GHASP: an Hα kinematic survey of spiral galaxies – X. Surface photometry, decompositions and the Tully–Fisher relation in theR_cband

Abstract

We present R c -band surface photometry for 170 of the 203 galaxies in GHASP, Gassendi H-Alpha survey of SPirals, a sample of late-type galaxies for which high-resolution FabryPerot H maps have previously been obtained. Our data set is constructed by new R c -band observations taken at the Observatoire de Haute-Provence (OHP), supplemented with Sloan Digital Sky Survey (SDSS) archival data, obtained with the purpose of deriving homogeneous photometric profiles and parameters. Our results include R c -band surface brightness profiles for 170 galaxies and ugriz profiles for 108 of these objects. We catalogue several parameters of general interest for further reference, such as total magnitude, effective radius and isophotal parameters -magnitude, position angle, ellipticity and inclination. We also perform a structural decomposition of the surface brightness profiles using a multi-component method in order to separate disks from bulges and bars, and to observe the main scaling relations involving luminosities, sizes and maximum velocities.We determine the R c -band Tully Fisher relation using maximum velocities derived solely from Hα rotation curves for a sample of 80 galaxies, resulting in a slope of −8.1 ± 0.5, zero point of −3.0 ± 1.0 and an estimated intrinsic scatter of 0.28 ± 0.07. We note that, different from the TF-relation in the near-infrared derived for the same sample, no change in the slope of the relation is seen at the low-mass end (for galaxies with V max < 125 km/s). We suggest that this different behaviour of the Tully Fisher relation (with the optical relation being described by a single power-law while the near-infrared by two) may be caused by differences in the stellar mass to light ratio for galaxies with V max < 125 km/s.

GHASP: an H α kinematics survey of spiral galaxies – XII. Distribution of luminous and dark matter in spiral and irregular nearby galaxies using Rc-band photometry

“…The remaining galaxies are available in the online version. The surface brightness profiles decomposition for the 27 galaxies from SDSS are shown in this work while we do not present the remaining 73 galaxies from OHP because they have already been published in Barbosa et al (2015). Note that 4 of the 27 SDSS galaxies have not been decomposed, for these galaxies, we just show the observed surface brightness profiles.…”

“…We use a sample of 100 spiral and irregular nearby galaxies with high resolution Hα rotation curves (RCs), derived from 2D velocity fields, and the optical R c -band photometry: 73 from surface brightness photometry obtained at the Observatoire de Haute Provence (OHP) (Barbosa et al 2015) and 27 from SDSS DR7 (Abazajian et al 2009) archival data. The RCs of this sample are selected from the GHASP survey, which contains 203 galaxies observed with the 1.93 m telescope of the OHP using a Fabry-Perot interferometer scanning around the Hα emission line with high spectral and spatial resolutions.…”

“…The isophotal level used as reference is 23.5 mag arcsec −2 . The OHP surface brightness profiles are taken from Barbosa et al (2015). The SDSS data are taken from SDSS DR7 (Abazajian et al 2009), which provides imaging and calibration in the ugriz pass bands.…”

“…The SDSS data are taken from SDSS DR7 (Abazajian et al 2009), which provides imaging and calibration in the ugriz pass bands. The R c surface brightness profiles were computed by using the multi-band scaling relation (Barbosa et al 2015) to transform the SDSS ugriz-bands into R c -band:…”

“…The radial profile decomposition of the 73 OHP R c -band data has been done by Barbosa et al (2015). We utilize exactly the same method for the 27 remaining galaxies for which we used SDSS data.…”