[Lofarpwg] LOFAR LBA census draft -- ready for commenting

[Anna Bilous]

Hi Patrick,


>
> Figure 2: I don't think having the dynamic spectra adds a lot, so I would
> remove them. In addition I had a question about the cleaned freq vs phase
> plots: why are there white rows which do not appear in the uncleaned
> version? Rows with empty samples appear as orange for other rows.
>
> I'm not sure for now about removing dynamic spectra, I think they make a
good illustration of how much band was deleted. I'll take a look at the
color issue.



> Figure 3: I don't really see the point in showing for each pulsar & beam
> what fraction of the data was deleted. I think that if this information
> should be available to the reader, then it should be in a table in the
> appendix. At the moment the figures in the paper itself (excluding the
> appendix) is dominated by plots which show that the data is non-ideal (two
> large figures about dropped packets & RFI, two small figures about
> interesting stuff related to the sample). If you want to show something
> related to the zapped fraction, I would make a histogram of the fraction of
> useful data, which is much smaller. I also don't think there is a reason to
> keep the inset. As you already do, you can simply state in the text that
> there is no correlation with date. Making the plot was a useful diagnostic
> for us, but the information in the inset will not be particularly useful
> for the reader.
>
>
I agree with that, that plot remained from the days when we were trying to
assess the amount of damage. I'll move the information to the summary table
in Appendix and add a short description to the text.

Cheers,
Anya






> Section 4: I think this is part of "Observations and data reduction", so I
> would make it a subsection of section 3.
>
> It would be great to have this published!
>
> Cheers,
> Patrick
>
>
> Abstract - remove "Despite some telescope malfunction". I think it only
> puts off readers from reading the paper, and it is not particularly useful
> for the reader to read at this point.
>
> Section 2: 2nd paragraph - Add a sentence at the end like "The consequence
> is that only 88 out of the 194 pulsars which are in the HBA census were
> observed and discussed here." At the moment the text doesn't quite
> explicitly states if only HBA pulsars were observed, or all pulsars HBA
> pointings are available for (without the pulsar necessarily being detected).
>
> 3rd paragraph:
>
> with AN incoherent dedispersion scheme.
>
> only compensated FOR between channels
>
> The proposed source sample therefore ONLY? included pulsars with
> sufficiently (if only is not missing from the sentence, then I don't get
> the point of the paragraph)
>
> without ephemerides updateS.
>
> hoping to DETECT strong single pulses.
>
> Last paragraph of section 2: At the moment it just says "here is a plot"
> without a conclusion attached to it. I think it is there to back up the
> last statement from the previous paragraph. So I would delete the last
> paragraph and simply write: "with some preference for closer/brighter
> sources (SEE FIG. 1)."
>
> Caption Fig. 1: I would remove "(see text for more information)", since
> the text kind of says this is done in an, at least for the reader,
> undefined way. Also, "THE scattering time was estimated with THE Galactic"
>
> Footnote 2: Either in THE original ATNF (and end the sentence with a .)
>
> Section 3:
>
> "(beam 0 on the NOMINAL POSITION OF THE TARGET"
>
> "private sources" - clarify these is Lovell and GBT positions.
>
>
> observations at the Jodrell, Lovell -> observations with the Lovell
> telescope at Jodrell Bank
>
> in many cases the initial DM -> in many cases the DM as derived from
> higher-frequency observations
>
> “old” -> these incorrect
>
>
> of THE relative signal strength difference
>
> "for each time/frequency data cell in phase-integrated dynamic spectrum" -
> I'm not 100% sure what this means, so please clarify. Phase-integrated
> means integrated over pulse longitude? So that means you get 300 (nr freq
> channels) numbers per 5 second subint?
>
> Caption Fig. 2: An example of diagnostic plots without (left) and with
> (right) dropped packed cleaning APPLIED for one observation of THE bright
> pulsar B0809+74. The upper row of plots shows the statistic of THE two
> polarizations, the lower PLOTS SHOW THE dynamic and folded spectra,
> waterfall diagram, and the average profile.
>
> Figure 2: The plots should have tick marks. The horizontal labelling of
> the top plots is confusing. There are four pannels. The upper three have (I
> assume) a horizontal axis corresponding to frequency (as shown at the top).
> Only the lower panel has dP as the horizontal axis. However, for the middle
> two plots this is not clear from the figure. Having tickmarks in all panels
> would help. Possibly reducing the gap to zero for the first 3 panels would
> also clarify they share the same horizontal axis, but the lower panel not.
>
>
> For a few pulsars (namely,
> B0105+68, B0643+80, B0656+14), the data was contaminated
> to the point where no cleaning (manual or automatic) could help.
> Thus, we exclude these pulsars from our sample.
> ->
> For only 3 pulsars (namely, B0105+68, B0643+80, B0656+14), the RFI
> prevented useful analysis, hence they were exclude from our sample.
>
>
> "Overall, the fraction of band that has been deleted due to dropped
> packages or RFIs is quite substantial" - I fully agree with Joeri's
> suggestion related to this paragraph.
>
> Section 3.1
>
> We adjusted pulsar period P and DM with the PSRCHIVE pro-
> gram pdmp, maximizing integrated S/N of the frequency- and
> time-averaged profile over the set of trial values of P and DM.
> ->
> We adjusted THE FOLD PERIOD AND THE INTRA-CHANNEL DISPERSION DELAY (i.e.
> adjusting the pulse period would involve sending a missile to the pulsar!)
> with the PSRCHIVE program pdmp, maximizing (remove integrated) THE S/N of
> the frequency and time-averaged profile. REMOVE REST OF SENTENCE
>
> initial number of PHASE bins
>
> Caption figure 3:
> Pulsars are ordered by the maximum deleted fraction.
> ->
> Pulsars are ordered by the highest deleted fraction of the beams.
>
> Same caption: Delete "Pulsars B0656+14, B0105+68, and B0643+80,
> were excluded from the analysis due to unmanagable RFI contamina-
> tion." -> Already said in text, so no need to repeat this, especially
> given the text is quite negative.
>
> Back to section 3.1:
>
> thus for brighter pulsars THE DM may have A BIAS depending on the assumed
> profile evolution.
>
> About the same sentence: you quote the pdmp DM's right? In that case the
> "assumed profile evolution" is that there is no profile evolution. It would
> be good to clarify this.
>
> Fig. 4 shows THE CORRELATION BETWEEN DM and the estimated scattering time
> over period for the detected and non-detected pulsars.
>
> Section 3.2 - I agree with Joeri this should not be part of "Observations
> and data reduction"
>
> Section 4:
>
> Folded data files were calibrated
> ->
> The folded data were calibrated
>
> A coherence factor of 0.85 was used: is there a ref for the 0.85?
>
> The off-pulse windows
> ->
> The on and off-pulse windows (surely you need the on-pulse window as well
> as the off pulse window).
>
> Judging from the relatively well-measured spectra (e.g.
> PSRs B0809+74, B1133+16, B1508+55, and others), the LBA
> measurements stay within the spread of literature points, which
> is by a factor of few.
> ->
> For those pulsars for which multiple spectra have been published (e.g.
> PSRs B0809+74, B1133+16, B1508+55, and others), the LBA measurements are
> consistent with the reported fluxes, which vary by a factor of a few.
>
> adopting adopted -> adopting
>
> THE total flux density error
>
> Interestingly, 19 out of 44 detected pulsars WERE DETECTED WITH THE
> HIGHEST S/N IN A side beam
>
> TEC (like DM) should not be in italics in equation 1 and the text.
>
> 5.1
>
> combined with the literature measurements
> ->
> combined with published measurements (i.e. not a measure of literature,
> which might be so many kg of A&A papers per year).
>
> PL is undefined
>
> 5.2 - It would be great if the suggestions of Michael and Joeri could be
> used to beef up this a bit, which would also help the conclusion section
> and the abstract.
>
> That's it! Great work!
>
>
>
> On 16/08/19 07:53, Anna Bilous wrote:
>
> Dear all,
>
> please find attached the draft of LBA census. Please let us (myself,
> Louis, JM & Vlad) know if you have any comments on it. We would like
> to submit it on Aug 30 due to Louis'es graduation constraints. Sorry
> for the quite short notice, but the paper is short and very simple, so
> it should not take long to read it.
>
> Cheers,
> Anya
>
>
>
> _______________________________________________
> lofarpwg mailing listlofarpwg at astron.nlhttp://mailman.astron.nl/listinfo/lofarpwg
>
>
> --
> Dr. Patrick Weltevrede, senior lecturer in pulsar astrophysics
> Jodrell Bank Centre for Astrophysics,
> School of Physics and Astronomy, University of Manchester
>
> Office 3.210 Alan Turing Building
> Tel: +44 (0) 16127 54162
> Website: http://www.jodrellbank.manchester.ac.uk/
>
>
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