NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-05-19 T10:21:48 PDT
Help | Comment | NED Home

For refcode 1989ApJ...346..653K:
Retrieve 27 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
1989ApJ...346..653K INTERSTELLAR MATTER IN EARLY-TYPE GALAXIES: OPTICAL OBSERVATIONS DONG-WOO KIM Department of Astronomy, University of California Los Angeles Received 1988 October 7; accepted 1989 May 11 ABSTRACT The results of optical observations are presented for a sample of 26 early-type galaxies that are bright in the infrared. Optical broad-band imaging (using B and R filters) and narrow-band imaging (using H{alpha} interference filters) have been performed to study dust patches and ionized gas. We have also made long-slit spectroscopy to determine gas kinematics. From direct imaging, we have detected dust lanes and ionized gas typically on a scale of 10"-20" in more than half of our galaxy sample. The spectroscopic data confirm the presence and distribution of the interstellar matter seen in the direct imaging. The dust lanes and ionized gas are distributed ia various ways--aligned along either the apparent major, or minor axis, or not even along either of them, indicating that triaxiality is in general required as a galaxy figure. Decoupled kinematics of interstellar gas and stars favors an external origin of the interstellar matter. For some isolated galaxies, however, an internal origin is not excluded. The rotation curves determined by optical emission lines are symmetric about the center in most galaxies observed. It appears that the interstellar matter is in a circularly rotating disk around the center. Galaxy masses and mass-to-light ratios are estimated using the rotation curves of the ionized gas. A trend that the mass-to-light ratio increases with radius is found; it suggests the presence of dark matter in early-type galaxies as in spirals. Ionized gas in early-type galaxies is very often accompanied by cold gas. For most early-type galaxies in our sample, the [N II] lines are stronger than H{alpha}, resembling the intensity ratios observed in a LINER galaxy where ionization is probably due to nuclear activity rather than stellar light. It seems that the ionized gas, and perhaps the cold gas and dust, does not directly originate in a cooling flow out of the hot X-ray-emitting gas. Subject headings: galaxies: internal motions - galaxies: interstellar matter - galaxies: photometry
Retrieve 27 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home