IJAA  Vol.4 No.3 , September 2014
TeV Blazars as the Sources of Ultra High Energy Cosmic Rays
ABSTRACT
The origin of ultra high energy cosmic rays (UHECRs) is still an open question in astroparticle physics. TeV blazars are a small group of active galactic nuclei (AGNs). They all have been observed in TeV gamma ray band, and show violent variabilities in flux at all wavelengths. So it is believed that they have abilities to produce UHECRs. To judge whether the TeV blazars can be the candidates of the origin of UHECRs, we collect the information of emission region of 38 TeV blazars, and estimate the maximum energy that the charged particle can be accelerated there. The results show that TeV blazars have abilities to accelerate cosmic rays to the energy above 1018 eV, some even higher than 1020 eV, and they may be the sources of UHECRs.

Cite this paper
Zhang, B. , Zhao, X. and Cao, Z. (2014) TeV Blazars as the Sources of Ultra High Energy Cosmic Rays. International Journal of Astronomy and Astrophysics, 4, 499-509. doi: 10.4236/ijaa.2014.43046.
References
[1]   Nagano, M., Hara, T., Hatano, Y., et al. (1984) Energy Spectrum of Primary Cosmic Rays between 1014.5 and 1018 eV. Journal of Physics G: Nuclear Physics, 10, 1295-1310.
http://dx.doi.org/10.1088/0305-4616/10/9/016

[2]   Abu-Zayyad, T., Belov, K., Bird, D.J., et al. (2001) Measurement of the Cosmic-Ray Energy Spectrum and Composition from 1017 to 1018.3 eV Using a Hybrid Technique. The Astrophysical Journal, 557, 686-699. http://dx.doi.org/10.1086/322240

[3]   Abbasi, R.U., Abu-Zayyad, T., Amann, J.F., et al. (2004) Measurement of the Flux of Ultrahigh Energy Cosmic Rays from Monocular Observations by the High Resolution Fly’s Eye Experiment. Physical Review Letters, 92, Article ID: 151101. http://dx.doi.org/10.1103/PhysRevLett.92.151101

[4]   Abraham, J., Abreu, P., Aglietta, M., et al. (2008) Observation of the Suppression of the Flux of Cosmic Rays above 4×1019 eV. Physical Review Letters, 101, Article ID: 061101.
http://dx.doi.org/10.1103/PhysRevLett.101.061101

[5]   Greisen K. (1966) End to the Cosmic-Ray Spectrum? Physical Review Letters, 16, 748-750.
http://dx.doi.org/10.1103/PhysRevLett.16.748

[6]   Zatsepin, G.T. and Kuz’Min, V.A. (1966) Upper Limit of the Spectrum of Cosmic Rays. JETP Letters, 4, 78-80.

[7]   Abbasi, R.U., Abu-Zayyad, T., Allen, M., et al. (2008) First Observation of the Greisen-Zatsepin-Kuzmin Suppression. Physical Review Letters, 100, Article ID: 101101.
http://dx.doi.org/10.1103/PhysRevLett.100.101101

[8]   Allard, D., Parizot, E. and Olinto, A.V. (2007) On the Transition from Galactic to Extragalactic Cosmic-Rays: Spectral and Composition Features from Two Opposite Scenarios. Astroparticle Physics, 27, 61-75. http://dx.doi.org/10.1016/j.astropartphys.2006.09.006

[9]   Berezinskii, V.S. and Grigor’eva, S.I. (1988) A Bump in the Ultra-High Energy Cosmic Ray Spectrum. Astronomy & Astrophysics, 199, 1-12.

[10]   Berezinsky, V., Gazizov, A.Z. and Grigoreva, S.I. (2005) Dip in UHECR Spectrum as Signature of Proton Interaction with CMB. Physics Letters B, 612, 147-153.
http://dx.doi.org/10.1016/j.physletb.2005.02.058

[11]   Nagano, M. and Watson, A.A. (2000) Observations and Implications of the Ultrahigh-Energy Cosmic Rays. Reviews of Modern Physics, 72, 689-732. http://dx.doi.org/10.1103/RevModPhys.72.689

[12]   Linsley, J. (1963) Evidence for a Primary Cosmic-Ray Particle with Energy 1020 eV. Physical Review Letters, 10, 146-148. http://dx.doi.org/10.1103/PhysRevLett.10.146

[13]   Chiba, N., Hashimoto, K., Hayashida, N., Honda, K., Honda, M., Inoue, N., et al. (1992) Akeno Giant Air Shower Array (AGASA) Covering 100 km2 Area. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 311, 338-349. http://dx.doi.org/10.1016/0168-9002(92)90882-5

[14]   Boyer, J.H., Knapp, B.C., Mannel, E.J. and Seman, M. (2002) FADC-Based DAQ for HiRes Fly’s Eye. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 482, 457-474.
http://dx.doi.org/10.1016/S0168-9002(01)01517-0

[15]   Abraham, J., Aglietta, M., Aguirre, I.C., Albrow, M., Allard, D., Allekotte, I., et al. (2004) Properties and Performance of the Prototype Instrument for the Pierre Auger Observatory. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 523, 50-95. http://dx.doi.org/10.1016/j.nima.2003.12.012

[16]   Nonaka, T., Abu-Zayyad, T., Allen, M., Azuma, R., Belz, J.W., Bergman, D.R., et al. (2009) The Present Status of the Telescope Array Experiment. Nuclear Physics B, Proceedings Supplements, 190, 26-31. http://dx.doi.org/10.1016/j.nuclphysbps.2009.03.064

[17]   Torres, D.F. and Anchordoqui, L.A. (2004) Astrophysical Origins of Ultrahigh Energy Cosmic Rays. Reports on Progress in Physics, 67, 1663-1730.

[18]   Dermer, C.D. and Razzaque, S. (2010) Acceleration of Ultra-High-Energy Cosmic Rays in the Colliding Shells of Blazars and Gamma-Ray Bursts: Constraints from the Fermi Gamma-Ray Space Telescope. The Astrophysical Journal, 724, 1366-1372.

[19]   Berezinsky, V. (2009) Ultra High Energy Cosmic Ray Protons: Signatures and Observations. Nuclear Physics B, Proceedings Supplements, 188, 227-232.
http://dx.doi.org/10.1016/j.nuclphysbps.2009.02.054

[20]   Urry, C.M. and Padovani, P. (1995) Unified Schemes for Radio-Loud Active Galactic Nuclei. Publications of the Astronomical Society of the Pacific, 107, 803-845.

[21]   Punch, M., Akerlof, C.W., Cawley, M.F., Chantell, M., Fegan, D.J., Fennell, S., et al. (1992) Detection of TeV Photons from the Active Galaxy Markarian 421. Nature, 358, 477-478.
http://dx.doi.org/10.1038/358477a0

[22]   Sahayanathan, S. and Godambe, S. (2012) Modelling the Very High Energy Flare of 3C 279 Using One-Zone Leptonic Model. Monthly Notices of the Royal Astronomical Society, 419, 1660-1666.
http://dx.doi.org/10.1111/j.1365-2966.2011.19829.x

[23]   Bhattacharjee, P. and Sigl, G. (2000) Origin and Propagation of Extremely High-Energy Cosmic Rays. Physics Reports, 327, 109-247. http://dx.doi.org/10.1016/S0370-1573(99)00101-5

[24]   Hillas, A.M. (1984) The Origin of Ultra-High-Energy Cosmic Rays. Annual Review of Astronomy and Astrophysics, 22, 425-444. http://dx.doi.org/10.1146/annurev.aa.22.090184.002233

[25]   Sigl, G. (2009) Time Structure and Multi-Messenger Signatures of Ultra-High Energy Cosmic Ray Sources. New Journal of Physics, 11, Article ID: 065014.

[26]   Halzen, F. and Zas, E. (1997) Neutrino Fluxes from Active Galaxies: A Model-Independent Estimate. The Astrophysical Journal, 488, 669-674.

[27]   Stanev, T. (2010) Ultra High Energy Cosmic Rays: Origin and Propagation. Modern Physics Letters A, 25, 1467-1481. http://dx.doi.org/10.1142/S0217732310033530

[28]   Murase, K., Dermer, C.D., Takami, H. and Migliori, G. (2012) Blazars as Ultra-High-Energy Cosmic-Ray Sources: Implications for TeV Gamma-Ray Observations. The Astrophysical Journal, 749, 63-77.

[29]   Vietri, M. (1998) On the Energy of Neutrinos from Gamma-Ray Bursts. The Astrophysical Journal, 507, 40-45.

[30]   Berezinsky, V., Gazizov, A. and Grigorieva, S. (2006) On Astrophysical Solution to Ultrahigh Energy Cosmic Rays. Physical Review D, 74, Article ID: 043005.
http://dx.doi.org/10.1103/PhysRevD.74.043005

[31]   Abbasi, R.U., Abu-Zayyad, T., Amann, J.F., Archbold, G., Belov, K., Belz, J.W., et al. (2006) Search for Cross-Correlations of Ultrahigh-Energy Cosmic Rays with BL Lacertae Objects. The Astrophysical Journal, 636, 680-684.

[32]   Gorbunov, D.S., Tinyakov, P.G., Tkachev, I.I. and Troitsky, S.V. (2004) Testing the Correlations between UltrahighEnergy Cosmic Rays and BL Lac-Type Objects with HiRes Stereoscopic Data. Journal of Experimental and Theoretical Physics Letters, 80, 145-148.
http://dx.doi.org/10.1134/1.1808838

[33]   Singh, S., Ma, C.P. and Arons, J. (2004) Gamma-Ray Bursts and Magnetars as Possible Sources of Ultrahigh Energy Cosmic Rays: Correlation of Cosmic Ray Event Positions with IRAS Galaxies. Physical Review D, 69, Article ID: 063003. http://dx.doi.org/10.1103/PhysRevD.69.063003

[34]   Smialkowski, A., Giller, M. and Michalak, W. (2002) Luminous Infrared Galaxies as Possible Sources of UHE Cosmic Rays. Journal of Physics G: Nuclear and Particle Physics, 28, 1359-1374.

[35]   Torres, D.F., Boldt, E., Hamilton, T. and Loewenstein, M. (2002) Nearby Quasar Remnants and Ultrahigh-Energy Cosmic Rays. Physical Review D, 66, Article ID: 023001.
http://dx.doi.org/10.1103/PhysRevD.66.023001

[36]   Tinyakov, P.G. and Tkachev, I.I. (2001) BL Lacertae Are Probable Sources of the Observed Ultrahigh Energy Cosmic Rays. Journal of Experimental and Theoretical Physics Letters, 74, 445-448.
http://dx.doi.org/10.1134/1.1434282

[37]   Tinyakov, P.G. and Tkachev, I.I. (2002) Tracing Protons through the Galactic Magnetic Field: A Clue for Charge Composition of Ultra-High-Energy Cosmic Rays. Astroparticle Physics, 18, 165-172.
http://dx.doi.org/10.1016/S0927-6505(02)00109-3

[38]   Gorbunov, D.S., Tinyakov, P.G., Tkachev, I.I. and Troitsky, S. (2002) Evidence for a Connection between the Gamma-Ray and the Highest Energy Cosmic-Ray Emissions by BL Lacertae Objects. Astrophysical Journal Letters, 577, 93-96.

[39]   Abraham, J., Abreu, P., Aglietta, M., Aguirre, C., Allard, D., Allekotte, I., et al. (2007) Correlation of the HighestEnergy Cosmic Rays with Nearby Extragalactic Objects. Science, 318, 938-943.
http://dx.doi.org/10.1126/science.1151124

[40]   Abraham, J., Abreu, P., Aglietta, M., Aguirre, C., Allard, D., Allekotte, I., et al. (2008) Correlation of the HighestEnergy Cosmic Rays with the Positions of Nearby Active Galactic Nuclei. Astroparticle Physics, 29, 188-204. http://dx.doi.org/10.1016/j.astropartphys.2008.01.002

[41]   Abbasi, R.U., Abu-Zayyad, T., Allen, M., Amman, J.F., Archbold, G., Belov, K., et al. (2008) Search for Correlations between HiRes Stereo Events and Active Galactic Nuclei. Astroparticle Physics, 30, 175-179. http://dx.doi.org/10.1016/j.astropartphys.2008.08.004

[42]   Abreu, P., Aglietta, M., Ahn, E.J., Allard, D., Allekotte, I., Allen, J., et al. (2010) Update on the Correlation of the Highest Energy Cosmic Rays with Nearby Extragalactic Matter. Astroparticle Physics, 34, 314-326. http://dx.doi.org/10.1016/j.astropartphys.2010.08.010

[43]   Abu-Zayyad, T., Aida, R., Allen, M., Anderson, R., Azuma, R., Barcikowski, E., et al. (2012) Search for Anisotropy of Ultrahigh Energy Cosmic Rays with the Telescope Array Experiment. The Astrophysical Journal, 757, 26-36.

[44]   Finley, C.B. (2006) Anisotropy of Arrival Directions of Ultrahigh Energy Cosmic Rays. Ph.D. Thesis, Columbia University, New York, 18.

[45]   Kotera, K., Allard, D., Murase, K., Aoi, J., Dubois, Y., Pierog, T., et al. (2009) Propagation of Ultrahigh Energy Nuclei in Clusters of Galaxies: Resulting Composition and Secondary Emissions. The Astrophysical Journal, 707, 370-386.

[46]   Abbasi, R.U., Abu-Zayyad, T., Al-Seady, M., Allen, M., Amman, J.F., Anderson, R.J., et al. (2010) Indications of Proton-Dominated Cosmic-Ray Composition above 1.6 EeV. Physical Review Letters, 104, Article ID: 161101. http://dx.doi.org/10.1103/PhysRevLett.104.161101

[47]   Abraham, J., Abreu, P., Aglietta, M., Ahn, E.J., Allard, D., Allekotte, I., et al. (2010) Measurement of the Depth of Maximum of Extensive Air Showers above 1018 eV. Physical Review Letters, 104, Article ID: 091101. http://dx.doi.org/10.1103/PhysRevLett.104.091101

[48]   Tavecchio, F., Ghisellini, G., Ghirlanda, G., Foschini, L. and Maraschi, L. (2010) TeV BL Lac Objects at the Dawn of the Fermi Era. Monthly Notices of the Royal Astronomical Society, 401, 1570-1586. http://dx.doi.org/10.1111/j.1365-2966.2009.15784.x

[49]   Aharonian, F., Akhperjanian, A.G., De Almeida U.B., Bazer-Bachi, A.R., Behera, B., Beilicke, M., et al. (2008) Discovery of VHE Gamma-Rays from the High-Frequency-Peaked BL Lacertae Object RGB J0152+017. Astronomy and Astrophysics, 481, L103-L107. http://dx.doi.org/10.1051/0004-6361:200809603

[50]   Zhang, J., Liang, E.W., Zhang, S.N. and Bai, J.M. (2012) Radiation Mechanisms and Physical Properties of GeV-TeV BL Lac Objects. The Astrophysical Journal, 752, 157.
http://dx.doi.org/10.1088/0004-637X/752/2/157

[51]   Yang, J. and Wang, J. (2010) Mechanism of Very High-Energy Radiation in BL Lacertae Object 3C 66A. Astronomy and Astrophysics, 511, 11-15. http://dx.doi.org/10.1051/0004-6361/200913035

[52]   Aliu, E., Archambault, S., Arlen, T., Aune, T., Beilicke, M., Benbow, W., et al. (2012) Discovery of High-Energy and Very High Energy Gamma-Ray Emission from the Blazar RBS 0413. The Astrophysical Journal, 750, 94-99.

[53]   Aharonian, F., Akhperjanian, A.G., De Almeida, U.B., Bazer-Bachi, A.R., Behera, B., Beilicke, M., et al. (2007) Discovery of VHE Gamma-Rays from the Distant BL Lacertae 1ES 0347-121. Astronomy and Astrophysics, 473, 25-28. http://dx.doi.org/10.1051/0004-6361:20078412

[54]   Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A.G., Anton, G., Balzer, A., et al. (2012) Discovery of HardSpectrum γ-Ray Emission from the BL Lacertae Object 1ES 0414+009. Astronomy and Astrophysics, 538, 103-111. http://dx.doi.org/10.1051/0004-6361/201118406

[55]   Prandini, E., Bonnoli, G. and Tavecchio, F. (2012) Estimating the Redshift of PKS 0447-439 through Its GeV-TeV Emission. Astronomy and Astrophysics, 543, 111-115. http://dx.doi.org/10.1051/0004-6361/201118289

[56]   Katarzynski, K. (2012) Hard MeV-GeV Spectra of Blazars. Astronomy and Astrophysics, 537, 47-55. http://dx.doi.org/10.1051/0004-6361/201116839

[57]   Aharonian, F., Akhperjanian, A.G., Anton, G., de Almeida, U.B., Bazer-Bachi, A.R., Becherini, Y., et al. (2010) Discovery of VHE γ-Rays from the BL Lacertae Object PKS 0548-322. Astronomy and Astrophysics, 521, 69-74. http://dx.doi.org/10.1051/0004-6361/200912363

[58]   Aliu, E., Aune, T., Beilicke, M., B?ttcher, M., Bouvier, A., Bradbury, S.M., et al. (2011) Multiwavelength Observations of the Previously Unidentified Blazar RX J0648.7+1516. The Astrophysical Journal, 742, 127-133.

[59]   Acciari, V.A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., et al. (2010) The Discovery of Gamma-Ray Emission from the Blazar RGB J0710+591. Astrophysical Journal Letters, 715, 49-55.

[60]   Anderhub, H. (2009) Discovery of Very High Energy Gamma-Rays from the Blazar S5 0716+714. Astrophysical Journal Letters, 704, 129-133.

[61]   Acciari, V., Aliu, E., Arlen, T., Bautista, M., Beilicke, M., Benbow, W., et al. (2009) Discovery of Very High Energy Gamma-Ray Radiation from the BL Lac 1ES 0806+524. Astrophysical Journal Letters, 690, 126-129.

[62]   Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A.G., Anton, G., Balzer, A., et al. (2012) Discovery of VHE Gamma-Ray Emission and Multi-Wavelength Observations of the BL Lacertae Object 1RXS J101015.9-311909. Astronomy and Astrophysics, 542, 94-103. http://dx.doi.org/10.1051/0004-6361/201218910

[63]   Reinthal, R., Rugamer, S., Lindfors, E.J., Mazin, D., Stamerra, A., Longo, F., et al. (2012) Multi-Wavelength Observations of the HBL 1ES 1011+496 in Spring 2008. Journal of Physics: Conference Series, 355, Article ID: 012017.

[64]   Rugamer, S., Angelakis, E., Bastieri, D., Dorner, D., Kovalev, Y.Y., L?hteenm?ki, A., et al. (2008) MAGIC and MultiWavelength Observations of Three HBLs in 2008.

[65]   Aharonian, F., Akhperjanian, A.G., Bazer-Bachi, A.R., Beilicke, M., Benbow, W., Berge, D., et al. (2007) Detection of VHE Gamma-Ray Emission from the Distant Blazar 1ES 1101-232 with HESS and Broadband Characterisation. Astronomy and Astrophysics, 470, 475-489.
http://dx.doi.org/10.1051/0004-6361:20077057

[66]   Yan, D., Zeng, H. and Zhang, L. (2012) Non-Variable TeV Emission from the Extended Jet of a Blazar in the Stochastic Acceleration Scenario: The Case of the Hard TeV Emission of 1ES 1101-232. Monthly Notices of the Royal Astronomical Society, 424, 2173-2179.
http://dx.doi.org/10.1111/j.1365-2966.2012.21376.x

[67]   Acciari, V.A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., et al. (2011) TeV and Multi-Wavelength Observations of Mrk 421 in 2006-2008. The Astrophysical Journal, 738, 25-43.

[68]   Finke, J.D., Dermer, C.D. and Bottcher, M. (2008) Synchrotron Self-Compton Analysis of TeV X-Ray-Selected BL Lacertae Objects. The Astrophysical Journal, 686, 181-194.

[69]   Shukla, A., Chitnis, V.R., Vishwanath, P.R., Acharya, B.S., Anupama, G.C., Bhattacharjee, P., et al. (2012) Multiwavelength Study of the TeV Blazar Mrk 421 during a Giant Flare. Astronomy and Astrophysics, 541, 140-148. http://dx.doi.org/10.1051/0004-6361/201118569

[70]   Aleksic, J., Alvarez, E.A., Antonelli, L.A., Antoranz, P., Ansoldi, S., Asensio, M., et al. (2012) Discovery of VHE Gamma-Rays from the Blazar 1ES 1215+303 with the MAGIC Telescopes and Simultaneous Multi-Wavelength Observations. Astronomy and Astrophysics, 544, 142-151.
http://dx.doi.org/10.1051/0004-6361/201219133

[71]   Weidinger, M. and Spanier, F. (2010) Modelling the Variability of 1ES1218+30.4. Astronomy and Astrophysics, 515, 18-23. http://dx.doi.org/10.1051/0004-6361/201014299

[72]   Acciari, V.A., Aliu, E., Aune, T., Beilicke, M., Benbow, W., Bottcher, M., et al. (2009) Multiwavelength Observations of a TeV-Flare from W Comae. The Astrophysical Journal, 707, 612-620.

[73]   Zhang, J. (2009) A Synchrotron Self-Compton Scenario for the Very High Energy Gamma-Ray Emission of the Intermediate BL Lacertae Object W Comae. Research in Astronomy and Astrophysics, 9, 777-782.

[74]   Tavecchio, F., Becerra-Gonzalez, J., Ghisellini, G., Stamerra, A., Bonnoli, G., Foschini, L., et al. (2011) On the Origin of the Gamma-Ray Emission from the Flaring Blazar PKS 1222+216. Astronomy and Astrophysics, 534, 86-93. http://dx.doi.org/10.1051/0004-6361/201117204

[75]   Aleksic, J., Antonelli, L.A., Antoranz, P., Backes, M., Barrio, J.A., Bastieri, D., et al. (2011) MAGIC Observations and Multiwavelength Properties of the Quasar 3C 279 in 2007 and 2009. Astronomy and Astrophysics, 530, 4-14. http://dx.doi.org/10.1051/0004-6361/201116497

[76]   Hayashida, M., Madejski, G.M., Nalewajko, K., Sikora, M., Wehrle, A.E., Ogle, P., et al. (2012) The Structure and Emission Model of the Relativistic Jet in the Quasar 3C 279 Inferred from Radio to High-Energy Gamma-Ray Observations in 2008-2010. The Astrophysical Journal, 754, 114-135.

[77]   Mizumura, Y., Kushida, J., Nishijima, K., Bicknell, G.V., Clay, R.W., Edwards, P.G., et al. (2012) Searches for Very High Energy gamma Rays from Blazars with CANGAROO-III Telescope in 2005-2009. Astroparticle Physics, 35, 563-572. http://dx.doi.org/10.1016/j.astropartphys.2012.01.002

[78]   Acciari, V.A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Cogan, P., et al. (2010) Discovery of Very High Energy Gamma Rays from PKS 1424+240 and Multiwavelength Constraints on Its Redshift. Astrophysical Journal Letters, 708, 100-106.

[79]   Costamante, L., Aharonian, F., Ghisellini, G. and Horns, D. (2003) The SED of the TeV BLLac 1ES 1426+428 after Correction for the TeV-IR Absorption. New Astronomy Reviews, 47, 677-680. http://dx.doi.org/10.1016/S1387-6473(03)00121-0

[80]   Kato, T., Kusunose, M. and Takahara, F. (2006) Constraining the Emission Properties of TeV Blazar H1426+428 by the Synchrotron Self-Compton Model. The Astrophysical Journal, 638, 653-658.

[81]   Chen, X., Fossati, G., Bottcher, M. andLiang, E. (2012) Time-Dependent Simulations of Emission from the FSRQ PKS 1510-089: Multiwavelength Variability of External Compton and Synchrotron Self-Compton Models. Monthly Notices of the Royal Astronomical Society, 424, 789-799.
http://dx.doi.org/10.1111/j.1365-2966.2012.21283.x

[82]   Aleksi, C.J., Alvarez, E.A., Antonelli, L.A., Antoranz, P., Asensio, M., Backes, M., et al. (2012) PG 1553+113: Five Years of Observations with MAGIC. The Astrophysical Journal, 748, 46-55.

[83]   Abdo, A.A., Ackermann, M., Ajello, M., Allafort, A., Aleksic, J., Acciari, V.A., et al. (2011) Insights into the HighEnergy Gamma-Ray Emission of Markarian 501 from Extensive Multifrequency Observations in the Fermi Era. The Astrophysical Journal, 727, 129-154.

[84]   Acciari, V.A., Arlen, T., Aune, T., Beilicke, M., Benbow, W., B?ttcher, M., et al. (2011) Spectral Energy Distribution of Markarian 501: Quiescent State versus Extreme Outburst. The Astrophysical Journal, 729, 2-10.

[85]   Albert, J., Aliu, E., Anderhub, H., Antoranz, P., Armada, A., Baixeras, C., et al. (2007) Variable Very High Energy Gamma-Ray Emission from Markarian 501. The Astrophysical Journal, 669, 862-883.

[86]   Anderhub, H., Antonelli, L.A., Antoranz, P., Sato, R., Ushio, M., Kataoka, J., et al. (2009) Simultaneous Multiwavelength Observation of Mkn 501 in a Low State in 2006. The Astrophysical Journal, 705, 1624-1631.

[87]   Katarzynski, K., Sol, H. and Kus, A. (2001) The Multifrequency Emission of Mrk 501. From Radio to TeV GammaRays. Astronomy and Astrophysics, 367, 809-825.
http://dx.doi.org/10.1051/0004-6361:20000538

[88]   Petry, D., Bottcher, M., Connaughton, V., Lahteenmaki, A., Pursimo, T., Raiteri, C.M., et al. (2000) Multiwavelength Observations of Markarian 501 during the 1997 High State. The Astrophysical Journal, 536, 742-755.

[89]   Pian, E., Vacanti, G., Tagliaferri, G., Ghisellini, G., Maraschi, L., Treves, A., et al. (1998) BeppoSAX Observations of Unprecedented Synchrotron Activity in the BL Lacertae Object Markarian 501. Astrophysical Journal Letters, 492, 17-20.

[90]   Sambruna, R.M., Aharonian, F.A., Krawczynski, H., Akhperjanian, A.G., Barrio, J.A., Bernl?hr, K., et al. (2000) Correlated Intense X-Ray and TEV Activity of Markarian 501 in 1998 June. The Astrophysical Journal, 538, 127-133.

[91]   Krawczynski, H., Hughes, S.B., Horan, D., Aharonian, F., Aller, M.F., Aller, H., et al. (2004) Multiwavelength Observations of Strong Flares from the TeV Blazar 1ES 1959+650. The Astrophysical Journal, 601, 151-164.

[92]   Tagliaferri, G., Foschini, L., Ghisellini, G., Maraschi, L., Tosti, G., Albert, J., et al. (2008) Simultaneous Multiwavelength Observations of the Blazar 1ES 1959+650 at a Low TeV Flux. The Astrophysical Journal, 679, 1029-1039.

[93]   Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A.G., Anton, G., Barnacka, A., et al. (2011) Simultaneous Multi-Wavelength Campaign on PKS 2005-489 in a High State. Astronomy and Astrophysics, 533, 110-118. http://dx.doi.org/10.1051/0004-6361/201016170

[94]   Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A.G., Anton, G., Balzer, A., et al. (2012) A Multiwavelength View of the Flaring State of PKS 2155-304 in 2006. Astronomy and Astrophysics, 539, 149-170. http://dx.doi.org/10.1051/0004-6361/201117509

[95]   Cerruti, M., Zech, A., Boisson, C. and Inoue, S. (2011) SF2A-2011: Proceedings of the Annual Meeting of the French Society of Astronomy and Astrophysics. 555-558.

[96]   Potter, W.J. and Cotter, G. (2012) Synchrotron and Inverse-Compton Emission from Blazar Jets—I. A Uniform Conical jet Model. Monthly Notices of the Royal Astronomical Society, 423, 756-765.
http://dx.doi.org/10.1111/j.1365-2966.2012.20918.x

[97]   Aleksic, J., Alvarez, E.A., Antonelli, L.A., Antoranz, P., Asensio, M., Backes, M., et al. (2012) Discovery of VHE Gamma-Ray Emission from the BL Lacertae Object B3 2247+381 with the MAGIC Telescopes. Astronomy and Astrophysics, 539, 118-123. http://dx.doi.org/10.1051/0004-6361/201117967

[98]   Acciari, V.A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., et al. (2011) Multiwavelength Observations of the Very High Energy Blazar 1ES 2344+514. The Astrophysical Journal, 738, 169-176.

[99]   Albert, J., Aliu, E., Anderhub, H., Antoranz, P., Armada, A., Baixeras, C., et al. (2007) Observation of Very High Energy gamma-Rays from the AGN 1ES 2344+514 in a Low Emission State with the MAGIC Telescope. The Astrophysical Journal, 662, 892-899.

[100]   Aleksic, J., Antonelli, L.A., Antoranz, P., Asensio, M., Backes, M., de Almeida, U.B., et al. (2013) The Simultaneous Low State Spectral Energy Distribution of 1ES 2344+514 from Radio to Very High Energies. Astronomy and Astrophysics, 556, 67-94. http://dx.doi.org/10.1051/0004-6361/201220714

[101]   Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A.G., Anton, G., de Almeida, U.B., et al. (2010) Multi-Wavelength Observations of H 2356-309. Astronomy and Astrophysics, 516, 56-66.
http://dx.doi.org/10.1051/0004-6361/201014321

 
 
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