The Phase‐resolved X‐Ray Spectra of the Crab Pulsar

Zhang, L.; Cheng, K. S.

doi:10.1086/339347

Cited by 25 publications

(23 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, one should also keep in mind the divergence of results in this regard, and also not rule out the possibility that α may be more or less constant in the leading edge of the first peak of the IP. This is particularly important in view of (a) the lack of quantitative analysis in this regard, and (b) a recent theoretical study prefers a monotonically increasing α at smaller phases within the IP, and neither a constant nor a decreasing α (Zhang & Cheng 2002). To accommodate the spectral hardening of PAH, they need to invoke emission other than synchrotron radiation from secondary pairs.…”

Section: Discussionmentioning

confidence: 99%

A review of X-ray spectral evolution in Crab pulsar

Vivekanand

2002

A&A

View full text Add to dashboard Cite

Abstract. Pravdo et al. (1997) claimed that the phase resolved x-ray spectrum in Crab pulsar (PSR B0531+21) shows a spectral hardening at the leading edge of the first peak of its integrated profile (IP); this was a new and unexpected result. This article reanalyzes their data, as well as some other related data, and argues that the spectrum is as likely to be unvarying (i.e., neither hardening nor softening).

show abstract

Section: Discussionmentioning

confidence: 99%

A review of X-ray spectral evolution in Crab pulsar

Vivekanand

2002

A&A

View full text Add to dashboard Cite

show abstract

“…Its profile shows a double-peaked feature from radio to γ-ray bands (Toor & Seward 1977;Pravdo & Serlemitsos 1981). The variation in photon index between the two peaks has been interpreted by both the outer-gap model (Zhang & Cheng 2002) and a phenomenological two-component model (Massaro et al 2000). A recent Chandra observation discovered a large photon index of the Crab's offpulse emission (Weisskopf et al 2011), which cannot be explained by any previous models.…”

Section: Nonthermal Emissionmentioning

confidence: 94%

Chandra Phase-resolved Spectroscopy of the High Magnetic Field Pulsar B1509−58

Takata

et al. 2017

ApJ

View full text Add to dashboard Cite

We report on a timing and spectral analysis of the young, high magnetic field rotation-powered pulsar (RPP) B1509−58 using Chandra continuous-clocking mode observation. The pulsar's X-ray light curve can be fit by the two Gaussian components and the pulsed fraction shows moderate energy dependence over the Chandra band. The pulsed X-ray spectrum is well described by a power law with a photon index 1.16(4), which is harder than the values measured with RXTE/PCA and NuSTAR. This result supports the log-parabolic model for the broadband X-ray spectrum. With the unprecedented angular resolution of Chandra, we clearly identified off-pulse X-ray emission from the pulsar, and its spectrum is best fit by a power law plus blackbody model. The latter component has a temperature of ∼0.14 keV with a bolometric luminosity comparable to the luminosities of other young and high magnetic field RPPs, and it lies between the temperature of magnetars and typical RPPs. In addition, we found that the nonthermal X-ray emission of PSR B1509−58 is significantly softer in the off-pulse phase than in the pulsed phase, with the photon index varying between 1.0 and 1.8 and anticorrelated with the flux. This is similar to the behavior of three other young pulsars. We interpreted it as different contributions of pair-creation processes at different altitudes from the neutron star surface according to the outer-gap model.

show abstract

“…These properties, along with the spectral properties that are not the subject of this paper, prompted substantial refinements of the physical models of pulsar high-energy activity, both outer gap models (Cheng, Ho, & Ruderman 1986;Zhang & Cheng 1997) as well as polar cap models (Sturrock 1971;Ruderman & Sutherland 1975;Daugherty & Harding 1982;Sturner, Dermer, & Michel 1995; see for recent critical review). Despite reiterated arguments in favor of polar gap models (Baring 2001) and outer gap models , both classes of models still suffer from serious problems.…”

Section: Introductionmentioning

confidence: 99%

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

Dyks

Rudak

2003

ApJ

303

350

View full text Add to dashboard Cite

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.

show abstract

The Phase‐resolved X‐Ray Spectra of the Crab Pulsar

Cited by 25 publications

References 15 publications

A review of X-ray spectral evolution in Crab pulsar

A review of X-ray spectral evolution in Crab pulsar

Chandra Phase-resolved Spectroscopy of the High Magnetic Field Pulsar B1509−58

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

Contact Info

Product

Resources

About