VLT Diffraction Limited Imaging and Spectroscopy in the NIR: Weighing the black hole in Centaurus A with NACO

Details VLT Diffraction Limited Imaging and Spectroscopy in the NIR: Weighing the black hole in Centaurus A with NACO VLT Diffraction Limited Imaging and Spectroscopy in the NIR: Weighing the black hole in Centaurus A with NACO

2005-07-05

arxiv.org/abs/astro-ph/0507094v2

Astrophys.J.643:226-237,2006

Astronomy and Astrophysics

Astrophysics

12 pages, 14 figures, including minor changes following the referee report; accepted for publication in The Astrophysical Jour

Scientific paper

10.1086/501494

We present high spatial resolution near-infrared spectra and images of the nucleus of Centaurus A (NGC 5128) obtained with NAOS-CONICA at the VLT. The adaptive optics corrected data have a spatial resolution of 0.06" (FWHM) in K- and 0.11" in H-band, four times higher than previous studies. The observed gas motions suggest a kinematically hot disk which is orbiting a central object and is oriented nearly perpendicular to the nuclear jet. We model the central rotation and velocity dispersion curves of the [FeII] gas orbiting in the combined potential of the stellar mass and the (dominant) black hole. Our physically most plausible model, a dynamically hot and geometrically thin gas disk, yields a black hole mass of M_bh = (6.1 +0.6/-0.8) 10^7 M_sun. As the physical state of the gas is not well understood, we also consider two limiting cases: first a cold disk model, which completely neglects the velocity dispersion; it yields an M_bh estimate that is almost two times lower. The other extreme case is to model a spherical gas distribution in hydrostatic equilibrium through Jeans equation. Compared to the hot disk model the best-fit black hole mass increases by a factor of 1.5. This wide mass range spanned by the limiting cases shows how important the gas physics is even for high resolution data. Our overall best-fitting black hole mass is a factor of 2-4 lower than previous measurements. With our revised M_bh estimate, Cen A's offset from the M_bh-sigma relation is significantly reduced; it falls above this relation by a factor of ~2, which is close to the intrinsic scatter of this relation. (Abridged)

Affiliated with

Also associated with

No associations

Rating

VLT Diffraction Limited Imaging and Spectroscopy in the NIR: Weighing the black hole in Centaurus A with NACO does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with VLT Diffraction Limited Imaging and Spectroscopy in the NIR: Weighing the black hole in Centaurus A with NACO, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and VLT Diffraction Limited Imaging and Spectroscopy in the NIR: Weighing the black hole in Centaurus A with NACO will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-58939