Published July 20, 2012 | Version v1
Journal article

KINEMATIC SIGNATURES OF BULGES CORRELATE WITH BULGE MORPHOLOGIES AND SÉRSIC INDEX

  • 1. Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, D-85748 Garching (Germany)
  • 2. Laboratory of Millimeter Astronomy, University of Maryland, College Park, MD 29742 (United States)
  • 3. Instituto de Astronomia, Universidad Nacional Autonoma de Mexico (UNAM), A.P. 70-264, 04510 Mexico, D.F. (Mexico)

Description

We use the Marcario Low Resolution Spectrograph at the Hobby-Eberly Telescope to study the kinematics of pseudobulges and classical bulges in the nearby universe. We present major axis rotational velocities, velocity dispersions, and h3 and h4 moments derived from high-resolution (σinst ≈ 39 km s–1) spectra for 45 S0 to Sc galaxies; for 27 of the galaxies we also present minor axis data. We combine our kinematics with bulge-to-disk decompositions. We demonstrate for the first time that purely kinematic diagnostics of the bulge dichotomy agree systematically with those based on Sérsic index. Low Sérsic index bulges have both increased rotational support (higher v/σ values) and on average lower central velocity dispersions. Furthermore, we confirm that the same correlation also holds when visual morphologies are used to diagnose bulge type. The previously noted trend of photometrically flattened bulges to have shallower velocity dispersion profiles turns out to be significant and systematic if the Sérsic index is used to distinguish between pseudobulges and classical bulges. The anti-correlation between h3 and v/σ observed in elliptical galaxies is also observed in intermediate-type galaxies, irrespective of bulge type. Finally, we present evidence for formerly undetected counter-rotation in the two systems NGC 3945 and NGC 4736.

Availability note (English)

Available from http://dx.doi.org/10.1088/0004-637X/754/1/67

Additional details

Identifiers

Publishing Information

Journal Title
Astrophysical Journal
Journal Volume
754
Journal Issue
1
Journal Page Range
[27 p.]
ISSN
0004-637X
CODEN
ASJOAB

INIS

Country of Publication
United States
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
43129662
Subject category
S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
Descriptors DEI
ABSORPTION SPECTROSCOPY; ASTRONOMY; ASTROPHYSICS; CORRELATIONS; EMISSION SPECTROSCOPY; GALAXIES; INDEXES; MORPHOLOGY; PHOTOMETRY; RESOLUTION; ROTATION; STAR CLUSTERS; TELESCOPES; UNIVERSE; VELOCITY
Descriptors DEC
DOCUMENT TYPES; MOTION; PHYSICS; SPECTROSCOPY