Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

The Accretion Disk and White Dwarf during the Quiescence of the Dwarf Novae VW Vulpeculae and χ Leonis

Colleen K. Henry and Edward M. Sion
Publications of the Astronomical Society of the Pacific
Vol. 113, No. 786 (August 2001), pp. 970-973
DOI: 10.1086/322912
Stable URL: http://www.jstor.org/stable/10.1086/322912
Page Count: 4
Subjects: Astronomy
Find more content in these subjects: Astronomy
  • Download PDF
  • Add to My Lists
  • Cite this Item
We're having trouble loading this content. Download PDF instead.

Page Thumbnails

Abstract

ABSTRACT We have carried out an International Ultraviolet Explorer archival comparative study of the two U Geminorum type dwarf novae VW Vulpeculae and χ Leonis. The spectrum of χ Leo does not show any C iv, a feature normally seen in the vast majority of other dwarf novae. For VW Vul, a single‐temperature high‐gravity photosphere does not produce a consistent fit. The best‐fit accretion disk model corresponds to \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $M_{\mathrm{wd}\,}=0.55\,M_{\odot }$ \end{document} , \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $i=41^{\circ }$ \end{document} , and \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $\dot{M}=10^{-9}\,M_{\odot }$ \end{document} yr−1. For χ Leo, we find that a white dwarf model with \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $T_{\mathrm{eff}\,}=33,000$ \end{document} K gives the best fit to the far‐UV spectrum. However, a model accretion disk with parameters \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $M=0.80\,M_{\odot }$ \end{document} , \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $i=60^{\circ }$ \end{document} , and \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $\dot{M}=10^{-10}\,M_{\odot }$ \end{document} yr−1 also gives a satisfactory fit to the far‐UV continuum. However, the accretion rate derived for VW Vul is within a factor of 3 of the critical value, while the accretion rate of χ Leo is within a factor of 60 of the critical rate. If we have identified the accreting white dwarf in χ Leo, then it strengthens the overall conclusion that the white dwarfs in cataclysmic variables above the period gap appear to be a factor of 1.5–2 times hotter than the accreting white dwarfs in dwarf novae below the period gap.

Notes and References

This item contains 18 references.

REFERENCES
  • ['Hubeny, I. 1988, Comput. Phys. Commun., 52, 103']
  • ['Hubeny, I., & Lanz, T. 1995, ApJ, 439, 875']
  • ['LaDous, C. 1991, A&A, 252, 100']
  • ['Lyons, K., Stys, D., Slevinsky, R., Sion, E., & Wood, J. 2001, AJ, 122, 327']
  • ['Massa, F., & Fitzpatrick, E. 2000, ApJS, 126, 517']
  • ['Ritter, H., & Kolb, U. 1998, A&AS, 129, 83']
  • ['Shafter, A. W. 1983, Ph.D. thesis, UCLA']
  • ['———. 1986, AJ, 92, 658']
  • ['Shafter, A., Wheeler, J. C., & Cannizzo, J. K. 1986, ApJ, 305, 261']
  • ['Sion, E. M., Cheng, F. H., Szkody, P., Sparks, W., Gaensicke, B., Huang, M., & Mattei, J. 1998, ApJ, 496, 449']
  • ['Smak, J. 1984, Acta Astron., 34, 317']
  • ['Szkody, P. 1987, ApJS, 63, 685']
  • ['Szkody, P., Mattei, J., Waagen, E., & Stablein, C. 1991, ApJS, 76, 359']
  • ['Thorstensen, J. R., Taylor, C. J., & Kemp, J. 1998, PASP, 110, 1405']
  • ['Urban, J., Lyons, K., Mittal, R., Nadalin, I., DiTuro, P., & Sion, E. 2000, PASP, 112, 1611']
  • ['Verbunt, F. 1987, A&AS, 71, 339']
  • ['Wade, R. A., & Hubeny, I. 1998, ApJ, 509, 350']
  • ['Warner, B. 1995, Cataclysmic Variable Stars (Cambridge: Cambridge Univ. Press)']