Two-Pole Caustic Model for High-Energy Light Curves of Pulsars

By J. Dyks, B. Rudak. 2003

254 citations recorded by the source corpus.

We present a new model of high-energy light curves from rotation-powered pulsars. The key ingredient of the model is the gap region (i.e., the region where particle acceleration is taking place and high-energy photons originate) that satisfies the following assumptions: (1) the gap region extends from each polar cap to the light cylinder; (2) the gap is thin and confined to the surface of last open magnetic-field lines; (3) photon emissivity is uniform within the gap region. The model light curves are dominated by strong peaks (either double or single) of caustic origin. Unlike other pulsar models with caustic effects, the double peaks arise from a crossing two caustics, each of which is associated with a different magnetic pole. The generic features of the light curves are consistent with the observed characteristics of pulsar light curves: (1) the most natural (in terms of probability) shape consists of two peaks (separated by 0.4 to 0.5 in phase for large viewing angles); (2) the peaks possess well-developed wings; (3) there is a bridge (interpeak) emission component; (4) there is a nonvanishing off-pulse emission level; (5) the radio pulse occurs before the leading high-energy peak. The model is well suited for four gamma-ray pulsars—Crab, Vela, Geminga, and B1951+32—with double-peak light curves exhibiting the peak separation of 0.4 to 0.5 in phase. Here we apply the model to the Vela pulsar. Moreover, we indicate the limitation of the model in accurate reproducing of the light curves with single pulses and narrowly separated (about 0.2 in phase) pulse peaks. We also discuss the optical polarization properties for the Crab pulsar in the context of the two-pole caustic model.

Subfields: Astronomy and Astrophysics, Oceanography

View Paper: https://www.semanticscholar.org/paper/d7899abd0dd12c81a110717e04f07fcf4a3445c1

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. A. Spitkovsky
2. A. Harding
3. A. Philippov
4. Xue-Ning Bai
5. Bing Zhang
6. B. Cerutti
7. A. Muslimov
8. E. Orlando

In Oceanography

1. Simon Johnston
2. A. Spitkovsky
3. P. Weltevrede
4. Xue-Ning Bai
5. C. Espinoza
6. R. Romani
7. K. Watters
8. A. Harding

Citations in the corpus

• AN ATLAS FOR INTERPRETING γ-RAY PULSAR LIGHT CURVES (2008, methodology): “This is the " two-pole caustic " (TPC) model (Dyks & Rudak 2003), which is thus intermediate between the polar cap (PC) and outer gap (OG) pictures.”
• High-Altitude Emission from Pulsar Slot Gaps: The Crab Pulsar (2008, background): “They found that such emission formed caustic patterns, like those of the ‘‘two-pole caustic’’ model proposed by Dyks & Rudak (2003) to naturally explain the double-peaked profiles of -ray pulsars.”
• THE LARGE AREA TELESCOPE ON THE FERMI GAMMA-RAY SPACE TELESCOPE MISSION (2009, background): “Some also predict emission between the polar cap and outer magnetosphere extremes (Muslimov & Harding 2003; Dyks & Rudak 2003).”
• High-Altitude Particle Acceleration and Radiation in Pulsar Slot Gaps (2004, background): “In their recent attempt to explain the observed high-energy light curves of pulsars, Dyks & Rudak (2003) concentrated on a purely geometrical model by postulating that the emission is produced in a relatively narrow region along the last open magnetic field lines of a pulsar magnetosphere.”
• MODELING OF GAMMA-RAY PULSAR LIGHT CURVES USING THE FORCE-FREE MAGNETIC FIELD (2009, methodology): “…1982, 1996), the slot gap model (SG, or two-pole caustic model, TPC for short; Arons & Scharlemann 1979; Arons 1983; Muslimov & Harding 2003, 2004; Dyks & Rudak 2003; Dyks et al. 2004), the outer gap model(OG, Cheng et al. 1986a,b; Romani & Yadigaroglu 1995; Yadigaroglu 1997; Cheng et al. 2000),…”
• Modelling high-energy pulsar light curves from first principles (2015, background): “…from the stellar surface up to the light-cylinder in some cases (slot-gap Arons & Scharlemann 1979; Arons 1983; Muslimov & Harding 2003, 2004, two-pole caustics Dyks & Rudak 2003 models), but the Fermi-LAT data currently favor emission from the outer magnetosphere (e.g., Abdo et al. 2010).”
• FERMI LARGE AREA TELESCOPE OBSERVATIONS OF THE CRAB PULSAR AND NEBULA (2009, background): “…models (Romani 1996), in which the emission extends between the null charge surface and the light cylinder, and the two-pole caustic (TPC) models (Dyks & Rudak 2003) which might be realized in SG acceleration models (Muslimov & Harding 2004), in which the emission takes place between the neutron…”