Hostname: page-component-848d4c4894-pjpqr Total loading time: 0 Render date: 2024-06-28T20:14:35.472Z Has data issue: false hasContentIssue false

An Observatory for Mapping the Far UV Diffuse Galactic Emission Line Background

Published online by Cambridge University Press:  12 April 2016

F.L. Roesler
Affiliation:
Dept. of Physics, University of Wisconsin, Madison, WI 53706
J. Harlander
Affiliation:
Dept. of Physics, University of Wisconsin, Madison, WI 53706
R.J. Reynolds
Affiliation:
Dept. of Physics, University of Wisconsin, Madison, WI 53706

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A new instrumental concept for interference spectroscopy called Spatial Heterodyne Spectroscopy (SHS) is described. This instrument as currently demonstrated could provide important information on the structure, excitation, and dynamics of the ≃ 105 K component of the interstellar medium by providing velocity-resolved (20 km s−1) maps of the faint FUV emission line background over a hemisphere of the sky within a 5-6 year observation period. We are currently studying concepts expected to reduce this time by at least an order of magnitude.

In the SHS technique, an all-reflection dispersive interferometer produces a Fourier transform of the spectrum as two-dimensional spatial frequencies on an imaging detector. The system does not require scanning, and measures its own internal alignment state. Although the system suffers the conventional Fourier transform multiplex disadvantage associated with the photon noise in the background FUV continuum, we estimate that for a broad-band survey Spatial Heterodyne Spectroscopy as currently demonstrated can provide 4-5 fold gains over practical grating spectrometers of similar dimensions and spatial and spectral resolution. Field widened methods currently being studied promise additional gains of two orders of magnitude.

Type
V. Long Term Future Issues
Copyright
Copyright © Kluwer 1990

References

Bergman, J.N.: 1980, Ap. J. 236, 577 CrossRefGoogle Scholar
Cox, D.P. and Smith, B.W.: 1974, Ap. J. (Letters) 189, L105 CrossRefGoogle Scholar
Harlander, J. and Roesler, F. L.: 1990, SPIE 1235, in PressGoogle Scholar
Jenkins, E.B.: 1978, Ap. J. 219, 845 Google Scholar
Martin, C. and Bowger, S.: 1990, Ap. J. 350, 242 Google Scholar
McKee, C.F. and Ostriker, J.P.: 1977, Ap. J. 218, 148 Google Scholar
Spitzer, L. Jr.: 1956, Ap. J. 124, 20 CrossRefGoogle Scholar
Williamson, F.O., Sanders, W.T., Kraushaar, W.L., McCammon, D., Borken, R., and Bunner, A.N.: 1974, Ap. J. (Letters) 193, L133 Google Scholar