8-12 juin, 2014


Exploring the limits of DiskFit Photometry

Colin Lewis (Queen's University)

Colin Lewis, Kristine Spekkens

We present simulations that test the accuracy and precision of the photometric branch of DiskFit, a program developed for modelling asymmetries such as bars in disk galaxy images or velocity fields. We simulate observations of barred and unbarred systems with properties similar to those targeted by the Spitzer Survey of Stellar Structure in Galaxies (S4G), and compare the surface brightness profiles and disk, bar and bulge properties recovered by DiskFit to the known input values. We find that in an S4G-like survey, the ellipticities of galactic components such as disks and bars are under-estimated when there are fewer than 14 pixels across their minor axes for ellipticities higher than 0.8, and that the Sersic bulge parameters of late-type disks are difficult to recover. We discuss strategies for mitigating these issues, improving DiskFit's ability to recover physically meaningful galactic parameters from disk galaxy images.

Mode de présentation: Affiche