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Physical Sciences and Mathematics Commons™
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Full-Text Articles in Physical Sciences and Mathematics
A Dearth Of Dark Matter In Ordinary Elliptical Galaxies, Aaron J. Romanowsky, N. G. Douglas, M. Arnaboldi, K. Kuijken, M. R. Merrifield, N. R. Napolitano, M. Capaccioli
A Dearth Of Dark Matter In Ordinary Elliptical Galaxies, Aaron J. Romanowsky, N. G. Douglas, M. Arnaboldi, K. Kuijken, M. R. Merrifield, N. R. Napolitano, M. Capaccioli
Aaron J. Romanowsky
The kinematics of the outer parts of three intermediate-luminosity elliptical galaxies were studied with the Planetary Nebula Spectrograph. The galaxies' velocity-dispersion profiles were found to decline with the radius, and dynamical modeling of the data indicates the presence of little if any dark matter in these galaxies' halos. This unexpected result conflicts with findings in other galaxy types and poses a challenge to current galaxy formation theories.
Tracing The Star Stream Through M31 Using Planetary Nebula Kinematics, H. R. Merrett, K. Kuijken, M. R. Merrifield, Aaron J. Romanowsky, N. G. Douglas, N. R. Napolitano, M. Arnaboldi, M. Capaccioli, K. C. Freeman, O. Gerhard, N. W. Evans, M. I. Wilkinson, C. Halliday, T. J. Bridges, D. Carter
Tracing The Star Stream Through M31 Using Planetary Nebula Kinematics, H. R. Merrett, K. Kuijken, M. R. Merrifield, Aaron J. Romanowsky, N. G. Douglas, N. R. Napolitano, M. Arnaboldi, M. Capaccioli, K. C. Freeman, O. Gerhard, N. W. Evans, M. I. Wilkinson, C. Halliday, T. J. Bridges, D. Carter
Aaron J. Romanowsky
We present a possible orbit for the Southern Stream of stars in M31, which connects it to the Northern Spur. Support for this model comes from the dynamics of planetary nebulae (PNe) in the disc of M31: analysis of a new sample of 2611 PNe obtained using the Planetary Nebula Spectrograph reveals ∼20 objects with kinematics inconsistent with the normal components of the galaxy, but which lie at the right positions and velocities to connect the two photometric features via this orbit. The satellite galaxy M32 is coincident with the stream both in position and velocity, adding weight to the …