The SLUGGS survey: wide-field stellar kinematics of early-type galaxies
- Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)
- University of California Observatories, 1156 High Street, Santa Cruz, CA 95064 (United States)
- Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia)
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)
- Department of Physics and Astronomy, Faculty of Sciences, Macquarie University, Sydney, NSW 2109 (Australia)
- Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW (Australia)
We present stellar kinematics of 22 nearby early-type galaxies (ETGs), based on two-dimensional (2D) absorption line stellar spectroscopy out to ∼2-4 R {sub e} (effective radii), as part of the ongoing SLUGGS Survey. The galaxies span a factor of 20 in intrinsic luminosity, as well as a full range of environment and ETG morphology. Our data consist of good velocity resolution (σ{sub inst} ∼ 25 km s{sup –1}) integrated stellar-light spectra extracted from the individual slitlets of custom made Keck/DEIMOS slitmasks. We extract stellar kinematics measurements (V, σ, h {sub 3}, and h {sub 4}) for each galaxy. Combining with literature values from smaller radii, we present 2D spatially resolved maps of the large-scale kinematic structure in each galaxy. We find that the kinematic homogeneity found inside 1 R {sub e} often breaks down at larger radii, where a variety of kinematic behaviors are observed. While central slow rotators remain slowly rotating in their halos, central fast rotators show more diversity, ranging from rapidly increasing to rapidly declining specific angular momentum profiles in the outer regions. There are indications that the outer trends depend on morphological type, raising questions about the proposed unification of the elliptical and lenticular (S0) galaxy families in the ATLAS{sup 3D} survey. Several galaxies in our sample show multiple lines of evidence for distinct disk components embedded in more slowly rotating spheroids, and we suggest a joint photometric-kinematic approach for robust bulge-disk decomposition. Our observational results appear generally consistent with a picture of two-phase (in-situ plus accretion) galaxy formation.
- OSTI ID:
- 22365333
- Journal Information:
- Astrophysical Journal, Vol. 791, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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