Preface

The topic of the XVII IAC Winter School is ‘3D Spectroscopy’: a powerful astronomical observing technique, which has been in use since the early stages of the first prototype instruments about a quarter of a century ago. However, this technique is still not considered a standard common user tool among most present-day astronomers.

3D Spectroscopy (hereafter ‘3D’) is also called ‘integral field spectroscopy’ (IFS), sometimes ‘two-dimensional’ or even ‘area’ spectroscopy, and commonly also ‘three-dimensional’ spectroscopy; in other areas outside astronomy it is called ‘hyperspectral imaging’, and so forth. It is already this diversity in the nomenclature that perhaps reflects the level of confusion. For practical reasons, the organizers of this Winter School and the Euro3D network (which will be introduced below) have adopted the terminology ‘3D’, which is intuitively descriptive, but, as a caveat early on, is conceptually misleading if we restrict our imagination to the popular picture of the ‘datacube’ (Figure 1.1). Although this term will commonly be used throughout this book, we need to point out for the reasons given later in the first chapter that the idealized picture of an orthogonal cube with two spatial, and one wavelength, coordinate(s) is inappropriate in the most general case.

Whatever the terminology, it is the aim of this Winter School to help alleviate the apparent lack of insight into 3D instrumentation, its use for astronomical observations, the complex problems of data reduction and analysis, and to spread knowledge among a significant number of international young researchers at the beginning of their career.