The Effect of General Relativistic Frame Dragging on Millisecond Pulsar Visibility for the H.E.S.S. Telescope

1
Unraveling the Emission Geometry of the Fermi
Millisecond Pulsars

• C. Venter, A. K. Harding, L. Guillemot
• (astro-ph0911.0872v1)
• Second Fermi Symposium, Washington, DC
• 2 5 November 2009

2
New Gamma-ray MSPs
J0034-0534 1.877 0.259 0.54 ( 0.22 - 0.14)
11.5 15.5 0.706
Abdo et al. 2009, Science, 325, 848 Venter et al.
(2009) (astro-ph0911.0872v1) Abdo et al. 2009,
in preparation (see talk of L. Guillemot)
3
Recycled Pulsars
Alpar et al. (1982) Archibald et al.
(2009) http//www.mcgill.ca/channels/announcements
/item/?item_id106788
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Millisecond Pulsars
5
Standard Accelerator Geometries
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Accelerator Geometries
pair-starved polar cap
slot gap / TPC
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SR Effects Retardation
Sweepback only
Projected field lines from single pole
plus aberration
and travel time delay
Yadigaroglu (1997)
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Formation of Caustics

• Emission on trailing field lines
• Bunches in phase
• Arrives at inertial observer simultaneously

• Emission on leading field lines
• Spreads out in phase
• Arrives at inertial observer at different times

• Caustic emission
• Dipole magnetic field
• Outer edge of open volume

(Observed Static retarded dipole, for x lt 1)
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PSPC E-field Matching of Solutions
Matching Criteria

• E matching for E(2) lt E(3)
• E E(3)
• E lt 0

Pair-starved case (unscreened PC model)
Muslimov Harding (2004) Venter et al. (2009)
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Radio Beam Geometry
Harding et al. (2007) Gonthier (2004)
Model of Arzoumanian, Chernoff Cordes (2002)
400 MHz Kijak Gil (2003) Frequency-dependent
cone width of Mitra Deshpande (1999)
Total flux
Cone radius
Cone position
Cone width
Emission altitude
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RESULTS MSP Light Curves (P 2, 3, 5 ms
various a, z)
TPC1
OG1
PSPC
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Radio Beam Geometry
a 70o, P 2 ms
a 70o, P 5 ms
Radio _at_ 1400 MHz
Cone size width P-0.35
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Light Curve Calculation
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TPC Phaseplot as function of a
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Light Curves as function of z
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E.g. TPC OG, a 30o
TPC2 (30,60)
OG1 (30,60)
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E.g. TPC OG, a 70o, 80o
TPC1 (70,80)
OG1 (80,70)
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E.g. PSPC, a 40o
PC2 (40,80)
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PSR J00300451
TPC

• 0.45
• d 0.16

OG
D
d
20
PSR J02184232
TPC
OG
d 0.5
21
PSR J0437-4715
TPC
OG
d 0.45
22
PSR J0613-0200
TPC
OG
d 0.42
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PSR J07511807
TPC
OG
d 0.42
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PSR J16142230
TPC
OG

• 0.48
• d 0.20

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PSR J1744-1134
PSPC
d 0.85
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PSR J2124-3358
PSPC
d 0.85
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PSR J0034-0534
Preliminary
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Fits of a and z
J0034 0534 30 70 30
70
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Conclusions

• Pulse shape lag outer magnetospheric
  (high-altitude) emission (OG / SG / unscreened
  PC)
• Unexpected implication screening / pair cascades
• We need to find new ways of creating pairs in
  low-spin-down magnetospheres (Compactness, Larger
  E, smaller rc, larger B)
• Exclusive differentiation between PSPC vs. TPC /
  OG models
• OG / SG gamma trails radio with large lag
• PSPC radio has small lag w.r.t. gamma
• fW lt 4 (1) extended emission (wide beaming
  angle)
• Few radio-quiet MSPs expected larger radio beam
  widths than for canonical pulsars
• Reasonable agreement with parameters inferred
  from MSP polarization measurements

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Future Work

• Using full acceleration models to study
  gamma-ray
• Spectra (phase-resolved phase-averaged)
• Luminosities / Efficiencies
• Light curves
• Constrain electrodynamical quantities B-field
  structure
• Population studies
• Compare Galactic Field and Globular Cluster MSP
  properties?

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THANKS!
He stretches out the north over empty space He
hangs the earth on nothing. (Job 267 NKJ)