Coordinated Multiwavelength Observation of 3C 66A during the WEBT Campaign of 2003-2004
| dc.contributor.author | Mirabal, N. | |
| dc.contributor.author | et al. | |
| dc.date.accessioned | 2020-09-08T17:38:05Z | |
| dc.date.available | 2020-09-08T17:38:05Z | |
| dc.date.issued | 2005-06-09 | |
| dc.description | M. B¨ottcher, J. Harvey, M. Joshi, M. Villata, C. M. Raiteri, D. Bramel, R.Mukherjee, T. Savolainen, W. Cui, G. Fossati, I. A. Smith, D. Able, H. D. Aller, M.F. Aller, A. A. Arkharov, K. Baliyan, D. Barnaby, A. Berdyugin, E. Benıtez, P. Boltwood, M. Carini, D. Carosati, S. Ciprini, J. M. Coloma, S. Crapanzano, J. A.de Diego, A. Di Paola, M. Dolci, J. Fan, A. Frasca, V. Hagen-Thorn, D. Horan M. Ibrahimov, G. N. Kimeridze, Y. A. Kovalev, Y. Y. Kovalev, O.Kurtanidze, A. Lahteenmaki, L. Lanteri, V. M. Larionov, E. G. Larionova, E.Lindfors, E. Marilli N. Mirabal, M. Nikolashvili, K. Nilsson, J. M. Ohlert, T.Ohnishi, A. Oksanen, L. Ostorero, G. Oye, I. Papadakis, M. Pasanen, C.Poteet, T. Pursimo, K. Sadakane, L. A. Sigua, L. Takalo, J. B. Tartar, H.Ter¨asranta, G. Tosti, R. Walters, K. Wiik, B. A. Wilking, W. Wills, E.Xilouris, A. B. Fletcher, M. Gu,C.-U. Lee, S. Pak, H.-S. Yim | en_US |
| dc.description.abstract | The BL Lac object 3C 66A was the target of an extensive multiwavelength monitoring campaign from 2003 July through 2004 April (with a core campaign from 2003 September to 2003 December) involving observations throughout the electromagnetic spectrum. Radio, infrared, and optical observations were carried out by the WEBT-ENIGMA collaboration. At higher energies, 3C 66A was observed in X-rays (RXTE), and at very high energy (VHE) in γ-rays (STACEE, VERITAS). In addition, the source has been observed with the VLBA at nine epochs throughout the period 2003 September to 2004 December, including three epochs contemporaneous with the core campaign. A gradual brightening of the source over the course of the campaign was observed at all optical frequencies, culminating in a very bright maximum around 2004 February 18. The WEBT campaign revealed microvariability with flux changes of ~5% on timescales as short as ~2 hr. The source was in a relatively bright state, with several bright flares on timescales of several days. The spectral energy distribution (SED) indicates a νFν peak in the optical regime. A weak trend of optical spectral hysteresis with a trend of spectral softening throughout both the rising and decaying phases has been found. On longer timescales, there appears to be a weak indication of a positive hardness-intensity correlation for low optical fluxes, which does not persist at higher flux levels. The 3-10 keV X-ray flux of 3C 66A during the core campaign was historically high and its spectrum very soft, indicating that the low-frequency component of the broadband SED extends beyond ~10 keV. No significant X-ray flux and/or spectral variability was detected. STACEE and Whipple observations provided upper flux limits at >150 and >390 GeV, respectively. The 22 and 43 GHz data from the three VLBA epochs made between 2003 September and 2004 January indicate a rather smooth jet with only very moderate internal structure. Evidence for superluminal motion (8.5 ± 5.6 h⁻¹ c) was found in only one of six components, while the apparent velocities of all other components are consistent with 0. The radial radio brightness profile suggests a magnetic field decay ∝r⁻¹ and, thus, a predominantly perpendicular magnetic field orientation. | en_US |
| dc.description.sponsorship | The work of M. B¨ottcher and M. Joshi at Ohio University and of G. Fossati and I. A. Smith at Rice University was partially supported through NASA’s RXTE guest observer program, award no. NNG 04GB13G. The European Institutes belonging to the ENIGMA collaboration acknowledge EC funding under contract HPRN-CT-2002-00321. The UMRAO is partially supported by funds from the NSF and from the University of Michigan’s Department of Astronomy. The work of T. Savolainen was partly supported by the Finnish Cultural Foundation. The St.-Petersburg group was supported by Federal Programs “Astronomy” (grant 40.022.1.1.1001) and “Integration” (grant B0029). J. H. Fan’s work is partially supported by the National 973 project (NKBRSF G19990754) of China, the National Science Fund for Distinguished Young Scholars (10125313). V. Hagen-Thorn and V. Larionov acknowledge support from the Russian Foundation for Basic Research, project 05-02-17562. The work at the Mt. Abu Infrared Observatory was supported by the DOS, Govt. of India. W. Cui nd D. Able gratefully acknowledge support from the Department of Energy. The RATAN-600 observations were partlysupported by the NASA JURRISS Program (grant W-19611) and the Russian Foundation for Basic Research (grant 05-02-17377). | en_US |
| dc.description.uri | https://iopscience.iop.org/article/10.1086/432609 | en_US |
| dc.format.extent | 27 pages | en_US |
| dc.genre | journal articles preprints | en_US |
| dc.identifier | doi:10.13016/m2pspt-73oi | |
| dc.identifier.citation | M. Böttcher et al., Coordinated Multiwavelength Observation of 3C 66A during the WEBT Campaign of 2003-2004, ApJ 631 169 (2005), doi: https://doi.org/10.1086/432609 | en_US |
| dc.identifier.uri | https://doi.org/10.1086/432609 | |
| dc.identifier.uri | http://hdl.handle.net/11603/19606 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | IOP | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Physics Department Collection | |
| dc.relation.ispartof | UMBC Joint Center for Earth Systems Technology (JCET) | |
| dc.relation.ispartof | UMBC Center for Space Sciences and Technology (CSST) / Center for Research and Exploration in Space Sciences & Technology II (CRSST II) | |
| dc.rights | This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author. | |
| dc.rights | © 2005. The American Astronomical Society. All rights reserved | |
| dc.title | Coordinated Multiwavelength Observation of 3C 66A during the WEBT Campaign of 2003-2004 | en_US |
| dc.type | Text | en_US |