Results update?

Vegard
Vegard
Joined: 2 Sep 11
Posts: 8
Credit: 13,739,271
RAC: 0
Topic 196730

Hi,

I am wondering, if there were any pulsar discoveries in the last months? There were times in the beginning of last year when there were regular announcements of discoveries.

And what about the Fermi measurements? Did we find any pulsars there (from FGRP1)? Will there be any papers about pulsar discoveries?

It is also almost a year ago when the normal S6 computations ended. Will there be a paper about the results/exclusion limits soon? (Is the data analysis of the E@H results still quite complex or do you 'just have to plot the results' (or use a standard limit calculation tool and that's it)?)

Cheers!

Bernd Machenschalk
Bernd Machenschalk
Moderator
Administrator
Joined: 15 Oct 04
Posts: 4,305
Credit: 248,903,445
RAC: 34,468

Results update?

In general, Einstein@Home Clients compute like single pixels of a large picture. These pixels need to be combined together to see the full picture and to possibly spot what may be a detection. This is what we call "post-processing".

The publishing process then takes some more time. For the paper depending on the method and earlier publications the method and setup has to be described in detail, how the search was set up and why it was done that way, what was done before to verify the validity of the method and setup etc. Finally all three of our searches are part of efforts within collaborations, each of which having their own special rules for publishing results, like internal reviews to go through and so forth.

Each of these things takes quite some time and is mostly limited by manpower.

The Radio-Pulsar search has relatively fast feedback because of comparably small "pictures" to be put together (single independent "beams") and rather generous publication rules by the PALFA collaboration. We are e.g. allowed to announce the discovery of a new pulsar before the paper has been published. Indeed we had rather few new discoveries there recently, which is most likely due to the region of the sky that we are currently searching ("outer galaxy").

For each Gravitational Wave search, post-processing starts only after the whole "run" has completed. It then usually takes several months up to years. As we don't have reference data (like known GW pulsars that we could re-detect), each single feature in the "picture" of such a run needs careful (and sometimes tedious) investigation to convince us whether it is a gravitational wave, a bug in the code, an artifact of the instruments, the statistics, of how the parameter space is cut up into workunits, or whatever. A (preliminary) paper has to be written. Then everything - search setup, all computational code involved in pre-processing, "crunching" (E@H application) and post-processing, as well as the paper has to be reviewed internally within the LVC, a collaboration of ~600 people. Just the reviews could easily take another year. So for the GW searches, feedback to the public is very slow.

As for the Gamma-Ray search I know that Holger Pletsch, the scientist in charge, has just returned to his desk to finish a paper about the results of the first search that ran on E@H (FGRP1). It's still not clear at least to me what rules of the FERMI collaboration (that includes the Max-Planck-Society and NASA) will apply to this publication, so I can still not say much about a publication date. But I would expect this to be rather months than weeks ahead.

BM

BM

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,579
Credit: 307,073,271
RAC: 154,658

Thank you Bernd for that

Thank you Bernd for that excellent precis. I often have wondered about that sort of 'backend' stuff. I guess we would all like quick feedback on the work, like the score held up on cards just after an Olympic dive. But in the careful world of frontier science research involving quite large collaborations - the modern trend it seems - then tedium and sure-footing is the method.

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

Bernd Machenschalk
Bernd Machenschalk
Moderator
Administrator
Joined: 15 Oct 04
Posts: 4,305
Credit: 248,903,445
RAC: 34,468

FWIW this is finally the

FWIW this is finally the announcement of the long-awaited paper about FGRP1.

BM

BM

fadedrose
fadedrose
Joined: 6 Apr 13
Posts: 263
Credit: 316,405
RAC: 0

Mike is right. This is a

Mike is right. This is a very good piece. I no longer will wonder if everytime I upload that you'll tell me I caught somethng.

So, it's like a giant quilt, in terms I understand, and then you look it all over for flaws or anomolies, and probably send a few patches in for reworking. And it takes time, years perhaps, to search.

I love it.

Do you good people mind if I make stupid comments on things beyond me? I feel like an intruder but am drawn to your information-sharing, ALL of you. You are so lucky to have found work that is also your hobby, love, interest, and fascination, apparent in your posts...

Wouldn't mind knowing who named the Computer Brothers, Trillions and Eddie and why they're late.

Bernd Machenschalk
Bernd Machenschalk
Moderator
Administrator
Joined: 15 Oct 04
Posts: 4,305
Credit: 248,903,445
RAC: 34,468

RE: Wouldn't mind knowing

Quote:
Wouldn't mind knowing who named the Computer Brothers, Trillions and Eddie and why they're late.

I'll answer that in the original thread.

BM

BM

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,579
Credit: 307,073,271
RAC: 154,658

RE: I love it. Same

Quote:
I love it.


Same here. What especially draws me to this project is the high level of rigour in self examination of the intellectual processes used to reach conclusions from the measured data.

Quote:
Do you good people mind if I make stupid comments on things beyond me?


Go for it. We only slap people for rudeness etc, not mere stupidity .... :-) :-)

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

Filipe
Filipe
Joined: 10 Mar 05
Posts: 184
Credit: 391,353,545
RAC: 259,164

RE: At the time of the

Quote:

At the time of the first newsletter we were completing the first
follow-up (FU1), which looked at a total of 16 million candidates. Out
of these, the next stage (FU2) followed up about 5.5 million, using a
different set-up to increase the sensitivity. The data were split into
40 segments, each with a longer coherent observation time, namely 140
hours versus the 60 hours used in FU1. About one in every five
candidates that was looked at with FU2 was deemed worthy of being
further inspected with the third follow-up stage (FU3).

The third and final stage uses data segments of 140 hours coherent
observation time (like FU2) but with a much finer grid in parameter
space, again zooming in and increasing the sensitivity. According to
our studies, this should give us at least a 40% increase in
signal-to-noise ratio. This is sufficient to confidently separate a
possible signal from the background. In fact we expect to have no more
than a few candidates coming out of FU3, which could be confirmed or
discarded based on specific candidate-tailored studies.

We have gone from analysing 16 million candidates on FU1 to 1million on FU3.

Is there any preliminary result or how many potential candidates left after the final of the FU3 run?

tullio
tullio
Joined: 22 Jan 05
Posts: 2,118
Credit: 61,407,735
RAC: 0

The European Pulsar Timing

The European Pulsar Timing Array has published on the "Monthly Notices if the Royal Astronomicak Society" an article describing the results of a 25 years old research based on 5 European big radio telescopes, Effelsberg, Nancay, Westerbok, Lovell and Sardinia. They observed the timing of signals of a number of pulsars, which can be increased or decreased by the arrival of a low frequency gravitational wave, that can have a frequency of a billionth of an hertz. They claim to have discovered the existence of a Gravitational Waves Background similar to the Cosmic Macrowave Background.

Tullio

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.