Calibrating Stellar Velocity Dispersions Based on Spatially Resolved H-band Spectra for Improving the M_(BH)-σ_* Relation
Abstract
To calibrate stellar velocity dispersion measurements from optical and near-IR stellar lines, and to improve the black hole mass (M_(BH))-stellar velocity dispersion (σ_*) relation, we measure σ_* based on high-quality H-band spectra for a sample of 31 nearby galaxies, for which dynamical M_(BH) is available in the literature. By comparing velocity dispersions measured from stellar lines in the H-band with those measured from optical stellar lines, we find no significant difference, suggesting that optical and near-IR stellar lines represent the same kinematics and that dust effect is negligible for early-type galaxies. Based on the spatially resolved rotation and velocity dispersion measurements along the major axis of each galaxy, we find that a rotating stellar disk is present for 80% of galaxies in the sample. For galaxies with a rotation component, σ_* measured from a single aperture spectrum can vary by up to ~20%, depending on the size of the adopted extraction aperture. To correct for the rotational broadening, we derive luminosity-weighted σ_* within the effective radius of each galaxy, providing uniformly measured velocity dispersions to improve the M_(BH)-σ_* relation.
Additional Information
© 2013 American Astronomical Society. Received 2013 January 20; accepted 2013 February 19; published 2013 March 21. We thank the anonymous referee for constructive suggestions, which improved the manuscript. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2012-006087). J.H.W. acknowledges the support by the Korea Astronomy and Space Science Institute (KASI) grant funded by the Korea government (MEST).Attached Files
Published - 0004-637X_767_1_26.pdf
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Additional details
- Eprint ID
- 38261
- Resolver ID
- CaltechAUTHORS:20130503-104250488
- 2012-006087
- National Research Foundation of Korea
- Ministry of Education, Science and Technology (Korea)
- Korea Astronomy and Space Science Institute (KASI)
- Created
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2013-05-03Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field