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Discovery of soft X-ray flux from 2A 1102+384 = Markarian 421During April 1976 a soft X-ray flux was detected with SAS 3 from the vicinity of 2A 1102+384. The average flux densities were 4.3 x 10 to the -11th and 14 x 10 to the -11th erg/sq cm per sec in the energy bands 0.1-0.28 keV and 1-6 keV, respectively. There is an indication of variability over about 0.5 day in the lowest energy band. An upper limit of 3 x 10 to the 20th H atoms per sq cm is found for the gas column density to the X-ray source. In May 1978, observations with the modulation collimators of SAS 3 yielded an accurate (40 arcsec error radius) position for the X-ray source (2-6 keV) at right ascension 11 h 1 m 39.7 s, declination + 38 deg 28 min 51 sec (equinox 1950). The earlier tentative identification by Ricketts et al. (1976) with the BL Lacertae object B2 1101+38 = Markarian 421 is thus confirmed.
Document ID
19790039205
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Hearn, D. R.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Marshall, F. J.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Jernigan, J. G.
(MIT Cambridge, Mass., United States)
Date Acquired
August 9, 2013
Publication Date
January 15, 1979
Publication Information
Publication: Astrophysical Journal
Subject Category
Astrophysics
Accession Number
79A23218
Funding Number(s)
CONTRACT_GRANT: NAS5-11450
Distribution Limits
Public
Copyright
Other

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