Discovery of a Pulsar Wind Nebula Candidate in the Cygnus Loop

Abstract

We report on a discovery of a diffuse nebula containing a pointlike source in the southern blowout region of the Cygnus Loop supernova remnant, based on Suzaku and XMM-Newton observations. The X-ray spectra from the nebula and the pointlike source are well represented by an absorbed power-law model with photon indices of 2.2+/-0.1 and 1.6+/-0.2, respectively. The photon indices as well as the flux ratio of F_nebula/F_pointlike ~ 4 lead us to propose that the system is a pulsar wind nebula, although pulsations have not yet been detected. If we attribute its origin to the Cygnus Loop supernova, then the 0.5-8 keV luminosity of the nebula is computed to be 2.1e31 (d/540pc)^2 ergs/s, where d is the distance to the Loop. This implies a spin-down loss-energy E_dot ~ 2.6e35 (d/540pc)^2 ergs/s. The location of the neutron star candidate, ~2 degrees away from the geometric center of the Loop, implies a high transverse velocity of ~1850 (d/540pc)(t/10kyr)^{-1} km/s, assuming the currently accepted age of the Cygnus Loop.

6 pages, 3 figures, accepted for publication in The Astrophysical Journal Letters

References in corpus (8)

• The XMM-Newton Serendipitous Survey. V. The Second XMM-Newton Serendipitous Source Catalogue
• The 400 square degrees ROSAT PSPC galaxy cluster survey: Catalog and statistical calibration
• Pulsar Wind Nebulae in the Chandra Era
• Possible Charge-Exchange X-Ray Emission in the Cygnus Loop Detected with Suzaku
• Fermi Large Area Telescope Observations of the Cygnus Loop Supernova Remnant
• The Plasma Structure of the Cygnus Loop from the Northeastern Rim to the Southwestern Rim
• The Plasma Structure of the Southwestern Region of the Cygnus Loop with the XMM-Newton Observatory
• Isolated Neutron Stars

Cited by in corpus (6)

• The Second Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
• Asymmetric supernova remnants generated by Galactic, massive runaway stars
• The Cygnus Loop's Distance, Properties, and Environment Driven Morphology
• Stellar Binaries That Survive Supernovae
• New continuum and polarization observations of the Cygnus Loop with FAST II. Images and analyses
• Multi-wavelength insights into the pulsar wind nebula candidate near 1LHAASO J0343+5254u: an obscured merging galaxy cluster?