Sardinia Radio Telescope observations of Abell 194. The intra-cluster magnetic field power spectrum
| Autor: | Franco Vazza, Matteo Murgia, Gianni Bernardi, F. de Gasperin, Melanie Johnston-Hollitt, Raimondo Concu, Federica Govoni, M. Rossetti, Torsten A. Ensslin, Luigina Feretti, Tracy E. Clarke, Richard A. Perley, Rosita Paladino, Chiara Ferrari, M. Brienza, Marisa Girardi, G. B. Taylor, G. Giovannini, F. Gastaldello, H. Junklewitz, V. Vacca, W. Boschin, L. Gregorini, P. Parma, Sergio Poppi, Ettore Carretti, Emanuela Orrú, G. Valente, Annalisa Bonafede, S. Colafrancesco, Dominique Eckert, F. Loi, Andrea Melis |
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| Přispěvatelé: | Astronomy, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Govoni, F., Murgia, M., Vacca, V., Loi, F., Girardi, M., Gastaldello, F., Giovannini, G., Feretti, L., Paladino, R., Carretti, E., Concu, R., Melis, A., Poppi, S., Valente, G., Bernardi, G., Bonafede, A., Boschin, W., Brienza, M., Clarke, T. E., Colafrancesco, S., De Gasperin, F., Eckert, D., Enã lin, T. A., Ferrari, C., Gregorini, L., Johnston-Hollitt, M., Junklewitz, H., Orrã¹, E., Parma, P., Perley, R., Rossetti, M., B Taylor, G., Vazza, F., Joseph Louis LAGRANGE ( LAGRANGE ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Enßlin, T. A., Orrù, E. |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
VELOCITY DISPERSIONS
Electron density Cosmology and Nongalactic Astrophysics (astro-ph.CO) Large-scale structure of Universe Radio galaxy [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph] FOS: Physical sciences REPRESENTATIVE SAMPLE Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics clusters: general [Galaxies] magnetic fields 01 natural sciences Power law Radio telescope 0103 physical sciences FARADAY-ROTATION MAPS 010303 astronomy & astrophysics Galaxy cluster Astrophysics::Galaxy Astrophysics galaxies: clusters: individual: Abell 194 VLA OBSERVATIONS Physics 010308 nuclear & particles physics SCALE-INDEPENDENT METHOD Spectral density RICH CLUSTERS Astronomy and Astrophysics Astronomy and Astrophysic Polarization (waves) Astrophysics - Astrophysics of Galaxies clusters: individual: Abell 194 [Galaxies] Magnetic field Space and Planetary Science galaxies: clusters: general Astrophysics of Galaxies (astro-ph.GA) ALL-SKY SURVEY X-RAY large-scale structure of Universe HYDRA-A CLUSTER [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] GALAXY CLUSTERS Galaxies: clusters: general Galaxies: clusters: individual: Abell 194 Magnetic fields Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Astronomy and astrophysics, 603:A122. EDP Sciences Astronomy & Astrophysics (0004-6361), 603, A122 Astron.Astrophys. Astron.Astrophys., 2017, 603, pp.A122. ⟨10.1051/0004-6361/201630349⟩ Astron.Astrophys., 2017, 603, pp.A122. 〈10.1051/0004-6361/201630349〉 Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2017, 603, pp.A122. ⟨10.1051/0004-6361/201630349⟩ NASA Astrophysics Data System |
| ISSN: | 0004-6361 |
| DOI: | 10.1051/0004-6361/201630349⟩ |
| Popis: | We study the intra-cluster magnetic field in the poor galaxy cluster Abell 194 by complementing radio data, at different frequencies, with data in the optical and X-ray bands. We analyze new total intensity and polarization observations of Abell 194 obtained with the Sardinia Radio Telescope (SRT). We use the SRT data in combination with archival Very Large Array observations to derive both the spectral aging and Rotation Measure (RM) images of the radio galaxies 3C40A and 3C40B embedded in Abell 194. The optical analysis indicates that Abell 194 does not show a major and recent cluster merger, but rather agrees with a scenario of accretion of small groups. Under the minimum energy assumption, the lifetimes of synchrotron electrons in 3C40B measured from the spectral break are found to be 157 Myrs. The break frequency image and the electron density profile inferred from the X-ray emission are used in combination with the RM data to constrain the intra-cluster magnetic field power spectrum. By assuming a Kolmogorov power law power spectrum, we find that the RM data in Abell 194 are well described by a magnetic field with a maximum scale of fluctuations of Lambda_max=64 kpc and a central magnetic field strength of =1.5 microG. Further out, the field decreases with the radius following the gas density to the power of eta=1.1. Comparing Abell 194 with a small sample of galaxy clusters, there is a hint of a trend between central electron densities and magnetic field strengths. Comment: Accepted by Astronomy and Astrophysics, 29 pages, 15 figures. Abstract abridged. A pdf version with high-quality figures can be downloaded from http://erg.oa-cagliari.inaf.it/preprints/a194_paper.pdf |
| Databáze: | OpenAIRE |
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