The curved spectrum of the young pulsar halo LHAASO J0248+6021 is explained by a time-dependent energy-loss bump in the electron spectrum that remains close to the cutoff, unifying it with the shifted bump observed in the older Geminga halo.
Geminga's puzzling pulsar wind nebula
4 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
We report on six new Chandra observations of the Geminga pulsar wind nebula (PWN). The PWN consists of three distinct elongated structures - two $\approx 0.2 d_{250}$ pc long lateral tails and a segmented axial tail of $\approx 0.05 d_{250}$ pc length, where $d_{250}=d/(250 {\rm pc})$. The photon indices of the power law spectra of the lateral tails, $\Gamma \approx 1$, are significantly harder than those of the pulsar ($\Gamma \approx 1.5$) and the axial tail ($\Gamma \approx 1.6$). There is no significant diffuse X-ray emission between the lateral tails -- the ratio of the X-ray surface brightness between the south tail and this sky area is at least 12. The lateral tails apparently connect directly to the pulsar and show indication of moving footpoints. The axial tail comprises time-variable emission blobs. However, there is no evidence for constant or decelerated outward motion of these blobs. Different physical models are consistent with the observed morphology and spectra of the Geminga PWN. In one scenario, the lateral tails could represent an azimuthally asymmetric shell whose hard emission is caused by the Fermi acceleration mechanism of colliding winds. In another scenario, the lateral tails could be luminous, bent polar outflows, while the blobs in the axial tail could represent a crushed torus. In a resemblance to planetary magnetotails, the blobs of the axial tail might also represent short-lived plasmoids which are formed by magnetic field reconnection in the relativistic plasma of the pulsar wind tail.
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UNVERDICTED 4representative citing papers
Discrete ICS simulation shows continuous approximations overestimate evolved cutoff energies, leading to lower inferred electron injection cutoffs for Geminga at 95% CL and potential overestimation of acceleration in PeV sources.
A two-zone diffusion model fitted to HAWC morphology and spectrum data constrains Geminga's slow-diffusion zone to 30-70 pc and injection index p ≤ 2.17, reproducing AMS-02 positrons as a derived outcome.
Simulations indicate that CTA's angular resolution and LHAASO-KM2A's large area will improve morphological separation of diffusion-based pulsar halos from simpler spatial models.
citing papers explorer
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Spectral energy-loss bump and $\gamma$-ray pulsar halos
The curved spectrum of the young pulsar halo LHAASO J0248+6021 is explained by a time-dependent energy-loss bump in the electron spectrum that remains close to the cutoff, unifying it with the shifted bump observed in the older Geminga halo.
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Discrete treatment of inverse Compton scattering: implications on parameter estimation in gamma-ray astronomy
Discrete ICS simulation shows continuous approximations overestimate evolved cutoff energies, leading to lower inferred electron injection cutoffs for Geminga at 95% CL and potential overestimation of acceleration in PeV sources.
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Constraining the slow-diffusion zone size and electron injection spectral index for the Geminga pulsar halo
A two-zone diffusion model fitted to HAWC morphology and spectrum data constrains Geminga's slow-diffusion zone to 30-70 pc and injection index p ≤ 2.17, reproducing AMS-02 positrons as a derived outcome.
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Resolving diffusion signatures in distant pulsar halos with current and future experiments
Simulations indicate that CTA's angular resolution and LHAASO-KM2A's large area will improve morphological separation of diffusion-based pulsar halos from simpler spatial models.