README web version of /home/usg/OPS/MTS/readme_xml/readme_81019400

Principal Investigator Email Address

```
brandner@mpia.de
```

Estimated Total Execution Time (hours, including overheads)

4 hours (1 hour per OB, 2 OBs for Arches & 2 OBs for Quintuplet)

General Description

We will use NACO with IR-WFS (and N90C10 for Arches and N20C80 for Quintuplet,
 respectively) to obtain high quality astrometric observations of the centers of
 the Arches and Quintuplet starburst clusters. We will use S13 in K-band to oversample
 the Point Spread Function to improve centroiding of individual sources. Small dither
 steps (boxsize 0.8 arcsec) will help to minimize the effect of optical distortions
 across the field of view. Open loop sky frames with the same DIT and NDIT, though
 for only five dither positions in a nearby, less crowded field will be obtained
 after the template of AO corrected observations in each of the OBs. This 2nd epoch
 astrometric data will enable us to identify cluster members based on the proper
 motion. Cluster members will be followed up spectroscopically with SINFONI in a
 later observing period.

Because of the crowded nature of the cluster center, for Arches five potential natural
 guide stars for the IR-WFS have been selected. The guide stars are labeled R1 to
 R5 in order of decreasing Strehl ratio (see arches_chart2.jpg for details). In case
 stable AO performance cannot be achieved on R1 because, e.g., of source confusion
 or binarity, please use R2 instead (and R3 in case also R2 should be too crowded
 and so on). 

For Quintuplet, one isolated, bright NGS (R1) is specified. The S13 field is placed
 such that the bright NGS R1 is located just outside the field of view of S13.

Waiver Requests

```
No Waiver Request was submitted
```

Critical Observing Condition Constraints

```
N/A
```

Time-Critical Aspects

```
N/A
```

Special Execution Requirements

```
N/A
```

Special Calibration Information

```
N/A
```

ToO Information

```
N/A
```

ToO Activators List

```
N/A
```

Is this a Pre-imaging run ?

```
false
```

Pre-imaging Requirements

```
N/A
```

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 ?

```
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 PSF reference star OBs, do the names of those OBs begin with PSF_ ?

```
N/A
```

If there are Finding Charts attached to your OBs, is the field-of-view of at least one of these charts 2' x 2' (with clearly labelled field orientation) ?

Have you clearly marked and labelled your wavefront reference objects R1, R2, R3, ... (as specified in the NAOS Preparation Software) on your Finding Charts ?

Have you specified the magnitude of the brightest object in the field-of-view for each OB ?

Are there objects in any of your fields (including standard stars) which are brighter than the limits specified in the User Manual and on NACO web Pages ?

If the previous answer is yes, have you given a list of OBs and a justification for the brightness limit violation in the general description field ?

```
N/A
```

Last creation of page: Tue Oct 6 15:40:23 2009
If you have comments, please contact usd-help@eso.org