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Session 50 - Active Galaxies.
Display session, Tuesday, January 16
North Banquet Hall, Convention Center

[50.10] Simultaneous Far-UV and X-ray Observations of NGC 3516 with HUT and ASCA

G. Kriss, B. Espey, A. Davidsen, W. Zheng, Z. Tsvetanov, J. Krolik (JHU), T. Kii, C. Otani (ISAS), T. J. Turner, R. Petre (NASA/GSFC), T. Takahashi, M. Tashiro (U. Tokyo), S. Murakami (Osaka City U.), T. Mihara, M. Matsuoka (RIKEN), H. Kunieda (Nagoya U.)

We observed the Seyfert 1 galaxy NGC 3516 during the flight of Astro-2 in March 1995 using the Hopkins Ultraviolet Telescope. Simultaneous X-ray observations were made using the Japanese X-ray satellite ASCA. The far-UV spectrum shows a reddened power law with f_\nu \sim \nu^-1.89 and extinction of E(B--V)=0.06. Intrinsic absorption in the ionized resonance doublets of \sc O vi, \sc N v, Si \sc iv, and \sc C iv is visible as well as neutral hydrogen absorption. The redshifted Lyman limit is sharp and opaque. For b = 10 km s^-1 the intrinsic neutral hydrogen column is 3.5 \times 10^17 cm^-2. The ASCA spectrum shows an absorbed power law of energy index \sim 0.9 with prominent \sc O vii and \sc O viii absorption edges. A weak, narrow Fe K emission line from cold material is present as well as a broad, redshifted Fe K feature similar to that reported in MCG-6-30-15 and in NGC 4151. We will discuss warm absorber models for the UV and X-ray absorption.

This work was supported by NASA contract NAS 5-27000 and NASA ASCA guest investigator grant NAG 5-2935 to the Johns Hopkins University.

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