Мақола

The WEBT campaign on the BL Lac object PG 1553+113 in 2013. An analysis of the enigmatic synchrotron emission

C. M. RaiteriINAF, Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese, ItalyA. StamerraINAF, Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese, ItalyM. VillataINAF, Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese, ItalyV. M. LarionovIsaac Newton Institute of Chile, St Petersburg Branch, 198504 St Petersburg, RussiaJ. A. Acosta‐PulidoInstituto de Astrofisica de Canarias (IAC), La Laguna, E-38200 Tenerife, SpainM. J. ArévaloDepartamento de Astrofisica, Universidad de La Laguna, La Laguna, E-38205 Tenerife, SpainA. A. ArkharovPulkovo Observatory, 196140 St Petersburg, RussiaR. BachevInstitute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko shosse Blvd, 1784 Sofia, BulgariaE. BenítezInstituto de Astronomía, Universidad Nacional Autónoma de México, 04510 Mexico DF, MexicoV. BozhilovDepartment of Astronomy, University of Sofia "St. Kliment Ohridski", BG-1164 Sofia, BulgariaG. A. BormanCrimean Astrophysical Observatory, P/O Nauchny, 298409 CrimeaC. S. BuemiINAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania, ItalyP. CalcideseOsservatorio Astronomico della Regione Autonoma Valle d'Aosta, Saint-Barthélemy, I-11020 Nus, ItalyM. I. CarnereroDepartamento de Astrofisica, Universidad de La Laguna, La Laguna, E-38205 Tenerife, SpainD. CarosatiEPT Observatories, Tijarafe, E-38780 La Palma, Spain,R. A. ChigladzeAbastumani Observatory, Mt Kanobili, 0301 Abastumani, GeorgiaG. DamljanovićAstronomical Observatory, Volgina 7, 11060 Belgrade, SerbiaA. Di PaolaINAF, Osservatorio Astronomico di Roma, I-00040 Monte Porzio Catone, ItalyVictor DoroshenkoSouthern Station of the Sternberg Astronomical Institute, Moscow M.V. Lomonosov State University, P/O Nauchny, 298409 CrimeaН. В. ЕфимоваPulkovo Observatory, 196140 St Petersburg, RussiaSh. A. EhgamberdievUlugh Beg Astronomical Institute, Maidanak Observatory, UzbekistanM. GirolettiINAF, Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna, ItalyP. A. González-MoralesInstituto de Astrofisica de Canarias (IAC), La Laguna, E-38200 Tenerife, SpainAna Belén Griñón-MarínDepartamento de Astrofisica, Universidad de La Laguna, La Laguna, E-38205 Tenerife, SpainT. S. GrishinaAstronomical Institute, St Petersburg State University, 198504 St Petersburg, RussiaD. HiriartInstituto de Astronomía, Universidad Nacional Autónoma de México, 22800 Ensenada, BC, MexicoS. IbryamovInstitute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko shosse Blvd, 1784 Sofia, BulgariaS. A. KlimanovPulkovo Observatory, 196140 St Petersburg, RussiaE. N. KopatskayaAstronomical Institute, St Petersburg State University, 198504 St Petersburg, RussiaO. M. KurtanidzeEngelhardt Astronomical Observatory, Kazan Federal University, 422526 Tatarstan, RussiaS. O. KurtanidzeAbastumani Observatory, Mt Kanobili, 0301 Abastumani, GeorgiaA. KurtenkovInstitute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko shosse Blvd, 1784 Sofia, BulgariaL. V. LarionovaAstronomical Institute, St Petersburg State University, 198504 St Petersburg, RussiaЕ. Г. ЛарионоваAstronomical Institute, St Petersburg State University, 198504 St Petersburg, RussiaC. LázaroDepartamento de Astrofisica, Universidad de La Laguna, La Laguna, E-38205 Tenerife, SpainA. LähteenmäkiAalto University Department of Radio Science and Engineering, PO BOX 13000, FI-00076 AALTO, FinlandP. LetoINAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania, ItalyGoran MarkovićFaculty of Mathematics, University of Belgrade, Studentski trg 16, 11000 Belgrade, SerbiaD. O. MirzaqulovUlugh Beg Astronomical Institute, Maidanak Observatory, UzbekistanA. A. MokrushinaAstronomical Institute, St Petersburg State University, 198504 St Petersburg, RussiaD. A. MorozovaAstronomical Institute, St Petersburg State University, 198504 St Petersburg, RussiaR. MújicaInstituto Nacional de Astrofísica, Óptica y Electrónica, 72840 Puebla, MexicoS. V. NazarovCrimean Astrophysical Observatory, P/O Nauchny, 298409 CrimeaM. G. NikolashviliAbastumani Observatory, Mt Kanobili, 0301 Abastumani, GeorgiaJ. OhlertE. OvcharovDepartment of Astronomy, University of Sofia "St. Kliment Ohridski", BG-1164 Sofia, BulgariaS. PaianoINAF-Osservatorio Astronomico di Padova, Vicolo Osservatorio 5, I-35122 Padova, ItalyA. Pastor YabarDepartamento de Astrofisica, Universidad de La Laguna, La Laguna, E-38205 Tenerife, SpainE. PrandiniISDC - Science Data Center for Astrophysics, CH-1290 Versoix, Geneva, SwitzerlandVenkatessh RamakrishnanAalto University Metsähovi Radio Observatory, Metsähovintie 114, FI-02540 Kylmälä, FinlandA. C. SadunDepartment of Physics, University of Colorado Denver, CO, 80217-3364 USAE. SemkovInstitute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko shosse Blvd, 1784 Sofia, BulgariaL. A. SiguaAbastumani Observatory, Mt Kanobili, 0301 Abastumani, GeorgiaA. StrigachevInstitute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko shosse Blvd, 1784 Sofia, BulgariaJ. TammiAalto University Metsähovi Radio Observatory, Metsähovintie 114, FI-02540 Kylmälä, FinlandM. TornikoskiAalto University Metsähovi Radio Observatory, Metsähovintie 114, FI-02540 Kylmälä, FinlandC. TrigilioINAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania, ItalyYu. V. TroitskayaAstronomical Institute, St Petersburg State University, 198504 St Petersburg, RussiaI. S. TroitskyAstronomical Institute, St Petersburg State University, 198504 St Petersburg, RussiaG. UmanaINAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania, ItalyS. VelascoInstituto de Astrofisica de Canarias (IAC), La Laguna, E-38200 Tenerife, SpainO. VinceAstronomical Observatory, Volgina 7, 11060 Belgrade, Serbia

Monthly Notices of the Royal Astronomical Societyjournal2015en

ABI

Аннотация

A multifrequency campaign on the BL Lac object PG 1553+113 was organized by the Whole Earth Blazar Telescope (WEBT) in 2013 April-August, involving 19 optical, two near-IR, and three radio telescopes. The aim was to study the source behaviour at low energies during and around the high-energy observations by the Major Atmospheric Gamma-ray Imaging Cherenkov telescopes in April-July. We also analyse the UV and X-ray data acquired by the Swift and XMM-Newton satellites in the same period. The WEBT and satellite observations allow us to detail the synchrotron emission bump in the source spectral energy distribution (SED). In the optical, we found a general bluer-when-brighter trend. The X-ray spectrum remained stable during 2013, but a comparison with previous observations suggests that it becomes harder when the X-ray flux increases. The long XMM-Newton exposure reveals a curved X-ray spectrum. In the SED, the XMM-Newton data show a hard near-UV spectrum, while Swift data display a softer shape that is confirmed by previous Hubble Space Telescope/Cosmic Origins Spectrograph and International Ultraviolet Explorer observations. Polynomial fits to the optical-X-ray SED show that the synchrotron peak likely lies in the 4-30eV energy range, with a general shift towards higher frequencies for increasing X-ray brightness. However, the UV and X-ray spectra do not connect smoothly. Possible interpretations include: (i) orientation effects, (ii) additional absorption, (iii) multiple emission components, and (iv) a peculiar energy distribution of relativistic electrons. We discuss the first possibility in terms of an inhomogeneous helical jet model

Мавзулар

Astrophysics and Cosmic Phenomena Astrophysical Phenomena and Observations Dark Matter and Cosmic Phenomena

Идентификаторлар

DOI: 10.1093/mnras/stv1884

Иқтибослар ва манбалар

3 та иқтибос 71 та фойдаланилган манба

Кўрсаткичлар — AkademScholar · Тез орада