The study of TeV variability and the duty cycle of Mrk 421 from 3 Yr of observations with the Milagro observatory
Por:
Abdo A.A., Abeysekara A.U., Allen B.T., Aune T., Barber A.S., Berley D., Braun J., Chen C., Christopher G.E., Delay R.S., Deyoung T., Dingus B.L., Ellsworth R.W., Fraija N., González M.M., Goodman J.A., Hays E., Hoffman C.M., Hüntemeyer P.H., Imran A., Kolterman B.E., Linnemann J.T., Marinelli A., McEnery J.E., Morgan T., Mincer A.I., Nemethy P., Patricelli B., Pretz J., Ryan J.M., Parkinson, PMS, Schneider M., Shoup A., Sinnis G., Smith A.J., Vasileiou V., Walker G.P., Williams D.A., Yodh G.B.
Publicada:
20 feb 2014
Resumen:
TeV-flaring activity with timescales as short as tens of minutes and an orphan TeV flare have been observed from the blazar Markarian 421 (Mrk 421). The TeV emission from Mrk 421 is believed to be produced by leptonic synchrotron self-Compton (SSC) emission. In this scenario, correlations between the X-ray and the TeV fluxes are expected, TeV orphan flares are hardly explained, and the activity (measured as duty cycle) of the source at TeV energies is expected to be equal to or less than that observed in X-rays if only SSC is considered. To estimate the TeV duty cycle of Mrk 421 and to establish limits on its variability at different timescales, we continuously observed Mrk 421 with the Milagro observatory. Mrk 421 was detected by Milagro with a statistical significance of 7.1 standard deviations between 2005 September 21 and 2008 March 15. The observed spectrum is consistent with previous observations by VERITAS. We estimate the duty cycle of Mrk 421 for energies above 1 TeV for different hypotheses of the baseline flux and for different flare selections and we compared our results with the X-ray duty cycle estimated by Resconi et al. The robustness of the results is discussed. © 2014. The American Astronomical Society. All rights reserved..
Filiaciones:
Abdo A.A.:
Department of Physics and Astronomy, Michigan State University, 3245 BioMedical Physical Sciences Building, East Lansing, MI 48824, United States
Operational Evaluation Division, Institute for Defense Analyses, 4850 Mark Center Drive, Alexandria, VA 22311-1882, United States
Abeysekara A.U.:
Department of Physics and Astronomy, Michigan State University, 3245 BioMedical Physical Sciences Building, East Lansing, MI 48824, United States
Allen B.T.:
Department of Physics and Astronomy, University of California, Irvine, CA 92697, United States
Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, United States
Aune T.:
Santa Cruz Institute for Particle Physics, University of California, 1156 High Street, Santa Cruz, CA 95064, United States
Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, United States
Barber A.S.:
Department of Physics and Astronomy, Michigan State University, 3245 BioMedical Physical Sciences Building, East Lansing, MI 48824, United States
Department of Physics, University of Utah, Salt Lake City, UT 84112, United States
Berley D.:
Department of Physics, University of Maryland, College Park, MD 20742, United States
Braun J.:
Department of Physics, University of Maryland, College Park, MD 20742, United States
Chen C.:
Department of Physics and Astronomy, University of California, Irvine, CA 92697, United States
Christopher G.E.:
Department of Physics, New York University, 4 Washington Place, New York, NY 10003, United States
Delay R.S.:
Department of Physics and Astronomy, University of California, Irvine, CA 92697, United States
Deyoung T.:
Department of Physics, Pennsylvania State University, University Park, PA 16802, United States
Dingus B.L.:
Group P-23, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
Ellsworth R.W.:
Department of Physics and Astronomy, George Mason University, 4400 University Drive, Fairfax, VA 22030, United States
Fraija N.:
Univ Nacl Autonoma Mexico, Inst Astron, Mexico City 04510, DF, Mexico
González M.M.:
Univ Nacl Autonoma Mexico, Inst Astron, Mexico City 04510, DF, Mexico
Goodman J.A.:
Department of Physics, University of Maryland, College Park, MD 20742, United States
Hays E.:
NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States
Hoffman C.M.:
Group P-23, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
Hüntemeyer P.H.:
Department of Physics, Michigan Technological University, Houghton, MI 49931, United States
Imran A.:
Group P-23, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
Kolterman B.E.:
Department of Physics, New York University, 4 Washington Place, New York, NY 10003, United States
Linnemann J.T.:
Department of Physics and Astronomy, Michigan State University, 3245 BioMedical Physical Sciences Building, East Lansing, MI 48824, United States
Marinelli A.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico
McEnery J.E.:
NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States
Morgan T.:
Department of Physics, University of New Hampshire, Morse Hall, Durham, NH 03824, United States
Mincer A.I.:
Department of Physics, New York University, 4 Washington Place, New York, NY 10003, United States
Nemethy P.:
Department of Physics, New York University, 4 Washington Place, New York, NY 10003, United States
Patricelli B.:
Univ Nacl Autonoma Mexico, Inst Astron, Mexico City 04510, DF, Mexico
Pretz J.:
Group P-23, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
Ryan J.M.:
Department of Physics, University of New Hampshire, Morse Hall, Durham, NH 03824, United States
Schneider M.:
Santa Cruz Institute for Particle Physics, University of California, 1156 High Street, Santa Cruz, CA 95064, United States
Shoup A.:
Ohio State University, Lima, OH 45804, United States
Sinnis G.:
Group P-23, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
Smith A.J.:
Department of Physics, University of Maryland, College Park, MD 20742, United States
Vasileiou V.:
Department of Physics, University of Maryland, College Park, MD 20742, United States
Laboratoire Univers et Particules de Montpellier, Université Montpellier 2, CNRS/IN2P3, CC 72, Place Eugéne Bataillon, F-34095 Montpellier Cedex 5, France
Walker G.P.:
Group P-23, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
National Security Technologies, Las Vegas, NV 89102, United States
Williams D.A.:
Santa Cruz Institute for Particle Physics, University of California, 1156 High Street, Santa Cruz, CA 95064, United States
Yodh G.B.:
Department of Physics and Astronomy, University of California, Irvine, CA 92697, United States
All Open Access; Green
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