Skip to main content Accessibility help

Explaining the flat-spectrum radio core Sgr A* with GRMHD simulations of jets

  • Monika A. Mościbrodzka (a1)


The supermassive black hole in the center of the Milky Way, Sgr A*, displays a nearly flat radio spectrum which is typical for jets in Active Galactic Nuclei. Indeed, time dependent, magnetized models of radiatively inefficient accretion flows, which are commonly used to explain the millimeter, near-infrared, and X-ray emission of Sgr A* also often produce jet-like outflows. However, the emission from these models so far has failed to reproduce the flat radio spectrum. We show that current GRMHD simulations can naturally reproduce the flat spectrum, when using a two-temperature plasma in the disk and a constant electron temperature plasma in the jet. This assumption is consistent with current state-of-the art simulations, in which the electron temperature evolution is not explicitly modeled. Stronger magnetization and stronger shearing seen in the jet sheath could possibly explain the difference in electron heating between jet and disk. The model images and spectra are consistent with the radio sizes and spectrum of Sgr A*.



Hide All
An, T., Goss, W. M., Zhao, J.-H., et al. 2005, ApJL, 634, L49
Bower, G. C., Falcke, H., Wright, M. C., & Backer, D. C. 2005, ApJL, 618, L29
Bower, G. C., Goss, W. M., Falcke, H., Backer, D. C., & Lithwick, Y. 2006, ApJL, 648, L127
Bower, G. C., Markoff, S., Brunthaler, A., et al. 2014, ApJ, 790, 1
Brinkerink, C., Moscibrodzka, M., Fraga-Encinas, R., & Falcke, H., 2014, in preparation
Dexter, J., Agol, E., Fragile, P. C., & McKinney, J. C. 2010, ApJ, 717, 1092
Doeleman, S. S., Weintroub, J., Rogers, A. E. E., et al. 2008, Nature, 455, 78
Doeleman, S. S., Fish, V. L., Schenck, D. E., et al. 2012, Science, 338, 355
Falcke, H., Goss, W. M., Matsuo, H., et al. 1998, ApJ, 499, 731
Falcke, H. & Markoff, S. B. 2013, Classical and Quantum Gravity, 30, 244003
Fish, V. L., Doeleman, S. S., Beaudoin, C., et al. 2011, ApJL, 727, L36
Marrone, D. P., Moran, J. M., Zhao, J.-H., & Rao, R. 2006, ApJ, 640, 308
Melia, F. & Falcke, H. 2001, ARAA, 39, 309
Mościbrodzka, M., Gammie, C. F., Dolence, J. C., Shiokawa, H., & Leung, P. K. 2009, ApJ, 706, 497
Mościbrodzka, M. & Falcke, H. 2013, A&A, 559, L3
Mościbrodzka, M., Falcke, H., Shiokawa, H., & Gammie, C. F. 2014, A&A, 570, AA7
Neilsen, J., Nowak, M. A., Gammie, C., et al. 2013, ApJ, 774, 42
Noble, S. C., Leung, P. K., Gammie, C. F., & Book, L. G. 2007, Classical and Quantum Gravity, 24, 259
Schödel, R., Morris, M. R., Muzic, K., et al. 2011, A&A, 532, A83
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Proceedings of the International Astronomical Union
  • ISSN: 1743-9213
  • EISSN: 1743-9221
  • URL: /core/journals/proceedings-of-the-international-astronomical-union
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed