EUROPEAN SOUTHERN OBSERVATORY La Silla Science Operations: NTT
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Introduction

This document is designed to guide you through the Phase II of your Service Observations (SO) at the NTT. Most of this document is also relevant for Director Disctretionary Time (DDT) and, in some cases, for Target of Opportunity (ToO) observations.

During this Phase II, you will prepare all the observations to be executed for your program. The observations are defined using "Observation Blocks" (OBs). Each OB specifies an individual observing sequence that can --and should-- be scheduled and executed completely without interruption. OBs can specify simple operations like "acquire one R-band image with EMMI" as well as complex operations like "Preset the telescope, identify the star and move it to the 0.6" slit, and obtain a sequence of jittered spectra in the K band through the low resolution grism, then another sequence of jittered spectra in the J band" with SofI. To prepare your OBs, you will use the P2PP tool.

In addition to the OBs, you will have to prepare finding charts for all OBs, and to write up a README file describing your strategy. All these informations, which constitute your "Information Package" are to be submitted to the NTT Team, who will review them. Accepted OBs are queued for scheduling, while rejected OBs will be returned to you, and must be corrected and re-submitted before scheduling can begin. One of the NTT Team members will be your support astronomer. His name and email have been or will soon be sent to you. Don't hesitate to contact him for any question related to the strategy of your observations, or their implementation in OBs: an iteration at this stage can save a lot of time and headache at a later time. If you don't receive a reply within a couple of days, re-send your message to nttt@eso.org: it happens that one of the astronomer cannot access his email, but nttt is checked several times every day.

Below is a list of the tasks that you will have to complete. Note that a small fraction of the NTT time is devoted to Service Observations (as opposed to ~50% for the VLT). The Service Observation nights are listed in the following table:

Service Observation Nights - P68

start - end        number of        Deadline for info submission  
                   nights           and/or remarks
---------------------------------------------------------------------------
17 - 18 Oct 2001   1                delegated SO for 68.B-0267, 30 Sep.
18 - 19 Nov 2001   1                19 Oct
26 - 27 Nov 2001   1                19 Oct
14 - 15 Dec 2001   0.5              delegated SO for 68.C-0465, 30 Nov
17 - 20 Jan 2002   3                15 Dec
16 - 19 Feb 2002   3                15 Jan
09 - 11 Mar 2002   3                15 Feb
---------------------------------------------------------------------------
Total              12.5
---------------------------------------------------------------------------

Note that

• these nights are not evenly distributed over the period, and
• delegated SO means that these nights are attributed to one given program, whose observations will be performed by NTT staff (hence delegated). They are not available for normal flexible scheduling service observing.

The dead-line for a given night is listed in the table, and is set about ONE MONTH before that night (except for the first night, for which the dead line is Sep.30.) If your objects are only observable later in the semester, you can submit your Information Package at a later date. Nevertheless we strongly encourage you to submit it asap.

For DDTC observations: pls send us the information package as soon as possible after the time has been allocated, and in any case one week before the observations (non-overriding DDT observations are scheduled either during Reserved time or during SO time).

For ToO observations, send us the information NOW.

Phase II Preparation

All NTT Service Observation PI must complete the following steps:

• 1-Install the P2PP Tool: refer to http://www.eso.org/observing/p2pp/P2PP-tool.html for instructions. Be sure to retrieve the Java version, P2PP v.2.*. For help with this installation, pls contact usg-help@eso.org (not the NTT: we are P2PP users, but have no special knowledge about the installation of that program; the specialists are at USG).

• 2-Install the appropriate P2PP Instrument Package(s). You can retrieve them from the following web pages. Be sure to retrieve the latest version.

  For help with this, contact nttt@eso.org or your support astronomer.For EMMI and SUSI, you will see that, for each instrument, there are two complete sets of observation templates, i.e. the "old" ones (with names such as RILDOT02), and the "new" ones, with names such as RILD_img_obs_Jitter. You are ##*>strongly<*## recommended to use the new ones (although the old ones will still be supported during P68, but they will cause some extra overhead). A valid reason for using the old ones would be if you already have everything ready, everything representing many OBs.

• 3-Read the NTT general documentation, linked from http://www.ls.eso.org/lasilla/sciops/ntt especially the "Observing with the NTT" page.

• 4-Read the instrument specific pages, EMMI , SuSI , SofI . Please download and read the instrument User's Manual and the corresponding Template Signature File Manual, which describes the parameters of the templates used to build the OBs.

• 5-If needed, discuss your observing strategy with your support astronomer. Unless you are a very experienced NTT observer, I strongly recommend at least one iteration.

• 6-Create Observation Blocks (OBs), following instructions and advice in P2PP User's Manual. Your P2PP ID and Password were included in your notification message.

  For P2PP specific problems, pls contact usg-help@eso.org . For NTT, instrument and template problems, contact your support astronomer. You must create one OB for each observation; each OB must include an acquisition template. Observations that have to be repeated must have the corresponding number of copies of the same OB (use the "duplicate" function in P2PP).

  WARNING: the "OB check-in/check-out" procedure described in the P2PP manual is for VLT observations.

  *******IT IS NOT USED FOR THE NTT OBSERVATIONS*********

  If you check in your OBs, we will not see them, we will not schedule them, we will not perform the observations. (sorry to insist...) While preparing the OBs, just use the normal automatic save to disk (local cache). The instructions on how to send the OBs to the NTT are given later.

  • For OPC-pre-approved TARGET OF OPPORTUNITY observations, please provide a model of the OB you want to execute, assuming a typical object. Leave the coordinates to 00:00:00, 00:00:00. When you trigger the ToO, send us the coordinates, and the adjusted exposure times if needed. You don't have to provide multiple copies of these model OBs. The email triggering a ToO must be sent to nttt@eso.org, lasilla@eso.org, visas@eso.org, usg@eso.org, jmelnick@eso.org, and must arrive before 16h00. In addition to the information needed to complete the OBs (coordinates, exp.time, finder...), it must include the Prog. ID. The La Silla ToO policy is found at: http://www.ls.eso.org/lasilla/sciops/ntt/observing/documents/ToORulesFinal.html .
  • For Emergency ToO, just send the OBs or the information to build the OBs as described in the ToO Rules lined above.
  • For DDT, send us the OBs as for any normal SO program.

   

  We take care of the standard calibration OBs (defined in the table below): you don't have to define OBs for these, and you don't have to take them into account when computing your total time. Just mention in your README file (see below) that you want standard calibrations. If you want more calibrations, or specific calibrations, you will have to prepare the corresponding OBs, and the night-time calibrations will be charged on your time credit.

  NTT Standard Calibrations
  -------------------------------------------------------------------
  +Common:
     we take care of all the "technical" OBs, including setup, focus...
  +SuSi:
     Biases, Twilight Flats (if possible) or Dome Flat fields.
     2 Landolt Standard star fields during the night if it is photometric
  +EMMI Imaging:
     Biases, Twilight Flats (if possible) or Dome Flat fields.
     2 Landolt Standard Star Fields during the night if photometric
  +EMMI Spectroscopy:
    Biases, Dome Flats, day-time wavelength calibration frames.
    1 spectrophotometric standard star with broad slit during the night
  +SofI Imaging:
    "Special Dome Flats" (cf manual)
     2 photometric standard stars during the night
  +SofI Spectroscopy:
     Dome flats,
     1 Hip standard stars during the night.
  ----------------------------------------------------------------
  In case of doubt, please consult with your support astronomer
  ----------------------------------------------------------------

  IMPORTANT NOTE: The total time of your OBs must not be larger than the time allocated to your program. This includes the total exposure time, plus overhead. P2PP has a function that will help you estimate the total time of your OBs. Below is table giving some guidelines for computing the overhead.

NTT Overheads
----------------------------------------------------------
ACTION                              OVERHEAD
Pointing                            2 min per pointing
Pointing, with special acquisition
   such as move to slit:            4 min per pointing
                                    + image exp.time
EMMI Red:                           3 min per exposure
EMMI Blue:                          2 min per exposure
SuSI:                               1 min per exposure
SofI Imaging:                       30% of exposure time
                                    (average)
                                    ( = 1.25s per DIT
                                       + 1 DIT per NDIT)
SofI spectroscopy:                  15% of exposure time
                                    (average)
----------------------------------------------------------

While completing the P2PP process, you may find the following tools :

• ESO Exposure Time Calculators: http://www.eso.org/observing/etc
• Various User Support Tools found on the User Support Services and Tools page: http://www.eso.org/observing/support.html
• ESO Archive home page: http://archive.eso.org

 

• 7-Create the finding charts. We DO NEED ONE finding chart per target. These finding charts MUST have the following characteristics:
  • finding charts should be created as Postscript files, Level 2 or higher. (The Postscript level is given on the first line of each Postscript file.)
  • clearly indicate the ESO Observing Run ID (in the header of this message).
  • clearly indicate the PI Name
  • clearly indicate the OB Name or Target Name, as used in the associated OB.
  • the entire instrument field-of-view must be shown, but no more than ~2x the field-of-view - the target(s) position(s) must be clearly indicated
  • North and East must be clearly indicated
  • the scale must be indicated by drawing a bar and writing the bar length in arcseconds or arcminutes, or indicating the size of the field
  • the images should be negative, i.e. images should be dark and the background should be light
  • whenever possible, finding charts should have similar central wavelength to observations (e.g. DSS charts are often inappropriate for near-IR observations - this can be very problematic for spectroscopy in crowded fields).
  • positions of spectroscopic acquisition reference stars should be marked
  • if appropriate, spectroscopic finding charts must indicate the slit position(s) clearly
  • when appropriate (for example, faint objects near sky background), spectroscopic programmes should submit TWO finding charts: (1) full instrument field; and (2) magnified image identifying spectroscopic targets
• do not submit anything other than Postscript files. In particular, do not submit FITS nor GIF files.

The reason for these very constraining rules is that all the finders will be printed in advance. A finder without these information will be unidentified, lost and therefore useless.

The only exception to this rule is the ToO observations for which the target is not yet known. If you *really* feel a finder is not needed for your program, you can try to convince your support astronomer, but it is very probable that it will take you less effort to generate the finders than to get permission not to provide them...

To create the finders (i.e. get a DSS image and write on it), you may find skycat useful. You can find it at http://archive.eso.org . Note that a very nice "plug-in" is available for skycat, designed to make "Service Observing compliant" finding charts. Information can be found at http://www.eso.org/observing/p2pp/P2PP-FC-cookbook.html

• 8-fill in a README file. README files must follow the format given in the README template available at the end of this message. An example is available at http://www.eso.org/observing/p2pp/readme-example.txt .We suggest you simply copy and edit the template.

  If you have more than one program accepted, please submit one README file per program. A possible exception to this is if the two programs are subsets of a same program (eg. 68.A-0123(A) and 68.A-0123(B)) on the same instrument.

  This README file should be be named using the ESO Observing Run ID as follows: ESO_OBSERVING_RUNID.README. Example: 68.A-0123A.README

  The README file has the following sections:

  • Header - basic identification information (ESO Programme ID, PI, etc). Please provide an estimate of total execution time for your programme, including all operations overheads.
  • Programme Description - a brief description of the submitted OBs, how you wish them to be executed, and any other technical information you think would help us execute your programme properly (e.g. suggested sequencing of science and calibration OBs).

    Specific sub-sections are:

  • General Overview - short summary of observing programme, providing ESO with any information needed to met your science objective. Decision paths and/or OB modification requests which depending on the outcome of previously executed OBs are normally not allowed.
  • Critical Observing Condition Constraints - any critical information about required observing conditions
  • Time Critical Aspects - if your OBs must be executed within specific time windows or in some time specific sequence, please describe those constraints here. For the programs in "delegated service mode", which have a given night allocated: it is a good idea to remind it here.
  • Special Calibration Information - if you have submitted calibration OBs, please describe them here, why you have submitted them, and how they should be executed relative to your science OBs (e.g. same night, once per observing run, etc.). In particular, you MUST provide the magnitude and spectral type for all user supplied photometric or spectrophotometric calibration stars.
  • ToO Information - please indicate that this is a Target of Opportunity programme and give any special details
  • Pre-Imaging Requirements - if some of your OBs are pre-imaging OBs for the rest of your OBs, please give details here.
  • OB Information - some details about what you have submitted including:
    • Number of submitted OBs and finding charts
    • Association of Calibration OBs with Science OBs (see example).
  • Destination Address for Data Products - if your OBs are executed, any resultant data will be shipped to this address on CD-ROM disks or DAT tapes.

   

• 9-Prepare your Information package, that will contain all the information to be sent to the NTT Team; I suggest you create a directory for that purpose, e.g. NTT_68.A-0123A.

  IMPORTANT NOTE: THIS PROCEDURE IS QUITE DIFFERENT FROM THAT USED FOR THE VLT SERVICE OBSERVING. Don't send your OBs to the VLT repository; use this procedure:

• export all your OBs to that directory (in P2PP: select all OBs in main window, then File>Export and point to the SO_NTT directory). You should have a collection of .obx files.
• include all the finding chart *.ps files - include the 68.A-0123A.README file
• create a TAR file of the directory. Name this file after your program ID. From the directory above SO_NTT, type:
           tar cvf NTT_68.A-0123A.tar NTT_68.A-0123A
  It may be a good idea to compress the resulting file:
           gzip NTT_68.A-0123A.tar
• ftp the resulting file to ESO
  • ftp ftp.eso.org
  • user: anonymous
  • password: your email address
  • cd /incoming/general (note that you are allowed to write in that area, but not to read)
  • bin
  • put NTT_68.A-0123A.tar.gz
  • quit
• Notify the NTT Team (nttt@eso.org) and your support astronomer that you transfered your Information Package, mentioning the name of the file you put on ftp.eso.org.

• 10- Wait for the acknowledgement from your support astronomer. He will check your OBs and will possibly suggest you some changes. When everything is done, your OBs will be ready for execution at the telescope. Sorry to be so directive, but this is the only way for us to get all the information we need to execute your observations.

Sorry to be so directive, but this is the only way for us to get all the information we need to execute your observations.

2001-08-10