To appear in the Astronomical Journal, August 2002 Molecular Gas in Elliptical Galaxies: Distribution and Kinematics L. M. Young Physics Department, New Mexico Institute of Mining and Technology, Socorro, NM 87801
[email protected] ABSTRACT I present interferometric images (∼7′′ resolution) of CO emission in five elliptical galaxies and nondetections in two others. These data double the number of elliptical galaxies whose CO emission has been fully mapped. The sample galaxies have 108 9 to 5×10 M⊙ of molecular gas distributed in mostly symmetric rotating disks with diameters of 2 to 12 kpc. Four out of the five molecular disks show remarkable alignment with the optical major axes of their host galaxies. The molecular masses are a few percent of the total dynamical masses which are implied if the gas is on circular orbits. If the molecular gas forms stars, it will make rotationally supported stellar disks which will be very similar in character to the stellar disks now known to be present in many ellipticals. Comparison of stellar kinematics to gas kinematics in NGC 4476 implies that the molecular gas did not come from internal stellar mass loss because the specific angular momentum of the gas is about three times larger than that of the stars. Subject headings: galaxies: individual (UGC 1503, NGC 807, NGC 3656, NGC 4476, NGC 5666, NGC 4649, NGC 7468) — galaxies: elliptical and lenticular, cD — galaxies: ISM — galaxies: kinematics and dynamics — galaxies: evolution — ISM: molecules arXiv:astro-ph/0205162v1 10 May 2002 1. Introduction It is now well known that elliptical galaxies often do have interstellar media with some cold neutral gas and dust.