Application Purposes

jon b.
jon b.
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Topic 196391

I was wondering what the specific functions of each different application are. Thanks in advance.

tullio
tullio
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Application Purposes

Quote:
I was wondering what the specific functions of each different application are. Thanks in advance.


They are specified in your Results window. One is looking for gravitational waves, another for binary radio pulsars. There is another one looking for gamma-ray pulsars in data coming from the Fermi Gamma-ray Large Area Telescope but they are rare and I see you are not crunching any,
Tullio

Mike Hewson
Mike Hewson
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RE: I was wondering what

Quote:
I was wondering what the specific functions of each different application are. Thanks in advance.


We're looking at different types of signal emission from more or less the same subset of celestial objects - end stage stellar systems with compact masses and relativistic dynamics ie. large and moving fast, giving out some rhythmic signal not varying too much in time frequency.

[ There are non-rhythmic and/or rapidly evolving sources for sure, but we don't do those here. ]

So take something like the Sun, but several times its mass or even as a binary system, and let it get old over billions of years with the nuclear fires burning out. Gravity wins in the end so contraction to large masses in small volumes ( compaction ) occurs where spin and magnetic fields magnify in strength during that process. There are alot of variants upon what you wind up with - black holes, neutron stars, white dwarfs, binary combinations of same etc.

By as yet poorly defined mechanisms they beam electromagnetic radiation ( we look at radio waves and gamma rays ) that looks cyclic to us on Earth if the overall geometry is right. Think lighthouse. We point a radio-telescope or satellite borne gamma-detector in various sky directions in the hope of something to find - again of rhythmic type.

We haven't yet, but are optimistic of, detecting gravitational waves from the very same objects. This is not a lighthouse, rather more like omnidirectional broadcast. We use essentially omnidirectional receivers in a network to confidently detect and locate. These convert 'spacetime' displacements to a fluctuant photon count and thence to an electrical signal.

In all cases we here at E@H look at a time series of readings from some instrument(s). We have to reliably find some regularity within this series in the presence of a whole host of confounding factors - from stuff happening in the sky to stuff happening on Earth to stuff happening within our instruments themselves. All this stuff of non-science interest we collectively call 'noise'.

Generically this goes by the moniker 'signal processing' which is a highly computationally expensive task for the large data sets we receive. This is why E@H exists as the computing power required readily dwarfs the assets held by various science groups. So we ask the public to donate the use of their personal equipment, internet bandwidth, power costs and time. For which we are ever grateful !! :-)

Now if you're in the mood to punish yourself with some of the technical detail, general algorithmic approach, underlying mathematics etc then might I recommend at least a browse thru my Fourier Stuff threads stickied here in the Science section. Start at Part 1 .... :-)

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

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