Status of pulsar radio timing for GLAST

Created 30 October 2006, Lucas G & David S. Updated 29 January 2007

First, we list pulsar observations by radiotelescope, then we group them together into a master list. We concentrate on the 215 pulsars listed at https://confluence.slac.stanford.edu/display/GLAMCOG/Pulsar+Timing.
References to “the radio timing page” mean https://confluence.slac.stanford.edu/display/SCIGRPS/Radio+timing+for+GLAST .

Parkes
D. Manchester added the number of year 2006 Parkes observations to Roger’s two lists (available at “Oct 20” on radio timing page), to give an idea of which pulsars are being monitored independently of GLAST’s requests.

125 of ”our” pulsars have been observed at least once, 90 have been observed at least 5 times, and 33 have been observed at least 10 times.

To summarize: 24 of “our” southern pulsars are currently orphans –Parkes “should” observe these only for GLAST.

Nançay
I. Cognard sends us files called snr.all, which contain one line per observation, for all observations since the BON backend was installed two years ago. A single line looks like this:

file=./20060802/1853+0056.1368.53949.1304.asc snr=6.057636 tint=1200.17 snrn=0.175

In this example, the 210 µJy pulsar J1853+0056 was detected with a signal-to-noise ratio of 6.06 in 20 minutes on August 2nd.  It is shown in the pot, below (presumably the snr = 6 vs 7 discrepancy is because the plot and the file were made at different times with different parameters). Having looked at the light curves for the 14 Arecibo targets discussed below, it is clear that a cut n’ dry SNR value for a clear detection is not easy to define.

Another possibility for the different lines is:

0030+04    53285.950671    6.317105 3480.95

Jodrell
Aris Noutsos has made a summary of the pulsar observations in the Jodrell Bank Observatory (JBO), which is available in the following page :

http://www.jb.man.ac.uk/~anoutsos/GLAST_JBO.html

In 2006, Jodrell has collected data for 90 of the 215 pulsars (41,8 %) that are in our list of interest. Among these 90 pulsars, we're told that the timing is good for 35 of them (38,8 %). Another list of 18 pulsars need more data. Bad profiles are found for 37 pulsars (41,1 %) so that timing these objects may need other instruments. Although there's still evident timing noise in some pulsars data files, they are confident that these data files will eventually give accurate ephemerides. In addition, there are links to 2 other data files on the page. These files contain timing residuals and pulse profiles at 1.4 GHz for each pulsar.

Arecibo
A proposal was submitted (available at “Oct 18” on radio timing page), to begin timing 22 GLAST pulsars with Arecibo.  Of these, 14 were already observed with Nançay and 13 detected. Of those detected, 2021+3651 (S1400 = 100 µJy) was difficult. The one not seen was 1930+1852, which has S1400 = 60 µJy. The faintest of the 22-14=8 pulsars not observed at Nançay, but with a catalogue radio flux, was 1853+01 (S1400 = 190 µJy). Two fainter pulsars were detected and one can thus hope that they would all be detectable (except for the one without a known radio flux, 2043+2740).

Effelsberg
M. Kramer in principle submitted a time request – it’d be nice to get a copy.
 
Summary of observations

A summary of the observational data on our 215 pulsars can be found at : Observational data status.
There are 24 “orphans” in the Parkes-only declination range. For dec > -40°, 71 of the GLAST candidates are being observed by Nançay and 90 pulsars are monitored by Jodrell. For the moment, 3 dec>-40° pulsars are orphans,  though the Effelsberg report might reduce this number.

Update (January 24): Yesterday, I. Cognard (Nançay) sent us an update of their observationnal data. J1838-0549 as well as J1853+0011 have been monitored by the Nançay radiotelescope, so that there are now 3 orphans in the northern sky. Furthermore, J0034-0534 which was only observed by Jodrell has been observed 22 times by Nançay.

Appendix – the names of the 27 orphans
In the first list below are given the names of the 5 pulsars in the northern sky that have never been observed by Jodrell (in 2006) and Nançay (since 2004) (some have never been seen at radio wavelengths though). The second list gives the names of the 24 pulsars in the Parkes-only declination range with 0 observations in 2006, sorted by log(Edot):

X - time with X-rays
Yellow rows - Never seen at radio wavelengths
Green rows - There soon will be attempts to observe it (N = Nançay, J = Jodrell, P = Parkes)