Status of pulsar simulation for DC 2

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Status of pulsar simulation for DC 2
Massimiliano Razzano Nicola Omodei GLAST DC
II Software Workshop (Goddard Space Flight
Center, June 27th-29th 2005)
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g ray pulsar simulation for GLAST

• PulsarSpectrum is a simulator developed in Pisa
  used for simulating gamma ray emission from
  pulsars
• Key features
• It can reproduce spectra and lightcurves of known
  g ray pulsars
• Flexible architecture to facilitate creation of
  pulsar sources
• Advanced simulation of timing effects due to
  period changes and motion of GLAST and Earth in
  Solar System
• Full phenomenological model now implemented
• Pulsar parameters easy to implement
• Capability of simulation of pulsar catalogs
• Fully compatible with GLAST-LAT standard software
  environment (Gleam, observationsSim)

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An overview of PulsarSpectrum
Simulator Engine
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The phenomenological model (I)lightcurve
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The phenomenological model (II)spectrum
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The phenomenological model (III)the final product

• We combine lightcurve and spectrum
• ? TH2D ROOT histogram
• Now multiplication, but more complicated
  combination laws are not so difficult to achieve

According to the flux the photons are then
extracted and the time arrivals of photons are
de-corrected
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The extraction of the photonsthe SpectObj
package
SpectObj transforms Nn (ph/keV/s/m2) into ph Nn
? NnAdetDtDE Compute also the cumulative
function of Nv values in the choosen spectral
range P(tk) SE1,E2Nn(tk,Ek)
Next photon is at tN when P(tN ) 1
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Period derivatives
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Barycentric decorretions
The first step in data analysis is to transform
the photon arrival time at the spacecraft
(expressed in MET) to the Solar System Barycenter
(expressed in TDB) The simulator must
de-correct for these effects At present 3 main
effects are taken into account

• Conversion TT?TDB
• Geometric corrections due to lighttravel time
  from GLAST to Solar System Barycenter
• Relativistic delay due to gravitaional field of
  Sun (Shapiro delay)

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Simulating pulsar catalogs
PulsarSpectrum is also been tested for simulation
of many pulsar in the sky. This features allow
the possibility to simulate entire pulsar
catalog. For each pulsar a log file is produced
in order to keep track of the simulated pulsars

• Up to now
• simulated catalog of EGRET pulsars
• Tests with catalog provided by A.Harding with
  more than 1k pulsars

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Pulsar database
For each pulsar simulated in DC2 there must be a
correspondant entry in the pulsar database (D4)
PulsarSpectrum

• PulsarSpectrum next implemented features (under
  tests) are devoted to interfacing with database
• Multiple entries (that allows the possibility to
  insert different ephemerides for different
  periods as in observations)
• Output txt file that can be converted with
  gtpulsardb in a FITS file compatible with SAE
  standard.

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PulsarSpectrum and Science Tools
Testing the SAE Pulsar Analysis Tools
Thanks to the simulation of timing effects, like
barycentric decorrections) PulsarSpectrum is
useful for testing Pulsar Analysis Tools in the
SAE (glbary, pulsePhase, gtpulsarDb, stpsearch)
Simulations and ScienceTools report in Science
Tools 1st Checkout (Oct,12-Oct 29 2004) and 2nd
Checkout (Mar,21-Apr,8)
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Some screenshots from Checkout 2
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Summary for DC2
From http//glast.gsfc.nasa.gov/ssc/dev/psr_tools/
testplanDC2.html
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Summary on Pisa activities on pulsars

• Status of work
• Full simulation code implemented and tested
• Phenomenological model included
• Simulation of period change with time
• Effects of GLAST and Earth motion and of
  gravitational field of Sun on timing (barycentric
  de-corrections)
• Simulation of EGRET pulsars
• Use of PulsarSpectrum for testing the LAT
  Analysis Tools for pulsars
• Participation to Science Tools Checkouts. Up to
  now 1st and 2nd Checkout
• Development of visualization and analysis tool
  (not included is the Analysis Tool suite)
• Work on simulating catalogs of pulsars in
  preparation for DC2

• Work in progress and plans for future
• Inclusion of more realistic timing effects
  (timing noise, glitches,etc.)
• Development of simulation of binary pulsar
  systems
• Work with LAT Pulsar Science Group for studying
  GLAST performances on pulsar science
• Study of analysis techniques for pulsar blind
  searches
• Work on the development to fit optimally the
  requirements for DC2 (start January 2006)
• Provide output ephemerides database of the
  simulated pulsars to the DC2 users

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backup
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On going Pisa activities (Pulsars)

• Pulsar simulations
• Refine the model
• Optimize algorithms (simulating pulsars requires
  lot of time to simulate all timing effects)
• Adding more realistic timing effects (multiple
  ephemerides, timing noise, etc)
• Use EGRET data to simulate known gamma ray
  pulsars

• Pulsar Data Analysis
• Test Pulsar Analysis Tools for crosscheck the
  simulation?analysis chain
• Interface with Science Tools group to know
  simulation requirements and refine the model
• Partecipation to Science Tools Checkout as
  reviewers for the pulsar tools
• Development of visualisation and analysis tools (
  e.g. spectral) as for GRBs.

• LAT Pulsar Science
• Partecipation to the PSR/PWN/SNR Science Group
• Plan to work for pre-lauch papers on
• LAT performances on the observation of pulsars
• Expected LAT sensitivity for different pulsars
  emission scenarios

• Pulsars in DC2
• Development of PulsarSpectrum in order to fit the
  simulation requirements for DC2 (now this
  simulator is considered as basis for the pulsars
  simulation in DC2)
• Test of simulation of an extended catalog of fake
  pulsars
• Include realistic observation conditions
  (multiple ephemerides, pulsar database)
• Provide the ephemerides database of the simulates
  pulsars to the DC2 users