{"id":1985,"date":"2021-12-13T10:06:42","date_gmt":"2021-12-13T09:06:42","guid":{"rendered":"https:\/\/stel.asu.cas.cz\/en\/?page_id=1985"},"modified":"2024-02-09T14:39:01","modified_gmt":"2024-02-09T13:39:01","slug":"oes-spectrograph","status":"publish","type":"page","link":"https:\/\/stel.asu.cas.cz\/en\/telescope\/instrumentation\/oes-spectrograph\/","title":{"rendered":"Echelle spectrograph"},"content":{"rendered":"\n

Ond\u0159ejov Echelle Spectrograph (OES) is a fibre-fed high-resolution spectrograph. The light reflected from the main mirror is from primary focus directed via optical fiber to the coud\u00e9 room where it is reflected to a Zerodur echelle grating (by Richardson Grating Laboratories). The optical mirror reflects the light further to a equilateral prism (made by TOPTEC Turnov, CZ), which separates the orders that are then brought to a focus on the detector, which is a nitrogen-cooled CCD Camera Versarray 2048B (Roper Scientific, for more details see here<\/a>) with working temperature of the detector -110\u00b0C.<\/p>\n\n\n\n

The spectrograph can be fed independently through the same fiber by Thorium Argon calibration lamp and flat field calibration lamp. Also, the iodine cell is mounted on the telescope-spectrograph interface, providing a secondary (optional) spectral calibration source.<\/p>\n\n\n\n

A more detailed technical description with mechanical setup and all optical elements can be found in the report from the installation phase of the OES by Koubsk\u00fd at al., Ond\u0159ejov Echelle Spectrograph – OES, Publ. Astron. Inst. ASCR, 92:37\u201343, 2004<\/strong>.<\/a> For more details about OES see also Kab\u00e1th et al., 2020, PASP, 132, 5002<\/strong><\/a>.<\/p>\n\n\n\n

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Left<\/strong>: OES spectrograph optical layout and light path from the slit to the detector. A – slit, B – collimator, C – echelle grating, D – first parabolic mirror, E – small flat mirror, F – second parabolic mirror (optical elements D, E and F are parts of so called white pupil, making the light beam more narrow), G- prism, H – objective lens and dewar vessel. Right<\/strong>: Upper image – the mechanical parts holding the optical elements of the Ondrejov Echelle Spectrograph. Lower image – the detector with the dewar vessel. Credit: Miroslav \u0160lechta.<\/p>\n\n\n\n

Echelle<\/span> Grating<\/span><\/strong><\/h5>\n\n\n\n