M87 at metre wavelengths: the LOFAR picture

F. de Gasperin, E. Orrú, M. Murgia, A. Merloni, H. Falcke, R. Beck, R. Beswick, L. Birzan, A. Bonafede, M. Brüggen, G. Brunetti, K. Chyzy, J. Conway, J.H. Croston, T. Ensslin, C. Ferrari, G. Heald, S. Heidenreich, N. Jackson, G. Macario & 75 others J. McKean, G. Miley, R. Morganti, A. Offringa, R. Pizzo, D. Rafferty, H. Röttgering, A. Shulevski, M. Steinmetz, C. Tasse, S. van der Tol, W. van Driel, R.J. van Weeren, J.E. van Zwieten, A. Alexov, J. Anderson, A. Asgekar, M. Avruch, M. Bell, M.R. Bell, M.J. Bentum, G. Bernardi, P. Best, F. Breitling, J.W. Broderick, A. Butcher, B. Ciardi, R.J. Dettmar, J. Eislöffel, W. Frieswijk, H. Gankema, M. Garrett, M. Gerbers, J.M. Griessmeier, A.W. Gunst, T.E. Hassall, J. Hessels, M. Hoeft, A. Horneffer, A. Karastergiou, J. Köhler, Y. Koopman, M. Kuniyoshi, G. Kuper, P. Maat, G. Mann, M. Mevius, D.D. Mulcahy, H. Munk, R. Nijboer, J. Noordam, H. Paas, M. Pandey, V.N. Pandey, A. Polatidis, W. Reich, A.P. Schoenmakers, J. Sluman, O. Smirnov, C. Sobey, B. Stappers, J. Swinbank, M. Tagger, Y. Tang, I. van Bemmel, W. van Cappellen, A.P. van Duin, M. van Haarlem, J. van Leeuwen, R. Vermeulen, C. Vocks, S. White, M. Wise, O. Wucknitz, P. Zarka

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Abstract

Context: M 87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4 × 109 M⊙, whose activity is responsible for the extended (80 kpc) radio lobes that surround the galaxy. The energy generated by matter falling onto the central black hole is ejected and transferred to the intra-cluster medium via a relativistic jet and morphologically complex systems of buoyant bubbles, which rise towards the edges of the extended halo.

Aims: To place constraints on past activity cycles of the active nucleus, images of M 87 were produced at low radio frequencies never explored before at these high spatial resolution and dynamic range. To disentangle different synchrotron models and place constraints on source magnetic field, age and energetics, we also performed a detailed spectral analysis of M 87 extended radio-halo.

Methods: We present the first observations made with the new Low-Frequency Array (LOFAR) of M 87 at frequencies down to 20 MHz. Three observations were conducted, at 15−30 MHz, 30−77 MHz and 116−162 MHz. We used these observations together with archival data to produce a low-frequency spectral index map and to perform a spectral analysis in the wide frequency range 30 MHz–10 GHz.

Results: We do not find any sign of new extended emissions; on the contrary the source appears well confined by the high pressure of the intra-cluster medium. A continuous injection of relativistic electrons is the model that best fits our data, and provides a scenario in which the lobes are still supplied by fresh relativistic particles from the active galactic nuclei. We suggest that the discrepancy between the low-frequency radio-spectral slope in the core and in the halo implies a strong adiabatic expansion of the plasma as soon as it leaves the core area. The extended halo has an equipartition magnetic field strength of ≃10 μG, which increases to ≃13 μG in the zones where the particle flows are more active. The continuous injection model for synchrotron ageing provides an age for the halo of ≃40 Myr, which in turn provides a jet kinetic power of 6−10 × 1044 erg s-1.
Original languageEnglish
Pages (from-to)1-20
Number of pages20
JournalAstronomy & astrophysics
Volume547
Issue numberA56
DOIs
Publication statusPublished - 26 Oct 2012

Fingerprint

halos
radio
low frequencies
wavelength
wavelengths
spectral analysis
lobes
spectrum analysis
magnetic field
synchrotrons
injection
erg
harbors
relativistic particles
bubble
elliptical galaxies
harbor
spatial resolution
complex systems
energetics

Keywords

  • individual clusters
  • individual galaxies
  • radio continuum
  • EWI-22695
  • M 87
  • IR-83534
  • active galaxies
  • Jets
  • Virgo
  • METIS-296174
  • Non-thermal radiation mechanisms

Cite this

de Gasperin, F., Orrú, E., Murgia, M., Merloni, A., Falcke, H., Beck, R., ... Zarka, P. (2012). M87 at metre wavelengths: the LOFAR picture. Astronomy & astrophysics, 547(A56), 1-20. https://doi.org/10.1051/0004-6361/201220209
de Gasperin, F. ; Orrú, E. ; Murgia, M. ; Merloni, A. ; Falcke, H. ; Beck, R. ; Beswick, R. ; Birzan, L. ; Bonafede, A. ; Brüggen, M. ; Brunetti, G. ; Chyzy, K. ; Conway, J. ; Croston, J.H. ; Ensslin, T. ; Ferrari, C. ; Heald, G. ; Heidenreich, S. ; Jackson, N. ; Macario, G. ; McKean, J. ; Miley, G. ; Morganti, R. ; Offringa, A. ; Pizzo, R. ; Rafferty, D. ; Röttgering, H. ; Shulevski, A. ; Steinmetz, M. ; Tasse, C. ; van der Tol, S. ; van Driel, W. ; van Weeren, R.J. ; van Zwieten, J.E. ; Alexov, A. ; Anderson, J. ; Asgekar, A. ; Avruch, M. ; Bell, M. ; Bell, M.R. ; Bentum, M.J. ; Bernardi, G. ; Best, P. ; Breitling, F. ; Broderick, J.W. ; Butcher, A. ; Ciardi, B. ; Dettmar, R.J. ; Eislöffel, J. ; Frieswijk, W. ; Gankema, H. ; Garrett, M. ; Gerbers, M. ; Griessmeier, J.M. ; Gunst, A.W. ; Hassall, T.E. ; Hessels, J. ; Hoeft, M. ; Horneffer, A. ; Karastergiou, A. ; Köhler, J. ; Koopman, Y. ; Kuniyoshi, M. ; Kuper, G. ; Maat, P. ; Mann, G. ; Mevius, M. ; Mulcahy, D.D. ; Munk, H. ; Nijboer, R. ; Noordam, J. ; Paas, H. ; Pandey, M. ; Pandey, V.N. ; Polatidis, A. ; Reich, W. ; Schoenmakers, A.P. ; Sluman, J. ; Smirnov, O. ; Sobey, C. ; Stappers, B. ; Swinbank, J. ; Tagger, M. ; Tang, Y. ; van Bemmel, I. ; van Cappellen, W. ; van Duin, A.P. ; van Haarlem, M. ; van Leeuwen, J. ; Vermeulen, R. ; Vocks, C. ; White, S. ; Wise, M. ; Wucknitz, O. ; Zarka, P. / M87 at metre wavelengths: the LOFAR picture. In: Astronomy & astrophysics. 2012 ; Vol. 547, No. A56. pp. 1-20.
@article{3fe4a4b16d534d3e81717950f7b01013,
title = "M87 at metre wavelengths: the LOFAR picture",
abstract = "Context: M 87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4 × 109 M⊙, whose activity is responsible for the extended (80 kpc) radio lobes that surround the galaxy. The energy generated by matter falling onto the central black hole is ejected and transferred to the intra-cluster medium via a relativistic jet and morphologically complex systems of buoyant bubbles, which rise towards the edges of the extended halo.Aims: To place constraints on past activity cycles of the active nucleus, images of M 87 were produced at low radio frequencies never explored before at these high spatial resolution and dynamic range. To disentangle different synchrotron models and place constraints on source magnetic field, age and energetics, we also performed a detailed spectral analysis of M 87 extended radio-halo.Methods: We present the first observations made with the new Low-Frequency Array (LOFAR) of M 87 at frequencies down to 20 MHz. Three observations were conducted, at 15−30 MHz, 30−77 MHz and 116−162 MHz. We used these observations together with archival data to produce a low-frequency spectral index map and to perform a spectral analysis in the wide frequency range 30 MHz–10 GHz.Results: We do not find any sign of new extended emissions; on the contrary the source appears well confined by the high pressure of the intra-cluster medium. A continuous injection of relativistic electrons is the model that best fits our data, and provides a scenario in which the lobes are still supplied by fresh relativistic particles from the active galactic nuclei. We suggest that the discrepancy between the low-frequency radio-spectral slope in the core and in the halo implies a strong adiabatic expansion of the plasma as soon as it leaves the core area. The extended halo has an equipartition magnetic field strength of ≃10 μG, which increases to ≃13 μG in the zones where the particle flows are more active. The continuous injection model for synchrotron ageing provides an age for the halo of ≃40 Myr, which in turn provides a jet kinetic power of 6−10 × 1044 erg s-1.",
keywords = "individual clusters, individual galaxies, radio continuum, EWI-22695, M 87, IR-83534, active galaxies, Jets, Virgo, METIS-296174, Non-thermal radiation mechanisms",
author = "{de Gasperin}, F. and E. Orr{\'u} and M. Murgia and A. Merloni and H. Falcke and R. Beck and R. Beswick and L. Birzan and A. Bonafede and M. Br{\"u}ggen and G. Brunetti and K. Chyzy and J. Conway and J.H. Croston and T. Ensslin and C. Ferrari and G. Heald and S. Heidenreich and N. Jackson and G. Macario and J. McKean and G. Miley and R. Morganti and A. Offringa and R. Pizzo and D. Rafferty and H. R{\"o}ttgering and A. Shulevski and M. Steinmetz and C. Tasse and {van der Tol}, S. and {van Driel}, W. and {van Weeren}, R.J. and {van Zwieten}, J.E. and A. Alexov and J. Anderson and A. Asgekar and M. Avruch and M. Bell and M.R. Bell and M.J. Bentum and G. Bernardi and P. Best and F. Breitling and J.W. Broderick and A. Butcher and B. Ciardi and R.J. Dettmar and J. Eisl{\"o}ffel and W. Frieswijk and H. Gankema and M. Garrett and M. Gerbers and J.M. Griessmeier and A.W. Gunst and T.E. Hassall and J. Hessels and M. Hoeft and A. Horneffer and A. Karastergiou and J. K{\"o}hler and Y. Koopman and M. Kuniyoshi and G. Kuper and P. Maat and G. Mann and M. Mevius and D.D. Mulcahy and H. Munk and R. Nijboer and J. Noordam and H. Paas and M. Pandey and V.N. Pandey and A. Polatidis and W. Reich and A.P. Schoenmakers and J. Sluman and O. Smirnov and C. Sobey and B. Stappers and J. Swinbank and M. Tagger and Y. Tang and {van Bemmel}, I. and {van Cappellen}, W. and {van Duin}, A.P. and {van Haarlem}, M. and {van Leeuwen}, J. and R. Vermeulen and C. Vocks and S. White and M. Wise and O. Wucknitz and P. Zarka",
note = "eemcs-eprint-22695",
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doi = "10.1051/0004-6361/201220209",
language = "English",
volume = "547",
pages = "1--20",
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issn = "0004-6361",
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de Gasperin, F, Orrú, E, Murgia, M, Merloni, A, Falcke, H, Beck, R, Beswick, R, Birzan, L, Bonafede, A, Brüggen, M, Brunetti, G, Chyzy, K, Conway, J, Croston, JH, Ensslin, T, Ferrari, C, Heald, G, Heidenreich, S, Jackson, N, Macario, G, McKean, J, Miley, G, Morganti, R, Offringa, A, Pizzo, R, Rafferty, D, Röttgering, H, Shulevski, A, Steinmetz, M, Tasse, C, van der Tol, S, van Driel, W, van Weeren, RJ, van Zwieten, JE, Alexov, A, Anderson, J, Asgekar, A, Avruch, M, Bell, M, Bell, MR, Bentum, MJ, Bernardi, G, Best, P, Breitling, F, Broderick, JW, Butcher, A, Ciardi, B, Dettmar, RJ, Eislöffel, J, Frieswijk, W, Gankema, H, Garrett, M, Gerbers, M, Griessmeier, JM, Gunst, AW, Hassall, TE, Hessels, J, Hoeft, M, Horneffer, A, Karastergiou, A, Köhler, J, Koopman, Y, Kuniyoshi, M, Kuper, G, Maat, P, Mann, G, Mevius, M, Mulcahy, DD, Munk, H, Nijboer, R, Noordam, J, Paas, H, Pandey, M, Pandey, VN, Polatidis, A, Reich, W, Schoenmakers, AP, Sluman, J, Smirnov, O, Sobey, C, Stappers, B, Swinbank, J, Tagger, M, Tang, Y, van Bemmel, I, van Cappellen, W, van Duin, AP, van Haarlem, M, van Leeuwen, J, Vermeulen, R, Vocks, C, White, S, Wise, M, Wucknitz, O & Zarka, P 2012, 'M87 at metre wavelengths: the LOFAR picture' Astronomy & astrophysics, vol. 547, no. A56, pp. 1-20. https://doi.org/10.1051/0004-6361/201220209

M87 at metre wavelengths: the LOFAR picture. / de Gasperin, F.; Orrú, E.; Murgia, M.; Merloni, A.; Falcke, H.; Beck, R.; Beswick, R.; Birzan, L.; Bonafede, A.; Brüggen, M.; Brunetti, G.; Chyzy, K.; Conway, J.; Croston, J.H.; Ensslin, T.; Ferrari, C.; Heald, G.; Heidenreich, S.; Jackson, N.; Macario, G.; McKean, J.; Miley, G.; Morganti, R.; Offringa, A.; Pizzo, R.; Rafferty, D.; Röttgering, H.; Shulevski, A.; Steinmetz, M.; Tasse, C.; van der Tol, S.; van Driel, W.; van Weeren, R.J.; van Zwieten, J.E.; Alexov, A.; Anderson, J.; Asgekar, A.; Avruch, M.; Bell, M.; Bell, M.R.; Bentum, M.J.; Bernardi, G.; Best, P.; Breitling, F.; Broderick, J.W.; Butcher, A.; Ciardi, B.; Dettmar, R.J.; Eislöffel, J.; Frieswijk, W.; Gankema, H.; Garrett, M.; Gerbers, M.; Griessmeier, J.M.; Gunst, A.W.; Hassall, T.E.; Hessels, J.; Hoeft, M.; Horneffer, A.; Karastergiou, A.; Köhler, J.; Koopman, Y.; Kuniyoshi, M.; Kuper, G.; Maat, P.; Mann, G.; Mevius, M.; Mulcahy, D.D.; Munk, H.; Nijboer, R.; Noordam, J.; Paas, H.; Pandey, M.; Pandey, V.N.; Polatidis, A.; Reich, W.; Schoenmakers, A.P.; Sluman, J.; Smirnov, O.; Sobey, C.; Stappers, B.; Swinbank, J.; Tagger, M.; Tang, Y.; van Bemmel, I.; van Cappellen, W.; van Duin, A.P.; van Haarlem, M.; van Leeuwen, J.; Vermeulen, R.; Vocks, C.; White, S.; Wise, M.; Wucknitz, O.; Zarka, P.

In: Astronomy & astrophysics, Vol. 547, No. A56, 26.10.2012, p. 1-20.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - M87 at metre wavelengths: the LOFAR picture

AU - de Gasperin, F.

AU - Orrú, E.

AU - Murgia, M.

AU - Merloni, A.

AU - Falcke, H.

AU - Beck, R.

AU - Beswick, R.

AU - Birzan, L.

AU - Bonafede, A.

AU - Brüggen, M.

AU - Brunetti, G.

AU - Chyzy, K.

AU - Conway, J.

AU - Croston, J.H.

AU - Ensslin, T.

AU - Ferrari, C.

AU - Heald, G.

AU - Heidenreich, S.

AU - Jackson, N.

AU - Macario, G.

AU - McKean, J.

AU - Miley, G.

AU - Morganti, R.

AU - Offringa, A.

AU - Pizzo, R.

AU - Rafferty, D.

AU - Röttgering, H.

AU - Shulevski, A.

AU - Steinmetz, M.

AU - Tasse, C.

AU - van der Tol, S.

AU - van Driel, W.

AU - van Weeren, R.J.

AU - van Zwieten, J.E.

AU - Alexov, A.

AU - Anderson, J.

AU - Asgekar, A.

AU - Avruch, M.

AU - Bell, M.

AU - Bell, M.R.

AU - Bentum, M.J.

AU - Bernardi, G.

AU - Best, P.

AU - Breitling, F.

AU - Broderick, J.W.

AU - Butcher, A.

AU - Ciardi, B.

AU - Dettmar, R.J.

AU - Eislöffel, J.

AU - Frieswijk, W.

AU - Gankema, H.

AU - Garrett, M.

AU - Gerbers, M.

AU - Griessmeier, J.M.

AU - Gunst, A.W.

AU - Hassall, T.E.

AU - Hessels, J.

AU - Hoeft, M.

AU - Horneffer, A.

AU - Karastergiou, A.

AU - Köhler, J.

AU - Koopman, Y.

AU - Kuniyoshi, M.

AU - Kuper, G.

AU - Maat, P.

AU - Mann, G.

AU - Mevius, M.

AU - Mulcahy, D.D.

AU - Munk, H.

AU - Nijboer, R.

AU - Noordam, J.

AU - Paas, H.

AU - Pandey, M.

AU - Pandey, V.N.

AU - Polatidis, A.

AU - Reich, W.

AU - Schoenmakers, A.P.

AU - Sluman, J.

AU - Smirnov, O.

AU - Sobey, C.

AU - Stappers, B.

AU - Swinbank, J.

AU - Tagger, M.

AU - Tang, Y.

AU - van Bemmel, I.

AU - van Cappellen, W.

AU - van Duin, A.P.

AU - van Haarlem, M.

AU - van Leeuwen, J.

AU - Vermeulen, R.

AU - Vocks, C.

AU - White, S.

AU - Wise, M.

AU - Wucknitz, O.

AU - Zarka, P.

N1 - eemcs-eprint-22695

PY - 2012/10/26

Y1 - 2012/10/26

N2 - Context: M 87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4 × 109 M⊙, whose activity is responsible for the extended (80 kpc) radio lobes that surround the galaxy. The energy generated by matter falling onto the central black hole is ejected and transferred to the intra-cluster medium via a relativistic jet and morphologically complex systems of buoyant bubbles, which rise towards the edges of the extended halo.Aims: To place constraints on past activity cycles of the active nucleus, images of M 87 were produced at low radio frequencies never explored before at these high spatial resolution and dynamic range. To disentangle different synchrotron models and place constraints on source magnetic field, age and energetics, we also performed a detailed spectral analysis of M 87 extended radio-halo.Methods: We present the first observations made with the new Low-Frequency Array (LOFAR) of M 87 at frequencies down to 20 MHz. Three observations were conducted, at 15−30 MHz, 30−77 MHz and 116−162 MHz. We used these observations together with archival data to produce a low-frequency spectral index map and to perform a spectral analysis in the wide frequency range 30 MHz–10 GHz.Results: We do not find any sign of new extended emissions; on the contrary the source appears well confined by the high pressure of the intra-cluster medium. A continuous injection of relativistic electrons is the model that best fits our data, and provides a scenario in which the lobes are still supplied by fresh relativistic particles from the active galactic nuclei. We suggest that the discrepancy between the low-frequency radio-spectral slope in the core and in the halo implies a strong adiabatic expansion of the plasma as soon as it leaves the core area. The extended halo has an equipartition magnetic field strength of ≃10 μG, which increases to ≃13 μG in the zones where the particle flows are more active. The continuous injection model for synchrotron ageing provides an age for the halo of ≃40 Myr, which in turn provides a jet kinetic power of 6−10 × 1044 erg s-1.

AB - Context: M 87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4 × 109 M⊙, whose activity is responsible for the extended (80 kpc) radio lobes that surround the galaxy. The energy generated by matter falling onto the central black hole is ejected and transferred to the intra-cluster medium via a relativistic jet and morphologically complex systems of buoyant bubbles, which rise towards the edges of the extended halo.Aims: To place constraints on past activity cycles of the active nucleus, images of M 87 were produced at low radio frequencies never explored before at these high spatial resolution and dynamic range. To disentangle different synchrotron models and place constraints on source magnetic field, age and energetics, we also performed a detailed spectral analysis of M 87 extended radio-halo.Methods: We present the first observations made with the new Low-Frequency Array (LOFAR) of M 87 at frequencies down to 20 MHz. Three observations were conducted, at 15−30 MHz, 30−77 MHz and 116−162 MHz. We used these observations together with archival data to produce a low-frequency spectral index map and to perform a spectral analysis in the wide frequency range 30 MHz–10 GHz.Results: We do not find any sign of new extended emissions; on the contrary the source appears well confined by the high pressure of the intra-cluster medium. A continuous injection of relativistic electrons is the model that best fits our data, and provides a scenario in which the lobes are still supplied by fresh relativistic particles from the active galactic nuclei. We suggest that the discrepancy between the low-frequency radio-spectral slope in the core and in the halo implies a strong adiabatic expansion of the plasma as soon as it leaves the core area. The extended halo has an equipartition magnetic field strength of ≃10 μG, which increases to ≃13 μG in the zones where the particle flows are more active. The continuous injection model for synchrotron ageing provides an age for the halo of ≃40 Myr, which in turn provides a jet kinetic power of 6−10 × 1044 erg s-1.

KW - individual clusters

KW - individual galaxies

KW - radio continuum

KW - EWI-22695

KW - M 87

KW - IR-83534

KW - active galaxies

KW - Jets

KW - Virgo

KW - METIS-296174

KW - Non-thermal radiation mechanisms

U2 - 10.1051/0004-6361/201220209

DO - 10.1051/0004-6361/201220209

M3 - Article

VL - 547

SP - 1

EP - 20

JO - Astronomy & astrophysics

JF - Astronomy & astrophysics

SN - 0004-6361

IS - A56

ER -

de Gasperin F, Orrú E, Murgia M, Merloni A, Falcke H, Beck R et al. M87 at metre wavelengths: the LOFAR picture. Astronomy & astrophysics. 2012 Oct 26;547(A56):1-20. https://doi.org/10.1051/0004-6361/201220209