Compact fibre-optic format vhangers for a multislit echelle spectrometer initial results on the Dumbell nebula (NGC 6853).
Abstract
Eight compact fiberoptic format changers have been manufactured. These convert the shapes of line-emission sources, imaged in the focal plane of the 4.2-m William Herschel telescope, into three or five long entrance slits for the Manchester echelle spectrometer. The construction and performance of one such array, with 169 fibers feeding three parallel slits, is described in detail. Improvements which will enhance its performance by at least a factor of 2 are suggested, as is the best way of spectrally calibrating these data. A gas-spaced, optically contacted Fabry-Perot which produces white-light (Edser-Butler) on-axis fringes has been manufactured for this purpose. The initial use of the 169-fiber array on the core of the Dumbbell planetary nebula has revealed the presence of four separate velocity components in the forbidden O III 5007 A profiles. The existence of an inner, highly ionized shell, expanding radially at 12 km/s and contained within an outer one expanding at 31 km/s, is implied.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 1992
- DOI:
- 10.1093/mnras/256.1.97
- Bibcode:
- 1992MNRAS.256...97M
- Keywords:
-
- Astronomical Spectroscopy;
- Echelle Gratings;
- Fiber Optics;
- Planetary Nebulae;
- Spectrometers;
- Emission Spectra;
- Stellar Cores;
- Stellar Envelopes;
- Telescopes;
- Instrumentation and Photography