OSSE Observations of NGC 4151

reportActive / Technical Report | Accession Number: ADA461894 | Open PDF

Abstract:

We report results of a two-week observation of the Seyfert galaxy NGC 4151 with the Oriented Scintillation Spectrometer Experiment OSSE instrument on the Compton Gamma Ray Observatory GRO. The source had a very soft spectrum which is best represented by a broken power law or Sunyaev-Titarchuk thermal Comptonization model. It can be characterized by an exponential shape with an e-folding energy of 39 plus or minus 2 keV in the energy range 65 - 300 keV, and an intensity at 100 keV of 2.33 plus or minus 0.05 x 10 exp -5 photons sq cm s exp -1 keVexp -1. Source intensity variability of 25 was observed during the 14 days of our observations no significant change in spectral shape was detected for this period. The steepness and shape of the spectrum above 100 keV rule out chiexp 2 probability 7 x 10exp 4 simple pair cascade models in a compact source which have been suggested for Seyfert galaxies.

Author(s):
Maisack, M. ; Johnson, W. N. ; Kinzer, R. L. ; Strickman, M. S. ; Kurfess, J. D. ; Cameron, R. A. ; Jung, G. V. ; Grabelsky, D. A. ; Purcell, W. R. ; Ulmer, M. P.
Author Organization(s):
GEORGE MASON UNIV FAIRFAX VA
Pagination:
0018

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release; Distribution Is Unlimited.

RECORD

Collection: TR
Identifying Numbers
Contract/Grant Number(s):
DPRS-10987C
Monitor Series:
NASA
 Subject Terms
Joint Capability Areas:
JCA_6.3.3_Spectrum Management; JCA_8_Building Partnerships; JCA_6_Net Centric; JCA_6.3_Net Management; JCA_3_Force Application; JCA_8.1_Communicate; JCA_8.2_Shape; JCA_3.1.3_Maneuver to Influence; JCA_3.1_Maneuver; JCA_3.2_Engagement; JCA_1_Force Support; JCA_3.2.2_Non-Kinetic Means; JCA_8.1.1_Inform Domestic and Foreign Audiences; JCA_8.2.4_Leverage Capacities and Capabilities of Security Establishments; JCA_8.1.2_Persuade Partner Audiences; JCA_8.1.3_Influence Adversary and Competitor Audiences; JCA_8.2.1_Partner with Governments and Institutions; JCA_1.2.7_Experimentation; JCA_1.2_Force Preparation
Modernization Areas:
Space
Communities of Interest:
Energy and Power Technologies
Descriptor(s):
*SCINTILLATION, *GALAXIES, *GAMMA RAY SPECTRA, SOURCES, SHAPE, REPORTS, INTENSITY, VARIATIONS, COMPTON SCATTERING, PHOTONS, POWER, LAW ENFORCEMENT, SPECTROMETERS, OBSERVATORIES
Field(s)/Group(s):
Astronomy, Nuclear Physics and Elementary Particle Physics
Keyword(s):
GALAXIES INDIVIDUAL(NGC 4151), GALAXIES SEYFERT, ORIENTED SCINTILLATION SPECTROMETER EXPERIMENT, OSSE(ORIENTED SCINTILLATION SPECTROMETER EXPERIMENT)
Report Date:
1992 Jan 01
Creation Date:
2007 Feb 21