$Profiler$ - A Fast and Versatile New Program for Decomposing Galaxy Light Profiles (1607.08620v1)

Abstract: I introduce $Profiler$, a new, user-friendly program written in $Python$ and designed to analyse the radial surface brightness profiles of galaxies. With an intuitive graphical user interface, $Profiler$ can accurately model a wide range of galaxies and galaxy components, such as elliptical galaxies, the bulges of spiral and lenticular galaxies, nuclear sources, discs, bars, rings, spiral arms, etc., with a variety of parametric functions routinely employed in the field (S\'ersic, core-S\'ersic, exponential, Gaussian, Moffat and Ferrers). In addition to these, $Profiler$ can employ the broken exponential model (relevant for disc truncations or antitruncations) and two special cases of the edge-on disc model: namely along the major axis (in the disc plane) and along the minor axis (perpendicular to the disc plane). $Profiler$ is optimised to work with galaxy light profiles obtained from isophotal measurements which capture radial gradients in the ellipticity, position angle and Fourier harmonic profiles of the isophotes, and are thus often better at capturing the total light than two-dimensional image-fitting programs. Additionally, the one-dimensional approach is generally less computationally expensive and more stable. In $Profiler$, the convolution of either circular or elliptical models with the point spread function is performed in two-dimensions, and offers a choice between Gaussian, Moffat or a user-provided data vector (a table of intensity values as a function of radius) for the point spread function. I demonstrate $Profiler$'s features and operation by decomposing three case-study galaxies: the cored elliptical galaxy NGC 3348, the nucleated dwarf Seyfert I galaxy Pox 52, and NGC 2549, a structurally complex, double-barred galaxy which also displays a Type II truncated disc viewed edge-on. $Profiler$ is freely available at: https://github.com/BogdanCiambur/PROFILER