The understanding of high-energy astrophysical sources often depends on observations over the entire electromagnetic spectrum. Yet, extensive multifrequency observing campaigns can consume the resources of a large number of telescopes, including ground-based and satellite facilities, and usually involve large, unwieldy consortia of observers. Because most X-ray sources are variable on a short time-scale, there is an additional need to make the multifrequency observations simultaneous. The logistical difficulties involved in coordinating these observations, coupled with the vagaries of the weather at ground-based observing sites, mean that comparatively few such coordinated campaigns are attempted; of those that have been tried the success rate for achieving simultaneity is low.
In the present paper we argue that simultaneous X-ray, optical and ultraviolet observations could be achieved more logically, cheaply, and effectively by mounting a small boresighted optical/UV-telescope alongside future X-ray telescopes. A 12″ optical/UV monitor could, for instance, be incorporated into X-ray facilities such as the American AXAF or the European XMM missions with minimal impact on the total cost, weight, size, and telemetry requirements. Such a telescope, equipped with a position sensitive photoncounting detector, could provide two-dimensional photometric imaging of stars as faint asB=23.5 in a 1000 s exposure with a resolution that could easily be matched to that of the X-ray telescope. A series of wide- and narrow-band filters could be used to define spectral bands, while wide-field, low-resolution spectroscopy could be provided by a prism. Such an instrument could monitor not only the multifrequency variability of such active sources as quasars, Seyfert galaxies, BL Lac objects, X-ray binaries, cataclysmic variables, RS CVn stars, and flare stars, but also could provide astrometry, broadband colours, low-resolution spectroscopy, and imaging of constant sources and fortuitously observed field objects. Moreover, the concept of providing multifrequency simultaneous coverage of astrophysical objects in an unbiased way allows new phenomena to be discovered. A review is given of the scientific problems that require such a monitor, and some of the design and performance characteristics of a suitable monitor are discussed.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Allen, D.: 1981,Monthly Notices Roy. Astron. Soc. 197, 739.
Allington-Smith, J. R. and Schwarz, H. E.: 1984,Quart. J. Roy. Astron. Soc. 25, 267.
Bregman, J. N. et al.: 1982,Astrophys. J. 253, 19.
Bregman, J. N. et al.: 1984,Astrophys. J. 276, 454.
Charles, P. A. et al.: 1983,Monthly Notices Roy. Astron. Soc. 202, 657.
Chiapetti, L., Tanzi, E. G., and Treves, A.: 1980,Space Sci. Rev. 27, 3.
Córdova, F. A. and Mason, K. O.: 1984,Monthly Notices Roy. Astron. Soc. 206, 879.
Cowley, A. P., Crampton, D., Hutchings, J. B., Remillard, R., and Penfold, J. E. 1983,Astrophys. J. 272, 118.
Cruddace, R. G. and Dupree, A. K.: 1984,Astrophys. J. 277, 263.
Davidsen, A. et al.: 1974,Astrophys. J. 193, L25.
Fabian, A. C. et al.: 1981,Astron. Astrophys. 111, L9.
Haisch, B. M. et al.: 1981,Astrophys. J. 245, 1009.
Hertz, P. and Grindlay, J. E.: 1983,Astrophys. J. 267, L83.
Hutchings, J. B.: 1982, in P. Sanford, P. Laskarides, and J. Salton (eds.),Galactic X-ray Sources, John Wiley and Sons, New York.
Hutchings, J. B.: 1984,IAU Symp. 108, 305.
Ilovaisky, S. A., Chevalier, C., Motch, Ch., Pakull, M., van Paradijs, J., and Lub, J.: 1984,Astron. Astrophys. 140, 251.
Jensen, K. A., Córdova, F. A., Middleditch, J., Mason, K. O., Grauer, A. D., Horne, K. and Gomer, R.: 1983,Astrophys. J. 270, 211.
Jones, C. et al.: 1979,Astrophys. J. 234, L21.
Kahler, S. et al.: 1982,Astrophys. J. 252, 239.
Karpen, J. T. et al.: 1977,Astrophys. J.,216, 479.
Kemp, J. C., Barbour, M. S., Henson, G. D., Draus, D. J., Nolt, I. G., Radostitz, J. V., Priedhorsky, W. C., Terrell, J., and Walker, E. N.: 1983,Astrophys. J. 271, L65.
Khruzina, R. S. and Cherepashchuk, A. M.: 1983,Soviet Astron. Letters 9, 78.
Margon, B.: 1983, in W. H. G. Lewin and E. P. J. van den Heuvel (eds.)Accretion Driven Stellar X-ray Sources. Cambridge University Press, Cambridge, p. 287.
Margon, B. and Downes, R. A.: 1983,Astrophys. J. 274, L31.
Mason, K. O. and Córdova, F. A.: 1982,Astrophys. J. 262, 253.
Matthews, W. and Sandage, A.: 1963,Astrophys. J. 138, 30.
McClintock, J. E., London, R. A., Bond, H. E. and Grauer, A. D.: 1982,Astrophys. J. 258, 245.
Moffat, A. F. J. et al.: 1982, in C. W. H. De Loore and A. J. Willis (eds.), ‘Wolf-Rayet Stars: Observations, Physics, Evolution’,IAU Symp. 99, 577.
Moore, R. L. et al.: 1980,Astrophys. J. 235, 717.
Pedersen, H. et al.: 1982,Astrophys. J. 263, 325.
Petro, L., Bradt, H. V., Kelley, R. L., Horne, K., and Gomer, R.: 1981,Astrophys. J. 251, L7.
Priedhorsky, W. C. and Terrell, J.: 1983,Astrophys. J. 270, 233.
Sanders, W. T., Cassinelli, J. P., and Van der Hucht, K. A.: 1982, ‘Wolf-Rayet Stars: Observations, Physics, Evolution’,IAU Symp. 99, 589.
Tananbaum, H. et al.: 1979,Astrophys. J. 234, L9.
Tennant, A. et al.: 1981,Astrophys. J. 251, 15.
Walter, F. M., Cash, W., Charles, P. A., and Bowyer, C. S.: 1980,Astrophys. J. 236, 212.
Walter, F. M., Gibson, D. M., and Basri, G. S.: 1983,Astrophys. J. 267, 665.
Zamorani, G., Giommi, P, Maccacaro, T., and Tananbaum, H: 1984,Astrophys. J. 278, 28.
About this article
Cite this article
Córdova, F.A., Mason, K.O., Priedhorsky, W.C. et al. An imaging optical/UV monitor for X-ray astronomy observatories. Astrophys Space Sci 111, 265–290 (1985). https://doi.org/10.1007/BF00649970
- Cataclysmic Variable
- Seyfert Galaxy
- Photometric Imaging
- Ultraviolet Observation