Understanding PIT

The Phase I Tool (PIT) is the software application used by PIs to submit proposals for observing with IGRINS-2 at the Gemini Telescope, as well as for all other Gemini instruments.

The latest version of the PIT can be found here, along with installation instructions. A general overview of the PIT is provided on this page. Here, you can also find a set of tutorial videos prepared by Gemini to help PIs prepare their proposals using PIT.

Phase I Checklist for IGRINS-2 Proposals

In order to minimize common errors when creating a new IGRINS-2 program, PIs are encouraged to pay particular attention to the following aspects of the Phase I preparation.

Instrument configuration

IGRINS-2 has a single configuration available for all observations, providing wavelength coverage of 1.49-1.80 micron (H-band) and 1.96-2.46 micron (K-band) with a resolving power of R~45,000.

• For point-like sources, the observations use an ABBA sequence with an on-slit separation of 2.5 arcsec between the two positions (Nod along slit);
• For extended sources, the observations use an On-Off sequence, for which offsets to the sky are necessary (Nod to sky).

Calibrations

The required Night Basecal Time per observation is automatically calculated by the PIT and already includes the time needed for the Standard Telluric observations. If additional calibrations are deemed necessary by PIs, for example, to achieve a precision beyond that of the baseline set, these must be explicitly included as part of the Phase I proposal. The following calibrations are shared between different IGRINS-2 programs observed during a given night:

• Flats are taken each day as part of the daytime calibration;
• Sky emission observations for wavelength calibration are taken as nighttime partner calibrations.

Observation time

IGRINS-2 exposure times can be estimated using the IGRINS-2 ITC. The program time is not only the exposure time for your target; you also have to add overheads, including readout and setup time, among others. The ITC provides an inventory of the observation overheads and the total program time. Note that the minimum exposure time is 1.63 sec.

Observing constraints

The IGRINS-2 ITC can be used to estimate the required exposure time under your desired observing conditions to achieve your science goals. Sky background does not affect near-IR observations in the H and K bands, so no SB constraint is recommended unless demonstrably affects the science.

If absolute spectrophotometric calibration is required, photometric conditions should be selected (CC50). In this case, time for the necessary flux standard observations should be included. Due to the slit width (slit size: 0.33ʺ x 5ʺ), absolute flux calibration with IGRINS-2 is difficult in non-photometric or poor seeing conditions.

Scheduling constraints

Please specify any timing constraints on your observations in the Phase I of the proposal.