NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Collections About News Help Login

Press Enter or click the Search button to begin your search.

Back to Results
X-ray emitting BL Lacertae objects located by the scanning modulation collimator experiment on HEAO 1It is established that BL Lacertae objects constitute a class of X-ray emitter by precisely locating X-ray sources identified with Mrk 421, PKS 0548-322, PKS 2155-304, and 2A 1219+305. Irregular variations of the order of 1 mag, characteristic of BL Lacertae objects, are reported for the last two objects. The measurement of an extremely steep X-ray spectrum from Mrk 421, in contrast to previous flat X-ray spectra above 3 keV, suggests that different structural states of an accretion disk are being observed.
Document ID
19790049161
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
doi:10.1086/182929
Authors
Schwartz, D. A. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Griffiths, R. E. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Schwarz, J. (Harvard-Smithsonian Center for Astrophysics Cambridge, Mass., United States)
Doxsey, R. E. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Johnston, M. D. (MIT Cambridge, Mass., United States)
Date Acquired
August 9, 2013
Publication Date
April 15, 1979
Publication Information
Publication: Astrophysical Journal
Subject Category
Astronomy
Accession Number
79A33174
Funding Number(s)
CONTRACT_GRANT: NAS8-27972
CONTRACT_GRANT: NAS8-30543
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.

Related Records

There are no records associated with this record.
No Preview Available