NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-06-18 T00:25:41 PDT
Help | Comment | NED Home

For refcode 1991AJ....101.1647T:
Retrieve 13 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
1991AJ....101.1647T H{alpha} IMAGES OF EARLY TYPE GALAXIES WITH HOT GAS G. TRINCHIERI Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5,1-50125 Firenze, Italy S. DI SEREGO ALIGHIERI Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5,1-50125 Firenze, Italy and Space Telescope European Coordinating Facility, K. Schwarzschild Str. 2, D-8046 Garching bei Munchen, Federal Republic of Germany Received 28 June 1990; revised 24 January 1991 ABSTRACT We present H{alpha} imaging observations of 13 early type galaxies with known x-ray fluxes from the Einstein Observatory data, and long-slit spectroscopy of nine of these. We have detected H{alpha} emission in the central regions of ten objects. The line emission appears extended over a radius of 5-10 kpc, is generally peaked on the nucleus with regular elliptical isophotes, similar to the red continuum, although with a steeper radial distribution, Low surface brightness filamentary structure is also seen in a few cases (NGC 4406 and NGC 5846). To study the different phases of the interstellar medium in early type galaxies, we have compared the emissions due to hot (x ray) and warm (H{alpha}) gas. On average, galaxies with a larger content of hot gas also show a more powerful line emission. However, the scatter in the relation is significant, and suggests that other parameters must play a role. The depth of the gravitational potential and/or the shape of the objects are probably important in determining the amount of gas present in early type galaxies. Other galaxian properties, such as the optical luminosity, the radio power, or the far-infrared emission do not seem to relate with the H{alpha} emission. We estimate that post-asymptotic giant branch stars provide sufficient ionizing flux to explain the observed line emission.
Retrieve 13 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home