Boxy isophotes, discs and dust lanes in elliptical galaxies

• Published in: Monthly notices of the Royal Astronomical Society Vol. 216; no. 2; pp. 429 - 438
• Main Author: Lauer, T. R.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford University Press 01.09.1985; Blackwell Science
• Subjects: Astronomy; Astrophysics; Earth, ocean, space; Exact sciences and technology; Interstellar medium (ism) and nebulae in external galaxies; Stellar systems. Galactic and extragalactic objects and systems. The universe; Elliptical galaxies; Structure; Isophot
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/216.2.429

CCD images of 42 elliptical and S0 galaxies are examined for low-contrast structures or subtle distortions of the isophotes from perfect ellipses. 75 per cent of the galaxies have isophotes completely describable as concentric ellipses to within the photometry errors. ‘Boxy’ isophotes, stellar discs, and dust lanes are detected in the remaining 25 per cent of the sample. The boxy elliptical galaxies appear dynamically indistinguishable from normal ellipticals and are therefore different from boxy bulges, which rotate rapidly. Most of the galaxies with faint discs, however, appear dynamically similar to S0 galaxies. Nearly edge-on dust lanes are found in four galaxies, which suggests that dust lanes may commonly occur in elliptical galaxies.