P2PP: FLAMES Information

This page contains information specific to the creation of FLAMES Observations Blocks (OBs) for Service Mode programs. For more general OB creation information, see the P2PP Web page.

Requirement Compliance Policy: Observing runs which do not adhere to the procedures and policies presented in this document will not be scheduled for execution. If you feel you must violate one of these procedures or policies, you must submit a Phase 2 Waiver Request before submitting any Phase 2 material.

This document has the following sections:

News for Period 81
Read the Manuals
FLAMES P2PP Tutorial
Additional Requirements for FLAMES Finding Charts
Additional Conditions for Waiver Requests
FLAMES OB Requirements and Recommendations
FPOSS Requirements and Recommendations

News for Period 81

FLAMES/GIRAFFE CCD upgrade: the upgrade of the GIRAFFE CCD is planned to take place between March 15 and May 12, which means that FLAMES will be offline during this period. This upgrade is expected to increase the red sensitivity of GIRAFFE. Preliminary numbers obtained during laboratory tests suggest an improvement of up to a factor of 2 in the quantum efficiency for wavelengths redder than 650 nm, whereas for wavelengths bluer than 400 nm, the sensitivity is expected to decrease by a factor of 2 (see the plot showing the QE ratio between the new and old CCD). When final numbers and characteristics become available (only at the end of Commissioning), adjustments of the exposure times and possibly of the observing strategy might need to be applied for those programs using extreme blue or red setups.

We will evaluate the revisions that are necessary to be implemented and we will contact all users whose programs are affected by the upgrade. The goal is to be fully operational as soon as possible after the upgrade. More details about the implementation of the revisions will be provided to the individual PIs at the time of the Phase2 verification.

Read the Manuals

It is essential that all users read the following manuals:

FLAMES User Manual

FLAMES Template Reference Guide

FPOSS User's Manual

P2PP User's Manual

ARGUS commissioning report (if planning/planned to use ARGUS)

It is also useful to check the FLAMES Web pages for instrument status information and the FPOSS tool web page.

Further useful information and tools for the OB preparation can be found on the User Support Services and Tools Web page (for instance exposure time calculator, object visibility, catalogues, etc.)

FLAMES P2PP Tutorial

A FLAMES P2PP Tutorial has been prepared to guide you through the preparation of successful Observation Blocks (OBs).

Additional Requirements for FLAMES Finding Charts

In addition to the general requirements for finding charts, the following requirements should be fulfilled:

the field of view of all finding charts must be 25' by 25' in size, with a clear indication of field center and orientation,
the VLT Guide Star must be clearly indicated; a field of some 30" in diameter around the star must be clearly visible,
the Fiducial Stars must be clearly indicated; a field of some 10" in diameter around the star must be clearly visible,
in order to be able to evaluate the quality of the reference stars, we recommend to produce full-size A4 charts.

The above requested indications for the reference stars can be easily achieved by saving from FPOSS your fibre allocations in Skycat format and using the Skycat Finding Chart Plugin. This procedure is described in detail in the FPOSS User's Manual, Section 4.5.

Please, be reminded that from P73 finding charts must be in JPEG format and must be attached to the corresponding Observation Block in P2PP (see the Finding Chart Tutorial for more information).

Additional Conditions for Waiver Requests

In addition to the general Phase 2 Waiver Request policies waiver requests have to be submitted under the following conditions:

if the submitted OB contains a Target Setup file, which is valid for less than +/-1 hours in hour angle;
if a guide star outside the 25 arcmin diameter field has to be selected;
the same fibre configuration must be observed always on the same plate of the positioner;
if attached flat-fields (both in UVES and GIRAFFE mode) are needed.

FLAMES OB Requirements and Recommendations

Reference Stars Magnitudes, Hour Angle, and S/N Ratio

Starting with P76, it is mandatory to specify in the Instrument Comments field in P2PP (this is the one just below the User Comments field) the following FLAMES specific information (an example of the syntax is provided below):

magnitude of the VLT Guide Star of each field (in the range R=11-13mag)
magnitudes of the Fiducial Stars (in the range R = 8 - 15 mag with a recommended maximum delta R = 3 mag)
hour angle range in which the field configuration is valid
targeted S/N ratio per single exposure at some reference wavelength

Recommended Syntax: GS=mag; FACB=mag1,mag2,mag3,mag4; HA=+/-...h; S/N=... @ ...nm

Example: GS=12.5; FACB=10.4,11.1,11.2,12.6; HA=+/-3h; S/N=70 @ 580nm

HR Grating Resolutions and Wavelength Ranges

Due to the installation of a new high resolution grating in October 2003, the resolution of a number of the HR standard settings fell due to a decrease in the observed echelle order, with a corresponding increase in efficiency (46% on average) and wavelength coverage. The affected settings are: HR5, HR7, HR9, HR14, HR17, HR19, HR20, and HR22.

From P74, for the affected settings, users have had the choice of using either lower or higher order, "A" or "B" settings respectively (one must choose H447.1A or H447.1B, if, e.g., one wishes to use setting #5), which have the same central wavelength. Observations using the "B" settings have an efficiency between 25-70% of the "A" settings. Further details can be found here (table summarising all the high-res settings) and/or in the User Manual.

Also, from P74, the new setting HR15N/H665.0 has been made available for both Service and Visitor Mode users. This setting covers both H-alpha and the Li6707 line.

ARGUS Notes

ARGUS is the large integral field unit of FLAMES available on plate 2 only. For a technical description of this unit, please read the FLAMES User Manual and the ARGUS commissioning report. For the preparation of OBs please note the following:

The ARGUS long axis is along the North-South direction for a Position Angle of 0 degrees, with the PA entered in FPOSS being measured from North to East.
The fifteen ARGUS sky fibres are single fibres only.
The BIGGER field of view is obtained with the scale 1:1. The SMALLER field of view is obtained with scale 1:1.67.
Screen flats and a specphot standard are taken by the Observatory for all ARGUS observations. The specphot standards are selected from the lists available here.
The ARGUS fast template, which enables observations of different targets without reconfiguring the plate, is only available in Visitor Mode. This template saves on overheads, but only if (a) The ARGUS sky fibres are at the same radius and/or not used; (b) The plate scale is the same for the two observations.
When using the FLAMES_giraf_obs_argoff template, the offsets are relative to the telescope position. See the FLAMES Template Reference Guide for more details.
Recall that for ARGUS, the SSN, FPS, and PSSN numbers increase from right to left in the current (and only) version of the fibre table. This goes in the opposite direction with respect to Medusa/IFU fibres.

Total Execution Time

During the execution of the observation blocks at the telescope, the prepared field has to be configured on the Fiber Positioner plate for the expected mid-time of the science exposures defined in the OB. To properly determine this configuration time, the total execution time of the OB must be known.

This total execution time must include an estimate for the time required to attach the plate to the telescope rotator, the telescope overheads (preset, acquisition of guide star and the start of the active optics), the time for the acquisition of the Fiducial Stars, the instrument overheads (setup and CCD readout), and the science exposure times.

Starting with P73, this execution time has been computed automatically by external scripts within P2PP (and the field OB total execution time that needed to be filled out in all FLAMES acquisition templates has now disappeared).

In order to check the execution time of individual/multiple OBs, users can make use of the pull-down menu Reports->Execution Time from the main P2PP GUI. Alternatively, while working in the P2PP View OB window, the total execution time of the OB is also reported in the Execution Time entry (once the exposure time for that observation has been specified). Any time the exposure time is revised, please remember to click on RecalcExecTime, because the Execution Time entry is not updated automatically.

Configuration Wavelengths

The FLAMES acquisition templates require a configuration wavelength per instrument to be specified by the user. During the execution of the observation blocks at the telescope, the prepared field will be configured on the Fiber Positioner plate for these wavelengths.

Therefore, the selected configuration wavelengths must match the respective specified wavelength settings in the observation template(s) of the same OB.

Please, keep in mind when selecting the wavelength settings in combined mode (Giraffe + UVES), that a large difference in the configuration wavelengths will lead to increased fibre entrance losses of the UVES fibres depending on the airmass and length of the actual observation.

Simultaneous Calibrations

The FLAMES-Giraffe observing templates allow to specify the use of a simultaneous Thorium-Argon calibration lamp during the science exposure (possible values "ON" or "OFF"). If "ON" then the lamp is switched on for the entire science exposure, with intensities adjusted by the use of ND filters. Use of the lamp enables higher radial velocity accuracy (compared to the "OFF" option).

The intensity of the calibration spectra is adjusted according to the total exposure time. However, for wavelengths larger than 700nm, the object spectra adjacent to the 5 simultaneous calibration spectra can be contaminated by strong Argon lines. See here for an example of how this affects the observed images at 769.1nm. However, you may still choose to switch the lamp off even with blue settings if the objects are faint. If high wavelength accuracy is required and you are worried about contamination, then with a Waiver, you can bracket your main science target (with the lamp OFF), by short 60s exposures with the lamp ON.

Standard Calibrations

The FLAMES instrument is calibrated by the Science Operations staff in the morning after the science observations. All instrument setups used in the science observations are calibrated automatically.

The following table summarises the standard calibration products provided by the observatory. If additional calibrations are required, this must be discussed in advance with the support staff at USD (usd-help@eso.org).

FLAMES - UVES Science Data Calibration Plan
(per instrument setting, i.e. plate, fibre mode, and central wavelength)
Calibration	number	frequency [1/days]
Fibre Flatfields	3	1 / 1
Slit Flatfields	3	1 / 7
attached Fibre Flatfields	n	o.r.
Wavelength	1	1 / 1
Sim. Fibre Order Definition	1	1 / 1
Sim. Fibre Format Check	1	1 / 1
Bias	5	1 / 7
Dark	3	1 / 30
o.r. = on request only, corresponding OBs to be provided by user
n = number to be defined by user

FLAMES - GIRAFFE Science Data Calibration Plan
(per instrument setting, i.e., plate, fibre mode, resolution and central wavelength)
Calibration	number	frequency [1/days]
Flatfields	3	1 / 1
attached Flatfields	n	o.r.
Wavelength	1	1 / 1
Bias	5	1 / 7
Dark	3	1 / 30
IFU: Flux Standard	1+3	1 / 1
ARGUS: Flux Standard + attached Flatfields	1+3	1 / 1
o.r. = on request only, corresponding OBs to be provided by user
n = number to be defined by user

The nighttime calibrations which are marked "on request only" must be defined by the users, but only after the need for such calibrations has been properly justified (by the user) and the Waiver request has been approved (by ESO). The time to execute these calibrations will be deducted from the OPC allocated time of the proposal.

FPOSS Requirements and Recommendations

Guide and Fiducial Stars

For a successful execution of your program, we highly recommend to choose the VLT Guide Stars and the Fiducial Stars within the following magnitude limits:

Reference Star	R magnitude	Comments
VLT Guide Star	11 - 13	select guide stars close to 11 mag (but not brighter) if your constraints allow a seeing of >1.4". Guide stars up to 14 mag may be considered on a case-by-case basis, but experience has shown that the telescope active optics can fail to close (especially if the seeing degrades), leading to loss of time.
Fiducial Stars	8 - 15	the maximum difference in magnitude among the selected stars should not exceed 3 mag

Further requirements:

make sure that the Guide Star is selected inside the 25 arcmin field of view;
make sure that the Guide Star can be clearly identified in the 30" field of view of the guide probe;
make sure that the Fiducial Stars are isolated objects so that they can be clearly identified and well centered in the 2" field of view of the FACB fibres;
make sure that all four FACB fibres are allocated to Fiducial Stars even if only a minimum of 3 is required by FPOSS;
it is crucial that all reference stars (VLT Guide Star and Fiducial Stars) are given in the same astrometric system as the science targets.

Fibre Status Information

While configuring your field, please pay attention that none of your highest priority targets is allocated to the following fibres. Here, RP refers to the retractor position, which is the "fibre number" or "pivot number" visible in FPOSS when you allocate the fibres. The FPS number is the progressive fibre position number in the slit.

Type	Plate	RP	FPS	Status	Comments
IFU Sky	1	153	192	disabled	Low transmission
IFU Sky	2	153	192	disabled	Low transmission
IFU Sky	1	225	278	disabled	Low transmission
IFUSky	2	225	278	enabled	Low transmission
IFU Sky	1	259	320	enabled	Low transmission
IFU Sky	2	259	320	disabled	Low transmission
IFU Sky	1	229	183	enabled	Fibre FPS=183 (PSSN=15) has some problems. The fibre is in the corner of the array. Weak/no impact.
IFU	2	77	87-106	enabled	Transmission on plate 2 only 50% of other IFUs
IFU	1	25	23-42	enabled	Transmission on plate 1 only 65% of other IFUs
IFU	1	237	279-298	enabled	Transmission on plate 1 only 55% of other IFUs
IFU	1,2	253	300-319	enabled	Some fibres of the bundle fall outside the CCD detector; the exact number depends on the selected instrument setting
IFU	2	253	303	enabled	Fibre FPS=303 (PSSN=4) is broken and has zero transmission
Medusa	1,2	244,246	136,135	enabled	Fibres fall outside the CCD detector depending on the selected instrument setting
Medusa	1,2	242	137	enabled	Fibre falls outside the CCD detector
Medusa	2	122	66	enabled	Transmission only 56% on plate 2
Medusa	1	52	27	disabled
Medusa	2	116	58	disabled
Medusa	2	218	109	disabled
ARGUS Sky	2	5	1	disabled

Validity Check

Please keep in mind that Allocation OK in the Messages window of the FPOSS Control Panel means that your successful configuration is valid only at meridian. The safety margins encoded in the FPOSS tool are chosen to avoid fibre-fibre collisions at configuration time on the Fiber Positioner over a hour angle range of +/-4 hours for most of the configured fields.

However, as part of the basic FPOSS allocation sequence it is mandatory to check the actual hour angle range for which a configuration is valid (step Check HA range). This validity interval is recorded in the Target Setup file and must be reported in the Instrument Comments field in P2PP (cf the details given above). Try to maximise the valid hour angle range before saving the Target Setup file to increase the execution probability of your observation. In most cases this can be achieved by deallocating the few fibres which are found to be the most sensitive for collisions.

FPOSS Checksum

From P75, files produced by FPOSS include a checksum. Any FPOSS INS file manually edited after creation by FPOSS will not check into the Repository.