Long-Term multi-wavelength study of 1ES 0647+250

Loading...
Thumbnail Image

Access rights

openAccess

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2023-02-01

Major/Subject

Mcode

Degree programme

Language

en

Pages

20

Series

Astronomy and Astrophysics, Volume 670

Abstract

Context. The BL Lac object 1ES 0647+250 is one of the few distant ?-ray emitting blazars detected at very high energies (VHEs; 100 GeV) during a non-flaring state. It was detected with the MAGIC telescopes during a period of low activity in the years 2009 2011 as well as during three flaring activities in the years 2014, 2019, and 2020, with the highest VHE flux in the last epoch. An extensive multi-instrument data set was collected as part of several coordinated observing campaigns over these years. Aims. We aim to characterise the long-Term multi-band flux variability of 1ES 0647+250, as well as its broadband spectral energy distribution (SED) during four distinct activity states selected in four different epochs, in order to constrain the physical parameters of the blazar emission region under certain assumptions. Methods. We evaluated the variability and correlation of the emission in the different energy bands with the fractional variability and the Z-Transformed discrete correlation function, as well as its spectral evolution in X-rays and ? rays. Owing to the controversy in the redshift measurements of 1ES 0647+250 reported in the literature, we also estimated its distance in an indirect manner through a comparison of the GeV and TeV spectra from simultaneous observations with Fermi-LAT and MAGIC during the strongest flaring activity detected to date. Moreover, we interpret the SEDs from the four distinct activity states within the framework of one-component and two-component leptonic models, proposing specific scenarios that are able to reproduce the available multi-instrument data. Results. We find significant long-Term variability, especially in X-rays and VHE ? rays. Furthermore, significant (3 4I) correlations were found between the radio, optical, and high-energy (HE) ?-ray fluxes, with the radio emission delayed by about 400 days with respect to the optical and ?-ray bands. The spectral analysis reveals a harder-when-brighter trend during the non-flaring state in the X-ray domain. However, no clear patterns were observed for either the enhanced states or the HE (30 MeV < E < 100 GeV) and VHE ?-ray emission of the source. The indirect estimation of the redshift yielded a value of z = 0.45 ± 0.05, which is compatible with some of the values reported in the literature. The SEDs related to the low-Activity state and the three flaring states of 1ES 0647+250 can be described reasonably well with the both one-component and two-component leptonic scenarios. However, the long-Term correlations indicate the need for an additional radio-producing region located about 3.6 pc downstream from the gamma-ray producing region.

Description

Funding Information: We want to thank the anonymous referee for her/his useful comments and discussion. We would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF, MPG and HGF; the Italian INFN and INAF; the Swiss National Fund SNF; the grants PID2019-104114RB-C31, PID2019-104114RB-C32, PID2019-104114RB-C33, PID2019-105510GB-C31, PID2019-107847RB-C41, PID2019-107847RB-C42, PID2019-107847RB-C44, PID2019-107988GB-C22 funded by MCIN/AEI/10.13039/501100011033; the Indian Department of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-400/18.12.2020 and the Academy of Finland grant nr. 320045 is gratefully acknowledged. This work was also been supported by Centros de Excelencia “Severo Ochoa” y Unidades “María de Maeztu” program of the MCIN/AEI/ 10.13039/501100011033 (SEV-2016-0588, SEV-2017-0709, CEX2019-000920-S, CEX2019-000918-M, MDM-2015-0509-18-2) and by the CERCA institution of the Generalitat de Catalunya; by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project uniri-prirod-18-48; by the DFG Collaborative Research Centers SFB1491 and SFB876/C3; the Polish National Research Centre grant UMO-2016/22/M/ST9/00382; and by the Brazilian MCTIC, CNPq and FAPERJ. The Fermi-LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat à l’Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucléaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nuclearein Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K.A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d’Etudes Spatiales in France. This work performed in part under DOE Contract DE-AC02-76SF00515. The authors acknowledge the use of public data from the Swift data archive. This work makes use of observations from the KVA telescope. This work makes use of observations from the Liverpool Telescope, operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. This work makes use of observations from the Las Cumbres Observatory global telescope network. This article is based on observations made in the Observatorios de Canarias del IAC with the telescope PIRATE operated on the island of Tenerife by the Open University in the Observatorio del Teide. This research has made use of data from the OVRO 40-m monitoring program (Richards et al. 2011), supported by private funding from the California Insitute of Technology and the Max Planck Institute for Radio Astronomy, and by NASA grants NNX08AW31G, NNX11A043G, and NNX14AQ89G and NSF grants AST-0808050 and AST- 1109911. Part of this work is based on archival data, software, or online services provided by the Space Science Data Centre – ASI. D.P. acknowledges support from the Deutsche Forschungs gemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC-2094 – 390783311. T.H. was supported by the Academy of Finland projects 317383, 320085, 322535, and 345899. S.K. acknowledges support from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme under grant agreement No. 771282. W.M. gratefully acknowledges support by the ANID BASAL projects ACE210002 and FB210003, and FONDECYT 11190853. R.R. acknowledges support from ANID BASAL projects ACE210002 and FB210003, and ANID Fondecyt 1181620. Author contribution: J. A. Acosta Pulido: Las Cumbres, PIRATE and Liverpool telescope data reduction; D. Dorner: project management, coordinating MAGIC observations, theoretical interpretation, coordination of MWL data analysis, drafting the manuscript; V. Fallah Ramazani: modelling, optical data analysis, theoretical interpretation, drafting the manuscript; T. Hovatta: OVRO data analysis; S. Kiehlmann: OVRO data analysis; C. Leto: Swift data analysis; D. Morcuende: VHE γ-ray data analysis, redshift estimation, drafting the manuscript; J. Otero-Santos: VHE γ-ray data analysis, redshift estimation, modelling, variability and cross-correlation analysis, drafting the manuscript; D. Paneque: coordinating MAGIC observations, theoretical interpretation, Fermi-LAT data analysis, coordination of MWL data analysis, drafting the manuscript; M. Perri: Swift data analysis; E. Prandini: redshift estimation; A. C. S. Readhead: OVRO data analysis; F. Verrecchia: Swift data analysis. The rest of the authors have contributed in one or several of the following ways: design, construction, maintenance and operation of the instrument(s) used to acquire the data; preparation and/or evaluation of the observation proposals; data acquisition, processing, calibration and/or reduction; production of analysis tools and/or related Monte Carlo simulations; discussion and approval of the contents of the draft. Publisher Copyright: © Authors 2023

Keywords

BL Lacertae objects: individual: 1ES 0647+250, Galaxies: Active, Galaxies: jets, Gamma rays: galaxies

Other note

Citation

Acciari, V A, Aniello, T, Ansoldi, S, Antonelli, L A, Arbet Engels, A, Arcaro, C, Artero, M, Asano, K, Baack, D, Babia, A, Baquero, A, Barres De Almeida, U, Batkoviä, I, Becerra González, J, Bednarek, W, Bernardini, E, Hovatta, T & MAGIC Collaboration 2023, ' Long-Term multi-wavelength study of 1ES 0647+250 ', Astronomy and Astrophysics, vol. 670, A49 . https://doi.org/10.1051/0004-6361/202244477