How Dry Are Red Mergers?

Abstract

The focus of current research in galaxy evolution has increasingly turned to understanding the effect that mergers have on the evolution of systems on the red sequence. For those interactions purported to occur dissipationlessly (so called "dry mergers"), it would appear that the role of gas is minimal. However, if these mergers are not completely dry, then even low levels of gas may be detectable. The purpose of our study is to test whether early type galaxies with HI in or around them, or "wet" ellipticals, would have been selected as dry mergers by the criteria in van Dokkum (2005, AJ, 130, 2647). To that end, we examine a sample of 20 early types from the HI Rogues Gallery with neutral hydrogen in their immediate environs. Of these, the 15 brightest and reddest galaxies match the optical dry merger criteria, but in each case, the presence of HI means that they are not truly dry.

8 pages plus 1 table and 5 figures; accepted for publication in AJ

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Cited by in corpus (14)

• Physical properties and environments of nearby galaxies
• The ATLAS${}^{3D}$ project - XXV: Two-dimensional kinematic analysis of simulated galaxies and the cosmological origin of fast and slow rotators
• Early-type galaxies in different environments: an HI view
• Electromagnetic counterparts of supermassive black hole binaries resolved by pulsar timing arrays
• Star formation and nuclear activity in close pairs of early-type galaxies
• Cold gas and young stars in tidally-disturbed ellipticals at z=0
• Effects on Galaxy Evolution: Pair Interactions versus Environment
• Unveiling the Sigma-Discrepancy in IR-Luminous Mergers I: Dust & Dynamics
• Are Dry Mergers Dry, Moist, or Wet?
• Large-scale HI in nearby radio galaxies (II): the nature of classical low-power radio sources
• Bimodality in low luminosity E and S0 galaxies
• Hubble Space Telescope Images of Red Mergers: How Dry are They?
• ALMA observations of massive molecular gas reservoirs in dusty early-type galaxies
• The Dirt on Dry Mergers