XMM-Newton Phase II RPS Users Manual

5.2.3.2 Filling in time constraints

For each ''Fixed'' (i.e., fixed-time) observation, a special ''Time Constraints'' form must be filled in. Observations with Position Angle constraints should NOT be flagged as ''Fixed'' time observations. A screen shot of this page is displayed in Fig. 10.

Figure 10: Screen shot of the ''Time Constraints'' page in which entries for time-constrained observations must be made.

The form offers four different sections, labeled as:

• ''XMM-Newton Revolution''

• ''Absolute Time (UT)''

• ''Phase''

• ''Comments''

The first three sections are exclusive. This means that you can fill in only one section at a time depending on the kind of time constraint you want to use.

Inputs can be made either in the ''Earliest Revolution'' and ''Latest Revolution'' input fields (where relative times are required) or the ''Earliest Start Time'' and ''Latest Start Time'' input fields (where absolute times are required). The allowed input range for both is given in the documentation for the current AO. Input values for ''Latest Revolution'' have to be equal or greater than ''Earliest Revolution''. Input values for ''Latest Start Time'' have to be equal or greater than values of ''Earliest Start Time'' plus one hour. A specified range can also be left open at the minimum or maximum side or both (to allow for non-fixed repetitions) using the ''Any'' button.

There is also the possibility of repeating an observation, specifying the number of repetitions Repeat $x$ ''times'' (0-98), the period every $x$ ''orbits/days''(1-999 rev., 0.42-999.99 days) and the ''tolerance'' (1-998 rev., 0.04-period days).

For the special case of observations related to orbital phases the third section of the ''Time Constraints'' page offers additionally the possibility of specifying the ''Reference time for Phase 0'' in UT format YYYY.MM.DD.HH.MM.SS, the ''Period'' (0.4200-366) in days, the ''Phase'' requested, and finally the ''tolerance'' in days.

Example: To ask for repeated observations, spaced at certain time intervals, but at no particular time, enter an ''Earliest Revolution / Start Time'', a ''Latest Revolution / Start Time'' and specify how often the observation should be repeated. If, for example, two observations are needed, the ''Repeat'' parameter has to be set to 1 (repetition). Setting ''Repeat'' to 0 means that only one observation will be performed. The buttons at the bottom serve to either ''Commit'' your input, ''Clear Form'' or ''Delete Entry'' completely.

The XMM-Newton SOC will handle absolute (UT, orbital phase) and relative (XMM-Newton revolution) time entries into XRPS in the following way:

Observations which MUST be conducted at a fixed time.
For observations which MUST be conducted at a fixed time, e.g. an occultation experiment, absolute time entries must be entered into the proposal database via the ''Time Constraints'' page. The required format, as displayed on the form sheet, is YYYY.DDD.HH.MM.SS (i.e., four digits for the year, three digits for the day of the observations [the number of the day in that year] and two digits for hours, minutes and seconds in the 24 hours format). The separator is a dot, not a colon. Naturally, the requested time constraint has to be in agreement with the XMM-Newton visibility of the target. Therefore the user must perform a visibility check, using the XMM-Newton Target Visibility Tool. The absolute entry will be used by the SOC to check whether the target is visible. If so, the SOC will try to schedule the observations at the requested date and time.

Time-constrained observations that are not fixed to a particular date/time.
Complex repetition patterns should be described in the ''Comments'' section of the ''Time Constraints'' page. The SOC will then later on take care of the proper scheduling, interacting with the PI during the ''enhancement'' process of the observations within the proposal.

RGS Multipointing Mode.
For observations to be performed using the RGS Multipointing mode, any specific scheduling requirement must be specified as described above. If there is not any time constraint, the user must fill in the Time Details entering "Earliest Revolution" and "Latest Revolution" as "Any", four repetitions every 1 revolution, with tolerance zero. These are dummy values, and the scheduling details will be discussed during the Proposal Enhancement Phase. Also, please enter "RGS Multipointing Mode" in the "Comments" field.

Note: In the case of repeated observations, the science duration specified on the observation page applies to each observation. It is not the sum over all repeated observations (because each is, as the name suggests, handled as an individual observation).