The Hector instrument is the new multi-object facility at the Anglo-Australian Telescope. It consists of new-format hexabundle IFU’s, complex robotic positioner with magnetic system, unique sky-fibre system, guiding system, optical cable and two spectrographs. Light is captured at the telescope prime focus by optical fiber imaging bundles (hexabundles) at f/3.25 and delivered to the spectrograph slit via ~50 m long fiber cable. At the spectrograph end, the fibers are reformatted into a curved slit relaying unconverted telescope input. The spectrograph optics includes fast collimators and cameras reimaging the slit onto 4k x 4k E2V detectors at f/1.3 with magnification 1/2.5. The challenge of good image quality with the large pupil size (180 mm) and the field of view (±12° at detector) was met by introduction of several aspheric surfaces in the all-refractive design. The blue and red arms, 372-591 nm and 571-778 nm, respectively, are implemented with the help of a dichroic beam splitter in the diverging beam followed by a collimating doublet lens for each arm. An upgrade is possible to the infra-red arm with the help of an additional dichroic beam splitter. The dispersers are asymmetric VPH gratings with slanted fringes optimised for the passband of each arm. Optical performance of the dichroic beamsplitter and gratings has been confirmed and complemented by in-house metrology. The spectrograph throughput is predicted based on transmittance of materials and coatings.
The MCAO Assisted Visible Imager and Spectrograph (MAVIS) is a facility-grade visible MCAO instrument, currently under development for the Adaptive Optics Facility at the VLT. The adaptive optics system will feed both an imager and an integral field spectrograph, with unprecedented sky coverage of 50% at the Galactic Pole. The imager will deliver diffraction-limited image quality in the V band, cover a 30" x 30" field of view, with imaging from U to z bands. The conceptual design for the spectrograph has a selectable field-of-view of 2.5" x 3.6", or 5" x 7.2", with a spatial sampling of 25 or 50 mas respectively. It will deliver a spectral resolving power of R=5,000 to R=15,000, covering a wavelength range from 380 - 950 nm. The combined angular resolution and sensitivity of MAVIS fill a unique parameter space at optical wavelengths, that is highly complementary to that of future next-generation facilities like JWST and ELTs, optimised for infrared wavelengths. MAVIS will facilitate a broad range of science, including monitoring solar system bodies in support of space missions; resolving protoplanetary- and accretion-disk mechanisms around stars; combining radial velocities and proper motions to detect intermediate-mass black holes; characterising resolved stellar populations in galaxies beyond the local group; resolving galaxies spectrally and spatially on parsec scales out to 50 Mpc; tracing the role of star clusters across cosmic time; and characterising the first globular clusters in formation via gravitational lensing. We describe the science cases and the concept designs for the imager and spectrograph.
Based on the success of the SAMI integral field spectrograph (IFS) instrument on the Anglo-Australian Telescope (AAT), the capacity for large IFS nearby galaxy surveys on the AAT is being substantially expanded with a new instrument, Hector. The high fill-factor imaging fibre bundles ‘hexabundles’, of the type used on SAMI, are being improved and enlarged to cover 27-arcsec diameter. The aim is to reach 2 effective radii on most galaxies, where the galaxy rotation curve flattens and half of the angular momentum is accounted for. The boosted Hector spectral resolution of 1.3 Angstrom will enable higher order stellar kinematics to be measured on a larger fraction of galaxies than with any other IFS survey instrument. Hector will have 21 hexabundles over a 2-degree field feeding both the new Hector spectrograph and existing AAOmega spectrograph. Hector consists of new blue and red-arm spectrographs, coupled to the new high- efficiency hexabundles and a unique robotic positioner. The novel robotic positioning concept will compensate for varying telecentricity over the 2-degree-field of the AAT to recoup the light loss and correct the focus across the field. The main components are in hand, and prototypes are currently being tested ahead of commissioning in the next year. Hector will take integral field spectroscopy of 15,000 galaxies with z < 0.1 in the 4MOST WAVES-North and WAVES-South regions. The WAVES data, which will come later, will give the environment metrics necessary to relate how local and global environments influence galaxy growth through gas accretion, star formation and spins measured with Hector. The WALLABY ASKAP survey will trace HI gas across the Hector fields, which in combination with Hector will give a complete view of gas accretion and star formation.
Based on the success of the SAMI integral field spectrograph (IFS) instrument on the Anglo-Australian Telescope (AAT) the capacity for large IFS nearby galaxy surveys on the AAT is being substantially expanded with a new instrument called Hector. The high filling-fraction imaging fibre bundles ‘hexabundles’ of the type used on SAMI, are being enlarged to cover up to 30-arcsec diameter. The aim is to reach two effective radii on most galaxies, where the galaxy rotation curve flattens and >75% of the specific angular momentum of disk galaxies is accounted for. Driven by the key science case, Hector will have a 1.3A spectral resolution, enabling high-order stellar kinematics to be measured on a larger fraction of galaxies than with any other IFS instrument. Hector will be on sky in 2019.
The first module of Hector, Hector-I, will have 21 hexabundles and >42 sky fibres to observe 20 galaxies and a calibration star simultaneously. It consists of new blue and red-arm spectrographs that have been designed at the Australian Astronomical Observatory (AAO; now called AAO-Macquarie), coupled to the new hexabundles and robotic positioner from AAO-USydney (formerly the Sydney Astrophotonics Instrumentation Laboratory, SAIL) at Sydney University. A novel robotic positioning concept will compensate for varying telecentricity over the 2-degree-field of the AAT to recoup the 20% loss in light at the edge of the field. Hector-I will survey 15,000 galaxies. Additional modules in the future would result in 30,000 galaxies.
Hector will take integral field spectroscopy on galaxies with z<0.15 in the 4MOST WAVES-North and WAVES-South∗ regions. The WAVES data, which will come later, will give the environment metrics neces- sary to relate how local and global environments influence galaxy growth through gas accretion, star formation and spins measured with Hector. The WALLABY ASKAP† survey will trace HI gas across the Hector fields, which in combination with Hector will give a complete view of gas accretion and star formation.