Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/~palfa/observing.notes/obslog.20050404.txt Дата изменения: Thu Apr 7 20:53:57 2005 Дата индексирования: Sun Apr 10 23:50:28 2016 Кодировка: Поисковые слова: р п р п р п р п р п р п р п р п

Dear PALFA consortium members,

Ramesh and I have just wrapped up the first day of PALFA inner Galaxy
observations. The observing and quicklook went very smoothly, thanks to
the efficient scripts and GUI improvements - the work that has gone into
this is fantastic!

We have "detected" many "pulsars" at 16.675 ms and 75 ms, as well as a
a bona fide 343 ms pulsar based on quicklook (fold and single pulse):
it turns out to be a blind detection of B2020+28 at a ~14 arcmin offset.
I attach the two detection plots from Beam 3; it was detected more
strongly in Beam 4. (Known pulsars are listed only within 10 arcmin, so
this was a true blind detection!)

The full set of plots should be archived, once someone decides where they
should go; for now, they are at: http://www.naic.edu/~palfa/detections2/

I've typed up notes on the observing and various comments and feedback for
the script maintainers, which is attached below. Ramesh and I will be
observing through the rest of this week.
Cheers,
Shami

----------- obslog.04apr05.txt ---------
P2030 Observing Notes, 4 Apr 2005, Ramesh Bhat and Shami Chatterjee

B1737+13 used as test pulsar: weak, not convincing enough during setup.
B1933+16 used as test pulsar: strong!
Detected correctly in each beam, and usually in 2/3 adjacent beams.

Pulsar Detection!
G68.62-04.85.N_53464_0097:3
RA: 20:22:38.5 Dec 28:40:01.2
Period 0.34337 sec; DM = 74.2; S/N = 15.7? (27.6 on plot); Candidate 4

G68.62-04.85.N_53464_0097:4
RA: 20:22:38.5 Dec 28:40:01.2
Period 0.34338 sec; DM = 98.9; S/N = 38.6? (51.5 on plot); Candidate 2

But compare to B2020+28:
RA: 20:22:37.0671 Dec 28:54:23.104
Period 0.34340 sec; DM = 24.64; s1400 = 38 mJy; Offset = 14.2 arcmin
Fold at known period: pulse profile is similar.
= a blind detection of a known pulsar.

* This pulsar was not listed as "Nearby" on the quicklook plots.
What is the cut off used? 10 arcmin. Should this be expanded?
At 14.2 arcmin, we are still near outer beam coma lobes.
http://alfa.naic.edu/performance/beam_map/

* Plots to be posted to the web as Detections: where?
With precursor, or new page? For now, see
http://www.naic.edu/~palfa/detections2/

Script makeobs-new.py:
* Doing a great job, but non-transparent --
it creates very different patterns given slightly different start MJDs.
* It might be nice to show known pulsars on the planned pointings as well
(the infrastructure exists in the plot_pointings.py script)
Or maybe not: it might bias the observer. This is debatable.

Catalog Observing:
* Scan numbers increment by 1 for test (B1933+16)
but increment by 2 for catalog observing.
Possibly because catalog has pointings only on every other line?

RFI: We experienced continuous RFI, typically very short pulses
visible in the snap time series window.
* Coordination with Puntas Salinas was requested but it is
not clear if it was in effect.
* FAA Airport radar around ~1370 MHz?

Quicklook:
* Bug in plot order: It plots candidate 1, 10, 2, 3, 4, ...
* What are the criteria used to filter out candidates?
(It looks like all cands < 4ms are filtered out?)
* The single pulse plot (last one) should be retained in all cases.
* Common birdies at 16.675 ms and 74--76 ms

Post-observing:
* Until fill_observed.py is run, the database has no knowledge of
the day's observing. Should observers run fill_observed.py daily?
Since my writing, Jason says yes.
So, *must* observers run fill_observed.py daily?

(End of nitpicking)