GIARPS (GIAno and haRPS) is a project devoted to have on the same focal station of the Telescopio Nazionale Galileo (TNG) both the high resolution spectrographs HARPS-N (VIS) and GIANO (NIR) working simultaneously. This could be considered the first and unique worldwide instrument providing cross-dispersed echelle spectroscopy at a high resolution (R=115,000 in the visual and R=50,000 in the IR) and over in a wide spectral range (0.383 - 2.45 μm) in a single exposure. The science case is very broad, given the versatility of such an instrument and the large wavelength range. A number of outstanding science cases encompassing mainly extra-solar planet science starting from rocky planet search and hot Jupiters, atmosphere characterization can be considered. Furthermore both instrument can measure high precision radial velocity by means the simultaneous thorium technique (HARPS - N) and absorbing cell technique (GIANO) in a single exposure. Other science cases are also possible. Young stars and proto- planetary disks, cool stars and stellar populations, moving minor bodies in the solar system, bursting young stellar objects, cataclysmic variables and X-ray binary transients in our Galaxy, supernovae up to gamma-ray bursts in the very distant and young Universe, can take advantage of the unicity of this facility both in terms of contemporaneous wide wavelength range and high resolution spectroscopy.
HIRES, a high resolution spectrometer, is one of the first five instruments foreseen in the ESO roadmap for the E-ELT. This spectrograph should ideally provide full spectral coverage from the UV limit to 2.5 microns, with
a resolving power from R∼10,000 to R∼100,000. At visual/blue wavelengths, where the adaptive optics (AO)
cannot provide an efficient light-concentration, HIRES will necessarily be a bulky, seeing-limited instrument.
The fundamental question, which we address in this paper, is whether the same approach should be adopted in the near-infrared range, or HIRES should only be equipped with compact infrared module(s) with a much smaller aperture, taking advantage of an AO-correction. The main drawbacks of a seeing-limited instrument at all wavelengths are: i) Lower sensitivities at wavelengths dominated by thermal background (red part of the K-band). ii) Much higher volumes and costs for the IR spectrograph module(s). The main drawbacks of using smaller, AO-fed IR module(s) are: i) Performances rapidly degrading towards shorter wavelengths (especially J e Y bands). ii) Different spatial sampling of extended objects (the optical module see a much larger area on the sky). In this paper we perform a trade-off analysis and quantify the various effects that contribute to improve or deteriorate the signal to noise ratio. In particular, we evaluate the position of the cross-over wavelength at which AO-fed instruments starts to outperform seeing-limited instruments. This parameter is of paramount importance for the design of the part of HIRES covering the K-band.
Giano is a Cryogenic Spectrograph located in T.N.G. (Spain) and commissioned in 2013. It works in the range 950-2500
nm with a resolving power of 50000.
This instrument was designed and built for direct feeding from the telescope . However, due to constraints imposed on
the telescope interfacing during the pre-commissioning phase, it had to be positioned on the rotating building, far from
the telescope focus. Therefore, a new interface to the telescope, based on IR-transmitting ZBLAN fibers with 85μm core,
was developed. Originally designed to work directly at the f/11 nasmyth focus of the telescope, in 2011 it has decided to
use a fiber to feed it.
The beam from the telescope is focused on a double fiber boundle by a Preslit Optical Bench attached to the Nasmith A
interface of the telescope. This Optical Bench contains the fiber feeding system and other important features as a guiding
system, a fiber viewer, a fiber feed calibration lamp and a nodding facility between the two fibers. The use of two fibers
allow us to have in the echellogram two spectrograms side by side in the same acquisition: one of the star and the other
of the sky or simultaneously to have the star and a calibration lamp. Before entering the cryostat the light from the fiber
is collected by a second Preslit Optical Bench attached directly to the Giano cryostat: on this bench the correct f-number
to illuminate the cold stop is generated and on the same bench is placed an image slicer to increase the efficiency of the
Present telescopes and future extremely large telescopes make use of fiber-fed spectrographs to observe at optical and
infrared wavelengths. The use of fibers largely simplifies the interfacing of the spectrograph to the telescope. At a high
spectral resolution (R>50,000) the fibers can be used to achieve very high spectral accuracy.
GIANO is an infrared (0.95-2.5μm) high resolution (R=50,000) spectrometer   that was recently commissioned
at the TNG telescope (La Palma). This instrument was designed and built for direct feeding from the telescope .
However, due to constraints imposed on the telescope interfacing during the pre-commissioning phase, it had to be
positioned on the rotating building, far from the telescope focus. Therefore, a new interface to the telescope, based on
IR-transmitting ZBLAN fibers with 85μm core, was developed.
In this article we report the first, preliminary results of the effects of these fibers on the quality of the recorded spectra
with GIANO and with a similar spectrograph that we set-up in the laboratory. The effects can be primarily associated to
modal-noise (MN) that, in GIANO, is much more evident than in optical spectrometers, because of the much longer
GIANO is the high resolution near IR spectrograph recently commissioned at the 3.58m Telescopio Nazionale Galileo in
La Palma (Spain). GIANO is the first worldwide instrument providing cross-dispersed echelle spectroscopy at a
resolution of 50,000 over the 0.95 – 2.45 micron spectral range in a single exposure. There are outstanding science cases
in the research fields of exo-planets, Galactic stars and stellar populations that could strongly benefit from GIANO
observations down to a magnitude limit comparable to that of 2MASS. The instrument includes a fully cryogenic
spectrograph and an innovative fiber system transmitting out to the K band. It also represents a formidable laboratory to
test performances and prototype solutions for the next generation of high resolution near IR spectrographs at the ELTs.
First results from sky tests at the telescope and science verification occurred between July 2012 and October 2013 will