Suzaku News #084: Release of updated PIN tuned background files

[Newsletter for users of the Suzaku mission <suzakunews@lists.nasa.gov>]

1. Updated version of HXD-PIN tuned background modeling (LCFITDT)

The HXD-PIN "tuned" background model (LCFITDT model in Fukazawa
et al 2009, with 2.0ver0804 in the header keyword "METHODV") is
found to be gradually underestimating the true background by up to 3-4%
(as of 2013 December) for the data after 2012 August. Data analysis of
bright sources are not affected, but some cautions must be taken for
sources with a flux comparable to the PIN sensitivity. The HXD team has
identified and fixed the cause and prepared a new version (2.2ver1403
in the header keyword "METHODV") for the data taken AFTER 2012
August. Users are advised to use the new version. Note that there is
no problem for the tuned background before 2012 July. Please refer to
the following web site on the HXD-PIN tuned background:
  http://www.astro.isas.jaxa.jp/suzaku/analysis/hxd/pinnxb/tuned/
US-based users are directed to the Suzaku GOF Data Analysis page
  http://suzaku.gsfc.nasa.gov/docs/suzaku/aehp_data_analysis.html
and follow the relevant links.

2. Note on the HXD-PIN quick background

The HXD-PIN quick background files are either unusable (with zero
good time intervals) or absent for observations since 2012 August.
This is attributed to the change of operation parameters of HXD-PIN
from 2012 August to 2013 September. The background generator does not
work for the data in this period. Therefore, the HXD team recommend
users to rely exclusively on the tuned background files during this
period.  As for observations after 2013 October, the HXD team intends
to re-start the generation of quick background files, after a minor
update of the software has been completed.