1. Introduction

The Spectroscopic Interactive Pipeline and Graphical Interface (SIPGI) (Gargiulo et al. 2022) is an evolution of the VIMOS Interactive Pipeline and Graphical Interface (VIPGI). VIPGI is a complete data reduction environment, originally designed to carry out the reduction of spectroscopic data acquired with the VIMOS spectrograph at the European Southern Observatory (ESO) Very Large Telescope. VIPGI was designed for the reduction of the VIMOS VLT Deep Survey (VVDS) data, but its capabilities were sufficiently general to be easily adaptable to a variety of VIMOS data (Scodeggio et al. 2005, Garilli et al. 2012). During the years, the VIPGI efficiency and the quality of its data reduction products were such to make VIPGI the reduction pipeline of the major extragalactic surveys carried out with VIMOS: VVDS, zCosmos, VUDS, VIPERS, VANDELS for a total of more than 200000 spectra fully reduced and calibrated.

1.1. SIPGI: VIPGI and LBT

At the core of VIPGI (and SIPGI as well) is the Data Reduction Software (DRS), i.e. the set of programs and methods developed for the main steps of the data reduction.

The DRS is designed to be adaptable to other instruments. About ten years ago, SIPGI was born tuning the VIPGI core to make it able to reduce the spectroscopic data of the two main Large Binocular Telescope (LBT) spectrographs: MODS and LUCI.

Similarly to VIMOS, MODS is an optical spectrograph, so the main changes concerned the peculiarities of MODS data but not the deep core of the DRS. LUCI is a near infrared spectrograph and its different wavelength domain required deep revisions of the DRS. SIPGI has been used by the LBT spectroscopic data reduction center located at INAF-IASF Milan to reduce all the MODS and LUCI spectra acquired during the Italian time in the last ten years.

The documentation presented here is a cookbook to reduce MODS and LUCI spectra with this customized SIPGI version. The documentation is surely not complete, nor exhaustive of all SIPGI functions, features (and bugs). We rely on users feedback to improve it in the next versions.

For any question, comment, suggestion or for any request of help in the reduction of MODS/LUCI spectra, please contact lbt-italia-spec@inaf.it

1.2. Overview

SIPGI is composed by two main parts: the built-in data organizer and the DRS.

Although the data reduction recipes in DRS automate to a very large extent the task of reducing spectroscopic data, it does not address at all two important and problematic areas of the global data reduction activity: the organization of the (large) volume of the data and the validation of input data for reduction recipes. Each reduction recipe works under the assumption that the correct input (in term of calibration and scientific data) is provided to it, and could produce totally unpredictable results if this assumption were not to be met. To address these two points SIPGI is provided with a built-in data organizer that helps to manage the data and to provide the various recipes with the correct input. The organization of files is not optional in SIPGI. To be processed by the reduction recipes, raw FITS files must be ingested by the built-in data organizer.

Once files are properly digested and classified, all the recipes of the DRS can be used and their data products can be inspected using the analysis utilities (see Analysis Utilities).

1.3. How to use this manual

This manual is organized as follow: in Chapter 2 all the information necessary to install the software is provided, while in Chapter 3 a road-map for the data reduction of MODS and LUCI spectra with SIPGI is presented. Following the instructions provided in this Chapter, the user should hopefully be able to fully complete a data reduction. No information on the SIPGI basic concepts and/or on the SIPGI recipes is provided in Chapter 3. The user can retrieve this information by following the links that are embedded in the text.

In the following chapters a fully description of the software is provided. In Chapter 4, the SIPGI Auxiliary system files, i.e. a fundamental part of the SIPGI world, are presented; in Chapter 5, the functioning of the built-in data organizer is shown; in Chapter 6, a complete description of the graphical interface is provided; in Chapter 7, all the DRS recipes are described, and finally in Chapter 8, all the Analysis utilities are explained.

Although the cookbook in Chapter 3 should allow user to complete his/her data reduction, sometimes the spectra reduction may not be such a straightforward path due to data peculiarities. In this case, a complete view of what is the software and how it works could help in finding the best solution.

To summarize, we made all our efforts to allow users to reduce their LBT data skipping the boring manual part related to software functioning, but for a conscious use of SIPGI, it is strongly recommended to read Chapter 4,5,6,7,8 before Chapter 3 and before starting a data reduction.

Note

In this manual, we try to provide all the support for a quick and easy reduction, however we assume that the user handles the basic concepts behind the reduction of spectroscopic data.