Skip to main content Accessibility help
×
Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-05T04:24:10.621Z Has data issue: false hasContentIssue false

3 - Accretion onto white dwarfs

Published online by Cambridge University Press:  05 January 2014

Brian Warner
Affiliation:
University of Cape Town
Ignacio González Martínez-País
Affiliation:
Instituto de Astrofísica de Canarias, Tenerife
Tariq Shahbaz
Affiliation:
Instituto de Astrofísica de Canarias, Tenerife
Jorge Casares Velázquez
Affiliation:
Instituto de Astrofísica de Canarias, Tenerife
Get access

Summary

3.1 Accretion from the ISM and winds

3.1.1 Introductory remarks on white dwarfs

The spectra of white dwarfs (WD) are classified according to the scheme devised by Sion et al. (1983), of which we need here to use only the types DA (with strong H lines), DB (with He I lines and no H), and DZ (metallic lines, e.g., Ca, but excluding C, subdivided into DAZ and DBZ). In addition, magnetic fields in WDs play important roles in accretion processes. Their occurrence in isolated form (or as members of noninteracting binaries) is observed by Zeeman splitting or polarization, and the distribution of field strengths appears bimodal: Wickramasinghe and Ferrario (2000, 2005) conclude that ~16% of WDs have strong fields (≥0.5 MG); a much smaller fraction have lower fields, but there are indications of a rise of up to 25% at the kG level.

3.1.2 Accretion from the ISM

Most isolated WDs are of type DA or DB, but a small fraction at the cool end of the WD sequence are of type DZ (Fig. 3.1). The reason for ignoring carbon in this spectral type is because it can be dredged up from the interior, whereas the other metals must have a different origin. Levitation by radiation pressure is not strong enough to keep metals in the atmospheres of such stars (for T < 40,000 K), and gravitational settling time scales are short compared with the cooling time scale, so the metals must have been delivered from outside the star – such as from the interstellar medium (ISM).

Type
Chapter
Information
Publisher: Cambridge University Press
Print publication year: 2014

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Arras, P., Townsley, D. M., and Bildsten, L. 2006. Pulsational instabilities in accreting white dwarfs. ApJ, 643(June), L119–L122.Google Scholar
Baptista, R., Horne, K., Wade, R. A., Hubeny, I., Long, K. S., and Rutten, R. G. M. 1998. HST spatially resolved spectra of the accretion disk and gas stream of the nova-like variable UX Ursae Majoris. MNRAS, 298(Aug.), 1079–1091.Google Scholar
Barcelo, C., Liberati, S., Sonego, S., and Visser, M. 2008. Fate of gravitational collapse in semiclassical gravity. Phys. Rev. D, 77(4), 044032+.Google Scholar
Bondi, H., and Hoyle, F. 1944. On the mechanism of accretion by stars. MNRAS, 104, 273+.Google Scholar
Copperwheat, C. M., Marsh, T. R., Dhillon, V. S., Littlefair, S. P., Woudt, P. A., Warner, B., Steeghs, D., Gansicke, B. T., and Southworth, J. 2009. ULTRA-CAM observations of two accreting white dwarf pulsators. MNRAS, 393(Feb.), 157–170.Google Scholar
Dupuis, J., Fontaine, G., and Wesemael, F. 1993. A study of metal abundance patterns in cool white dwarfs. III – Comparison of the predictions of the two-phase accretion model with the observations. ApJS, 87(July), 345–365.Google Scholar
Edgar, R. 2004. A review of Bondi-Hoyle-Lyttleton accretion. New A Rev., 48(Sept.), 843–859.Google Scholar
Epelstain, N., Yaron, O., Kovetz, A., and Prialnik, D. 2007. A thousand and one nova outbursts. MNRAS, 374(Feb.), 1449–1456.Google Scholar
Fujimoto, M. Y. 1982. A theory of hydrogen shell flashes on accreting white dwarfs. I – Their progress and the expansion of the envelope. II – The stable shell burning and the recurrence period of shell flashes. ApJ, 257(June), 752–779.Google Scholar
Gänsicke, B. T., Marsh, T. R., Southworth, J., and Rebassa-Mansergas, A. 2008. Metal-rich debris discs around white dwarfs. Pages 149+ of: D., Fischer, F. A., Rasio, S. E., Thorsett, and A., Wolszczan (eds.), Astronomical Society of the Pacific Conference Series. Astronomical Society of the Pacific Conference Series, vol. 398.
Ghosh, P., and Lamb, F. K. 1978. Disk accretion by magnetic neutron stars. ApJ, 223(July), L83–L87.Google Scholar
Haberl, F., and Motch, C. 1996 (Feb.). Two spectrally distinct classes of intermediate polars discovered with ROSAT. Pages 145–146 of: H. U., Zimmermann, J., Trumper, & H., Yorke (eds.), Roentgenstrahlung from the Universe. Springer, 2001, Jan.
Harrop-Allin, M. K., Cropper, M., Hakala, P. J., Hellier, C., and Ramseyer, T. 1999. Indirect imaging of the accretion stream in eclipsing polars – II. HU Aquarii. MNRAS, 308(Sept.), 807–817.Google Scholar
Heerlein, C., Horne, K., and Schwope, A. D. 1999. Modelling of the magnetic accretion flow in HU Aquarii. MNRAS, 304(Mar.), 145–154.Google Scholar
Heise, J., Brinkman, A. C., Gronenschild, E., Watson, M., King, A. R., Stella, L., and Kieboom, K. 1985. An X-ray study of AM Herculis. I – Discovery of a new mode of soft X-ray emission. A&A, 148(July), L14–L16.Google Scholar
Hellier, C. 2001. Cataclysmic Variable Stars – How and Why they Vary (Springer Praxis Books / Space Exploration), Springer.
Hellier, C., Mukai, K., Ishida, M., and Fujimoto, R. 1996. The X-ray spectrum of the intermediate polar AO Piscium. MNRAS, 280(June), 877–887.Google Scholar
Horne, K. 1985. Images of accretion discs. I – The eclipse mapping method. MNRAS, 213(Mar.), 129–141.Google Scholar
Iben, I. Jr. 2003. Lessons from and about symbiotic novae (invited review talks). Pages 177+ of: R. L. M., Corradi, J., Mikolajewska, and T. J., Mahoney (eds.), Astronomical Society of the Pacific Conference Series. Astronomical Society of the Pacific Conference Series, vol. 303.
Ireland, M. J., Monnier, J. D., Tuthill, P. G., Cohen, R. W., De Buizer, J. M., Packham, C., Ciardi, D., Hayward, T., and Lloyd, J. P. 2007. Born-again protoplanetary disk around Mira B. ApJ, 662(June), 651–657.Google Scholar
Karovska, M., Hack, W., Raymond, J., and Guinan, E. 1997. First Hubble Space Telescope observations of Mira AB wind-accreting binary systems. ApJ, 482(June), L175+.Google Scholar
Kato, M. 2010. Accreting white dwarfs as supersoft X-ray sources. Astronomische Nachrichten, 331, 140+.Google Scholar
Kenyon, S. J. 1988. Book Review: The symbiotic stars. Cambridge University Press, 1986. Bulletin of the Astronomical Institutes of Czechoslovakia, 39(Mar.), 128+.Google Scholar
Latham, D. W., Liebert, J., and Steiner, J. E. 1981. The 1980 low state of AM Herculis. ApJ, 246(June), 919–934.Google Scholar
Marsh, T. R., and Horne, K. 1988. Images of accretion discs. II – Doppler tomography. MNRAS, 235(Nov.), 269–286.Google Scholar
Mineshige, S., and Wood, J. H. 1989. Viscous evolution of accretion discs in the quiescence of dwarf novae. MNRAS, 241(Nov.), 259–280.Google Scholar
O'Donoghue, D. 1986. The radius of the accretion disk in Z Cha between outbursts. MNRAS, 220(May), 23P–26P.Google Scholar
O'Donoghue, D., Buckley, D. A. H., Balona, L. A., Bester, D., Botha, L., Brink, J., Carter, D. B., Charles, P. A., Christians, A., Ebrahim, F., Emmerich, R., Esterhuyse, W., Evans, G. P., Fourie, C., Fourie, P., Gajjar, H., Gordon, M., Gumede, C., De Kock, M., Koeslag, A., Koorts, W. P., Kriel, H., Marang, F., Meiring, J. G., Menzies, J. W., Menzies, P., Metcalfe, D., Meyer, B., Nel, L., O'Connor, J., Osman, F., Du Plessis, C., Rall, H., Riddick, A., Romero-Colmenero, E., Potter, S. B., Sass, C., Schalekamp, H., Sessions, N., Siyengo, S., Sopela, V., Steyn, H., Stoffels, J., Scholtz, J., Swart, G., Swat, A., Swiegers, J., Tiheli, T., Vaisanen, P., Whittaker, W., and van Wyk, F. 2006. First science with the Southern African Large Telescope: peering at the accreting polar caps of the eclipsing polar SDSS J015543.40+002807.2. MNRAS, 372(Oct.), 151–162.Google Scholar
Patterson, J. 1998. Late evolution of cataclysmic variables. PASP, 110(Oct.), 1132–1147.Google Scholar
Patterson, J., Kemp, J., Richman, H. R., Skillman, D. R., Vanmunster, T., Jensen, L., Buckley, D. A. H., O'Donoghue, D., and Kramer, R. 1998. Rapid oscillations in cataclysmic variables. XIV. Orbital and spin ephemerides of FO Aquarii. PASP, 110(Apr.), 415–419.Google Scholar
Petterson, J. A. 1980. Accretion disks in cataclysmic variables. I – The eclipse-related phase shifts in DQ Herculis and UX Ursae Majoris. ApJ, 241 (Oct.), 247–256.Google Scholar
Potter, S. B., Romero-Colmenero, E., Watson, C. A., Buckley, D. A. H., and Phillips, A. 2004. Stokes imaging, Doppler mapping and Roche tomography of the AM Herculis system V834 Cen. MNRAS, 348(Feb.), 316–324.Google Scholar
Prialnik, D. 1986. The evolution of a classical nova model through a complete cycle. ApJ, 310(Nov.), 222–237.Google Scholar
Prialnik, D., and Kovetz, A. 1995. An extended grid of multicycle nova evolution models. ApJ, 445(June), 789–810.Google Scholar
Reimers, D., and Cassatella, A. 1985. The ultraviolet spectrum of the companion of Mira (o Ceti). Observational evidence for a disk formed by wind accretion. ApJ, 297(Oct.), 275–287.Google Scholar
Robertson, J. W., Honeycutt, R. K., and Turner, G. W. 1995. RZ Leonis Minoris, PG 0943+521, and V1159 Orionis: Three cataclysmic variables with similar and unusual outburst behavior. PASP, 107(May), 443−+.Google Scholar
Rutten, R. G. M., Dhillon, V. S., Horne, K., and Kuulkers, E. 1994. Spectral eclipse mapping of the accretion disk in the nova-like variable UX Ursae Majoris. A&A, 283(Mar.), 441–454.Google Scholar
Saito, R. K., and Baptista, R. 2009. Spin-cycle eclipse mapping of the 71 s oscillations in DQ Herculis: reprocessing sites and the true white dwarf spin period. ApJ, 693(Mar.), L16–L18.Google Scholar
Sanad, M. R., Bobrowsky, M., Hamdy, M. A., and Abo Elazm, M. S. 2009. Density effects on Mg II emission lines of Mira AB. AJ, 137(Mar.), 3479–3486.Google Scholar
Schwope, A. D., Beuermann, K., Jordan, S., and Thomas, H.-C. 1993. Cyclotron and Zeeman spectroscopy of MR Serpentisinlow andhighstatesofaccretion. A&A, 278(Nov.), 487–498.Google Scholar
Schwope, A. D., Brunner, H., Hambaryan, V., and Schwarz, R. 2002 (Jan.). LARPs – low-accretion rate polars. Pages 102+ of: B. T., Gänsicke, K., Beuermann, and K., Reinsch (eds.), The Physics of Cataclysmic Variables and Related Objects. Astronomical Society of the Pacific Conference Series, vol. 261.
Schwope, A. D., Mantel, K.-H., and Horne, K. 1997. Phase-resolved high-resolution spectropho-tometry of the eclipsing polar HU Aquarii. A&A, 319(Mar.), 894–908.Google Scholar
Sion, E. M., Cheng, F.-H., Huang, M., Hubeny, I., and Szkody, P. 1996. The cooling white dwarf in VW Hydri after normal outburst and superoutburst: HST evidence of a sustained accretion belt. ApJ, 471 (Nov.), L41+.Google Scholar
Sion, E. M., Greenstein, J. L., Landstreet, J. D., Liebert, J., Shipman, H. L., and Wegner, G. A. 1983. A proposed new white dwarf spectral classification system. ApJ, 269(June), 253–257.Google Scholar
Smak, J. 1994. Eclipses in cataclysmic variables with stationary accretion disks. IV. On the peculiar T(R) distributions. Acta Astron., 44(July), 265–276.Google Scholar
Szkody, P., Desai, V., and Hoard, D. W. 2000. Spectroscopy of GW Librae at quiescence. AJ, 119(Jan.), 365–368.Google Scholar
van Zyl, L., Warner, B., O'Donoghue, D., Sullivan, D., Pritchard, J., and Kemp, J. 2000. GW Librae: an accreting variable white dwarf. Baltic Astronomy, 9, 231–246.Google Scholar
Vogt, N. 1974. Photometric study of the dwarf nova VW Hydri. A&A, 36(Dec.), 369–378.Google Scholar
Walker, M. F. 1956. A Photometric investigation of the short-period eclipsing binary, Nova DQ Herculis (1934). ApJ, 123(Jan.), 68+.Google Scholar
Warner, B. 1972. Observations of rapid blue variables – VIII. The companion to Mira. MNRAS, 159, 95–100.Google Scholar
Warner, B. 1975. Observations of rapid blue variables – XV. VW Hydri. MNRAS, 170(Jan.), 219–228.Google Scholar
Warner, B. 1986a. Multiple optical orbital sidebands in intermediate polars. MNRAS, 219, 347–356.Google Scholar
Warner, B. 1986b. Accretion disk inclinations and absolute magnitudes of classical nova remnants. MNRAS, 222, 11–18.Google Scholar
Warner, B. 1987. Absolute magnitudes of cataclysmic variables. MNRAS, 227(July), 23–73.Google Scholar
Warner, B. 1995a. Cataclysmic Variable Stars. Cambridge University Press.
Warner, B. 1995b. The AM Canum Venaticorum Stars. Ap&SS, 225(Mar.), 249–270.Google Scholar
Warner, B. 2002 (Nov.). General properties of quiescent novae. Pages 3–15 of: M., Hernanz and J., Jose (eds.), Classical Nova Explosions. American Institute of Physics Conference Series, vol. 637.
Warner, B. 2004. Rapid oscillations in cataclysmic variables. PASP, 116(Feb.), 115–132.Google Scholar
Warner, B., and Cropper, M. 1984. High-speed photometry of the Intermediate Polar V1223 SGR. MNRAS, 206(Jan.), 261–271.Google Scholar
Warner, B., and Robinson, E. L. 1972. White dwarfs – more rapid variables. Nature, 239(Sept.), 2–7.Google Scholar
Warner, B., and van Zyl, L. 1998. Discovery of non-radial pulsations in the white dwarf primary of a cataclysmic variable star. Pages 321+ of: F.-L., Deubner, J., Christensen-Dalsgaard, and D., Kurtz (eds.), New Eyes to See Inside the Sun and Stars. IAU Symposium, vol. 185.
Warner, B., and Woudt, P. A. 2002. Dwarf nova oscillations and quasi-periodic oscillations in cataclysmic variables – II. A low-inertia magnetic accretor model. MNRAS, 335(Sept.), 84–98.Google Scholar
Warner, B., and Woudt, P. A. 2008. QPOs in CVs: an executive summary. AIP Conference Proceedings, 1054(1), 101–110.Google Scholar
Warner, B., and Woudt, P. A. 2009. The eclipsing intermediate polar V597 Pup (Nova Puppis 2007). MNRAS 2009(Aug.), 979–984.Google Scholar
Warner, B., Peters, W. L., Hubbard, W. B., and Nather, R. E. 1972. Observations of rapid blue variables – XI. DQ Herculis. MNRAS, 159, 321–335.Google Scholar
Watson, C. A., Dhillon, V. S., Rutten, R. G. M., and Schwope, A. D. 2003. Roche tomography of cataclysmic variables – II. Images of the secondary stars in AM Her, QQ Vul, IP Peg and HU Aqr. MNRAS, 341(May), 129–142.Google Scholar
Wesemael, F. 1979. Accretion from interstellar clouds and white dwarf spectral evolution. A&A, 72(Feb.), 104–110.Google Scholar
Wesemael, F., and Truran, J. W. 1982. Accretion of grains and element abundances in cool, helium-rich white dwarfs. ApJ, 260(Sept.), 807–814.Google Scholar
Wesemael, F., Greenstein, J. L., Liebert, J., Lamontagne, R., Fontaine, G., Bergeron, P., and Glaspey, J. W. 1993. An atlas of optical spectra of white-dwarf stars. PASP, 105(July), 761–778.Google Scholar
Wickramasinghe, D. T., and Ferrario, L. 2000. Magnetism in isolated and binary white dwarfs. PASP, 112(July), 873–924.Google Scholar
Wickramasinghe, D. T., and Ferrario, L. 2005. The origin of the magnetic fields in white dwarfs. MNRAS, 356(Feb.), 1576–1582.Google Scholar
Winget, D. E., and Kepler, S. O. 2008. Pulsating white dwarf stars and precision asteroseismology. ARA&A, 46(Sept.), 157–199.Google Scholar
Woudt, P. A., Warner, B., O'Donoghue, D., Buckley, D. A. H., Still, M., Romero-Colemero, E., and Vaisanen, P. 2010. Dwarf nova oscillations and quasi-periodic oscillations in cataclysmic variables – VIII. VW Hyi in outburst observed with the Southern African Large Telescope. MNRAS, 401 (Jan.), 500–506.Google Scholar

Save book to Kindle

To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×