Статья

Coordinated Multiwavelength Observations of BL Lacertae in 2000

M. BöttcherDepartment of Physics and Astronomy, Clippinger 339, Ohio University, Athens, OH 45701Alan P. MarscherDepartment of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215M. RavasioOsservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate, ItalyM. VillataIstituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Torino, Via Osservatorio 20, I-10025 Pino Torinese, ItalyC. M. RaiteriIstituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Torino, Via Osservatorio 20, I-10025 Pino Torinese, ItalyH. D. AllerDepartment of Astronomy, University of Michigan, 810 Dennison Building, Ann Arbor, MI 48109-1090M. F. AllerDepartment of Astronomy, University of Michigan, 810 Dennison Building, Ann Arbor, MI 48109-1090H. TerasrantaMetsähovi Radio Observatory, Helsinki University of Technology, Metsähovintie 114, 02540 Kylmälä, FinlandO. MangInstitut für Experimentelle und Angewandte Physik, Universität Kiel, Leibnitzstrasse 15-19, D-24118 Kiel, GermanyG. TagliaferriOsservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate, ItalyF. AharonianMax-Planck-Institut für Kernphysik, Postfach 10 39 80, D-69029 Heidelberg, GermanyH. KrawczynskiPhysics Department, Washington University, 1 Brookings Drive, CB 1105, St. Louis, MO 63130O. M. KurtanidzeAbastumani Observatory, 383762 Abastumani, GeorgiaM. G. NikolashviliAbastumani Observatory, 383762 Abastumani, GeorgiaM. IbrahimovIsaac Newton Institute of Chile, Uzbekistan BranchI. E. PapadakisIESL, Foundation for Research and Technology-Hellas, 711 10 Heraklion, Crete, GreeceK. TsinganosPhysics Department, University of Crete, 710 03 Heraklion, Crete, GreeceKunihiko SadakaneAstronomical Institute, Osaka Kyoiku University, Kashiwara-shi, Osaka 582-8582, JapanN. OkadaAstronomical Institute, Osaka Kyoiku University, Kashiwara-shi, Osaka 582-8582, JapanL. O. TakaloA. SillanpaaG. TostiOsservatorio Astronomico, Università di Perugia, Via B. Bonfigli, I-06126 Perugia, ItalyS. CipriniOsservatorio Astronomico, Università di Perugia, Via B. Bonfigli, I-06126 Perugia, ItalyA. FrascaOsservatorio Astrofisico di Catania, Viale A. Doria 6, I-95125 Catania, ItalyE. MarilliOsservatorio Astrofisico di Catania, Viale A. Doria 6, I-95125 Catania, ItalyR. M. RobbDepartment of Physics and Astronomy, University of Victoria, BC, CanadaJ. C. NobleInstitute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215S. G. JorstadInstitute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215V. A. Hagen‐ThornCenter for Astrophysics, Guangzhou University, Guangzhou 510400, ChinaV. M. LarionovAstronomical Institute, St. Petersburg State University, Bibliotechnaya Pl. 2, Petrodvoretz, 198504 St. Petersburg, RussiaR. NesciDipartimento di Fisica, Università La Sapienza, Piazzale A. Moro 2, I-00185 Rome, ItalyM. MaesanoDipartimento di Fisica, Università La Sapienza, Piazzale A. Moro 2, I-00185 Rome, ItalyRichard D. SchwartzDepartment of Physics and Astronomy, University of Missouri-St. Louis, 8001 Natural Bridge Road, St. Louis, MO 63121J. BaslerDepartment of Physics and Astronomy, University of Missouri-St. Louis, 8001 Natural Bridge Road, St. Louis, MO 63121P. W. GorhamJet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109H. IwamatsuDepartment of Astronomy, Faculty of Science, Kyoto University, Kyoto, JapanTakeo KatoDepartment of Astronomy, Faculty of Science, Kyoto University, Kyoto, JapanC. PullenE. BenítezJ. A. de DiegoMarko MoilanenNyrölä Observatory, Jyväskylän Sirius ry, Kyllikinkatu 1, 40950 Jyväskylä, FinlandA. OksanenNyrölä Observatory, Jyväskylän Sirius ry, Kyllikinkatu 1, 40950 Jyväskylä, FinlandD. RodriguezGuadarrama Observatory, C/ San Pablo 5, Villalba 28409, Madrid, SpainA. C. SadunDepartment of Physics, University of Colorado, P.O. Box 173364, Denver, CO 80217-3364M. KellyDepartment of Physics, University of Colorado, P.O. Box 173364, Denver, CO 80217-3364M. T. CariniDepartment of Physics and Astronomy, Western Kentucky University, 1 Big Red Way, Bowling Green, KY 42104H. R. MillerDepartment of Physics and Astronomy, Georgia State University, Atlanta, GA 30303S. CatalanoOsservatorio Astrofisico di Catania, Viale A. Doria 6, I-95125 Catania, ItalyD. Dultzin‐HacyanJ. H. FanCenter for Astrophysics, Guangzhou University, Guangzhou 510400, ChinaG. GhiselliniOsservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate, ItalyRyoko IshiokaDepartment of Astronomy, Faculty of Science, Kyoto University, Kyoto, JapanHannu KarttunenP. KeinänenN. A. KudryavtsevaAstronomical Institute, St. Petersburg State University, Bibliotechnaya Pl. 2, Petrodvoretz, 198504 St. Petersburg, RussiaM. LainelaL. LanteriIstituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Torino, Via Osservatorio 20, I-10025 Pino Torinese, ItalyЕ. Г. ЛарионоваAstronomical Institute, St. Petersburg State University, Bibliotechnaya Pl. 2, Petrodvoretz, 198504 St. Petersburg, RussiaKatsura MatsumotoDepartment of Astronomy, Faculty of Science, Kyoto University, Kyoto, JapanJ. R. MattoxDepartment of Chemistry, Physics, and Astronomy, Francis Marion University, P.O. Box 100547, Florence, SC 29501-0547I. McHardyDepartment of Physics and Astronomy, University of Southampton Highfield, Southampton SO17 1BJ, UKF. MontagniDipartimento di Fisica, Università La Sapienza, Piazzale A. Moro 2, I-00185 Rome, ItalyG. NucciarelliOsservatorio Astronomico, Università di Perugia, Via B. Bonfigli, I-06126 Perugia, ItalyL. OstoreroDipartimento di Fisica Generale, Università di Torino, Via P. Giuria 1, I-10125 Turin, ItalyJ. PapamastorakisIESL, Foundation for Research and Technology-Hellas, 711 10 Heraklion, Crete, GreeceM. PasanenG. SobritoIstituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Torino, Via Osservatorio 20, I-10025 Pino Torinese, ItalyMakoto UemuraDepartment of Astronomy, Faculty of Science, Kyoto University, Kyoto, Japan

The Astrophysical Journaljournal2003en

ABI

Аннотация

BL Lacertae was the target of an extensive multiwavelength monitoring campaign in the second half of 2000. Simultaneous or quasi-simultaneous observations were taken at radio (UMRAO and Metsaehovi) and optical(WEBT collaboration) frequencies, in X-rays (BeppoSAX and RXTE), and at VHE gamma-rays (HEGRA). The WEBT optical campaign achieved an unprecedented time coverage, virtually continuous over several 10 - 20 hour segments. It revealed intraday variability on time scales of ~ 1.5 hours and evidence for spectral hardening associated with increasing optical flux. During the campaign, BL Lacertae underwent a major transition from a rather quiescent state prior to September 2000, to a flaring state for the rest of the year. This was also evident in the X-ray activity of the source. BeppoSAX observations on July 26/27 revealed a rather low X-ray flux and a hard spectrum, while a BeppoSAX pointing on Oct. 31 - Nov. 2, 2000, indicated significant variability on time scales of < a few hours, and provided evidence for the synchrotron spectrum extending out to ~ 10 keV during that time. During the July 26/27 observation, there is a tantalizing, though not statistically significant, indication of a time delay of ~ 4 - 5 hr between the BeppoSAX and the R-band light curve. Also, a low-significance detection of a time delay of 15 d between the 14.5 GHz and the 22 GHz radio light curves is reported. Several independent methods to estimate the co-moving magnetic field in the source are presented, suggesting a value of ~ 2 e_B^{2/7} G, where e_B is the magnetic-field equipartition factor w.r.t. the electron energy density in the jet.

Темы

Astrophysics and Cosmic Phenomena Radio Astronomy Observations and Technology Computational Physics and Python Applications

Идентификаторы

DOI: 10.1086/378156

Цитирования и источники

Цитирований: 7 Использованных источников: 54

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