First light for the EWOCS (Extensive Westerlund One Chandra Survey) project

On June 2019, the panel for the evaluation of the proposals for observations with the NASA telescope Chandra, operating in the X-rays, which met up in Boston, has approved the Large Project: “Star formation in starburst: a deep ACIS-I observation of Westerlund 1“, led by the astronomer Mario Giuseppe Guarcello – INAF Astronomical Observatory of Palermo. More details on the project can be found here.

 

Almost one year later, the first Chandra observations of the dense stellar cluster Westerlund 1 have been delivered: a total of 50 ksec (slightly less than 14 hours) out of a total of 1 Msec (about 277 hours). The figures below show:

  • top-left panel: the entire ACIS-I image of Westerlund 1. The cluster core is clearly visible in the center of the field. The brightest source is the well known pulsar CXO J164710.20-455217.
  • top-right panel: a zoom into the core of Westerlund 1, at the center of the field. Green circles mark the position of the new massive members of the cluster selected in a recent study, some of which are detected in X-rays in this new image.
  • bottom-left panel: folded light curve (e.g. the time variation of the emitted flux) of the pulsar CXO J164710.20-455217.
  • bottom-right panel: the X-ray spectrum of CXO J164710.20-455217 (points with errors) with overplotted the model used to fit the data.

 

of Mario Giuseppe Guarcello  ( follow mguarce)