Related papers: The Low Geminga Halo Diffusion Coefficient and a G…
Here we investigate to what extent unresolved \gr pulsars contribute to the galactic diffuse emission, and further whether unresolved \gr pulsars can be made responsible for the excess of diffuse galactic emission above 1 GeV which has been…
Recent measurements of the Geminga and B0656+14 pulsars by the gamma-ray telescope HAWC (along with earlier measurements by Milagro) indicate that these objects generate significant fluxes of very high-energy electrons. In this paper, we…
Extended gamma-ray emission around isolated pulsars at TeV energies, also known as TeV halos, have been found around a handful of middle-aged pulsars. The halos are significantly more extended than their pulsar wind nebulae but much smaller…
The gamma-ray halo surrounding Geminga suggests a notable reduction in cosmic-ray diffusion. One potential explanation for this phenomenon is the projection effect of slow diffusion perpendicular to the average magnetic field (represented…
Observations by HAWC indicate that many young pulsars (including Geminga and Monogem) are surrounded by spatially extended, multi-TeV emitting regions. It is not currently known, however, whether TeV emission is also produced by recycled,…
The unexpectedly high flux of cosmic ray positrons detected at Earth may originate from nearby astrophysical sources, dark matter, or unknown processes of cosmic-ray secondary production. We report the detection, using the HighAltitude…
The new Voyager measurements of cosmic ray electrons between 6-60 MeV beyond 122 AU are very sensitive indicators of cosmic ray propagation and acceleration in the galaxy at a very low modulation level. Using a Monte Carlo diffusion model…
We report a search for radio continuum emission from the gamma-ray pulsar Geminga. We have used the VLA to image the location of the optical counterpart of Geminga at 74 and 326 MHz. We detect no radio counterpart. We derive upper limits to…
Pulsar halos are extended gamma-ray structures generated by electrons and positrons escaping from pulsar wind nebulae (PWNe), considered a new class of gamma-ray sources. They are ideal indicators for cosmic-ray propagation in localized…
Diffuse TeV emission has been observed by H.E.S.S. in the Galactic Center region, in addition to the GeV gamma rays observed by Fermi. We propose that a population of unresolved millisecond pulsars located around the Galactic Center,…
Cosmic rays propagating in the Galaxy may excite a streaming instability when their motion is super-alfvenic, thereby producing the conditions for their own diffusion. In this paper we present the results of a self-consistent solution of…
The propagation of particles accelerated at supernova remnant shocks and escaping the parent remnants is likely to proceed in a strongly non-linear regime, due to the efficient self-generation of Alfv\'en waves excited through streaming…
Geminga is an enigmatic radio-quiet gamma-ray pulsar located at a mere 250 pc distance from Earth. Extended very-high-energy gamma-ray emission around the pulsar has been detected by multiple water Cherenkov detector based instruments.…
In this paper we fit the observed galactic cosmic ray electron spectrum from a few MeV to 1 TeV. New data from Voyager from 5-60 MeV beyond the heliopause is used along with high energy data from the PAMELA, FERMI and AMS-2 instruments in…
We have obtained evidence of gamma-ray emission above 1 TeV from PSR1706-44, using a ground-based telescope of the atmospheric \v{C}erenkov imaging type located near Woomera, South Australia. This object, a $\gamma$-ray source discovered by…
We attempt to interpret the cosmic-ray positron excess by injection from the nearby pulsar Geminga, assuming a two-zone diffusion scenario and an injection spectrum with a low energy cutoff. Since the high energy positrons and electrons…
This paper explores small-scale departures from force-free electrodynamics around a rotating neutron star, extending our treatment of resistive instability in a quantizing magnetic field. A secondary, Cerenkov instability is identified:…
We present multiwavelength studies of the 106.6 ms gamma-ray pulsar PSR J1907+06 near the TeV source MGRO J1908+06. Timing observations with Fermi result in a precise position determination for the pulsar of R.A. = 19h07m547(2), decl. =…
Recent TeV observations of nearby pulsars with the HAWC telescope have been interpreted as evidence that the diffusion of high-energy electrons and positrons within pulsar wind nebulae is highly inefficient compared to the rest of the…
Very High Energy (VHE) gamma-rays in pulsars, and their surrounding halos, are interpreted to originate from the leptonic channel, electromagnetic interactions through electron inverse Compton (IC) scattering. In the hadronic scenario,…