Table 2

X-ray spectral quality classes defined based on the XMM pointing quality and the signal-to-noise ratio (S/N) of the spectrum.

Quality class N F X amin /F fit Flag PN counts MOS1 counts MOS2 counts



Pointing S/N med mean σ min max med min max med min max med

0 >6 547 1.00 1.0 0.3 1 25 11194 268 13 2626 105 6 2651 107
0/1/2 >4 281 1.01 1.1 0.5 2 8 1879 103 3 244 43 6 415 40
0/1/2 34 75 1.07 2 3 3 6 246 43 2 49 23 4 81 20
0/1/2 <3 96 0.78 52 191 4 3 177 16 1 34 6 1 55 5
NoData 1 5 2 2 1 1

Notes. The XMM pointing quality classes are: 0 = good quality (> 7 ks exposure time and < 1.5 × 10-5cts s-1cm-2 background level, 1 = low exposure time (> 3 ks), 2 = high background < 4.5 × 10-5cts s-1cm-2). Pointings with quality class 3 corresponding to both low exposure time and high background were not used for spectrum extraction.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.