X-Ray Studies of the Pulsar PSR J1420–6048 and Its TeV Pulsar Wind Nebula in the Kookaburra Region

Abstract

We present a detailed analysis of broadband X-ray observations of the pulsar PSR J1420−6048 and its wind nebula (PWN) in the Kookaburra region with Chandra, XMM-Newton, and NuSTAR. Using the archival XMM-Newton and new NuSTAR data, we detected 68 ms pulsations of the pulsar and characterized its X-ray pulse profile, which exhibits a sharp spike and a broad bump separated by ∼0.5 in phase. A high-resolution Chandra image revealed a complex morphology of the PWN: a torus-jet structure, a few knots around the torus, one long (∼7′) and two short tails extending in the northwest direction, and a bright diffuse emission region to the south. Spatially integrated Chandra and NuSTAR spectra of the PWN out to 2.′5 are well-described by a power-law model with a photon index Γ ≈ 2. A spatially resolved spectroscopic study, as well as NuSTAR radial profiles of the 3–7 keV and 7–20 keV brightness, showed a hint of spectral softening with increasing distance from the pulsar. A multiwavelength spectral energy distribution (SED) of the source was then obtained by supplementing our X-ray measurements with published radio, Fermi-LAT, and H.E.S.S. data. The SED and radial variations of the X-ray spectrum were fit with a leptonic multizone emission model. Our detailed study of the PWN may be suggestive of (1) particle transport dominated by advection, (2) a low magnetic-field strength (B ∼ 5 μG), and (3) electron acceleration to ∼PeV energies.

X-Ray Characterization of the Pulsar PSR J1849−0001 and Its Wind Nebula G32.64+0.53 Associated with TeV Sources Detected by H.E.S.S., HAWC, Tibet ASγ, and LHAASO

“…The degeneracy can be broken to a certain extent if we can constrain some of the parameters; e.g., measuring the expansion speed of the PWN can help determine V 0 and α V (Equation ( 2)), and B 0 can be well constrained if u CMB + u IR are known. Nonetheless, the values presented in Table 3, which are similar to the values inferred for other PWNe (e.g., Park et al 2023b), can account for the measurements.…”

Hard X-Ray Observation and Multiwavelength Study of the PeVatron Candidate Pulsar Wind Nebula “Dragonfly”

“…These features include a compact hard X-ray inner nebula undergoing SC burnoff, a large diffuse outer nebula in lower energy, and the absence of a GeV nebula. Opposite patterns are observed in two of our target PWNe, K3 (Park et al 2023b) and Rabbit (Park et al 2023a). These PWNe exhibit extended hard X-ray nebulae without a sign of SC burnoff, energy-insensitive morphologies, and bright GeV nebulae.…”

“…Combined with modeling of the multiwavelength (MW) spectral energy distribution (SED) of the PWNe over 20 decades of energy range, it allows the deduction of the key physical parameters that define the systems, such as the maximum particle energy and magnetic field. Our NuSTAR observation and MW SED modeling have functioned as powerful probes of PWNe as energetic leptonic cosmic-ray accelerators in our galaxy (e.g., Burgess et al 2022;Park et al 2023aPark et al , 2023b.…”

Investigating the Multiband Nonthermal Radiative Properties of HESS J1420−607

“…The pulsar has a spin-down luminosity of L = 1.03 ×10 37 erg s −1 . In the works of Park et al (2023), an age of 9 kyr was assumed based on the γ-ray-to-X-ray flux ratio (see Kargaltsev et al 2013), we have also adopted the age in this paper. Consequently, L 0 = 1.11 × 10 38 erg s −1 and τ 0 = 3.98 kyr were derived using Equations (5) and (6).…”