dc2 pulsar studies using known ephemeredes
DESCRIPTION
DC2 Pulsar studies using known ephemeredes. David Smith for Denis Dumora,Thierry Reposeur, Damien Parent, & Marie-Helène Grondin CENBG/In2p3/CNRS Bordeaux, France. Topics. Census Localization Sensitivity Multiwavelength lightcurves, and ephemeredes quality. - PowerPoint PPT PresentationTRANSCRIPT
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
David Smith for the Bordeaux 4 1
DC2 Pulsar studies using known DC2 Pulsar studies using known ephemeredesephemeredes
David Smith forDenis Dumora,Thierry Reposeur, Damien Parent, & Marie-Helène Grondin
CENBG/In2p3/CNRS Bordeaux, France
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
David Smith for the Bordeaux 4 2
TopicsTopics
1. Census
2. Localization
3. Sensitivity
4. Multiwavelength lightcurves, and ephemeredes quality.
5. Fluxes and Phase-resolved spectroscopy
6. Beyond DC2…
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
David Smith for the Bordeaux 4 3
1. Census1. Census
• Start from a single .fits file with all 55 days and the full sky, as per Thierry’s method (see e.g. Marcus’ posting, https://confluence.slac.stanford.edu/display/DC2/2006/05/03/New+Merged+DC2+Fits+File
)
• “Damien’s script” – loop over all 98 PSR’s listed in the ephemeredes D4.fits file (“DC2_pulsardb_v2.fits”) and execute gtselect gtbary gtpsearch gtpphase. Translate output to root, output is “storyboard” .pdf file with one page per pulsar, see
https://confluence.slac.stanford.edu/display/DC2/2006/04/24/Automatic+phase+analysis+of+pulsars
• We find 44 pulsars.
• Next slides: examples of script output (a few of the 98 pages…)
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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gtselect on 3° radius. Dark circle shows 0.5° “cookie cutter”.
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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Here, 1° cut.We played with <500/E cut: unsatisfying.
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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5 EGRET pulsars appear clearly.Here is the 6th.We can re-produce Max Razzano’s (*) result for ‘1951+32 but it’s not a “clean detection”,i.e. “stat test” not much above noise level of ~20.
(*) https://confluence.slac.stanford.edu/display/DC2/First+Analysis+of+EGRET+pulsars+with+DC2+Re-generated+data++%28M.Razzano%29
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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Sky map: of 98 pulsars listed in Sky map: of 98 pulsars listed in D4.fits, 44 are easily detected D4.fits, 44 are easily detected
• Of the 98 pulsars listed in the D4 ephemeredes, we pick up 35 (all crosses). Of those, 16(?) are in Jean Ballet’s catalog (other color crosses or other shapes).
• For fun also add Marcus’ sources? Tally overlap of his and the 98 and ours?
• As ‘1951+32 was seen by EGRET but not in 3rd catalog, so we have ones like that.
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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44 of 98: names & addresses44 of 98: names & addresses
44 seen in 2 cut sets
12 more in 1 cut set
“seen” ==1 criteria currently subjective, work in progress…
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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Sky map: of the 44 detections, 27 are Sky map: of the 44 detections, 27 are in J. Ballet catalog. in J. Ballet catalog.
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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27 of 44: names & addresses27 of 44: names & addressesMRF0030_v2 PSR_J1821p17MRF0039_v2 PSR_J2229p6114MRF0054_v2 PSR_J1836m0436MRF0066_v2 PSR_J1837m0559MRF0074_v2 PSR_J1841m0501MRF0082_v2 PSR_J1856p0113MRF0108_v2 PSR_J1852m2610MRF0126_v2 PSR_J1745m0952MRF0167_v2 PSR_B1055m52 EgretMRF0171_v2 PSR_J0633p1746 GemingaMRF0180_v2 PSR_J1739m2903MRF0184_v2 PSR_J0717m1235MRF0197_v2 PSR_J1420m6048MRF0200_v2 PSR_J0904m5008 See Omar's talkMRF0205_v2 PSR_J0955m5434MRF0209_v2 PSR_J1640m4648MRF0216_v2 PSR_J1104m6103MRF0223_v2 PSR_B0833m45 VelaMRF0231_v2 PSR_J1239m6515MRF0237_v2 PSR_J1638m5226MRF0239_v2 PSR_J1707m4729MRF0244_v2 PSR_J1741m3927MRF0249_v2 PSR_B0531p21 CrabMRF0260_v2 PSR_J1735m5757MRF0404_v2 PSR_J1015m5719MRF0470_v2 PSR_J1741m2019MRF0497_v2 PSR_J0837m3515
MRF0233_v2 is 1706-44
MRF0040_v2 is 1951+32
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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2. Localisation2. Localisation
• Science requirement is 0.5 arc minutes = 0.0083 degrees (for
what exposure and what background?). This is called SOURCELOC in the DC2 results we’re supposed to generate,
https://confluence.slac.stanford.edu/display/DC2/DC2+Analysis+Results
• 27 pulsars with known positions in D4.fits ephemeredes database and also positions in J. Ballet catalog (gtsrcid prob >70%)
• Plot distributions of position difference (next slide).
• Blazars will do this better in the long run, but pulsars have advantages at low galactic latitude, and can be seen quickly enough for ISOC to do monitoring.
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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PSR positions vs LAT Catalog positionsPSR positions vs LAT Catalog positions
RMS=0.014° (0.84 arc min)
Post DC2: better selection
of LAT catalog sources and
use of position uncertainties…
By Damien Parent
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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3. Sensitivity3. Sensitivity
• After closeout truth unveiled, will compare detections vs MC intensity ; pulse widths ; background level ; spectrum hardness…
• Meanwhile: for an idealized pulsar, detection versus intensity. For LAT paper?
Level seen for ‘1951…
Parabola.Here, 1E-6.
By Thierry Reposeur & Damien Parent
/cm²/s (>30 MeV)
Crab intensity
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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Determining pulsar sensitivity…Determining pulsar sensitivity…
• From L.M. Kuiper et al.(2001) pulsar “Total Pulse emission” is 2E-4 MeV/cm²/s, or ~7E-6 /cm²/s for E>30 MeV.• Preceding slide: ~1E-8 detection threshold for “crab” background level, so “sensitivity” is 0.07 Crab after one year.• For background level of PSR B1951+32, about 3 times higher. • After DC2 Truth Revealed will fill in plot for range of pulse shapes, spectra, backgrounds…
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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4a. Multiwavelength light curves4a. Multiwavelength light curves
• Absolute phase critical for much pulsar science, e.g. beam geometry versus energy.
• Radio peak defines phase=0 for most pulsars. Ephemeredes must be accurate and up to date.
B
Radio Cone
On-beam -ray ConeRadio Core
(Cartoon courtesy Alice Harding)
Crab, L.M. Kuiper et al.(2001)
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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6 x EGRET versus DC2 phases6 x EGRET versus DC2 phasesStudy by Denis Dumora
Dotted lines: Fierro light curves from Max R
Colored histos:DC2 results
Absolute phase is strange…
Stable weekly, daily.
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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4b. About ephemeredes quality4b. About ephemeredes quality
• A few of the DC2 pulsars had bad ephemeredes:
1055-52 had an unphysical f2 of 1E-12, making f1>0 within the 55 days (pulsars don’t normally speed up…)
1638-5226 had a database frequency quite different from the observed (gtpsearch) frequency.
• We’re working on having the best radio ephemeredes possible… in real life, accidents happen, so check your numbers (blind test results were useful to us, thanks Marcus).
• Another example on next slide.
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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Frequency drift…Frequency drift…
Several DC2 pulsars have wiiiide single peaks, not EGRET-like. Physics, or messyephemeredes? For this one, clear drift.Sharper peak if you set f1=f2=0.
Pisa made the tower straight but not the plot.
55
days
(MET s
eco
nds)
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
David Smith for the Bordeaux 4 1950 GeV
celeste nebula
5. Flux & Phase-resolved 5. Flux & Phase-resolved spectroscopyspectroscopy
• Again, important in understanding beam geometry.
• gtselect doesn’t include “phase” so use fselect instead.
• We have some preliminary non-DC2 likelihood results, but this will be a post-DC2 study.
Kuiper data & fits naïvely extended to 50 GeV
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Pulsar searches with known ephemeredes DC2 Closeout, 1 June 2006
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6. Beyond DC26. Beyond DC2
• currently fmerge fappend of the 7 one-week files but will want to do gtselect from the GSFC server but won’t want to fill the GUI in by hand for all 250 candidates thus we request a way to submit lists to the server
• Learn how to unpack the irf’s to see parameter vs parameter eg Area versus angle relative to detector?
• In real life, some first-year radio ephemeredes applied to weak gamma candidates will have gaps, overlaps, anomalies. We need to develop & exercise tools to handle this.
• Phase-resolved spectroscopy studies are only at their start.
• 1 GeV search then gtpsearch gives new pulsars, need to feed freq back to pre-cut.
• loosen cuts to get more photons? Go back to the merit tuples and learn how to put them in the right .fits format. Perhaps this will be a post-closeout study. Eduardo and I started looking at the merit files during the very first days of DC2, then bordeaux-psr went off to Science Tools and Fits land.
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ConclusionsConclusions
• Discoveries with two months of simulated data multiply the number of known radio-loud gamma ray pulsars by SEVEN.
• For our group, DC2 was a raging success : Before, we were ignorant about Science Tools ; now we’re in the thick of it, with bold plans to prepare for real data.
• For that, many thanks to the people who made DC2 happen.
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AppendixAppendix
Extra slides
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Crab Pulsar Limit Ap. J. 566, 343-357 (2002)
60 GeV
(Fierro et al)
CELESTE: Eo<26 GeV
<0.5 /minute