From Rings to Bulges: Evidence for Rapid Secular Galaxy Evolution atz∼ 2 from Integral Field Spectroscopy in the SINS Survey
Year: 2008
Type: article
Abstract: We present Hα integral field spectroscopy of well-resolved, UV/optically selected z ∼ 2 star-forming galaxies as part of the SINS survey with SINFONI on the ESO VLT. Our laser guide star adaptive optics and good seeing data show the presence of turbulent rotating star-forming outer rings/disks, plus central bulge/inner disk components, whose mass fractions relative to the total dynamical mass appear to scale with the [N II]/Hα flux ratio and the star formation age. We propose that the buildup of the central disks and bulges of massive galaxies at z ∼ 2 can be driven by the early secular evolution of gas-rich proto-disks. High-redshift disks exhibit large random motions. This turbulence may in part be stirred up by the release of gravitational energy in the rapid "cold" accretion flows along the filaments of the cosmic web. As a result, dynamical friction and viscous processes proceed on a timescale of <1 Gyr, at least an order of magnitude faster than in z ∼ 0 disk galaxies. Early secular evolution thus drives gas and stars into the central regions and can build up exponential disks and massive bulges, even without major mergers. Secular evolution along with increased efficiency of star formation at high surface densities may also help to account for the short timescales of the stellar buildup observed in massive galaxies at z ∼ 2.
Source: The Astrophysical Journal
DOI: 10.1086/591840
Authors: R. Genzel, A. Burkert, N. Bouché, G. Cresci, N. M. Förster Schreiber, A. Shapley, K. Shapiro, L. J. Tacconi, P. Buschkamp, A. Cimatti, E. Daddi, R. Davies, F. Eisenhauer, D. K. Erb, S. Genel, O. Gerhard, E. Hicks, D. Lutz, T. Naab, T. Ott, S. Rabien, A. Renzini, C. C. Steidel, A. Sternberg, S. J. Lilly
Institutions: Max Planck Institute for Extraterrestrial Physics, University of California, Berkeley, Ludwig-Maximilians-Universität München, University of California, Los Angeles, Osservatorio astronomico di Bologna, National Institute for Astrophysics, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, CEA Paris-Saclay, Center for Astrophysics Harvard & Smithsonian, Osservatorio Astronomico di Padova, California Institute of Technology, Tel Aviv University, ETH Zurich
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2143453411