During the last week Chandra completed the observing schedule as planned.

A real-time procedure was executed on Jan 27 to perform part of an annual check-out of A-side MUPS thrusters, which are selected for use when Chandra is in its safe-mode configuration. Thruster A3 was fired and performed nominally. An additional procedure was performed to open Isolation Valve 3 (MUPS A) which was closed during the thruster check-out procedure.

Another real-time procedure was executed on Feb 1 to swap the prime solid-state recorder (SSR) from the B-side to the A-side. This swap concludes a six-month interval of health and trending data collection on SSR-B. Real-time procedures were also executed on Feb 1 to perform a routine self-check of the Electrical Interface Assembly (EIA) Sequencer and to perform a diagnostic dump of the Control Processing Electronics (CPE).

A Chandra image release was issued on Jan 30 describing observations a spectacular, ongoing collision between at least three galaxy clusters. The giant galaxy cluster forming from this collision is Abell 2256. The composite image of Abell 2256 combines X-rays from Chandra and XMM with radio data collected by the Giant Metrewave Radio Telescope (GMRT), the Low Frequency Array (LOFAR), and the Karl G. Jansky Very Large Array (VLA), plus optical and infrared data from Pan-STARRs. Collisions and mergers like this are the main way that galaxy clusters can grow into the gigantic cosmic edifices seen today. These also act as the largest particle accelerators in the universe. For details see: https://chandra.si.edu/photo/2023/a2256/

Of note this week was the release on Jan 31 of CIAO 4.15.1. The primary changes introduced in the patch updates to support NumPy version 1.24, Updates to the ciao-contrib package and an upgrade to version 8.4.1 of SAOImage DS9. For details see: https://cxc.cfa.harvard.edu/ciao4.15/releasenotes/ciao_4.15.1_release.html

The schedule of targets for the next week is shown below.