IC 4767 (the 'X-galaxy') - The missing link for understanding galaxies with peanut-shaped bulges?

Abstract

view Abstract Citations (80) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS IC 4767 (the ``X-Galaxy''): The Missing Link for Understanding Galaxies with Peanut-shaped Bulges? Whitmore, Bradley C. ; Bell, Marylin Abstract Photometric and kinematic observations of the peculiar S0 galaxy IC 4767 (= ESO 104-G10, DC 1842-63 number 12, WR 115, "X-galaxy") are presented. At various intensities the bulge of this galaxy looks like a normal spheroidal system with elliptical isophotes, a well-defined rectangle, and a peanut-shaped or X-shaped structure with components aligned at oblique angles to the major axis. The B-V image reveals the presence of a thin inner dust lane nearly aligned with the major axis. This inner disk probably resulted from the dissipation of gas during a recent accretion event, as indicated by the presence of gas in rapid rotation which is only observed within 2" of the nucleus. The outer regions of the X-component are also rotating quite rapidly, indicating that the stars are in relatively circular orbits, consistent with a rotation field which is approximately cylindrical with respect to the disk. IC 4767 shows characteristics of both peanut-shaped galaxies and polar-ring galaxies, leading us to suggest similar origins for the two systems. In both cases we believe the accretion of material from a companion galaxy during a merger or tidal encounter causes the peculiar morphology. If the accreted material impacts the central galaxy at nearly a right angle to the disk, a polar-ring galaxy is produced. If the accreted material impacts the central galaxy at an oblique angle, a galaxy with a box-shaped or peanut-shaped nucleus may be produced. Further evidence to support the accretion hypothesis is the fact that the five most prominent peanut-shaped galaxies all have nearby companions within a few radii, many of the companions showing deformities or even luminous bridges with the peanut galaxies. Publication: The Astrophysical Journal Pub Date: January 1988 DOI: 10.1086/165933 Bibcode: 1988ApJ...324..741W Keywords: Elliptical Galaxies; Galactic Bulge; Galactic Structure; Interstellar Matter; Peculiar Galaxies; Seyfert Galaxies; Astronomical Photometry; Astronomical Spectroscopy; Galactic Nuclei; Isophotes; Ring Galaxies; Astrophysics; GALAXIES: INDIVIDUAL ALPHANUMERIC: IC 4767; GALAXIES: INTERNAL MOTIONS; GALAXIES: PHOTOMETRY; GALAXIES: STRUCTURE full text sources ADS | data products SIMBAD (11) NED (10)