University of Hertfordshire

LOFAR discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45

Research output: Contribution to journalArticle

Standard

LOFAR discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45. / Cassano, R.; Botteon, A.; Gennaro, G. Di; Brunetti, G.; Sereno, M.; Shimwell, T. W.; Weeren, R. J. van; Brüggen, M.; Gastaldello, F.; Izzo, L.; Bîrzan, L.; Bonafede, A.; Cuciti, V.; Gasperin, F. de; Rötttgering, H. J. A.; Hardcastle, M.; Mechev, A. P.; Tasse, C.

In: Astrophysical Journal Letters, 24.07.2019.

Research output: Contribution to journalArticle

Harvard

Cassano, R, Botteon, A, Gennaro, GD, Brunetti, G, Sereno, M, Shimwell, TW, Weeren, RJV, Brüggen, M, Gastaldello, F, Izzo, L, Bîrzan, L, Bonafede, A, Cuciti, V, Gasperin, FD, Rötttgering, HJA, Hardcastle, M, Mechev, AP & Tasse, C 2019, 'LOFAR discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45', Astrophysical Journal Letters.

APA

Cassano, R., Botteon, A., Gennaro, G. D., Brunetti, G., Sereno, M., Shimwell, T. W., ... Tasse, C. (Accepted/In press). LOFAR discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45. Astrophysical Journal Letters.

Vancouver

Cassano R, Botteon A, Gennaro GD, Brunetti G, Sereno M, Shimwell TW et al. LOFAR discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45. Astrophysical Journal Letters. 2019 Jul 24.

Author

Cassano, R. ; Botteon, A. ; Gennaro, G. Di ; Brunetti, G. ; Sereno, M. ; Shimwell, T. W. ; Weeren, R. J. van ; Brüggen, M. ; Gastaldello, F. ; Izzo, L. ; Bîrzan, L. ; Bonafede, A. ; Cuciti, V. ; Gasperin, F. de ; Rötttgering, H. J. A. ; Hardcastle, M. ; Mechev, A. P. ; Tasse, C. / LOFAR discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45. In: Astrophysical Journal Letters. 2019.

Bibtex

title = "LOFAR discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45",
abstract = "In this Letter, we report the discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45 ($z=0.616$) with the LOw Frequency ARray (LOFAR) at 120-168 MHz. This is one of the most distant radio halos discovered so far. The diffuse emission extends over $\sim$ 1 Mpc and has a morphology similar to that of the X-ray emission as revealed by XMM-Newton data. The halo is very faint at higher frequencies and is barely detected by follow-up 1-2 GHz Karl G.~Jansky Very Large Array (JVLA) observations, which enable us to constrain the radio spectral index to be $\alpha\leq 1.5-1.6$, i.e.; with properties between canonical and ultra-steep spectrum radio halos. Radio halos are currently explained as synchrotron radiation from relativistic electrons that are re-accelerated in the intra-cluster medium (ICM) by turbulence driven by energetic mergers. We show that in such a framework radio halos are expected to be relatively common at $\sim150$ MHz ($\sim30-60\{\%}$) in clusters with mass and redshift similar to PSZ2 G099.86+58.45; however, at least 2/3 of these radio halos should have steep spectrum and thus be very faint above $\sim 1$ GHz frequencies. Furthermore, since the luminosity of radio halos at high redshift depends strongly on the magnetic field strength in the hosting clusters, future LOFAR observations will also provide vital information on the origin and amplification of magnetic fields in galaxy clusters.",
keywords = "astro-ph.GA, astro-ph.CO",
author = "R. Cassano and A. Botteon and Gennaro, {G. Di} and G. Brunetti and M. Sereno and Shimwell, {T. W.} and Weeren, {R. J. van} and M. Br{\"u}ggen and F. Gastaldello and L. Izzo and L. B{\^i}rzan and A. Bonafede and V. Cuciti and Gasperin, {F. de} and R{\"o}tttgering, {H. J. A.} and M. Hardcastle and Mechev, {A. P.} and C. Tasse",
note = "6 pages, 3 figures, accepted (2019, July 17) for publication in ApJ Letter",
year = "2019",
month = "7",
day = "24",
language = "English",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "IOP Publishing Ltd.",

}

RIS

TY - JOUR

T1 - LOFAR discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45

AU - Cassano, R.

AU - Botteon, A.

AU - Gennaro, G. Di

AU - Brunetti, G.

AU - Sereno, M.

AU - Shimwell, T. W.

AU - Weeren, R. J. van

AU - Brüggen, M.

AU - Gastaldello, F.

AU - Izzo, L.

AU - Bîrzan, L.

AU - Bonafede, A.

AU - Cuciti, V.

AU - Gasperin, F. de

AU - Rötttgering, H. J. A.

AU - Hardcastle, M.

AU - Mechev, A. P.

AU - Tasse, C.

N1 - 6 pages, 3 figures, accepted (2019, July 17) for publication in ApJ Letter

PY - 2019/7/24

Y1 - 2019/7/24

N2 - In this Letter, we report the discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45 ($z=0.616$) with the LOw Frequency ARray (LOFAR) at 120-168 MHz. This is one of the most distant radio halos discovered so far. The diffuse emission extends over $\sim$ 1 Mpc and has a morphology similar to that of the X-ray emission as revealed by XMM-Newton data. The halo is very faint at higher frequencies and is barely detected by follow-up 1-2 GHz Karl G.~Jansky Very Large Array (JVLA) observations, which enable us to constrain the radio spectral index to be $\alpha\leq 1.5-1.6$, i.e.; with properties between canonical and ultra-steep spectrum radio halos. Radio halos are currently explained as synchrotron radiation from relativistic electrons that are re-accelerated in the intra-cluster medium (ICM) by turbulence driven by energetic mergers. We show that in such a framework radio halos are expected to be relatively common at $\sim150$ MHz ($\sim30-60\%$) in clusters with mass and redshift similar to PSZ2 G099.86+58.45; however, at least 2/3 of these radio halos should have steep spectrum and thus be very faint above $\sim 1$ GHz frequencies. Furthermore, since the luminosity of radio halos at high redshift depends strongly on the magnetic field strength in the hosting clusters, future LOFAR observations will also provide vital information on the origin and amplification of magnetic fields in galaxy clusters.

AB - In this Letter, we report the discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45 ($z=0.616$) with the LOw Frequency ARray (LOFAR) at 120-168 MHz. This is one of the most distant radio halos discovered so far. The diffuse emission extends over $\sim$ 1 Mpc and has a morphology similar to that of the X-ray emission as revealed by XMM-Newton data. The halo is very faint at higher frequencies and is barely detected by follow-up 1-2 GHz Karl G.~Jansky Very Large Array (JVLA) observations, which enable us to constrain the radio spectral index to be $\alpha\leq 1.5-1.6$, i.e.; with properties between canonical and ultra-steep spectrum radio halos. Radio halos are currently explained as synchrotron radiation from relativistic electrons that are re-accelerated in the intra-cluster medium (ICM) by turbulence driven by energetic mergers. We show that in such a framework radio halos are expected to be relatively common at $\sim150$ MHz ($\sim30-60\%$) in clusters with mass and redshift similar to PSZ2 G099.86+58.45; however, at least 2/3 of these radio halos should have steep spectrum and thus be very faint above $\sim 1$ GHz frequencies. Furthermore, since the luminosity of radio halos at high redshift depends strongly on the magnetic field strength in the hosting clusters, future LOFAR observations will also provide vital information on the origin and amplification of magnetic fields in galaxy clusters.

KW - astro-ph.GA

KW - astro-ph.CO

M3 - Article

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

ER -