XMM RPS Users' Manual

   
Filling in EPIC MOS details

Fig. 12 displays a screen shot of an EPIC MOS exposure form sheet. The following (mandatory) entries must be made there.

MOS camera unit

When first entering this page, the ``Instrument'' query will have the two options ``EPIC MOS 1'' and ``EPIC MOS 2'' from which users must choose one, because exposures are defined independently for both instruments. Once specified, and once all entries have been made and successfully committed to memory, this is not a selectable parameter anymore, but the fixed entry will appear on the form sheet, as displayed in Fig. 12. Therefore, it is not possible to copy a MOS-1 exposure and then change it to MOS-2.

EPIC optical blocking filters

The allowed choice of filters is presented in Tab. 1.

   

Table 1: EPIC filters

Filter1	Description
OPEN	No blocking filter
THIN	Thin aluminium
MEDIUM	Medium aluminium
THICK	Thick aluminium Polypropylene
CLOSED1	Blocked filter position

Note to Table 1:
1) Only the highlighted filters are recommended for use.

MOS modes of operation

The descriptions of the EPIC modes in the UHB and XRPS differ because of the changes that the modes and their names have undergone with time. The mapping of mode names is tabulated in Tab. 2.

 

Table 2: Mapping of EPIC MOS mode names

UHB name	XRPS name1
FULL WINDOW (600$\times$600)	PRI FULL MOS
REFRESHED FRAME STORE (600$\times$600)2	PRI PART RFS
PARTIAL WINDOW (100$\times$100)3	PRI PART W2
PARTIAL WINDOW (300$\times$300)3	PRI PART W3
PARTIAL WINDOW (100$\times$100)4	PRI PART W4
PARTIAL WINDOW (300$\times$300)4	PRI PART W5
FULL WINDOW 2 NODES (600$\times$600)	PRI PART W6
TIMING	FAST UNCOMP

Notes to Table 2:
1) During AO-1 only the highlighted modes are recommended for use.
2) Variable live time for full field imaging of bright extended sources. About 200 ms duty cycle; 6-7% live time.
3) 1 node readout.
4) Free running readout.

Exposure offset entry

The exposure offset should be left at its default value of 0 s to ensure continuous operation of the instrument. Only under special circumstances, under which one would not want the instrument to operate for a certain amount of time, an offset with respect to the previous instrument exposure, if any, would be defined here.

  

Figure 12: Screen shot of an EPIC MOS exposure form sheet for a FULL WINDOW imaging exposure with a length of 45 ks and an offset with respect to the previous exposure of 0 s. The THIN optical blocking filter was chosen.