A Keck/LRIS Spatially-Resolved Spectroscopic Study of a LINER Galaxy SDSS J091628.05+420818.7

Bae Hyun-Jin

Woo Jong-Hak

Yagi Masafumi

Yoon Suk-Jin

Yoshida Michitoshi

Astrophysical Journal

Using spatially resolved spectra obtained with the Low Resolution Imaging Spectrometer at the Keck I telescope, we investigate the nature of ionizing sources and kinematic properties of emission-line gas in a LINER galaxy SDSS J091628.05+420818.7, which is a nearby (z = 0.0241) and bright (M-r = -20.2) early-type galaxy. After subtracting stellar absorption features using a combination of simple stellar population models, we measure the flux, line-of-sight velocity, and velocity dispersion of four emission lines, i.e., H alpha, H beta, [O III] lambda 5007, and [N II] lambda 6584, to study radial change of emission-line fluxes and velocities. Compared to the point-spread function of the observation, the emission-line region is slightly extended but comparable to the seeing size. The central concentration of emission-line gas suggests that ionization is triggered by a nuclear source, excluding old stellar population as ionizing sources. We find that emission-line gas is counter-rotating with respect to stellar component and that the [O III] lambda 5007 line is blueshifted compared to other emission lines, possibly due to an outflow.

galaxies: active

galaxies: kinematics and dynamics

Astronomy. Space sciences [ 440 ]

eng

IOP Publishing Ltd

(c) 2012. The American Astronomical Society. All rights reserved. Printed in the U.S.A.

[ISSN] 0004-637X

[DOI] 10.1088/0004-637X/753/1/10

[NCID] AA00553242

[DOI] http://dx.doi.org/10.1088/0004-637X/753/1/10