Disks in elliptical galaxies

Abstract

view Abstract Citations (148) References (25) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Disks in Elliptical Galaxies Rix, Hans-Walter ; White, Simon D. M. Abstract We investigate the abundance and strength of disk components in elliptical galaxies by studying the photometric properties of models containing a spheroidal r^1/4^-law bulge and a weak exponential disk. For such idealized models the disk can be detected by a characteristic deviation of the isophotes from perfect ellipses (residuals of the form σI = α_4_ cos 4θ with α_4_ > 0) or by deviations of the luminosity profile from a perfect r^1/4^ law. The α_4_ test is quite sensitive to weak disks if they are nearly edge-on. However, for random viewing angles, even disks containing 20% of the total light are expected to be too face-on for the α_4_ signal to be detectable in more than half of the cases. For most such galaxies the residuals in the luminosity profile are also too small for an unambiguous detection of the disk. "Pointed" isophotes are observed in a substantial fraction of elliptical galaxies. If we interpret these isophote distortions in the framework of our models, then the statistics of observed samples suggest that almost all radio- weak (or "nonboxy") ellipticals could have disks containing roughly 20% of the light. We show the "E5" galaxy NGC 4660 to have the photometric signatures of a disk containing a third of the light. Publication: The Astrophysical Journal Pub Date: October 1990 DOI: 10.1086/169242 Bibcode: 1990ApJ...362...52R Keywords: Astronomical Photometry; Disk Galaxies; Elliptical Galaxies; Galactic Structure; Luminosity; Charge Coupled Devices; Dynamic Characteristics; Fourier Series; Morphology; Astrophysics; GALAXIES: PHOTOMETRY; GALAXIES: STRUCTURE; STARS: STELLAR DYNAMICS full text sources ADS | data products SIMBAD (1) NED (1)