We use cookies to ensure that we give you the best experience on our website. You can change your cookie settings at any time. Otherwise, we'll assume you're OK to continue.

Durham University

Department of Physics

Staff profile

Publication details for Prof Richard Bower

Swinbank, A. M., Balogh, M. L., Bower, R. G., Hau, G. K. T., Allington-Smith, J. R., Nichol, R. C. & Miller, C. J. (2005). Gemini Multi-Object Spectrograph Integral Field Spectroscopy of a Merging System with Enhanced Balmer Absorption. Astrophysical Journal 622(1): 260-266.

Author(s) from Durham


In this paper we present the three-dimensional dynamics of the galaxy SDSS J101345.39+011613.66, selected for its unusually strong Balmer absorption lines [W0(Hδ) = 7.5 Å]. Using the Gemini Multi-Object Spectrograph-South integral field unit (IFU) in nod+shuffle mode, we have mapped the continuum and optical absorption lines of this z = 0.1055 field galaxy. This galaxy has a disturbed morphology, with a halo of diffuse material distributed asymmetrically toward the north. Using the [O II] emission line (W0[O img1.gif] = 4.1 Å), we find that the gas and hot OB stars are offset from the older stars in the system. The gas also has a spatially extended and elongated morphology with a velocity gradient of 100 ± 20 km s-1 across 6 kpc in projection. Using the strong Hγ and Hδ absorption lines, we find that the A stars are widely distributed across the system and are not centrally concentrated, arguing that the A star population has formed in molecular clouds outside the nucleus. By cross-correlating the spectra from the data cube with an A star template, we find evidence that the A star population has a 40 km s-1 shear in the same direction as the gas. The disturbed morphology, strong color gradients, and strong Hδ and Hγ absorption lines in SDSS J101345.39 argue that this is a recent tidal interaction/merger between a passive elliptical and a star-forming galaxy. Although based on a single object, these results show that we can spatially resolve and constrain the dynamics of this short-lived (yet important) phase of galaxy formation in which the evolutionary process takes galaxies from star-forming to their quiescent end products.