Did elliptical galaxies form by mergers or by dissipative collapse

Journal Article · Sat Jul 01 04:00:00 EDT 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/185485· OSTI ID:5556434

Kormendy, J ^[1]

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1. Dominion Astrophysical Observatory, Victoria (Canada)

Observed parameter scaling laws show that lower-luminosity ellipticals have higher central densities and smaller core radii; if they formed by mergers, they are very unlike their progenitors. In the extreme case of M32, the central surface brightness is mu0 less than about 12 V mag/sq arcsec and the core radius is r(c) less than about 0.001 kpc, while plausible progenitor disk galaxies have mu0 of about 22 V mag/sq arcsec and r(c) of about 0.5 kpc. M32 must have formed by a dissipative collapse, whether or not a merger was involved. The cooling diagram also shows that low-luminosity ellipticals formed with more dissipation than high-luminosity ellipticals. Thus the merger picture of galalxy formation requires essential aspects of the dissipative collapse picture. 38 refs.

• OSTI ID: 5556434
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 342; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BASIC INTERACTIONS
BRIGHTNESS
CONFIGURATION
COOLING
ELLIPTICAL CONFIGURATION
GALACTIC EVOLUTION
GALAXIES
GRAVITATIONAL COLLAPSE
GRAVITATIONAL INTERACTIONS
INTERACTIONS
MORPHOLOGY
OPTICAL PROPERTIES
PHOTOMETRY
PHYSICAL PROPERTIES