ORBIT-BASED DYNAMICAL MODELS OF THE SOMBRERO GALAXY (NGC 4594)

Journal Article · Tue Sep 20 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/739/1/21; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21587547

Jardel, John R; Gebhardt, Karl; Kormendy, John; Kinzler, Jeffry ^[1]; Shen, Juntai ^[2]; Fisher, David B ^[3]; Lauer, Tod R ^[4]; Richstone, Douglas; Gueltekin, K ^[5]

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1. Department of Astronomy, University of Texas at Austin, 1 University Station C1400, Austin, TX 78712 (United States)
2. Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)
3. Laboratory for Millimeter-Wave Astronomy, Department of Astronomy, CSS 1204, University of Maryland, College Park, MD 20742-2421 (United States)
4. National Optical Astronomy Observatories, P.O. Box 26732, Tucson, AZ 85726 (United States)
5. Department of Astronomy, Dennison Building, University of Michigan, Ann Arbor, MI 48109 (United States)

We present axisymmetric, orbit-based models to study the central black hole (BH), stellar mass-to-light ratio (M/L), and dark matter (DM) halo of NGC 4594 (M104, the Sombrero Galaxy). For stellar kinematics, we use published high-resolution kinematics of the central region taken with the Hubble Space Telescope, newly obtained Gemini long-slit spectra of the major axis, and integral field kinematics from the Spectroscopic Areal Unit for Research on Optical Nebulae instrument. At large radii, we use globular cluster kinematics to trace the mass profile and apply extra leverage to recovering the DM halo parameters. We find a BH of mass M{sub .} = (6.6 {+-} 0.4) x 10{sup 8} M{sub sun} and determine the stellar M/L{sub I} = 3.4 {+-} 0.05 (uncertainties are the 68% confidence band marginalized over the other parameters). Our best-fit DM halo is a cored logarithmic model with asymptotic circular speed V{sub c} = 376 {+-} 12 km s{sup -1} and core radius r{sub c} = 4.7 {+-} 0.6 kpc. The fraction of dark to total mass contained within the half-light radius is 0.52. Taking the bulge and disk components into account in our calculation of {sigma}{sub e} puts NGC 4594 squarely on the M-{sigma} relation. We also determine that NGC 4594 lies directly on the M-L relation.

• OSTI ID: 21587547
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 739; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BLACK HOLES
GALAXIES
MATTER
NONLUMINOUS MATTER
ORBITS
PHOTOMETRY
SIMULATION
STAR CLUSTERS