README web version of /home/usg/OPS/MTS/readme_xml/readme_75061700

Principal Investigator Email Address

```
petitjean@iap.fr
```

Estimated Total Execution Time (hours, including overheads)

```
23h
```

General Description

Numerical simulations of the IGM in a cosmological context suggest that
 the Lyman-$\alpha$ forest traces the dark matter fluctuations on  scales larger
 than the Jeans length of the gas ($\sim$ 0.5-2 arcmin at $z\sim 2.5$).
Transverse flux correlation (measured in space) and longitudinal flux correlation
 (measured
in velocity) can be compared to probe the geometry of the universe. The strong transverse
 correlation signal found from our recent FORS observations of quasar pairs may be
 difficult to reconcile with the longitudinal correlation signal within the standard
 structure formation
paradigm. However, this could be due to the limitations of the observations namely
the low spectral resolution and/or the very limited wavelength range accessible
 with FORS. We therefore propose to observe with UVES a statistically significant
 sample of QSO pairs at $z$~$\geq$~2.5 with separations ranging from 0.6 to a few
 arcmin. This will also allow to study in detail the velocity gradients between lines
 of sight.

Waiver Requests

A Waiver Request was submitted to ask for permission to have OBs with
 time execution larger than one hour.

Critical Observing Condition Constraints

```
THN and seeing smaller than 0.9 arcsec
```

Time-Critical Aspects

```
None
```

Special Execution Requirements

```
None
```

Special Calibration Information

```
None
```

ToO Information

```
None
```

ToO Activators List

```
None
```

Is this a Pre-imaging run ?

```
false
```

Pre-imaging Requirements

```
None
```

Source(s) of Pre-imaging

---(Empty)---

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 ?

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 ?

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 ?

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 need secondary guiding, are there suitable objects within 30 arcsec from your target ?

```
N/A
```

Last creation of page: Tue Oct 6 15:40:08 2009
If you have comments, please contact usd-help@eso.org