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Photoionized features in the X-ray spectrum of Ex Hydrae

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Luna, G. J. M., Raymond, J., Brickhouse, Nancy, Mauche, Christopher W., Proga, D., Steeghs, D. and Hoogerwerf, R.. (2010) Photoionized features in the X-ray spectrum of Ex Hydrae. Astrophysical Journal, Vol.711 (No.2). pp. 1333-1337. ISSN 0004-637X

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Official URL: http://dx.doi.org/10.1088/0004-637X/711/2/1333

Abstract

We present the first results from a long (496 ks) Chandra High Energy Transmission Grating observation of the intermediate polar EX Hydrae ( EX Hya). In addition to the narrow emission lines from the cooling post-shock gas, for the first time we have detected a broad component in some of the X-ray emission lines, namely, O VIII lambda 18.97, Mg XII lambda 8.42, Si XIV lambda 6.18, and Fe XVII lambda 16.78. The broad and narrow components have widths of similar to 1600 km s(-1) and similar to 150 km s(-1), respectively. We propose a scenario where the broad component is formed in the pre-shock accretion flow, photoionized by radiation from the post-shock flow. Because the photoionized region has to be close to the radiation source in order to produce strong photoionized emission lines from ions such as O VIII, Fe XVII, Mg XII, and Si XIV, our photoionization model constrains the height of the standing shock above the white dwarf surface. Thus, the X-ray spectrum from EX Hya manifests features of both magnetic and non-magnetic cataclysmic variables.

Item Type:

Journal Article

Subjects:

Q Science > QB Astronomy

Divisions:

Faculty of Science > Physics

Library of Congress Subject Headings (LCSH):

Cataclysmic variable stars

Journal or Publication Title:

Astrophysical Journal

Publisher:

IOP Publishing

ISSN:

0004-637X

Official Date:

10 March 2010

Dates:

Date	Event
10 March 2010	Published

Volume:

Vol.711

Number:

No.2

Number of Pages:

Page Range:

pp. 1333-1337

Identifier:

10.1088/0004-637X/711/2/1333

Status:

Peer Reviewed

Publication Status:

Published

Access rights to Published version:

Restricted or Subscription Access

Funder:

United States. National Aeronautics and Space Administration (NASA), United States. Dept. of Energy

Grant number:

GO7-8026X (NASA), NAS8-03060 (NASA), DE-AC52-07NA27344 (DoE)

Related URLs:

Other Repository

References:

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