README web version of /home/usg/OPS/MTS/readme_xml/readme_81008003

Principal Investigator Email Address

• sluse@ari.uni-heidelberg.de

Estimated Total Execution Time (hours, including overheads)

• 17.6h

General Description

• (1) Brief explanation: this is the spectro-photometric monitoring observations
   of the gravitationally lensed quasar J1131-1231 in MXU mode in view of a study of
   chromatic microlensing. The setup and the program philosophy are identical to those
   of the first RUNS of this program (P81->P83). The MXU slits contain the three
   brightest images of the main target (J1131-1231; CURVED slit) as well as several
   reference/field stars (that will be used for deconvolution purposes) and a few slits
   on sky. 
  (2) Requirement for Our Observation:  Accurate mask alignment both of the PSF stars
   AND the target is *crucial*.  We have planned 10 epochs (night1 -> night10),
   with two set of grisms per epoch (OB#1=grism1=GR300V+GR600B; OB#2=grism2=GR300V+GR600z).
   The SAME mask is used for each OB and 2 grisms are used in each OB (Note that the
   NA should then reset the LADC between 2 grisms). The epochs are separated by about
   10 days (sometimes more when no service runs are planned with FORS2). If technical
   time becomes available, please don't hesitate to run OBs that were previously not
   run, e.g., due to bad weather. The following tentative schedule  http://obswww.unige.ch/~sluse/J1131.html
    gives the ideal observing dates, given the moon illumination and moon distance.
   We have tried to put our prefered dates during planned service mode runs, as scheduled
   on the ESO pages. Please tell us if this schedule is modified. We will update our
   page regularly.
  A key issue is to keep as close as possible to the 10 days sampling. It is not critical
   if OB#1 and OB#2 are not obtained the same night (see Time-Critical Aspects for
   details), however obtaining OB#1 and #2 the same night would be optimal. It is also
   very important to continue the observations as long as possible in the period, even
   at high airmass. 
  (3) Properties of Our Science Target: The brightest components of the lens (=main
   target) have a V magnitude between 17.9-19. The other targets are field stars with
   similar or brighter magnitude than the target.

Waiver Requests

• 181.B-0080D.01.WAV: a) observations with bin 1x1 + b) Multimode observations:
   use of 300V+600B and of 300V+600z in a single OB. 
  NOTE: because of multimode observations the Night Astronomer should reset the LADC
   between 2 grisms.

Critical Observing Condition Constraints

• Observations with conditions slightly worse than those specified are still
   acceptable in exceptional cases --> we prefer getting good temporal sampling
   and good temporal coverage in conditions slightly off the ideal, rather than always
   excellent weather conditions but sparce sampling. This should however be applied
   *only* if one or several epochs have been missed due, e.g. to very bad weather.
    In practice we can accept seeing up to 1.0 arcsec.
  However, note that this is the kind of program that will not be hurt by excellent
   seeing, if possible at all.

Time-Critical Aspects

• This is a monitoring program, with the goal of taking 1 observing point
   per period of 10 days. See :  http://obswww.unige.ch/~sluse/J1131.html for optimal
   time observation dates (2 set of grisms per epoch, namely GR300V+GR600B=grism1 and
   GR300V+GR600z=grism2).
  It is not critical if OB#2 (grism2) cannot be obtained the same night as OB#1. In
   such a case, try to obtain OB#2 at any time **before the next scheduled epoch**.
   
  The optimal situation is however to obtain OB#1 and OB#2 the same night.

Special Execution Requirements

• ---(Empty)---

Special Calibration Information

• If possible, a spectroscopic twightlight flat field through the science
   mask should be obtained once during the period. We have provided 4 different OBs
   for this purpose. CAL_TWFF_MXU_J1131_grism600z/600B/300V/3grisms. These OBs are
   either for an individual grism or a set of the 3 grisms. 
  For these OBs, the FIELD RA-DEC has to be changed manually as well as the guess
   exposure time (estimated based on previous twFF see hereafter). 
  Similar Twighlight FF have been successfully obtained during P83 (see ANTU NR 2009-08-03/04)
   with exp. time of 60s, 100s, 100+200s for grisms GR600B, GR300V and GR600z.  
  
  We are aware this is technically difficult and can be done only on a best effort
   basis. It would however be important to get them in order to check for slit illumination
   problems with dome flat fields.

ToO Information

• ---(Empty)---

ToO Activators List

• ---(Empty)---

Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

• ---(Empty)---

Source(s) of Pre-imaging

• FORS2

Pre-imaging sources not listed above

• ---(Empty)---

Do all your OBs comply with the instrument-specific requirements listed
 on the instrument-specific Phase 2 web page ?

• YES

If this is a pre-imaging run, did you select PRE-IMAGING for the Observing
 Category for each Observing Template ?

• N/A

Do all your finding charts comply with both the general and instrument-specific
 Phase 2 Web Pages ?

• YES

If you submitted OBs for standard stars, did you specify the magnitude
 and spectral type of all standard stars in the OBs ?

• N/A

Have you included OBs for any calibrations that you need but which are
 not part of the Calibration Plan ?

• N/A

If you are observing Moving Targets, have you attached suitable ephemeris
 files to your OBs?

• N/A

If you have preferences which OBs should be executed first, did you make
 use of the User Priority field in the OBs ?

• YES

If this is a run that requires coordinated observations with other facilities,
 did you give proper instructions in the Time-Critical Aspects Section ?

• N/A

If you have prepared your finding charts with tools other than FIMS,
 do they comply with the specifications on the FORS1 Phase 2 web page ?

• N/A