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17th European White Dwarf Workshop: High resolution EUV spectroscopy of Feige 24
Barstow, Martin (2010)
clipboard
mla
clipboard		 Barstow M. "17th European White Dwarf Workshop: High resolution EUV spectroscopy of Feige 24.", timms video, Universität Tübingen (2010): https://timms.uni-tuebingen.de:443/tp/UT_20100816_011_eurowd_0001. Accessed 26 Apr 2024.
apa
clipboard		 Barstow, M. (2010). 17th European White Dwarf Workshop: High resolution EUV spectroscopy of Feige 24. timms video: Universität Tübingen. Retrieved April 26, 2024 from the World Wide Web https://timms.uni-tuebingen.de:443/tp/UT_20100816_011_eurowd_0001
harvard
clipboard		 Barstow, M. (2010). 17th European White Dwarf Workshop: High resolution EUV spectroscopy of Feige 24 [Online video]. 16 August. Available at: https://timms.uni-tuebingen.de:443/tp/UT_20100816_011_eurowd_0001 (Accessed: 26 April 2024).
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Information
title: 17th European White Dwarf Workshop: High resolution EUV spectroscopy of Feige 24
alt. title: 17th European White Dwarf Workshop - White dwarf structure and evolution
creator: Barstow, Martin (author)
subjects: Astronomie, Physik, Astrophysik, Workshop, White Dwarf, High resolution EUV spectroscopy, Feige 24, Martin Barstow
description: 17th European White Dwarf Workshop, 16. bis 20. August 2010
abstract: High resolution EUV spectroscopy of Feige 24 (M.A. Barstow1, M. P. Kowalski2, K.S. Wood2, D.J. Yentis2,3, G.G. Fritz4, J.S. Lapington1, T.W. Barbee, Jr.5, and R.G. Cruddace2) (1. Dept. of Physics and Astronomy, University of Leicester, Leicester LE1 7RH UK, 2. Naval Research Laboratory, Code 7655, 4555 Overlook Ave., SW, Washington, DC 20375, USA, 3. Deceased 4. PRAXIS, Inc., 5845 Richmond Hwy, Suite 700, Alexandria, VA 22303 USA, 5. Lawrence Livermore National Laboratory, MS L-353, 7000 East Ave., P.O. Box 808, Livermore, CA 94550 USA) We report the first high-resolution (R=4000) spectroscopic observation of the binary DA white dwarf Feige 24 in the extreme-ultraviolet band 220-250 . A stellar atmosphere model assuming a homogeneous element distribution yields a best fit to the data that excludes a significant abundance of photospheric helium, a surprising result contrary to predictions by common envelope evolution theory. The upper limit on the photospheric helium abundance is 2.5x10-6 (90% confidence), and the lower limit on the overlying layer of hydrogen is 10-12.92 Msolar. An ionized He component (3.6 x 1017 cm-2) is clearly present along the line-of-sight, which if completely interstellar implies a He ionization fraction of 0.7, considerably higher than is typical of the local interstellar medium.
publisher: ZDV Universität Tübingen
contributor: ZDV Universität Tübingen (producer)
creation date: 2010-08-16
dc type: image
localtype: video
identifier: UT_20100816_011_eurowd_0001
language: eng
rights: Url: https://timmsstatic.uni-tuebingen.de/jtimms/TimmsDisclaimer.html?638497428250375115