ESO Spectroscopic Facility

Abstract

We present the concept of a novel facility dedicated to massively-multiplexed spectroscopy. The telescope has a very wide field Cassegrain focus optimised for fibre feeding. With a Field of View (FoV) of 2.5 degrees diameter and a 11.4m pupil, it will be the largest etendue telescope. The large focal plane can easily host up to 16.000 fibres. In addition, a gravity invariant focus for the central 10 arc-minutes is available to host a giant integral field unit (IFU). The 3 lenses corrector includes an ADC, and has good performance in the 360-1300 nm wavelength range. The top level science requirements were developed by a dedicated ESO working group, and one of the primary cases is high resolution spectroscopy of GAIA stars and, in general, how our Galaxy formed and evolves. The facility will therefore be equipped with both, high and low resolution spectrographs. We stress the importance of developing the telescope and instrument designs simultaneously. The most relevant R&D aspect is also briefly discussed.

Streams, Substructures, and the Early History of the Milky Way

“…Zoom-in cosmological hydrodynamical simulations such as AURIGA (Grand et al 2017), FIRE (Hopkins et al 2014), or those based on N-body methods combined with semi-analytic models such as Aquarius (Cooper et al 2010), are very useful for understanding the general properties of stellar halos and how they might relate to e.g. merger history (Tissera et al 2013, Pillepich et al 2015, El-Badry et al 2018. Some of these simulations are beginning to find look-alikes to the Milky Way also in terms of their merger history, as reported for example in Fattahi et al (2019).…”

“…The PFS 28 on Subaru (Tamura et al 2016) is an instrument that could potentially help with the chemical labelling, although its highest resolution mode has R ∼ 5000 and so obtaining detailed chemical abundances for many elements will not be feasible. The MSE 29,30 is another interesting facility being considered, but there are no (other) concrete plans at the time of writing of this review, although Pasquini et al (2018) discuss in some detail a concept developed at ESO whose main science driver is high-resolution follow-up of Gaia targets, in a case termed "the Milky way as a Model Galaxy Organism".…”

Streams, substructures and the early history of the Milky Way

“…Zoom-in cosmological hydrodynamical simulations such as AURIGA (Grand et al 2017), FIRE (Hopkins et al 2014), or those based on N-body methods combined with semi-analytic models such as Aquarius (Cooper et al 2010), are very useful for understanding the general properties of stellar halos and how they might relate to e.g. merger history (Tissera et al 2013, Pillepich et al 2015, El-Badry et al 2018). Some of these simulations are beginning to find look-alikes to the Milky Way also in terms of their merger history, as reported for example in Fattahi et al ( 2019)/ Large fully cosmological hydrodynamical simulations such as the Illustris suite and its successor IllustrisTNG (Naiman et al 2018) also contain Milky Waylike galaxies.…”

“…The PSF 28 on Subaru (Tamura et al 2016) is an instrument that could potentially help with the chemical labelling, although its highest resolution mode has R ∼ 5000 and so obtaining detailed chemical abundances for many elements will not be feasible. The MSE 29,30 is another interesting facility being considered, but there are no (other) concrete plans at the time of writing of this review, although Pasquini et al (2018) discuss in some detail a concept developed at ESO whose main science driver is high-resolution follow-up of Gaia targets, in a case termed "the Milky way as a Model Galaxy Organism".…”

“…The turn of the century is approximately the time that the phrase "Galactic archaeology" was adopted widely by the community, as it begins to appear more frequently both in talks as in the printed literature, also in part because of the very influential reviews by Bland-Hawthorn & Freeman (2000), Freeman & Bland-Hawthorn (2002) (see also Bland-Hawthorn 1999, who introduced the term "near-field cosmology"). Impetus to the field was undoubtedly given by the discovery by Ibata et al (1994) of the Sagittarius dwarf as direct evidence of an ongoing merger, and to some extent subsequently by discovery of debris streams near the Sun from a past merger in the Hipparcos 6 data (Perryman et al 1997) by .…”