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UES: Utrecht Echelle Spectrograph. UES on the WHT Nasmyth platform. High-res. spectrograph (WHT 1992- 2002 ) Spectral range 300-1100nm Cross-dispersion, 3 prisms + 2 diffraction gratings Resolving power between 50.000 - 80.000. 2. UES optical design. 3m. 3m. 3.
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UES: Utrecht Echelle Spectrograph • UES on the WHT • Nasmyth platform. • . High-res. spectrograph (WHT 1992- 2002 ) Spectral range 300-1100nm Cross-dispersion, 3 prisms + 2 diffraction gratings Resolving power between 50.000 - 80.000 2
UES optical design 3m 3m 3
Optical elements + detector 4k x 4k Fairchildt Collimador Prisms (3) Gratings (2) Camera 4
pre-optics Microlense arrays (Amus) 50mm fibers (UV050125140, Ceramoptep) 6
Coupling to OSIRIS inside OSIRIS 8
Design Image sliced on the Nasmyth focus into 12 square 357 m (0.43 arcsec) microlenses feeding 50 m diameter fibers 2 calibration fibers 4 sky fibers
Light enclosed in fibers 66% 19% 84% at 1” 6% 57% at 1.5” 38% at 2”
Performance • R ~ 50,000 (1.5-3.5 Å/mm and FWHM ~ 3 pixel) 16% throughput on blaze (0.4 original 0.65 fiber 0.8 pre-optics 0.90 folds 0.84@1”) • New detector is larger (40962 15 m) • 40 mm (x limited by corr. plate) 61 mm (y CCD) • ~ 1-2 m/s long-term precision 370-570 nm contiguous 570-900 nm partially (estimated)
10ºC<T<20ºC T stability GTC foundations ≈ 0.3 K T variations damped by x5 Data (T, RH) being taken since February 2012 Planning a seismic study by Geology Dept. (ULL) Coudé room
Isolating structure Al 3.15 x 2.5 x 2 m (38.4 m2) stability +/- 0.1K Ref. temperature TBD T = 10ºC implies losses 110w 250w chiller, 20l/min Environment
Vacuum chamber • Stainless steel AISI 304 • 2.9m x 1.6m (1.5m Ø) • mass 1320 Kg • 4 isomatic dampers • Thermal transmission (238w/K): • conduction: 96w/K • convection: 140w/K • radiation (net): 2w/K
All optical elements at a constant temperature (TBD) 3 hangers to join bench to chamber (G10). Thermal transmission (6w/K): Conduction: 5.3w/K Convection: NA (pressure under 200 mTorr) Radiation (net): 0.7w/K Optical bench
HORUS data reduction and analysis software • Basic processing: bias, flatfielding • Extraction: standard, optimal, perfectionism • Calibration: flux (rough), wavelength (critical) • RVs: cross-correlation, template matching, research! • Spectral classification: stars, galaxies, clusters • Stellar parameters: Teff, logg, [Fe/H], micro, [ /Fe] …
Zooming-in 20
Science Lab data Na-Ar Na-Ne Th-Ar
Lab studies • Stability with temperature • Stability with image • Spectrophotometric precision • Solar center-to-limb variation Shift (pixels) Frame #
HORUS • Estimates indicate 2 years of work and 350 000 euros needed • Have used internal (IAC) funding for design studies and some components (200 000 euros for detector from Spectral Instruments + about 15000 euros recently for design and fibers and hardware) • IAC internal (Severo Ochoa) funding secured (200 000 euros) • Vacuum chamber is delayed: internal review + funding issues • Attractive alternative is to take it under a simplified form to GTC while vacuum-chamber development continues
HORUS • Most high-resolution science projects do not require extreme stability • Pre-optics can be optimized for poor seeing conditions that GTC cannot use effectively now • HORS can use Nasmyth platform: it fits and with a shorter length (reduced losses) • Essentially ready to go!
HORUS issues • Wavelength calibration: can use ICM? otherwise a supply from IACUB) • CCD had faulty electronics: now solved • CCD cryocooler: can be stored in isolated cabinet • Fiber-fed. Fibers in hand. Several fiber links produced for lab tests • Acquisition electronics: working, if too simple • Missing folder: on lease from P. L. Palle (solar lab at Teide Observatory) calibration unit is needed (ThAr hollow-cathode + power