Research output: Contribution to journal › Article › peer-review
- 1602.08869v1
Accepted author manuscript, 306 KB, PDF document
- aa27817-15
Final published version, 281 KB, PDF document
- M. Giroletti
- F. Massaro
- R. D'Abrusco
- R. Lico
- D. Burlon
- N. Hurley-Walker
- M. Johnston-Hollitt
- J. Morgan
- V. Pavlidou
- M. Bell
- G. Bernardi
- R. Bhat
- J. D. Bowman
- F. Briggs
- R. J. Cappallo
- B. E. Corey
- A. A. Deshpande
- A. Ewall-Rice
- D. Emrich
- B. M. Gaensler
- And 37 others
- R. Goeke
- L. J. Greenhill
- B. J. Hazelton
- L. Hindson
- D. L. Kaplan
- J. C. Kasper
- E. Kratzenberg
- L. Feng
- D. Jacobs
- N. Kurdryavtseva
- E. Lenc
- C. J. Lonsdale
- M. J. Lynch
- B. McKinley
- S. R. McWhirter
- D. A. Mitchell
- M. F. Morales
- E. Morgan
- D. Oberoi
- A. R. Offringa
- S. M. Ord
- B. Pindor
- T. Prabu
- P. Procopio
- J. Riding
- A. E. E. Rogers
- A. Roshi
- N. Udaya Shankar
- K. S. Srivani
- R. Subrahmanyan
- S. J. Tingay
- M. Waterson
- R. B. Wayth
- R. L. Webster
- A. R. Whitney
- A. Williams
- C. L. Williams
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Original language | English |
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Article number | A141 |
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Number of pages | 9 |
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Journal | Astronomy & Astrophysics |
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Volume | 588 |
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Early online date | 1 Apr 2016 |
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DOIs | |
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Publication status | E-pub ahead of print - 1 Apr 2016 |
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Abstract
Low-frequency radio arrays are opening a new window for the study of the sky, both to study new phenomena and to better characterize known source classes. Being flat-spectrum sources, blazars are so far poorly studied at low radio frequencies. We characterize the spectral properties of the blazar population at low radio frequency compare the radio and high-energy properties of the gamma-ray blazar population, and search for radio counterparts of unidentified gamma-ray sources. We cross-correlated the 6,100 deg^2 Murchison Widefield Array Commissioning Survey catalogue with the Roma blazar catalogue, the third catalogue of active galactic nuclei detected by Fermi-LAT, and the unidentified members of the entire third catalogue of gamma-ray sources detected by \fermilat. When available, we also added high-frequency radio data from the Australia Telescope 20 GHz catalogue. We find low-frequency counterparts for 186 out of 517 (36%) blazars, 79 out of 174 (45%) gamma-ray blazars, and 8 out of 73 (11%) gamma-ray blazar candidates. The mean low-frequency (120--180 MHz) blazar spectral index is $\langle \alpha_\mathrm{low} \rangle=0.57\pm0.02$: blazar spectra are flatter than the rest of the population of low-frequency sources, but are steeper than at $\sim$GHz frequencies. Low-frequency radio flux density and gamma-ray energy flux display a mildly significant and broadly scattered correlation. Ten unidentified gamma-ray sources have a (probably fortuitous) positional match with low radio frequency sources. Low-frequency radio astronomy provides important information about sources with a flat radio spectrum and high energy. However, the relatively low sensitivity of the present surveys still misses a significant fraction of these objects. Upcoming deeper surveys, such as the GaLactic and Extragalactic All-Sky MWA (GLEAM) survey, will provide further insight into this population.
Notes
This is the accepted version of the following article: Giroletti, M. et al., A&A, 588 (2016) A141, which has been published in final form at DOI: http://dx.doi.org/10.1051/0004-6361/201527817. This article may be used for non-commercial purposes in accordance with the EDP Sciences self-archiving policies.
ID: 10290895