English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We report the detection using ASCA data of a hard X-ray source in thevicinity of the radio pulsar PSR B1853+01 which is located within the supernovaremnant (SNR) W44. PSR B1853+01, a 267ms pulsar, has to date only been detectedin the radio band. Previous observations at soft X-ray energies (e.g., withROSAT HRI) have failed to detect any significant X-ray emission (pulsed orunpulsed) from the pulsar. Over the 0.5--4.0keV band, the ASCA data show softthermal emission from W44 with a morphology very similar to that observedearlier by Einstein and ROSAT. In the high energy band (4.0--9.5 keV), the SNRis, for the most part, invisible, although a source coincident with theposition of PSR B1853+01 is evident. The observed ASCA spectra, extracted froma region around the PSR position, are consistent with a power-law origin(photon index =~2.3) for the X-ray emission from this source at a flux level(flux density ~~0.5 10^-6 Jy at 1 keV) consistent with previous upper limits.Timing analysis of the hard X-ray source failed to detect pulsations at thepulsar's period. We conclude that the new hard source in W44 represents anX-ray synchrotron nebula associated with PSR B1853+01.

Discovery of an X-Ray Synchrotron Nebula Associated with the Radio Pulsar PSR B1853+01 in the Supernova Remnant W44