Resolving the Bow Shock and Tail of the Cannonball Pulsar PSR J0002+6216

Abstract

We present X-ray and radio observations of the recently discovered bow-shock pulsar wind nebula (PWN) associated with PSR J0002+6216, characterizing the PWN morphology, which was unresolved in previous studies. The multifrequency, multiepoch Very Large Array (VLA) radio observations reveal a cometary tail trailing the pulsar and extending up to 5.′3, with multiple kinks along the emission. The presented radio continuum images from multiconfiguration broadband VLA observations are one of the first results from the application of multiterm multifrequency synthesis deconvolution in combination with the AWProject gridder implemented in the Common Astronomy Software Applications (CASA) package. The X-ray emission observed with Chandra extends to only 21″, fades quickly, and has some hot spots present along the extended radio emission. These kinks could indicate the presence of density variations in the local interstellar medium or turbulence. The bow-shock standoff distance estimates a small bow-shock region with a size of 0.003–0.009 pc, consistent with the pulsar spin-down power of E ̇ = 1.51 × 1035 erg s−1 estimated from timing. The high-resolution radio image reveals the presence of an asymmetry in the bow-shock region, which is also present in the X-ray image. The broadband radio image shows an unusually steep spectrum along with a flat-spectrum sheath, which could indicate varying opacity or energy injection into the region. Spatially resolved X-ray spectra provide marginal evidence of synchrotron cooling along the extended tail. Our analysis of the X-ray data also shows that this pulsar has a low spin-down power and one of the lowest X-ray efficiencies observed in these objects.

Cannonball or Bowling Ball: Proper Motion and Parallax for PSR J0002+6216

“…If we compare our total proper motion and position angle with the initial estimates of these parameters found from Fermi data in Paper I (μ tot = 115 ± 33 mas yr −1 and θ PA = 121°± 13°), we find differences of 2.37σ and 0.59σ, respectively. The agreement in position angle is expected, as the prior estimate of that value also matched well with the direction of the orientation of the PWN as described in Paper I and later in Kumar et al (2023), with the later finding a position angle of θ PA = 111°.13 ± 0°.52.…”

“…which would be a few times smaller than the best estimates from Kumar et al (2023), and among the smallest standoffs known.…”

“…Schinzel et al (2019, henceforth Paper I) noted that the 115 ms γ-ray and radio pulsar PSR J0002+6216 was found at the head of a bow-shock pulsar wind nebula (PWN). Follow-up radio and X-ray observations resolved the PWN and showed that it was consistent with a high-Mach shock formed from the wind from the energetic high-velocity PSR J0002+6216 coming into ram pressure balance with its surrounding medium (Kumar et al 2023). Remarkably, the tail of the PWN extends at least 7′-10′ from PSR J0002+6216, pointing backward toward the geometric center of the Galactic SNR CTB-1 (G116.9+0.2) 28′ away.…”

“…Interestingly, this result of a higher-than-expected density also has implications for the bow shock of PSR J0002+6216. As described in Kumar et al (2023), the pulsar is moving rapidly through the local ISM, generating a bow shock around it and trailing a long and highly collimated tail of emission for several arcminutes. Paper I estimated a Mach number » 200  from initial measurements and comparisons with systems with similar morphology (Kargaltsev & Pavlov 2008;Ng et al 2012).…”

MeerKAT caught a Mini Mouse: serendipitous detection of a young radio pulsar escaping its birth site

“…At a distance of 12 arcmin from the Mini Mouse head, we also identified a circular feature that we classify as a candidate SNR based on its morphology, the apparent centre of which is found in the direction indicated by the tail of the Mini Mouse. The relative positions of the Mini Mouse and of the faint candidate remnant are strongly reminiscent of three similar nebulae with radio pulsar engines: the original Mouse (Yusef-Zadeh & Bally 1987 ;Camilo et al 2002 ), the 'Frying Pan' (K este ven et al 1987 ;Camilo et al 2009 ) nebula, and the 'Cannon ball' pulsar PSR J0002 + 6216 (Schinzel et al 2019 ;Kumar et al 2023 ). All three systems have an accompanying SNR, which have been associated with the birth of the escaping pulsars.…”