S5 early results paper

Anonymous
Topic 13762

Quote:
2) fine-tune instrumentation to look for the same but weaker patterns

Describing this as 'fine-tuning the instruments' is really not very accurate.

The construction of the LIGO detectors was completed in 1999, when the serious commissioning work began. Since that time, the strain sensitivity has increased by more than two orders of magnitude: noise evolution graph.

The road-map for the LIGO detectors includes two more significant upgrades, so that by 2014 the instruments will be one order of magnitude more sensitive than during the S5 run. This means that we can observe a spatial volume that is 1000 times larger than what was visible during S5 (the visible volume grows like the cube of the sensitivity).

Describing this evolution as 'fine-tuning' of the instrument is really not accurate! It's like saying that a Porsche 911 is just a 'fine-tuned' version of a Ford Model T.

In addition, we are continuing to improve our analysis methods. For example see this paper on improved analysis methods.

As the detectors and the data analysis methods improve, our chances of making a CW source detection go up. But in absolute terms we can't say how probable this is, because we do not know how big neutron star 'mountains' are. See Figure 5 of this paper to see some reasonable solid UPPER LIMITS on what the expected maximum strain is, as a function of the (fractional) mountain-height epsilon.

Bruce Allen
Bruce Allen
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S5 early results paper

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After all my time here : It's just hit me ..... how ambitious we are!!! :-)

The numbers are quite staggering. Einstein knew this too. After calculating the probable size of the effect he promptly despaired of ever measuring it.

Keep your chin up! The LIGO instruments routinely measure separation changes in a 4-kilometer baseline which are one thousand times smaller than an atomic nucleus. That's also quite staggering!

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