Tall White Bar in the Power Spectrum
20 Jan 2011 14:07:15 UTC
Topic 195590
(moderation:
Hi. Whenever I look at the Arecibo power spectrum, the bars are usually short and dark grey. But in the task that is running currently, the leftmost bar is taller than the others, and gets quite high at certain times (even higher than shown in the screenshot).
Could someone tell me what this means?
[The source being a few degrees away from the centre of the galaxy excites me. :D]
Tall White Bar in the Power Spectrum
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It's likely to be a terrestrial source, such as a radar.
Tullio
RE: It's likely to be a
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As in, the white bar alone is noise? Thanks.
That's at the low frequency
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That's at the low frequency end, it'll be Earth trash like the wall electricity supply @ 50-60 Hz. Electric motors, refrigeration compressors, that sort of thing. The LIGO IFO's were full of that plus harmonics. There could be a pulsar signal in amongst it but it's harder to pull that out.
Unless of course we're picking up some pretty decent air conditioners down at Galactic Centre. Do Fujitsu deliver to there? :-) :-)
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Hi! Actually the telescope
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Hi!
Actually the telescope wasn't pointed to the Galactic center at that time. You can see the coordinates in the lower right corner of the screen. The crosshair is indicating a position near constellation Auriga, the Galactic Center is in Sagittarius.
(If the crosshair would be a bit more in the direction of Taurus I would have suspected that this is a real pulsar signal form the Pulsar in M1, the famous Crab Nebula, but I think it's way too far off). But the target area is indeed in the galactic plane where most detectable pulsars are found.
CU
HB
RE: That's at the low
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Thanks, Mike. That was helpful.
Hi. Look closer, the teapot is to the right and just beneath the source. (For the record, I did say the source was a few degrees away from the GC.) In the screenshot, Auriga is seen on the other end. Oh, and a location in Auriga with a negative declination? I think not. :)
On my second BRP3 run, bars
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On my second BRP3 run, bars 2,3 and 5 from left are always higher than others and sometimes get even bigger and white. But is it the Arecibo power spectrum or the Parkes spectrum?
Tullio
RE: Hi. Look closer, the
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You are so right, I'm really sorry. I should have known better, I regularly do measurements on Epsilon Aurigae :-(.
CU
HB
Still local noise? :)
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Still local noise? :)
I also had white bars 2,3 and
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I also had white bars 2,3 and 5 on a run, coming and going. My latest run had a fixed 1 white bar, typically noise.
Tullio
Ah, thanks.
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Ah, thanks.