XMM-Newton Users' Handbook

... profile¹

A King profile has the form $A(1/([1+(r/r_c)^2]^{\alpha}))$, where $r$ is the radial distance from the centre of the PSF, $r_c$ is the core radius and $\alpha$ is the slope of the King model.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... lists.²

An event list is a table with one line per received event, listing (among others) attributes of the events such as the x and y position at which they were registered, their arrival time and their energy.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... passage)³

The Target Visibility Checker, a tool to check the visibility of any target in the sky for XMM-Newton, provides also information on the orbital phase when the target visibility starts and ends.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

...uhb:fig:epic_sens ⁴

The 5$\sigma$ value represents a relatively conservative limit which crudely takes into account the fact that there are additional systematic background effects which have yet to be characterised in detail. For the effective beam area of XMM-Newton, the appropriate limit for purely Poissonian background fluctuations to yield $\le 1$ spurious source per field is about 3.5 - 4$\sigma$.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... \AA⁵

The formula for conversion of wavelengths into energies is $\lambda$(Å) $\times$E(keV) = 12.3985

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... Handbook⁶

http://xmm.esac.esa.int/external/xmm_sw_cal/calib/documentation/CALHB/

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... HEASARC⁷

http://heasarc.gsfc.nasa.gov/Tools/w3pimms.html

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... time⁸

Frametransfer time is the time needed to transfer the charge accumulated on the continuously exposed CCD during an integration time into the storage area. It amounts to $\simeq$0.1740 ms. The sum of the frametransfer time and of the time needed to read out all the pixels in the storage area is the frametime. The frametime depends on the sizes, shapes and positions of the windows. For a full frame it amounts to about 11 ms. The only time when source photons are not properly recorded by the detector is during charge transfer. Therefore, the deadtime is equal to the frametransfer time.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... sources⁹

Observations of the white dwarf GD153 with various EPIC pn read-out modes and filters yielded large inconsistencies between the spectra below 0.5 keV. A strong correlation is seen between apparent count rates and read-out mode (slower read-out results in higher count-rates and harder spectrum) and filters (medium filter reduces the count rate more than expected from the thin/medium ratio). The most-likely explanation for this effect is pile-up. In principle three kinds of pile-up at low energies are possible: pile-up of two source X-ray photons, pile-up of a source photon with electronic noise and pile-up of a source X-ray photon with optical photons from the source. The white dwarf spectrum ($kT=25$ eV, Black-body) has its maximum at 75 eV, which is below the low-energy event threshold of the instrument (20 adu (not CTI corrected) which effectively corresponds to about 115 eV at the focus position). I.e. the bulk of the photons do not directly produce events above the threshold. However pile-up can bring the energy of sub-threshold events above threshold. The increasing effective area of the instrument below 100 eV supports photon pile-up from very soft sources. A very strong source of pile-up is the steeply increasing number of noise events, from which only a small tail is visible above the threshold. Source photons with energies below the threshold (which would nominally not be detected) have a high probability to "gain energy" by fortuitously adding to noise. For weak sources (and/or fast readout) this is most likely the dominant pile-up effect.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.