README web version of /home/usg/OPS/MTS/readme_xml/readme_76031201

Principal Investigator Email Address

```
r.j.wilman@durham.ac.uk
```

Estimated Total Execution Time (hours, including overheads)

```
0.5
```

General Description

This is a pre-imaging run to obtain a ~8 min (in total) R-band exposure
 centred on two QSOs. These QSOs (at redshifts 2.4 and 1.18) have HST STIS UV spectroscopy
 of the low-z Ly-alpha forest, and the pre-imaging will be used to select galaxies
 for follow-up FORS2 MXU spectroscopy. The ultimate aim of the programme is to probe
 the correlation between absorbers in the QSO sightlines and the surrounding galaxy
 populations.

Waiver Requests

```
No Waiver Request was submitted
```

Critical Observing Condition Constraints

photometric conditions
seeing < 0.8 arcsec
grey time

Time-Critical Aspects

as early in Period 76 as possible, in order to allow adequate time for
 mask preparation.
The FORS2 MXU spectroscopy is 20-22 February 2006.

Special Execution Requirements

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Special Calibration Information

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ToO Information

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ToO Activators List

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Is this a Pre-imaging run ?

```
true
```

Pre-imaging Requirements

As listed in the OB constraints, we require photometric conditions and
 seeing < 0.8 arcsec (for star-galaxy separation). We will then select galaxies
 in the R-band magnitude range 23.5 to 24.5, which are expected to have a median
 redshift of 1 and interquartile range 0.55-1.6, close in redshift to the STIS QSO
 absorbers.

Please centre on the QSO (nominal target position of the OB and centre of finding
 chart), using the full 6.8 arcmin FORS2 field of view. The exposure is split into
 two halves, with a 35 arcsec S shift between them, to circumvent the 33 arcsec FORS2
 CCD gap.

Source(s) of Pre-imaging

```
FORS2
```

Pre-imaging sources not listed above

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

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

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

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 ?

```
N/A
```

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 FORS2 Phase 2 web page ?

```
N/A
```

Last creation of page: Tue Oct 6 15:40:09 2009
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