20 research outputs found

    LBT/ARGOS adaptive optics observations of z2\sim 2 lensed galaxies

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    Gravitationally lensed systems allow a detailed view of galaxies at high redshift. High spatial- and spectral-resolution measurements of arc-like structures can offer unique constraints on the physical and dynamical properties of high-z systems. We present near-infrared spectra centred on the gravitational arcs of six known z ~ 2 lensed star-forming galaxies of stellar masses of 10^9-10^11 Msun and star formation rate (SFR) in the range between 10 and 400 Msun/yr. Ground layer adaptive optics (AO)-assisted observations are obtained at the Large Binocular Telescope (LBT) with the LUCI spectrographs during the commissioning of the ARGOS facility. We used MOS masks with curved slits to follow the extended arched structures and study the diagnostic emission lines. Combining spatially resolved kinematic properties across the arc-like morphologies, emission line diagnostics and archival information, we distinguish between merging and rotationally supported systems, and reveal the possible presence of ejected gas. For galaxies that have evidence for outflows, we derive outflow energetics and mass-loading factors compatible with those observed for stellar winds in local and high-z galaxies. We also use flux ratio diagnostics to derive gas-phase metallicities. The low signal-to-noise ratio in the faint Hβ\beta and nitrogen lines allows us to derive an upper limit of ~ 0.15 dex for the spatial variations in metallicity along the slit for the lensed galaxy J1038. Analysed near-infrared spectra presented here represent the first scientific demonstration of performing AO-assisted multi-object spectroscopy with narrow curved-shape slits. The increased angular and spectral resolution, combined with the binocular operation mode with the 8.4-m-wide eyes of LBT, will allow the characterisation of kinematic and chemical properties of a large sample of galaxies at high-z in the near future.Comment: 18 pages, 13 figures, accepted for publication in A&

    The ARGOS vibration compensation system

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    Multiconjugate adaptive optics simulator for the Thirty Meter Telescope: design, implementation, and results

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    We present a multiconjugate adaptive optics (MCAO) system simulator bench, Herzberg NFIRAOS Optical Simulator (HeNOS). HeNOS is developed to validate the performance of the MCAO system for the Thirty Meter Telescope, as well as to demonstrate techniques critical for future AO developments. We focus on describing the derivations of parameters that scale the 30-m telescope AO system down to a bench experiment and explain how these parameters are practically implemented on an optical bench. While referring to other papers for details of AO technique developments using HeNOS, we introduce the functionality of HeNOS, in particular, three different single-conjugate AO modes that HeNOS currently offers: a laser guide star AO with a Shack\u2013Hartmann wavefront sensor, a natural guide star AO with a pyramid wavefront sensor, and a laser guide star AO with a sodium spot elongation on the Shack\u2013Hartmann corrected by a truth wavefront sensing on a natural guide star. Laser tomography AO and ultimate MCAO are being prepared to be implemented in the near future.Peer reviewed: YesNRC publication: Ye

    High-resolution morphology and surface photometry of KIG 685 and KIG 895 with ARGOS+LUCI using the Large Binocular Telescope

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    We aim to refine the sample of isolated early-type galaxies in the Analysis of the interstellar Medium of Isolated Galaxies (AMIGA) catalog via high-resolution imaging. Here, we report the result from a pilot study investigating two candidates, KIG 685 and KIG 895, in K-band with the laser guide star and wavefront sensing facility ARGOS using the Large Binocular Telescope (LBT). Observations, obtained during the commissioning time, achieved a point spread function (PSF) of ≈0.25″. We present the data reduction and the PSF analysis from the best closed-loop exposures to investigate the galaxies' morphological structure, including their nuclear region. We used PROFILER for the decomposition of the azimuthal 1D light distribution and GALFIT for the 2D analysis, accounting for ARGOS's PSF. KIG 685 was found to be a S0 galaxy and has been modeled with two Sérsic components representing a pseudobulge (n = 2.87 ± 0.21, n = 2.29 ± 0.10) and a disk (n = 0.95 ± 0.16, n = 0.78 ± 0.10). Nearly symmetric ring-/shell-like structures emerge after subtracting the GALFIT model from the image. KIG 895 shows a clear irregular arm-like structure, in which the northern outer arm is reminiscent of a tail. The galaxy body is a disk, best fitted by a single Sérsic profile (n = 1.22 ± 0.1; n = 1.32 ± 0.12), that is, KIG 895 is a bulge-less, very late-type spiral. ARGOS high-resolution images clearly showed interaction signatures in KIG 895. We suggest that the ring-/shell-like residuals in KIG 685, a bona fide early-type galaxy, point toward a past accretion event.© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimWe are deeply indebted to the unknown referee for substantial suggestions. We thank Dr. Bogdan Ciambur both for proving us the PROFILER program and for the assistance. We thank Dr. Francesco La Barbera for having provided us the SPIDER K‐band dataset. R.R. thanks dr. Michael Jones for the English revision. R.R. and P.M. acknowledge funding from the INAF PRIN‐SKA 2017 program 1.05.01.88.04. L.V.M. acknowledges support from the grant AYA2015‐65973‐C3‐1‐R (MINECO/FEDER, UE). IRAF is distributed by the National Optical Astronomy Observatories, which are operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. We acknowledge the usage of the HyperLeda database ( http://leda.univ‐lyon1.fr )

    High‐resolution morphology and surface photometry of KIG 685 and KIG 895 with ARGOS+LUCI using the Large Binocular Telescope

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    We aim to refine the sample of isolated early‐type galaxies in the Analysis of the interstellar Medium of Isolated Galaxies (AMIGA) catalog via high‐resolution imaging. Here, we report the result from a pilot study investigating two candidates, KIG 685 and KIG 895, in K‐band with the laser guide star and wavefront sensing facility ARGOS using the Large Binocular Telescope (LBT). Observations, obtained during the commissioning time, achieved a point spread function (PSF) of ≈0.25″. We present the data reduction and the PSF analysis from the best closed‐loop exposures to investigate the galaxies' morphological structure, including their nuclear region. We used PROFILER for the decomposition of the azimuthal 1D light distribution and GALFIT for the 2D analysis, accounting for ARGOS's PSF. KIG 685 was found to be a S0 galaxy and has been modeled with two Sérsic components representing a pseudobulge (n1D = 2.87 ± 0.21, n2D = 2.29 ± 0.10) and a disk (n1D = 0.95 ± 0.16, n2D = 0.78 ± 0.10). Nearly symmetric ring‐/shell‐like structures emerge after subtracting the GALFIT model from the image. KIG 895 shows a clear irregular arm‐like structure, in which the northern outer arm is reminiscent of a tail. The galaxy body is a disk, best fitted by a single Sérsic profile (n1D = 1.22 ± 0.1; n2D = 1.32 ± 0.12), that is, KIG 895 is a bulge‐less, very late‐type spiral. ARGOS high‐resolution images clearly showed interaction signatures in KIG 895. We suggest that the ring‐/shell‐like residuals in KIG 685, a bona fide early‐type galaxy, point toward a past accretion event

    Resolving the host galaxy of a distant blazar with LBT/LUCI 1 + ARGOS

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    BL Lac objects emitting in the very high energy (VHE) regime are unique tools to peer into the properties of the extragalactic background light (EBL). However, due to the typical absence of features in their spectra, the determination of their redshifts has proven challenging. In this work, we exploit the superb spatial resolution delivered by the new Advanced Rayleigh guided Ground layer adaptive Optics System (ARGOS) at the Large Binocular Telescope to detect the host galaxy of HESS J1943+213, a VHE emitting BL Lac shining through the Galaxy. Deep H-band imaging collected during the ARGOS commissioning allowed us to separate the contribution of the nuclear emission and to unveil the properties of the host galaxy with unprecedented detail. The host galaxy is well fitted by a Sérsic profile with index of n ̃ 2 and total magnitude of HHost ̃ 16.15 mag. Under the assumption that BL Lac host galaxies are standard candles, we infer a redshift of z ̃ 0.21. In the framework of the current model for the EBL, this value is in agreement with the observed dimming of the VHE spectrum due to the annihilation of energetic photons on the EB
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