Non-X-ray Background Database and Tools

The non-X-ray background (NXB) is residual signal that is not produced by celestial X-rays focused by the optics and cannot be removed using established screening methods. For XRISM Resolve and Xtend, this is largely due to high-energy charged particles, and much of this signal is eliminated using (for example) information from the anti-coincidence detector on Resolve or event grades on Xtend. Both instruments routinely observe the dark limb of the Earth, and since no celestial X-rays are collected during these times, this 'night Earth' data can be used to model and correct for the NXB in XRISM observations that require it.

The XRISM team has developed provisional databases of NXB data for each instrument, along with recipes for extracting NXB spectra and including them in spectral fitting. These can be accessed using the links below.

Resolve

Resolve NXB database and spectral extraction recipes

Resolve NXB spectral model

Xtend

Xtend NXB database and spectral extraction recipes

Xtend NXB spectral model

Xtend NXB image generation recipe

Email the Science Data Center (SDC) helpdesk with any questions: XRISM-SDC-help@lists.nasa.gov