S4 data... What's new?

barkster
barkster
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Topic 189989

Aside from verifying the increased sensitivity of the LIGO detectors... What's else new is going to be gained from the S4 data over the S3?

Other than the duration of the data measurement, is there anything about the way the S4 data is being collected that is different from the S3?

"No, I'm not a scientist... but I did stay at a Holiday Inn Express."

Ben Owen
Ben Owen
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S4 data... What's new?

It's not just the sensitivity, it's that the instrument is more stable. That is, the sensitivity doesn't fluctuate as much from one hour (or whatever) to the next. That's very important for long term pulsar searches.

And we can do a longer term search because there's more data, and more of you contributing CPU power. We don't know yet how long we'll keep digging into S4, because S5 is starting in November. The raw noise level for that won't actually be so much below that of S4, but S5 is going to last for about a year, so there'll be plenty of data to play with.

The really big change from S3 is that Livingston is able to operate at all during the day. New seismic isolation kept it from losing lock every time the local lumberjacks felled a tree. So you'll see some L1 work units.

Ben

rbpeake
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RE: ... S5 is starting in

Message 17928 in response to message 17927

Quote:

... S5 is starting in November. The raw noise level for that won't actually be so much below that of S4, but S5 is going to last for about a year, so there'll be plenty of data to play with.

Ben

Reading between the lines sort of, it sounds like S4 sensitivity approaches that of S5, and if that is true, then there is a fair to middling chance S4 might make a discovery? (Perhaps I am reading too much between the lines! ;)

Chipper Q
Chipper Q
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Hi, barkster – some small bit

Hi, barkster – some small bit of news from the client side – planning on adding a 2nd-hand box (hopefully several) here in the shop, to help with crunching S5. I know the difference will be negligible for E@H, but hey, it's news :) The experience of putting together a cluster should be quite valuable. I was also taught to answer the “What's new?” question with “c over lambda”, so as to never forget the equation “nu = c / lambda”, and dang if that didn't work good!

And Bob asked,

Quote:
Reading between the lines sort of, it sounds like S4 sensitivity approaches that of S5, and if that is true, then there is a fair to middling chance S4 might make a discovery?


Some very interesting discussions in other threads about dark matter and what it might be made of, and why there's a high degree of certainty regarding its existence. In a paper that Ben mentioned, the LIGO data has already been used to show that, if dark matter is in the form of primordial black holes in a galaxy's halo, then there aren't more than 63 coalescences per year of these things for our Milky Way's halo (from 5 kpc – 50 kpc, for non-spinning black holes in the range of 0.2 – 1 solar mass). It's a discovery in my book, anyway :)

rbpeake
rbpeake
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RE: Some very interesting

Message 17930 in response to message 17929

Quote:
Some very interesting discussions in other threads about dark matter and what it might be made of, and why there's a high degree of certainty regarding its existence. In a paper that Ben mentioned, the LIGO data has already been used to show that, if dark matter is in the form of primordial black holes in a galaxy's halo, then there aren't more than 63 coalescences per year of these things for our Milky Way's halo (from 5 kpc – 50 kpc, for non-spinning black holes in the range of 0.2 – 1 solar mass). It's a discovery in my book, anyway :)

Thanks, Chipper, this sort of news is great to get! :)

Chipper Q
Chipper Q
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Speaking of news, how about

Speaking of news, how about Very High Energy (VHE) gamma ray objects? A couple of objects (within 1 degree from the plane of the Milky Way) have been detected emitting only gamma rays, that is, they have no corresponding image optically, and aren't emitting x-rays either, and so are currently 'a complete mystery'.

If they aren't charged, rotating, black hole SNRs - why not? And what might some other possibilities be? If the matter/anti-matter ratio is conserved in the formation of a black hole (is it?), are primordial anti-matter black holes a possibility?

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