PM
Well, technically, it's an effect on the CMB (I make that distinction, only because the CMB is EM radiation, which light is also, but the SZ effect isn't technically on optical light). As for the analogy, it's sorta, kinda like that, but, since it's an inelastic collision, I really don't like to have it thought of that way, since a satellite and Jupiter don't actually collide . ...
Ok, that's more devilish stuff than I had hoped for, but in georgeeze -- where I enclose the mass fields with a handy large black box -- it can be a beginning analogy. Perhaps when we discover more about the process we call gravity the analogy will look a little better. In other words, perhaps gravitons come in many flavors (species) to allow particle physicists to go either completely insane or willingly purchase more property to exand the zoo. :)

But I think I see your point since the mass movement of the galaxies altering the CMB wavlelength is an indirect effect as opposed to the mass motion of Jupiter being considered more of a direct effect even if a multi-species pseudo hypothetical graviton model is evisioned, or something worse.