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arXiv · 0807.3034

In Search of the Largest Velocity Dispersion Galaxies

S. Salviander·G. A. Shields·K. Gebhardt·M. Bernardi·J. B. Hyde
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Abstract

We present Hobby-Eberly Telescope (HET) observations for galaxies at redshift z < 0.3 from the Sloan Digital Sky Survey (SDSS) showing large velocity dispersions while appearing to be single galaxies in HST images. The high signal-to-noise HET spectra provide more definitive velocity dispersions. The maximum velocity dispersion we find is 444 km/s. Emission-line widths in QSOs indicate that black holes can exist with masses exceeding 5 billion solar masses, implying velocity dispersions greater than 500 km/s by the local black hole mass - velocity dispersion relationship. This suggests either that QSO black hole masses are overestimated or that the black hole - bulge relationship changes at high black hole mass. The latter option is consistent with evidence that the increase in velocity dispersion with luminosity levels off for the brightest elliptical galaxies.

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S. Salviander, G. A. Shields, K. Gebhardt, M. Bernardi, J. B. Hyde. 2008-07-18. In Search of the Largest Velocity Dispersion Galaxies. https://doi.org/10.1086/591959

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