G. Falcini

GIANO-TNG spectroscopy of red supergiants in the young star cluster RSGC2

Aims. The inner disk of the Galaxy has a number of young star clusters dominated by red supergiants that are heavily obscured by dust extinction and observable only at infrared wavelengths. These clusters are important tracers of the recent star formation and chemical enrichment history in the inner Galaxy. Methods. During the technical commissioning and as a first science verification of the GIANO spectrograph at the Telescopio Nazionale Galileo, we secured high-resolution (R � 50 000) near-infrared spectra of three red supergiants in the young Scutum cluster RSGC2. Results. Taking advantage of the full YJHK spectral coverage of GIANO in a single exposure, we were able to identify several tens of atomic and molecular lines suitable for chemical abundance determinations. By means of spectral synthesis and line equivalent width measurements, we obtained abundances of Fe and other iron-peak elements such as V, Cr, Ni, of alpha (O, Mg, Si, Ca and Ti) and other light elements (C, N, Na, Al, K, Sc), and of some s-process elements (Y, Sr). We found iron abundances between half and one third solar and solar-scaled [X/Fe] abundance patterns of iron-peak, alpha and most of the light elements, consistent with a thin-disk chemistry. We found a depletion of [C/Fe] and enhancement of [N/Fe], consistent with CN burning, and low 12 C/ 13 C abundance ratios (between 9 and 11), requiring extra-mixing processes in the stellar interiors during the post-main-sequence evolution. Finally, we found a slight [Sr/Fe] enhancement and a slight [Y/Fe] depletion (by a factor of ≤2), with respect to solar.

The GIANO spectrometer: towards its first light at the TNG

GIANO is a high resolution (R50,000) IR spectrograph which provides a quasi-complete coverage of the 0.95- 2.5μm wavelengths range in a single exposure. The instrument was integrated and tested in Arcetri-INAF (Florence, Italy) and will be commisioned at the 3.58m TNG Italian telescope in La Palma. The major scientific goals include the search for rocky planets with habitable conditions around low-mass stars, quantitative spectroscopy of brown dwarfs, accurate chemical abundances of high metallicity stars and stellar clusters. This presentation describes the status of the instrument and presents the first results obtained in laboratory during the acceptance tests.

The GIANO-TNG spectrometer

GIANO is an infrared (0.9-2.5 μm cross-dispersed echelle spectrometer designed to achieve high resolution, high throughput, wide band coverage and very high stability for accurate radial velocity measurements. It also includes polarimetric capabilities and a low resolution mode with RS ~ 400 and complete 0.75-2.5 μm coverage. This makes it a very versatile, common user instrument which will be permanently mounted and available on the Nasmyth-B foci of the Telescopio Nazionale Galileo (TNG) located at Roque de Los Muchachos Observatory (ORM), La Palma, Spain. The project is fast-track and relies on well known, relatively standard technologies. It has been recognized as one of the top priority instrumental projects of INAF (the Italian National Institute of Astronomy) and received its first financing for the phase-A study in October 2003. Integration in the laboratory is planned to start before the end of 2006, commissioning at the telescope is foreseen within 2007 and scientific operations in 2008. One of the most important scientific goals is the search for rocky planets with habitable conditions around low-mass stars. If completed on time, GIANO will be the first and only IR instrument operating worldwide providing the combination of efficiency, spectral resolution, wavelength coverage and stability necessary for this type of research. With its unique combination of high and low resolution modes, GIANO will also be a very flexible common-user instrument ideal e.g. for quantitative spectroscopy of brown dwarfs, stars and stellar clusters as well as for the determination of the spectral energy distribution of faint/red objects such as high redshift galaxies. The expected limiting magnitudes are such that GIANO will be able to deliver good quality HR spectra of any 2MASS object and LR spectra of any object detected in the UKIDSS large area survey.

Lines and continuum sky emission in the near infrared: observational constraints from deep high spectral resolution spectra with GIANO-TNG

Aims. Determining the intensity of lines and continuum airglow emission in the H-band is important for the design of faint-object infrared spectrographs. Existing spectra at low or medium resolution cannot disentangle the true sky continuum from instrumental effects (e.g. diffuse light in the wings of strong lines). We aim to obtain, for the first time, a high-resolution infrared spectrum that is deep enough to set significant constraints on the continuum emission between the lines in the H-band. Methods. During the second commissioning run of the GIANO high-resolution infrared spectrograph at La Palma Observatory, we pointed the instrument directly at the sky and obtained a deep spectrum that extends from 0.97 to 2.4 μm. Results. The spectrum shows about 1500 emission lines, a factor of two more than in previous works. Of these, 80% are identified as OH transitions; half of these are from highly excited molecules (hot-OH component) that are not included in the OH airglow emission models normally used for astronomical applications. The other lines are attributable to O2 or unidentified. Several of the faint lines are in spectral regions that were previously believed to be free of line emission. The continuum in the H-band is marginally detected at a level of about 300 photons/m2/s/arcsec2/μm, equivalent to 20.1 AB-mag/arcsec2. The observed spectrum and the list of observed sky lines are published at the CDS. Conclusions. Our measurements indicate that the sky continuum in the H-band could be even darker than previously believed. However, the myriad of airglow emission lines severely limits the spectral ranges where very low background can be effectively achieved with lowor medium-resolution spectrographs. We identify a few spectral bands that could still remain quite dark at the resolving power foreseen for VLT-MOONS (R 6600).

A GIANO-TNG high-resolution infrared spectrum of the airglow emission

Aims. A flux-calibrated high-resolution spectrum of the airglow emission is a practical λ-calibration reference for astronomical spectral observations. It is also useful for constraining the molecular parameters of the OH molecule and the physical conditions in the upper mesosphere. Methods. We used the data collected during the first technical commissioning of the GIANO spectrograph at the Telescopio Nazionale Galileo (TNG). The high-resolution (R � 50 000) spectrum simultaneously covers the 0.95–2.4 μm wavelength range. Relative flux calibration is achieved by the simultaneous observation of a spectrophotometric standard star. Results. We derived a list of improved positions and intensities of OH infrared lines. The list includes Λ-split doublets, many of which are spectrally resolved. Compared with previous works, the new results correct errors in the wavelengths of the Q-branch transitions. The relative fluxes of OH lines from different vibrational bands show remarkable deviations from theoretical predictions: the Δv = 3, 4 lines are a factor of 2 and 4 brighter than expected. We also found evidence of a significant fraction (1–4%) of OH molecules with a non-thermal population of high-J levels. Finally, we list wavelengths and fluxes of 153 lines not attributable to OH. Most of these can be associated with O2, while 37 lines in the H band are not identified. The O2 and unidentified lines in the H band account for � 5% of the total airglow flux in this band.

High resolution near IR spectroscopy with GIANO-TNG

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 be presented.

GIANO: an ultrastable IR echelle spectrometer optimized for high-precision radial velocity measurements and for high-throughput low-resolution spectroscopy

GIANO is an infrared (0.9-2.5 μm) cross-dispersed echelle spectrometer designed to achieve high throughput, high resolving power, wide band coverage and high accuracy radial velocity measurements. It also includes polarimetric capabilities and a low resolution mode that make it a very versatile, common user instrument which will be permanently mounted and available at one of the Nasmyth foci of the Telescopio Nazionale Galileo (TNG) located at Roque de Los Muchachos Observatory (ORM), La Palma, Spain. GIANO was selected by INAF as the top priority instrument among those proposed within the Second Generation Instrumentation Plan of the TNG. More information on this project can be found at the web page http://www.bo.astro.it/giano

GIANO-B online data reduction software at the TNG

GIANO-B is the high resolution near-infrared (NIR) spectrograph of the Telescopio Nazionale Galileo (TNG), which started its regular operations in October 2017. Here we present GIANO-B Online Data Reduction Software (DRS) operating at the Telescope. GIANO-B Online DRS is a complete end-to-end solution for the spectrograph real-time data handling. The Online DRS provides management, processing and archival of GIANO-B scientific and calibration data. Once the instrument control software acquires the exposure ramp segments from the detector, the DRS ensures the complete data flow until the final data products are ingested into the science archive. A part of the Online DRS is GOFIO software, which performs the reduction process from ramp-processed 2D spectra to extracted and calibrated 1D spectra. A User Interface (UI) developed as a part of the Online DRS provides basic information on the final reduced data, thus allowing the observer to take decisions in real-time during the night and adjust the observational strategy as needed.

Performances of the cryogenic system of GIANO-TNG

GIANO-TNG is a cryogenic high resolution infrared spectrometer whose optics include large aspheric mirrors and cross-dispersing prisms mounted over a ≃1.5 m2 aluminum bench. To achieve the highest possible spectral stability and repeatability the bench is internally filled with liquid nitrogen whose boil-off pressure is actively controlled and stabilized to a fraction of mbar. The bench is isostatically mounted inside a ≃2.5 m3 cryostat. We present the characteristics and performances of the cryogenic system of GIANO which include, in particular, a temperature uniformity and long-term stability of a few mK and a remarkably low consumption of liquid nitrogen (less than 1 liter/hr).

GIARPS: commissioning and first scientific results

GIARPS (GIAno and haRPS) is a project devoted to have on the same focal station of the Telescopio Nazionale Galileo (TNG) both high resolution spectrographs, HARPS–N (VIS) and GIANO–B (NIR), working simultaneously. This could be considered the first and unique worldwide instrument providing cross-dispersed echelle spectroscopy at a resolution of 50,000 in the NIR range and 115,000 in the VIS 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 its large wavelength range. A number of outstanding science cases encompassing mainly extra-solar planet science starting from rocky planets search and hot Jupiters to atmosphere characterization can be considered. Furthermore both instruments can measure high precision radial velocities by means the simultaneous thorium technique (HARPS–N) and absorbing cell technique (GIANO–B) in a single exposure. Other science cases are also possible. GIARPS, as a brand new observing mode of the TNG started after the moving of GIANO–A (fiber fed spectrograph) from Nasmyth–A to Nasmyth–B where it was re–born as GIANO–B (no more fiber feed spectrograph). The official Commissioning finished on March 2017 and then it was offered to the community. Despite the work is not finished yet. In this paper we describe the preliminary scientific results obtained with GIANO–B and GIARPS observing mode with data taken during commissioning and first open time observations.