Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-26T13:34:35.963Z Has data issue: false hasContentIssue false
  • English
  • Français

Polarized Emission and the Discovery of New Magnetic CVs

Published online by Cambridge University Press:  12 April 2016

Gary D. Schmidt
Gary D. Schmidt*
Affiliation:
Steward Observatory, The University of Arizona, Tucson, AZ 85721 , USA

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.

Recent quasar surveys have identified several new magnetic cataclysmic variables accreting at remarkably low rates, ~10−13M⊙ yr−1. The new discoveries raise questions regarding selection effects that may influence the current sample and the traditional evolutionary conclusions that have been drawn. This paper reviews the techniques that have been used to identify polars, including a summary of the optical polarization as a function of accretion rate and magnetic field strength. The new, low-ṁ systems accrete without a shock and cooling is dominated by optical cyclotron emission in very well-defined harmonics. These binaries, which have been found to accrete at far below the rate corresponding to angular momentum loss by gravitational radiation, also appear to contain unusually cool white dwarfs, suggesting that they are either at an advanced age or in unusual evolutionary states.

Type
Part 1. Population and Evolution
Information
International Astronomical Union Colloquium , Volume 190: Magnetic Cataclysmic Variables , 2004 , pp. 22 - 32
Copyright
Copyright © Astronomical Society of the Pacific 2004

References

Ferrario, L., Wickramasinghe, D. T., & Schmidt, G. 2003, MNRAS, 338, 340 Google Scholar
Heise, J., Brinkman, A. C., Gronenschild, E., Watson, M., King, A. R., Stella, L, & Kieboom, K. 1985, A&A, 148, L14 Google Scholar
Howell, S. B., Nelson, L. A., & Rappaport, S. 2001, ApJ, 550, 897 Google Scholar
Lamb, D. Q., & Masters, A. R. 1979, ApJ, 234, L117 Google Scholar
Meggitt, S. M. A., & Wickramasinghe, D. T. 1982, MNRAS, 198, 71 CrossRefGoogle Scholar
Mennickent, R. E., & Diaz, M. P. 2002, MNRAS, 336, 767 CrossRefGoogle Scholar
Ramsay, G., Rosen, S. R., Mason, K. O., Cropper, M. S., & Watson, M. G. 1993, MNRAS, 262, 993 Google Scholar
Reimers, D., Hagen, H.-J., & Hopp, U. 1999, A&A, 343, 157 Google Scholar
Reimers, D. & Hagen, H.-J. 2000, A&A, 358, L45 Google Scholar
Rousseau, T., Fischer, A., Beuermann, K., & Woelk, U. 1996, A&A, 310, 526 Google Scholar
Schmidt, G. D., Ferrano, L., Wickramasinghe, D. T., & Smith, P. S. 2001, ApJ, 553, 823 Google Scholar
Schmidt, G. D., Hoard, D. W., Szkody, P., Melia, F., Honeycutt, R. K., & Wagner, R. M. 1999, ApJ, 525, 407 Google Scholar
Schmidt, G. D., Szkody, P., Smith, P. S., Silber, A., Tovmassian, G., Hoard, D. W., Gänsicke, B. T., & de Martino, D. 1996, ApJ, 473, 483 Google Scholar
Schwope, A. D. 2002, private communicationGoogle Scholar
Schwope, A. D., Beuermann, K., Jordan, S., & Thomas, H.-C. 1993, A&A, 278, 487 Google Scholar
Schwope, A. D., Schwarz, R., & Greiner, J. 1999, A&A, 348, 861 Google Scholar
Sion, E. M. 1999, PASP, 111, 532 CrossRefGoogle Scholar
Stockman, H. S. 1988, in Polarized Radiation of Circumstellar Origin, eds. Coyne, G. V., J., S., et al. (Vatican: Vatican Observatory), 237 Google Scholar
Szkody, P., Anderson, S. F., Schmidt, G. (+ 23 coauthors) 2003, ApJ, 583, 902 Google Scholar
Szkody, P., Vennes, S., Wagner, R. W., & Hastings, C. 1999, Annapolis Workshop on Magnetic Cataclysmic Variables, ed. Hoellier, C. & Mukai, K., ASP Conf. Ser., 157, 195 Google Scholar
Warner, B. 1995 Cataclysmic Variable Stars, (Cambridge: Cambridge Univ. Press), 343 Google Scholar
Wickramasinghe, D. T., & Ferrano, L. 2000, PASP, 112, 873 CrossRefGoogle Scholar
Woelk, U., & Beuermann, K. 1992, A&A, 256, 498 Google Scholar