Magnetic braking in galactic flows

Abstract

view Abstract Citations (15) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Magnetic braking in galactic flows Sparke, L. S. Abstract The nuclear fireworks of active galaxies are believed to derive their power from the kinetic energy of gas falling onto a massive central object; mass shed from evolving galactic stars is an obvious source of fuel for this process. But this ejected material shares the galactic rotation, and a centrifugal barrier will prevent it from reaching the nucleus, if its angular momentum is not removed. This paper shows that, if the large-scale galactic magnetic field has a strong enough radial component, magnetic torques can act to spin down the infalling matter. Rotation of the interstellar gas induces a toroidal magnetic field, amd Maxwell stresses remove angular momentum from the flow; gas can then fall inward to the galactic center. In this way, the monster in the nucleus can be fed on gas from a galaxy's own stars. The magnetic fields in M87 and NGC 1275, giant elliptical galaxies which are accreting from an intracluster medium, appear to be strong enough to allow magnetic braking. Publication: The Astrophysical Journal Pub Date: September 1982 DOI: 10.1086/160237 Bibcode: 1982ApJ...260..104S Keywords: Galactic Nuclei; Galactic Rotation; Interstellar Magnetic Fields; Magnetohydrodynamic Flow; Momentum Transfer; Stellar Mass Ejection; Active Galaxies; Angular Momentum; Elliptical Galaxies; Interstellar Gas; Magnetic Effects; Radial Velocity; Astrophysics full text sources ADS | data products NED (2)