# University of Hertfordshire

## The intergalactic magnetic field probed by a giant radio galaxy

Research output: Contribution to journalArticlepeer-review

### Standard

The intergalactic magnetic field probed by a giant radio galaxy. / O'Sullivan, S. P.; Machalski, J.; Eck, C. L. Van; Heald, G.; Brueggen, M.; Fynbo, J. P. U.; Heintz, K. E.; Lara-Lopez, M. A.; Vacca, V.; Hardcastle, M. J.; Shimwell, T. W.; Tasse, C.; Vazza, F.; Andernach, H.; Birkinshaw, M.; Haverkorn, M.; Horellou, C.; Williams, W. L.; Harwood, J. J.; Brunetti, G.; Anderson, J. M.; Mao, S. A.; Nikiel-Wroczynski, B.; Takahashi, K.; Carretti, E.; Vernstrom, T.; Weeren, R. J. van; Orru, E.; Morabito, L. K.; Callingham, J. R.

In: Astronomy & Astrophysics, 09.10.2018.

Research output: Contribution to journalArticlepeer-review

### Harvard

O'Sullivan, SP, Machalski, J, Eck, CLV, Heald, G, Brueggen, M, Fynbo, JPU, Heintz, KE, Lara-Lopez, MA, Vacca, V, Hardcastle, MJ, Shimwell, TW, Tasse, C, Vazza, F, Andernach, H, Birkinshaw, M, Haverkorn, M, Horellou, C, Williams, WL, Harwood, JJ, Brunetti, G, Anderson, JM, Mao, SA, Nikiel-Wroczynski, B, Takahashi, K, Carretti, E, Vernstrom, T, Weeren, RJV, Orru, E, Morabito, LK & Callingham, JR 2018, 'The intergalactic magnetic field probed by a giant radio galaxy', Astronomy & Astrophysics. https://doi.org/10.1051/0004-6361/201833832

### APA

O'Sullivan, S. P., Machalski, J., Eck, C. L. V., Heald, G., Brueggen, M., Fynbo, J. P. U., Heintz, K. E., Lara-Lopez, M. A., Vacca, V., Hardcastle, M. J., Shimwell, T. W., Tasse, C., Vazza, F., Andernach, H., Birkinshaw, M., Haverkorn, M., Horellou, C., Williams, W. L., Harwood, J. J., ... Callingham, J. R. (2018). The intergalactic magnetic field probed by a giant radio galaxy. Astronomy & Astrophysics. https://doi.org/10.1051/0004-6361/201833832

### Vancouver

O'Sullivan SP, Machalski J, Eck CLV, Heald G, Brueggen M, Fynbo JPU et al. The intergalactic magnetic field probed by a giant radio galaxy. Astronomy & Astrophysics. 2018 Oct 9. https://doi.org/10.1051/0004-6361/201833832

### Author

O'Sullivan, S. P. ; Machalski, J. ; Eck, C. L. Van ; Heald, G. ; Brueggen, M. ; Fynbo, J. P. U. ; Heintz, K. E. ; Lara-Lopez, M. A. ; Vacca, V. ; Hardcastle, M. J. ; Shimwell, T. W. ; Tasse, C. ; Vazza, F. ; Andernach, H. ; Birkinshaw, M. ; Haverkorn, M. ; Horellou, C. ; Williams, W. L. ; Harwood, J. J. ; Brunetti, G. ; Anderson, J. M. ; Mao, S. A. ; Nikiel-Wroczynski, B. ; Takahashi, K. ; Carretti, E. ; Vernstrom, T. ; Weeren, R. J. van ; Orru, E. ; Morabito, L. K. ; Callingham, J. R. / The intergalactic magnetic field probed by a giant radio galaxy. In: Astronomy & Astrophysics. 2018.

### Bibtex

@article{6f187b204f554b468b7fd7c6f3f5c4bd,
title = "The intergalactic magnetic field probed by a giant radio galaxy",
abstract = "Cosmological simulations predict that an intergalactic magnetic field (IGMF) pervades the large scale structure (LSS) of the Universe. Measuring the IGMF is important to determine its origin (i.e. primordial or otherwise). Using data from the LOFAR Two Metre Sky Survey (LoTSS), we present the Faraday rotation measure (RM) and depolarisation properties of the giant radio galaxy J1235+5317, at a redshift of $z = 0.34$ and 3.38 Mpc in size. We find a mean RM difference between the lobes of $2.5\pm0.1$ rad/m$^2$ , in addition to small scale RM variations of ~0.1 rad/m$^2$ . From a catalogue of LSS filaments based on optical spectroscopic observations in the local universe, we find an excess of filaments intersecting the line of sight to only one of the lobes. Associating the entire RM difference to these LSS filaments leads to a gas density-weighted IGMF strength of ~0.3 {\mu}G. However, direct comparison with cosmological simulations of the RM contribution from LSS filaments gives a low probability (~5%) for an RM contribution as large as 2.5 rad/m$^2$ , for the case of IGMF strengths of 10 to 50 nG. It is likely that variations in the RM from the Milky Way (on 11' scales) contribute significantly to the mean RM difference, and a denser RM grid is required to better constrain this contribution. In general, this work demonstrates the potential of the LOFAR telescope to probe the weak signature of the IGMF. Future studies, with thousands of sources with high accuracy RMs from LoTSS, will enable more stringent constraints on the nature of the IGMF. ",
keywords = "astro-ph.HE, astro-ph.CO, astro-ph.GA",
author = "O'Sullivan, {S. P.} and J. Machalski and Eck, {C. L. Van} and G. Heald and M. Brueggen and Fynbo, {J. P. U.} and Heintz, {K. E.} and Lara-Lopez, {M. A.} and V. Vacca and Hardcastle, {M. J.} and Shimwell, {T. W.} and C. Tasse and F. Vazza and H. Andernach and M. Birkinshaw and M. Haverkorn and C. Horellou and Williams, {W. L.} and Harwood, {J. J.} and G. Brunetti and Anderson, {J. M.} and Mao, {S. A.} and B. Nikiel-Wroczynski and K. Takahashi and E. Carretti and T. Vernstrom and Weeren, {R. J. van} and E. Orru and Morabito, {L. K.} and Callingham, {J. R.}",
note = "12 pages, 6 figures, 3 tables. This paper is part of the LOFAR surveys data release 1 and has been accepted for publication in a special edition of A&A that will appear in Feb 2019, volume 622. The catalogues and images from the data release will be publicly available on lofar-surveys.org upon publication of the journal. Reproduced with permission from Astronomy & Astrophysics. {\textcopyright} 2018 ESO",
year = "2018",
month = oct,
day = "9",
doi = "10.1051/0004-6361/201833832",
language = "English",
journal = "Astronomy & Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",

}

### RIS

TY - JOUR

T1 - The intergalactic magnetic field probed by a giant radio galaxy

AU - O'Sullivan, S. P.

AU - Machalski, J.

AU - Eck, C. L. Van

AU - Heald, G.

AU - Brueggen, M.

AU - Fynbo, J. P. U.

AU - Heintz, K. E.

AU - Lara-Lopez, M. A.

AU - Vacca, V.

AU - Hardcastle, M. J.

AU - Shimwell, T. W.

AU - Tasse, C.

AU - Vazza, F.

AU - Andernach, H.

AU - Birkinshaw, M.

AU - Haverkorn, M.

AU - Horellou, C.

AU - Williams, W. L.

AU - Harwood, J. J.

AU - Brunetti, G.

AU - Anderson, J. M.

AU - Mao, S. A.

AU - Nikiel-Wroczynski, B.

AU - Takahashi, K.

AU - Carretti, E.

AU - Vernstrom, T.

AU - Weeren, R. J. van

AU - Orru, E.

AU - Morabito, L. K.

AU - Callingham, J. R.

N1 - 12 pages, 6 figures, 3 tables. This paper is part of the LOFAR surveys data release 1 and has been accepted for publication in a special edition of A&A that will appear in Feb 2019, volume 622. The catalogues and images from the data release will be publicly available on lofar-surveys.org upon publication of the journal. Reproduced with permission from Astronomy & Astrophysics. © 2018 ESO

PY - 2018/10/9

Y1 - 2018/10/9

N2 - Cosmological simulations predict that an intergalactic magnetic field (IGMF) pervades the large scale structure (LSS) of the Universe. Measuring the IGMF is important to determine its origin (i.e. primordial or otherwise). Using data from the LOFAR Two Metre Sky Survey (LoTSS), we present the Faraday rotation measure (RM) and depolarisation properties of the giant radio galaxy J1235+5317, at a redshift of $z = 0.34$ and 3.38 Mpc in size. We find a mean RM difference between the lobes of $2.5\pm0.1$ rad/m$^2$ , in addition to small scale RM variations of ~0.1 rad/m$^2$ . From a catalogue of LSS filaments based on optical spectroscopic observations in the local universe, we find an excess of filaments intersecting the line of sight to only one of the lobes. Associating the entire RM difference to these LSS filaments leads to a gas density-weighted IGMF strength of ~0.3 {\mu}G. However, direct comparison with cosmological simulations of the RM contribution from LSS filaments gives a low probability (~5%) for an RM contribution as large as 2.5 rad/m$^2$ , for the case of IGMF strengths of 10 to 50 nG. It is likely that variations in the RM from the Milky Way (on 11' scales) contribute significantly to the mean RM difference, and a denser RM grid is required to better constrain this contribution. In general, this work demonstrates the potential of the LOFAR telescope to probe the weak signature of the IGMF. Future studies, with thousands of sources with high accuracy RMs from LoTSS, will enable more stringent constraints on the nature of the IGMF.

AB - Cosmological simulations predict that an intergalactic magnetic field (IGMF) pervades the large scale structure (LSS) of the Universe. Measuring the IGMF is important to determine its origin (i.e. primordial or otherwise). Using data from the LOFAR Two Metre Sky Survey (LoTSS), we present the Faraday rotation measure (RM) and depolarisation properties of the giant radio galaxy J1235+5317, at a redshift of $z = 0.34$ and 3.38 Mpc in size. We find a mean RM difference between the lobes of $2.5\pm0.1$ rad/m$^2$ , in addition to small scale RM variations of ~0.1 rad/m$^2$ . From a catalogue of LSS filaments based on optical spectroscopic observations in the local universe, we find an excess of filaments intersecting the line of sight to only one of the lobes. Associating the entire RM difference to these LSS filaments leads to a gas density-weighted IGMF strength of ~0.3 {\mu}G. However, direct comparison with cosmological simulations of the RM contribution from LSS filaments gives a low probability (~5%) for an RM contribution as large as 2.5 rad/m$^2$ , for the case of IGMF strengths of 10 to 50 nG. It is likely that variations in the RM from the Milky Way (on 11' scales) contribute significantly to the mean RM difference, and a denser RM grid is required to better constrain this contribution. In general, this work demonstrates the potential of the LOFAR telescope to probe the weak signature of the IGMF. Future studies, with thousands of sources with high accuracy RMs from LoTSS, will enable more stringent constraints on the nature of the IGMF.

KW - astro-ph.HE

KW - astro-ph.CO

KW - astro-ph.GA

U2 - 10.1051/0004-6361/201833832

DO - 10.1051/0004-6361/201833832

M3 - Article

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

ER -