HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 450 nm to 2450 nm with resolving powers from 3500 to 18000 and spatial sampling from 60 mas to 4 mas. It can operate in two Adaptive Optics modes - SCAO (including a High Contrast capability) and LTAO - or with NOAO. The project is preparing for Final Design Reviews. HARMONI is a work-horse instrument that provides efficient, spatially resolved spectroscopy of extended objects or crowded fields of view. The gigantic leap in sensitivity and spatial resolution that HARMONI at the ELT will enable promises to transform the landscape in observational astrophysics in the coming decade. The project has undergone some key changes to the leadership and management structure over the last two years. We present the salient elements of the project restructuring, and modifications to the technical specifications. The instrument design is very mature in the lead up to the final design review. In this paper, we provide an overview of the instrument's capabilities, details of recent technical changes during the red flag period, and an update of sensitivities.
HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 450nm to 2450nm with resolving powers from 3500 to 18000 and spatial sampling from 60mas to 4mas. It can operate in two Adaptive Optics modes - SCAO (including a High Contrast capability) and LTAO - or with NOAO. The project is preparing for Final Design Reviews. The Calibration Module (CM) is part of the HARMONI Instrument. It includes all the functionalities necessary to remove the instrumental signature from the observed science data, perform the technical calibrations needed to set up other sub-systems, and for monitoring the health of the instrument during operations. The CM is a complex and accurate optical configurable mechanism mainly composed by the following calibration units:
Integral Field Spectrograph Calibration Unit (ICU): It provides calibration for the integral field spectrograph. The ICU mimics the ELT pupil and F/# at the HARMONI entrance and provides with a set of illumination patterns by combining different light sources and focal plane masks.
Adaptive Optics Calibration Unit (AOCU): Intended for “Natural Guide Star Sensors (NGSS)” and “Laser Tomography Adaptive Optics (LTAO)” calibration.
Geometrical Calibration Unit (GCU): Using a well-known geometrical pattern of barely resolved point sources made of 480 optical fibers, this unit is intended for the NGSS guide probes.
In this paper, we present an overview of the CM design, describing its functional and optomechanical implementation.
HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 450nm to 2450nm with resolving powers from 3500 to 18000 and spatial sampling from 60mas to 4mas. It can operate in three Adaptive Optics modes – SCAO, HCAO and LTAO - or with NOAO. The project is preparing for Final Design Reviews. The Pick-Off Arm (POA) module is part of the Low Order Wavefront Subsystem (LOWFS) which provides field stabilisation and low-order wavefront sensing in seeing-limited and LTAO observing modes, measuring the motion of the instrument focal plane relative to the telescope wavefront sensors. The POA module provides the source acquisition and tracking capabilities with 6 μm accuracy over a technical field of 400 mm (120 arcseconds) in diameter. The acquired beam is then reflected into the AO bench (LOB). A two-axis theta-phi architecture is proposed, with a large 600mm diameter “theta” axis carrying at its perimeter a small “phi” axis; the combined rotation of both therefore allowing a 300mm long periscope carried on the phi axis to position a Pick-Off Mirror anywhere within the full technical field. A flow-down of the main requirements is presented, describing the interaction between the different error contributors and the overall accuracy budget. Furthermore, we present the POA baseline design, together with the analysis of the technologies used within the POA different units. Finally, the prototype activities developed are also described with preliminary results of tests demonstrating the required positioning accuracy.
HARMONI is the first light, adaptive optics assisted, integral field spectrograph for the European Southern Observatory’s Extremely Large Telescope (ELT). A work-horse instrument, it provides the ELT’s diffraction limited spectroscopic capability across the near-infrared wavelength range. HARMONI will exploit the ELT’s unique combination of exquisite spatial resolution and enormous collecting area, enabling transformational science. The design of the instrument is being finalized, and the plans for assembly, integration and testing are being detailed. We present an overview of the instrument’s capabilities from a user perspective, and provide a summary of the instrument’s design. We also include recent changes to the project, both technical and programmatic, that have resulted from red-flag actions. Finally, we outline some of the simulated HARMONI observations currently being analyzed.
HARMONI is the adaptive optics assisted, near-infrared and visible light integral field spectrograph for the Extremely Large Telescope (ELT). A first light instrument, it provides the work-horse spectroscopic capability for the ELT. As the project approaches its Final Design Review milestone, the design of the instrument is being finalized, and the plans for assembly, integration and testing are being detailed. We present an overview of the instrument’s capabilities from a user perspective, provide a summary of the instrument’s design, including plans for operations and calibrations, and provide a brief glimpse of the predicted performance for a specific observing scenario. The paper also provides some details of the consortium composition and its evolution since the project commenced in 2015.
HARMONI is the E-ELT’s first light visible and near-infrared integral field spectrograph. It will provide four different spatial scales, ranging from coarse spaxels of 60 × 30 mas best suited for seeing limited observations, to 4 mas spaxels that Nyquist sample the diffraction limited point spread function of the E-ELT at near-infrared wavelengths. Each spaxel scale may be combined with eleven spectral settings, that provide a range of spectral resolving powers (R ~3500, 7500 and 20000) and instantaneous wavelength coverage spanning the 0.5 – 2.4 μm wavelength range of the instrument. In autumn 2015, the HARMONI project started the Preliminary Design Phase, following signature of the contract to design, build, test and commission the instrument, signed between the European Southern Observatory and the UK Science and Technology Facilities Council. Crucially, the contract also includes the preliminary design of the HARMONI Laser Tomographic Adaptive Optics system. The instrument’s technical specifications were finalized in the period leading up to contract signature. In this paper, we report on the first activity carried out during preliminary design, defining the baseline architecture for the system, and the trade-off studies leading up to the choice of baseline.
HARMONI is a visible and near-infrared (0.47 to 2.45 μm) integral field spectrometer, providing the E-ELT's core
spectroscopic capability, over a range of resolving powers from R (≡λ/Δλ)~500 to R~20000. The instrument provides simultaneous spectra of ~32000 spaxels at visible and near-IR wavelengths, arranged in a √2:1 aspect ratio contiguous field. HARMONI is conceived as a workhorse instrument, addressing many of the E-ELT’s key science cases, and will
exploit the E-ELT's scientific potential in its early years, starting at first light. HARMONI provides a range of spatial
pixel (spaxel) scales and spectral resolving powers, which permit the user to optimally configure the instrument for a
wide range of science programs; from ultra-sensitive to diffraction limited, spatially resolved, physical (via morphology),
chemical (via abundances and line ratios) and kinematic (via line-of-sight velocities) studies of astrophysical sources.
Recently, the HARMONI design has undergone substantial changes due to significant modifications to the interface with
the telescope and the architecture of the E-ELT Nasmyth platform. We present an overview of the capabilities of
HARMONI, and of its design from a functional and performance viewpoint.
HARMONI is a visible and near-IR integral field spectrograph, providing the E-ELT's spectroscopic capability at first
light. It obtains simultaneous spectra of 32000 spaxels, at a range of resolving powers from R~4000 to R~20000,
covering the wavelength range from 0.47 to 2.45 μm. The 256 × 128 spaxel field of view has four different plate scales,
with the coarsest scale (40 mas) providing a 5″ × 10″ FoV, while the finest scale is a factor of 10 finer (4mas).
We describe the opto-mechanical design of HARMONI, prior to the start of preliminary design, including the main subsystems
- namely the image de-rotator, the scale-changing optics, the splitting and slicing optics, and the spectrographs.
We also present the secondary guiding system, the pupil imaging optics, the field and pupil stops, the natural guide star
wavefront sensor, and the calibration unit.
HARMONI has been conceived as a workhorse visible and near-infrared (0.47-2.45 microns) integral field spectrograph
for the European Extremely Large Telescope (E-ELT). It provides both seeing and diffraction limited observations at
several spectral resolutions (R= 4000, 10000, 20000). HARMONI can operate with almost any flavor of AO (e.g.
GLAO, LTAO, SCAO), and it is equipped with four spaxel scales (4, 10, 20 and 40 mas) thanks to which it can be
optimally configured for a wide variety of science programs, from ultra-sensitive observations of point sources to highangular
resolution spatially resolved studies of extended objects. In this paper we describe the expected performance of
the instrument as well as its scientific potential. We show some simulated observations for a selected science program,
and compare HARMONI with other ground and space based facilities, like VLT, ALMA, and JWST, commenting on
their synergies and complementarities.
Niranjan Thatte, Mathias Tecza, Fraser Clarke, Roger Davies, Alban Remillieux, Roland Bacon, David Lunney, Santiago Arribas, Evencio Mediavilla, Fernando Gago, Naidu Bezawada, Pierre Ferruit, Ana Fragoso, David Freeman, Javier Fuentes, Thierry Fusco, Angus Gallie, Adolfo Garcia, Timothy Goodsall, Felix Gracia, Aurelien Jarno, Johan Kosmalski, James Lynn, Stuart McLay, David Montgomery, Arlette Pecontal, Hermine Schnetler, Harry Smith, Dario Sosa, Giuseppina Battaglia, Neil Bowles, Luis Colina, Eric Emsellem, Ana Garcia-Perez, Szymon Gladysz, Isobel Hook, Patrick Irwin, Matt Jarvis, Robert Kennicutt, Andrew Levan, Andy Longmore, John Magorrian, Mark McCaughrean, Livia Origlia, Rafael Rebolo, Dimitra Rigopoulou, Sean Ryan, Mark Swinbank, Nial Tanvir, Eline Tolstoy, Aprajita Verma
We describe the results of a Phase A study for a single field, wide band, near-infrared integral field spectrograph for the
European Extremely Large Telescope (E-ELT). HARMONI, the High Angular Resolution Monolithic Optical & Nearinfrared
Integral field spectrograph, provides the E-ELT's core spectroscopic requirement. It is a work-horse instrument,
with four different spatial scales, ranging from seeing to diffraction-limited, and spectral resolving powers of 4000,
10000 & 20000 covering the 0.47 to 2.45 μm wavelength range. It is optimally suited to carry out a wide range of
observing programs, focusing on detailed, spatially resolved studies of extended objects to unravel their morphology,
kinematics and chemical composition, whilst also enabling ultra-sensitive observations of point sources.
We present a synopsis of the key science cases motivating the instrument, the top level specifications, a description of
the opto-mechanical concept, operation and calibration plan, and image quality and throughput budgets. Issues of
expected performance, complementarity and synergies, as well as simulated observations are presented elsewhere in
these proceedings[1].
Temperature variations in the NICMOS detectors arise from a variety of
thermal sources. These thermal variations lead to several image
artifacts which must be removed before making quantitative scientific
measurements from NICMOS data. Future instruments would do well to
minimize sources of thermal instabilities in their detectors. A related problem is the inability to directly measure detector temperature from bias due to the instability of the low-voltage power supply in NICMOS. Identifying ways to directly monitor detector temperatures would be an important benefit for future missions.
We describe the on-orbit performance of the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) aboard the Hubble Space Telescope (HST) following the installation of the NICMOS Cooling System (NCS). NICMOS is operated at a higher temperature (~77 K) than in the previous observing 1997-1998 period (~62 K). Due to the higher operating temperature, the detector QE is higher, while the well depth is less. The spatial structure of the flat field response remained essentially unchanged. We will show the effects of operating at the higher temperature and present current NICMOS calibration images. In addition, we present an overview of on-orbit testing and report on the re-enabling of NICMOS.
INTEGRAL is an optical fiber unit for performing 2D spectroscopy of extended objects at the 4.2 m. William Herschel Telescope (WHT). It is mounted at the GHRIL Nasmyth focus together with newly built acquisition, guiding, and calibration units. It makes use of the specially designed fiber spectrograph WYFFOS. This system allows up to six bundles to be mounted simultaneously. It currently contains three science oriented fiber bundles, any one of which can be easily and quickly placed in the telescope beam. Their spatial resolution elements (fiber core diameters) are 0'.45, 0'.9, and 2'.7, respectively. Hence, depending on the prevailing seeing conditions the instrument can be easily optimized for the scientific program. INTEGRAL was successfully commissioned at the WHT during a six night period in July 1997. Here we will discuss its main characteristics.
In this communication we describe two optical fiber systems contrived to perform simultaneous bidimensional spectroscopy of extended objects: 2D_FIS and HEXAFLEX II. The main component of 2D_FIS is an optical fiber bundle which links the auxiliary Cassegrain focus of the 4.2 m William Herschel Telescope (WHT) with the ISIS spectrograph. HEXAFLEX II has been designed for the Cassegrain focus of the 2.5 m Nordic Optical Telescope (NOT) and it uses the FLEX spectrograph. Both telescopes are at the Observatorio del Roque de los Muchachos, on the island of La Palma. The basic component, the fiber bundle, is similar in both systems although each one is adapted to the particular characteristics of the corresponding spectrograph and telescope. Each one of the bundles is composed of 125 fibers: 95 to observe the object and 30 to obtain the sky background signal. Details of the acquisition procedures are provided. These systems have been tested at the telescope with success. Some examples of results on astronomical objects are shown.
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