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High-resolution X-ray spectroscopy of four active galaxies - Probing the intercloud mediumThe focal plane crystal spectrometer (FPCS) on the Einstein Observatory has been used to perform a high-resolution spectroscopic search for oxygen X-ray line emission from four active galaxies: Fairall 9, Mrk 421, Mrk 501, and PKS 0548 - 322. Specifically, O VIII Ly-alpha and Ly-beta, whose unredshifted energies are 653 and 775 eV, respectively, were sought. No narrow-line emission was detected within the energy bands searched. Upper limits are calculated on the line flux from these sources of 30 eV equivalent width and use a photoionization model to place corresponding upper limits on the densities of diffuse gas surrounding the active nuclei. The upper limits on gas density range from about 0.02-50/cu cm and probe various radial distances from the central source. This is the first time high-resolution X-ray spectroscopy has been used to place constraints on the intercloud medium in active galaxies.
Document ID
19900054783
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Lum, Kenneth S. K.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Canizares, Claude R.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Markert, Thomas H.
(MIT Cambridge, MA, United States)
Arnaud, Keith A.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 14, 2013
Publication Date
July 20, 1990
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 358
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
90A41838
Funding Number(s)
CONTRACT_GRANT: NAG8-494
Distribution Limits
Public
Copyright
Other

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