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

In this paper, we present updated estimates of the velocity of the neutronstar (NS) in the supernova remnant (SNR) Cassiopeia A using over two decades ofChandra observations. We use two methods: 1.) recording NS positions fromdozens of Chandra observations, including the astrometric uncertainty estimateson the data points but not correcting the astrometry of the observations, and2.) correcting the astrometry of the 13 Chandra observations that have asufficient number of point sources with identified Gaia counterparts. Formethod #1, we find velocity of 280 $\pm$ 123 km s$^{-1}$, with an angle of 87$\pm$ 22 degrees south of east. For method #2, we find a velocity of 445 $\pm$90 km s$^{-1}$ at an angle of 68 $\pm$ 12 degrees south of east. Both of theseresults match with the explosion-center-estimated velocity of $\sim$350 kms$^{-1}$ and the previous 10 year baseline proper motion measurement of 570$\pm$ 260 km s$^{-1}$, but our use of additional data over a longer baselinehas led to a smaller uncertainty by a factor of 2$\unicode{x2013}$3. Ourestimates rule out velocities $\gtrsim$600 km s$^{-1}$ and better match withsimulations of Cassiopeia A that include NS kick mechanisms.

Updated Proper Motion of the Neutron Star in the Supernova Remnant Cassiopeia~A