HIGH-RESOLUTION ROTATION CURVES AND GALAXY MASS MODELS FROM THINGS

Journal Article · Mon Dec 15 04:00:00 EST 2008 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/136/6/2648· OSTI ID:21583083

Walter, F ^[1]; Brinks, E ^[2]; Trachternach, C ^[3]; Oh, S-H ^[4]; Kennicutt, Jr, R C ^[5]

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1. Max Planck Institute fuer Astronomy, Koenigstuhl 17, 69117 Heidelberg (Germany)
2. Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom)
3. Astronomisches Institut, Ruhr-Universitaet Bochum, Universitaetstrasse 150, 44780 Bochum (Germany)
4. Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia)
5. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)

We present rotation curves of 19 galaxies from The H I Nearby Galaxy Survey (THINGS). The high spatial and velocity resolution of THINGS make these the highest quality H I rotation curves available to date for a large sample of nearby galaxies, spanning a wide range of H I masses and luminosities. The high quality of the data allows us to derive the geometric and dynamical parameters using H I data alone. We do not find any declining rotation curves unambiguously associated with a cut-off in the mass distribution out to the last measured point. The rotation curves are combined with 3.6 {mu}m data from the Spitzer Infrared Nearby Galaxies Survey to construct mass models. Our best-fit dynamical disk masses, derived from the rotation curves, are in good agreement with photometric disk masses derived from the 3.6 {mu}m images in combination with stellar population synthesis arguments and two different assumptions for the stellar initial mass function (IMF). We test the cold dark matter (CDM) motivated cusp model, and the observationally motivated central density core model and find that (independent of IMF) for massive, disk-dominated galaxies, all halo models fit apparently equally well; for low-mass galaxies, however, a core-dominated halo is clearly preferred over a cusp-like halo. The empirically derived densities of the dark matter halos of the late-type galaxies in our sample are half of what is predicted by CDM simulations, again independent of the assumed IMF.

• OSTI ID: 21583083
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 6 Vol. 136; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPUTERIZED SIMULATION
DENSITY
DISTRIBUTION
DWARF STARS
EVOLUTION
GALACTIC EVOLUTION
GALAXIES
GEOMETRY
LUMINOSITY
MASS
MASS DISTRIBUTION
MATHEMATICS
MATTER
MOTION
NONLUMINOUS MATTER
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
ROTATION
SIMULATION
SPATIAL DISTRIBUTION
STARS