This section provides information on GSAOI data and GSAOI IRAF and DRAGON packages. For information about the basic format of all Gemini data see the Data Formats section in the Data and Results Gemini webpage
The GSAOI Integration Time Calculator (ITC) can be used to determine limiting magnitudes, exposure times, S/N ratios, background levels, etc. for a wide range of source properties, observing conditions and GSAOI configurations. The ITC is divided into five sections: (1) Spatial profile and brightness of source; (2) Spectral distribution of source; (3) Instrument and telescope configuration; (4) Observing conditions; and (5) Details of observation.
This section mainly describes how to prepare and check GSAOI observations at PhaseI/Phase II.
Given the complexity of the AO system, careful designing of GeMS/GSAOI observations is essential to achieve the desired performance required for the success of a science program. In this page we provide important information to guide the users with defining the observing strategies to follow with GeMS/GSAOI. The page also provides some guidelines to maximize observing efficiency and avoid some common errors. This information might be also useful to prepare a GeMS/GSAOI proposal submission (Phase I).
For Phase I observing proposals, the information presented in this section can be used to estimate the overheads associated with a new science target. This information could be also useful for the Phase II planning of your observing programs. All of the values listed on this page are included in OT calculations of the execution time of an observation. However, only the actual overheads incurred at the time of the observation will be charged to the program.The detailed overhead information is presented below.
An introduction to the Gemini Observing Tool (OT) is presented elsewhere. This page provides detailed information on GSAOI component, GeMS component and GSAOI iterator.
This page describes the suite of calibration frames routinely taken for GSAOI. Applicants are encouraged to review the information in the instrument and GeMS pages in order to understand the level of precision that can be achieved with the standard set of calibrations.
For all queue observations, a set of standard calibrations (the "baseline calibrations") will be taken by Gemini Staff to ensure the long-term utility of data in the archive. The baseline calibration set varies from instrument to instrument and from mode to mode. The table below describes the GSAOI baseline calibrations, as well as provides information on how and when to request additional frames.
Every night with GSAOI science, we take images of photometric standards in the same filters as the science for that night. The photometric zero-point is added to these tables and graphs the next morning. Photometric conditions are required, but observations can be collected during twilight.
The links below allow for quick search and download of GSAOI calibrations since semester 2012B from the Gemini Observatory Archive (GOA). Information on how to modify or use different queries for other calibrations can be found here.
NOTE: the links in the table will open in a new window.
GSAOI contains two filter wheels and one utility wheel. The two filter wheels have room for 27 broad- and narrow-band (zero redshifted) emission- and absorption line- filters. Each filter wheels also contains one blocked position for recording bias and dark frames. The list of the installed filters, central wavelengths, 50% cut-on and cut-off wavelengths, the Gemini Filter Number, transmission curves (plot and ASCII files), and the filter ID (internal) are listed in the table below.
GSAOI is designed to be used with GeMS at Gemini South. GSAOI is located at the f/32 output focus of Canopus and can deliver near diffraction limited images in the wavelength interval of 0.9 - 2.5 μm over a 85" x 85" field-of-view, with a scale of 0.02" per pixel. There are four gaps between the arrays of ~2.4mm, corresponding to ~2.5" on sky.
This section presents the expected imaging sensitivities for GSAOI. The first table lists the limiting magnitude, the saturation magnitude, the assumed Strehl ratio and the sky brightness for each filter. The second table lists the background contribution from different sources for all filters. The imaging sensitivities presented here are theoretical and have been obtained using a model for the object (point-source) and background signals. These estimated values are a good approximation of what it is expected for GSAOI.
Every night with GSAOI science, we take images of photometric standards in the same filters as the science for that night. The photometric zero-point is added to these tables and graphs the next morning. Photometric conditions are required, but observations can be collected during twilight.
In 2015 , there was a discrepancy between the UTEND keyword and the actual time of exposure completion. Only UTSTART and EXPTIME provided reliable timeing information. The problem was fixed in December 2015, and all archival data have been corrected.
The Gemini IRAF package currently supports imaging and long-slit reduction of FLAMINGOS-2 data. It is sufficient for initial assessment of the data, but a full science grade reduction might require a different effort. The IRAF package contains a "f2examples.cl" script for reducing example imaging and example spectroscopy datasets.
In the four sections of this form, select the appropriate astronomical source, telescope and instrument configuration, observing conditions, and observation parameters.
NIR background is highly variable
This page contains useful information for configuring F2 observations which should help reduce the number of iterations on the Phase II file between the PI and the NGO. It also contains an overview of the required OT observations and components for programs of different types. Before submitting your Phase II program to Gemini, use the F2 Phase II checklist to eliminate common mistakes.
For calculation of specific system overheads where these are critical to your observing program (for example time-resolved observations), the detailed information on this page may be used. The detailed overhead information is also useful for the Phase II planning of your observing program. The various overheads can be broken into the following categories:
The FLAMINGOS-2 team strongly recommends that PIs read this section and also that they start from the automatically-generated OT templates for FLAMINGOS-2 OT library when preparing F2 observations. The library contains detailed instructions for customising the template observations: changing targets, standard stars, slit widths, etc. This web page is intended to explain the various OT components in depth:
Please find more on Baseline Calibrations on the NIR instruments resources.
Recommended GCAL configurations and Exp. Times for F2 calibrations:
Quartz Halogen flats and Ar Arcs
Note the following:
All GCALflats are taken with: