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View Full Version : Supernova Remnant Acts as a Particle Accelerator



Fraser
2006-Nov-16, 02:39 AM
Instead of investing in particle accelerators here on Earth, physicists might consider just blowing up a few stars. New images taken by the Chandra X-Ray Observatory show how supernova remnant Cassiopeia A acts as a natural particle accelerator, firing out cosmic rays. As particles move around the remnant, they're accelerated by the tremendous magnetic fields, eventually nearing the speed of light. The images from Chandra show that the particles are being accelerated to the maximum rate predicted by theories.

Read the full blog entry (http://www.universetoday.com/2006/11/15/supernova-remnant-acts-as-a-particle-accelerator/)

iantresman
2006-Nov-16, 12:15 PM
* Cosmic rays are typically positive ions? What happens to the electrons?
* Is it magnetic fields, or electric fields, that accelerate ions?

Regards,
Ian Tresman

GOURDHEAD
2006-Nov-16, 01:28 PM
* Cosmic rays are typical positive ions? What happens to the electrons?
* Is it magnetic fields, or electric fields, that accelerate ions?
Regards,
Ian TresmanThey get accelerated also probably to greater velocities in a tendency to preserve the equipartition of energy in such a dynamic system.

Ions can be accelerated by either field. There will be strong coupling between the fields.

iantresman
2006-Nov-16, 02:24 PM
Ions can be accelerated by either field. There will be strong coupling between the fields.

Isn't it a changing magnetic field that generate an electric field, and it is the latter which is responsible for accelerating ions?

Regards,
Ian Tresman

ocalady
2006-Nov-16, 03:07 PM
Can the particles be accelerated to the speed of light? Is there enough energy to turn matter into energy?

antoniseb
2006-Nov-16, 03:47 PM
Can the particles be accelerated to the speed of light? Is there enough energy to turn matter into energy?
No there is not enough energy to get matter accelerated *to* the speed of light, but some particles can get pretty close. I'm not sure where the idea comes from that getting matter to the speed of light turns it to energy, but that is science fiction.

iantresman
2006-Nov-16, 04:45 PM
Can the particles be accelerated to the speed of light? Is there enough energy to turn matter into energy?

Double layers in a plasma that can accelerate particles to relativistic speeds, are known as relativistic double layers. See for example:


On the physics of relativistic double layers (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1982Ap&SS..87...21C) (1982) Carlqvist, P.

See also:
Creation of Gamma-Ray Burts by Electric Currents and Double Layers (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998tx19.confE..73O&db_key=AST&d ata_type=HTML&format=&high=4521318e0209463) (1998) Opher, E.; Opher, R.


Regards,
Ian Tresman

John Mendenhall
2006-Nov-16, 05:32 PM
No there is not enough energy to get matter accelerated *to* the speed of light, but some particles can get pretty close. I'm not sure where the idea comes from that getting matter to the speed of light turns it to energy, but that is science fiction.

Well said.

Favorite wild idea: Put a BB size object (of iron, maybe?) in a particle accelerator and run it up to some large fraction of the speed of light, just to see what happens.

Aside from the fact that the owners of the accelerator would never stand for it, I think the object would probably be quickly vaporized. And if it should hit anything while still solid, watch out! Momentum, remember, is mass X velocity^squared. You do the math.

hiro
2006-Nov-16, 06:15 PM
It seems like we still have to build multi-TeV accelerators. Well, nothing is free.

Jerry
2006-Nov-16, 09:34 PM
Given what we do know about accelerating particles to a high percentage of the speed of light, what we see in the expanding shells - long, long after the initial explosions - is an amazing phenomenon. There is much to learn.

Bearded One
2006-Nov-16, 10:11 PM
Instead of investing in particle accelerators here on Earth, physicists might consider just blowing up a few stars. I guess the insurance companies would give them a hard time, and the legal team would balk at the potential litigation from possible injured ET's and their interests.

:D

joedoe
2006-Nov-17, 02:38 AM
Magnetic or electric?

And where is the energy to "drive" it coming from? :eh:

It's suddenly a whole new universe :dance:

Will this mean some threads can now be moved from the ATM section and into the "mainstream" forums? :wall:

This is very exciting :clap: :razz:

iantresman
2006-Nov-17, 10:22 AM
Magnetic or electric?
And where is the energy to "drive" it coming from? :eh:

As far as I know, charged particles are accelerated only by electric fields, which in turn may be generated from changing magnetic fields.

And magnetic fields store energy. And all cosmic plasmas are magnetic.

Regards,
Ian Tresman

mugaliens
2006-Nov-17, 07:48 PM
Given what we do know about accelerating particles to a high percentage of the speed of light, what we see in the expanding shells - long, long after the initial explosions - is an amazing phenomenon. There is much to learn.

Jerry, your PM inbox is full. Can you clear it so I can send you a PM?

Thanks!

- Mugs

Jerry
2006-Nov-25, 12:48 AM
Done...when they merge the accounts, I got constipated...