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Minutes of the PALFA telecon: Friday July 8, 2005
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Online: JMC,JvL,IHS,FC,MM,DRL,JWTH,PCCF,RB,DJN,RR,VV,AAD,SC

Preliminary items:

- Senior review will not complete until next spring. Roger Blandford will
be the chair. Could be good or bad news for us, depending on how we
compete vs GW instruments. At earliest, 2008 fiscal year budget will be
affected. We should pass on any suggestions as to effective telescope
use to Bob Brown ASAP. He is producing a document that will be
submitted to the NSF on 31 July.

- PALFA spectrometer. Jeff Mock from the Berkeley area
will be at AO on July 18. An ALFA ASAP telecon will be held on July 22.
Please send comments about spectrometer wishes to
JMC by the end of next week (July 15) cc'd to
alfa_pulsar@naic.edu. AAD reminded us at the end of the telecon that
we should also think about notch filters to put in at the front end.
This would be built by AO staff but input on that is required soon also.

- PALFA paper I is now submitted. As are all proposals from the last round.

Main agenda:

1. 1906+07

- DRL has circulated a preliminary draft of an ApJ letter on 1906. Things
to be added are AO/GBT DDT data processing, some discussion about origins
and evolution of system, profile evolution (1998-2007) and future prospects.
The feeling is that this can be submitted by end of this month.
JMC comment: we should send Bob Brown the title, authorship and
journal asap so that he can include paper II (as well as paper I)
in the 31 July NAIC document to the NSF.

2. Follow-up observations of other pulsars.

- alfa_timing@naic.edu has been formed and some discussions about observing
have been carried out. The consensus now is to "just do something", i.e.
attempt to observe all 12 pulsars with current telescopes given time available
and see what happens. DRL noted that JB have been able to see 4/12 within 20
min observations. We are currently awaiting news from other scopes (Nancay and
WSRT active). Success rate could be higher if gridding observations could be
done at AO to reduce positional uncertainty. Some discussion was made about
possible strategies. It was agreed to try to discuss this offline. FC mentioned
that we should try to observe at least the 8 other pulsars in the coming session
at AO. All in agreement, so long as not too much time was taken. Ideally the
pulsars could be gridded in this time.

3. Use of PMB database in future.

- MAM will bring a LaCie with the PMB/AO overlap region to AO later this
month. It can then be copied locally, before being sent on to Cornell.

4. Search codes.

- Scott's LaCie with test data has left JB and is now at Cornell. It'll then
get sent onto UCB and UBC, and anyone else who wants a copy. Some progress
on the code was reported:

DRL - using COBRA at JB, a simple pipeline has been set up to process the
full resolution data using the tree algorithm. The next step will be to
test this against brute force dedispersion and then to implement PRESTO's
subband dedispersion on the data.

JMC/JD - using CTC have set up a full search pipeline using brute force
dedispersion and 7 CPUs. Takes 3.5 days to process data from a single 3-hr
transit at full resolution (1200 DMs, FFT search, SP search etc). 32 CPUs
are available in principle, so the processing rate can be ramped up here.
The code also allows tree-algorithm dedispersion but we so far have
chosen to use a list-of-DM approach.

After some further discussion it was agreed that we need to set up some search
processing milestones. End of the year was seen as a good deadline for getting
the final baseline code in place. We need a model as to how to do this, however,
so this is an action item. On the subject of the search code output format, things
seem to have been settled, though this might need one more iteration. JMC agreed
to look into this.

5. Data transport issues

JMC reported that, with help from Arun, they have successfully tested the burning
and shipping of 10 x 400 GB IDEs from AO -> CTC. Disks are now back at AO and Arun
is trying to get the pipeline in such a state that the operators can do the donkey
work required for future shipment. How the data will go out from CTC to the
rest of
the world is not quite clear. LaCies seem to be the option, though the AO->CTC
JBOD model might also be worth considering for those wishing to invest in
disks. JBOD boxes being used are from Granite Digital and cost
~300USD for a single slot box, 600 for a dual-slot, and 900 for a 4-slot
box. So 300USD is the "price of entry" into this approach since we
currently have 20 400-GB disks in circulation. Latest price was
300USD/400-GB disk.

6. Face-to-face meeting

Seems that AAS in Washington in Jan 2005 is looking like the next big opportunity
for this. There will be a 90-min ALFA session at the meeting and several
people have
expressed interest in attending, with a telecon call-in option for non attendees.

7. Observing parameters

Some discussion took place about what we should be doing re: integration times.
Should we go to 268 s (or longer) as proposed for this year, or stick with 134
s. FC raised the point that we should decide what Smin we want and base our time
on that. Going to 268 s would be roughly the same sensitivity wise as 134 s
with a 200 MHz BW system (next year?). No concensus was reached, it was agreed
to look into the simulation results before the next observing run (July 18).

8. Date of next meeting (telecon)

Monday August 1 at noon EDT!

Action items
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ALL - to recommend decisions on where to time specific pulsars
ALL - to send Bob Brown feedback re: senior review
JMC - to send out spectrometer specs
ALL - to send JMC final comments on specs ASAP
ALL - to think about notch filters for filterbank
ALL - to send comments to DRL about draft of 1906 paper
DRL - to continue 1906 paper and submit before Aug 1 if possible.
ALL - to think about gridding strategies --- can someone take the lead?
MAM - to bring PMB raw data to AO
JMC - to circulate contents of database for each candidate
??? - to draw up search code milestones (David N?)
ALL - to think about JBODs as a means of getting data from CTC
JMC - circulate simulation memos
ALL - to think about observing times
JMC - send LaCie disk to UCB
ALL - identify telescope for IR observations of J1906 and for other pulsars
* Gemini?
* Palomar (not until 2006, proposal deadline for summer month obs.
~ April 2006)