Circumstellar features in hot DA white dwarfs
Corresponding Author
N. P. Bannister
Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH
E-mail: [email protected]Search for more papers by this authorM. A. Barstow
Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH
Search for more papers by this authorJ. B. Holberg
Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
Search for more papers by this authorF. C. Bruhweiler
Institute for Astrophysics & Computational Sciences (IACS), Department of Physics, The Catholic University of America, Washington, DC 20064, USA
Search for more papers by this authorCorresponding Author
N. P. Bannister
Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH
E-mail: [email protected]Search for more papers by this authorM. A. Barstow
Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH
Search for more papers by this authorJ. B. Holberg
Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
Search for more papers by this authorF. C. Bruhweiler
Institute for Astrophysics & Computational Sciences (IACS), Department of Physics, The Catholic University of America, Washington, DC 20064, USA
Search for more papers by this authorABSTRACT
We present a phenomenological study of highly ionized, non-photospheric absorption features in high spectral resolution vacuum ultraviolet spectra of 23 hot DA white dwarfs. Prior to this study, four of the survey objects (Feige 24, REJ 0457−281, G191−B2B and REJ 1614−085) were known to possess these features. We find four new objects with multiple components in one or more of the principal resonance lines: REJ 1738+665, Ton 021, REJ 0558−373 and WD 2218+706. A fifth object, REJ 2156−546, also shows some evidence of multiple components, though further observations are required to confirm the detection. We discuss possible origins for these features including ionization of the local interstellar environment, the presence of material inside the gravitational well of the white dwarf, mass loss in a stellar wind and the existence of material in an ancient planetary nebula around the star. We propose ionization of the local interstellar medium as the origin of these features in G191−B2B and REJ 1738+665, and demonstrate the need for higher-resolution spectroscopy of the sample, to detect multiple interstellar medium velocity components and to identify circumstellar features that may lie close to the photospheric velocity.
REFERENCES
- Abbott D.C., 1982, ApJ, 259, 282
- Barstow M.A., Hubeny I., 1998, MNRAS, 299, 379
- Barstow M.A. et al., 1994a, MNRAS, 267, 647
- Barstow M.A. et al., 1994b, MNRAS, 271, 175
- Barstow M.A., Holberg J.B., Koester D., 1995, MNRAS, 274, L31
- Barstow M.A., Holberg J.B., Hubeny I., Lanz T., Bruhweiler F.C., Tweedy R.W., 1996, MNRAS, 279, 1120
- Barstow M.A., Dobbie P.D., Holberg J.B., Hubeny I., Lanz T., 1997, MNRAS, 286, 58
- Barstow M.A., Hubeny I., Holberg J.B., 1999, MNRAS, 307, 884
- Barstow M.A., Burleigh M.R., Bannister N.P., Holberg J.B., Hubeny I., Bruhweiler F.C., Napiwotzki R., 2001a, in H. Shipman, J. Provencal, eds, ASP Conf. Ser., Proc. 12th European White Dwarfs Workshop Heavy Elements in DA White Dwarfs. Astron. Soc. Pac. , San Francisco , pp. 128–134
- Barstow M.A., Bannister N.P., Holberg J.B., Hubeny I., Bruhweiler F.C., Napiwotzki R., 2001b, MNRAS, 325, 1149
- Bohlin R.C., Colina L., Finley D.S., 1995, AJ, 110, 1316
- Bruhweiler F.C., Kondo Y., 1982, ApJ, 259, 232
- Bruhweiler F.C., Kondo Y., 1983, ApJ, 269, 657
- Bruhweiler F., Barstow M., Holberg J., Sahu M., 1999, BAAS, 195, 3602
- Chayer P., Vennes S., Pradhan A.K., Thejll P., Beauchamp A., Fontaine G., Wesemael F., 1995b, ApJ, 454, 429
- Chayer P., Kruk J.W., Ake T.B., Dupree A.K., Malina R.F., Siegmund O.H.W., Sonneborn G., Ohl R.G., 2000, ApJ, 538, L91
- Dahn C.C. et al., 1988, AJ, 95, 237
- Dgani R., Soker N., 1998, ApJ, 495, 337
- Dickey J.M., Lockman F.J., 1990, ARA&A, 28, 215
- Dreizler S., Schuh S., 2001, in H.L. Shipman, J.L. Provencal, eds, ASP Conf. Ser., Proc. 12th European White Dwarf Workshop Stratified Non-LTE Model Atmospheres for Hot White Dwarfs. Astron. Soc. Pac. , San Francisco , pp. 69–78
- Driebe T., Schoenberner D., Bloecker T., Herwig F., 1998, A&A, 339, 123
- Dupree A.K., Raymond J.C., 1982, ApJ, 263, L63
- Dupree A.K., Raymond J.C., 1983, ApJ, 275, L71
- Dupuis J., Chayer P., Vennes S., Christian D.J., Kruk J.W., 2000, ApJ, 537, 977
- Finley D.S., Koester D., Basri G., 1997, ApJ, 488, 375
- Frisch P.C., York D.G., 1983, ApJ, 271, L59
- Fruscione A., Hawkins I., Jelinsky P., Wiercigroch A., 1994, ApJ Suppl., 94, 127
- Green P.J., Ali B., Napiwotzki R., 2000, ApJ, 540, 992
- Greenstein J.L., 1984, ApJ, 276, 602
- Grevesse N., Sauval A.J., 1998, Space Sci. Rev., 85, 161
- Heber U., Napiwotzki R., Lemke M., Edelmann H., 1997, A&A, 324, L53
- Holberg J.B., Bruhweiler F.C., Andersen J., 1995, ApJ, 443, 753
- Holberg J.B., Barstow M.A., Bruhweiler F.C., Collins J., 1996, AJ, 111, 2361
- Holberg J.B., Barstow M.A., Green E.M., 1997a, ApJ, 474, L127
- Holberg J.B., Barstow M.A., Lanz T., Hubeny I., 1997b, ApJ, 484, 871
- Holberg J.B., Barstow M.A., Sion E.M., 1997c, 3rd Conf. on Faint Blue Stars Photospheric and Non-Photospheric Features in the Spectra of Hot White Dwarfs, Davis Press, Schenectady , NY , p. 331
- Holberg J.B., Barstow M.A., Sion E.M., 1998, ApJ Suppl., 119, 207 (HBS)
- Holberg J.B., Barstow M.A., Sion E.M., 1999a, in ASP Conf. Ser. Vol. 169, 11th European Workshop on White Dwarfs Elemental Abundances in Hot White Dwarfs. Astron. Soc. Pac. , San Francisco , p. 485
- Holberg J.B., Bruhweiler F.C., Barstow M.A., Dobbie P.D., 1999b, ApJ, 517, 841
- Holberg J.B., Bruhweiler F.C., Barstow M.A., Dobbie P.D., 1999c, BAAS, 195, 7201
- Holberg J.B., Barstow M.A., Bruhweiler F.C., Hubeny I., Green E.M., 1999d, ApJ, 517, 850
- Holberg J.B., Barstow M.A., Bruhweiler F.C., Hubeny I., 2000, BAAS, 197, 8304
- Holberg J.B., Barstow M.A., Hubeny I., Sahu M.S., Bruhweiler F.C., Landsman W.B., 2002, BAAS, 200, 7205
- Kun M., 1998, ApJ Suppl., 115, 59
- Lallement R., Ferlet R., Lagrange A.M., Lemoine M., Vidal-Madjar A., 1995, A&A, 304, 461
- Langill P.P., Kwok S., Hrivnak B.J., 1994, Publ. Astron. Soc. Pac., 106, 736
- MacDonald J., 1992, ApJ, 394, 619
- Marsh M.C. et al., 1997, MNRAS, 286, 369
- Napiwotzki R., 1999, A&A, 350, 101
- Napiwotzki R., Schönberner D., 1995, ApJ, 301, 545
- Paresce F., 1984, AJ, 89, 1022
- Saffer R.A., Livio M., Yungelson L.R., 1998, ApJ, 502, 394
- Sahu M.S. et al., 1999, ApJ, 523, L159
- Schuh S., Dreizler S., 2001, in H.L. Shipman, J.L. Provencal, eds, ASP Conf. Ser., Proc. 12th European White Dwarf Workshop Application of Stratified Non-LTE Model Atmospheres to Hot DA White Dwarfs. Astron. Soc. Pac. , San Francisco , pp. 79–84
- Sion E.M., Holberg J.B., Barstow M.A., Scheible M.P., 1997, AJ, 113, 364
- Tweedy R.W., Kwitter K.B., 1994, ApJ, 433, L93
- Tweedy R.W., Napiwotzki R., 1994, AJ, 108, 978
- Unglaub K., Bues I., 2000, A&A, 359, 1042
- Vennes S., Lanz T., 2001, ApJ, 553, 399
- Vennes S., Thorstensen J.R., 1994, AJ, 108, 1881
- Vennes S., Thejll P., Shipman H.L., 1991, in White Dwarfs Abundances of Trace Heavy Elements in Hot DA White Dwarfs, Kluwer, Dordrecht , p. 235
- Vennes S., Chayer P., Hurwitz M., Bowyer S., 1996, ApJ, 468, 898
- Vidal-Madjar A. et al., 1998, A&A, 338, 694
- Wegner G., 1974, MNRAS, 166, 271
- Weinberger R., 1989, A&A Suppl., 78, 301
- Wolff B., Koester D., Dreizler S., Haas S., 1998, A&A, 329, 1045
- Wolff B., Jordan S., Koester D., Reimers D., 2000, A&A, 361, 629
- Wolff B., Kruk J.W., Koester D., Allard N.F., Ferlet R., Vidal-Madjar A., 2001, A&A, 373, 674
- Wood M.A., 1995, White Dwarfs Theoretical White Dwarf Luminosity Functions: DA Models. Lecture Notes in Physics, Vol. 443, Springer-Verlag , p. 41
- Zuckerman B., Reid I.N., 1998, ApJ, 505, L143
