Neutral hydrogen in elliptical galaxies - A bimodal distribution

1980 ◽  
Vol 242 ◽  
pp. 931 ◽  
Author(s):  
R. H. Sanders
Keyword(s):  
Neutral Hydrogen ◽  
Bimodal Distribution ◽  
Elliptical Galaxies

scholarly journals The Cold Gas Content of Elliptical Galaxies

1996 ◽  
Vol 171 ◽  
pp. 393-393
Author(s):  
W.K. Huchtmeier ◽  
L.J. Sage ◽  
C. Henkel
Keyword(s):  
Molecular Hydrogen ◽  
Neutral Hydrogen ◽  
Elliptical Galaxies ◽  
Radial Velocities ◽  
The Other ◽  
Gas Content ◽  
Global Properties ◽  
Two Samples ◽  
Nearby Galaxies ◽  
Cold Gas

The 100m radiotelescope at Effelsberg has been used to observe two samples of elliptical galaxies in the 21cm line of neutral hydrogen. One sample is defined by the elliptical galaxies in the Revised-Shapely-Ames catalog (RSA) (Huchtmeier 1994, Astron.Astrophys 286, p.389); the other sample is defined by all elliptical galaxies with IRAS 100 μ fluxes ≥ 500mJy north of declination –310 (Huchtmeier, Sage, Henkel 1995 Astron.Astrophys. in press). Among the detected galaxies there are 23 (RSA) and 24 (IRAS) isolated elliptical galaxies free of confusion by nearby galaxies with similar radial velocities. Global properties of these two samples of elliptical galaxies are discussed: their HI-properties, optical and IR luminosities, their optical colors, their masses of dust and of molecular hydrogen.

scholarly journals A search for neutral hydrogen in red elliptical galaxies

1985 ◽  
Vol 217 (4) ◽  
pp. 779-786 ◽  
Author(s):  
P. N. Appleton ◽  
W. B. Sparks ◽  
A. Pedlar ◽  
A. Wilkinson
Keyword(s):  
Neutral Hydrogen ◽  
Elliptical Galaxies

Limits to the neutral hydrogen content of elliptical galaxies

1975 ◽  
Vol 80 ◽  
pp. 581 ◽  
Author(s):  
G. S. Shostak ◽  
M. S. Roberts ◽  
S. D. Peterson
Keyword(s):  
Hydrogen Content ◽  
Neutral Hydrogen ◽  
Elliptical Galaxies

scholarly journals Neutral Hydrogen Observations of the Dwarf Elliptical Galaxies NGC 185 and NGC 205

1983 ◽  
Vol 100 ◽  
pp. 307-308
Author(s):  
S. T. Gottesman ◽  
D. W. Johnson
Keyword(s):  
Neutral Hydrogen ◽  
Elliptical Galaxies ◽  
Small Population ◽  
Young Stars ◽  
Dwarf Elliptical Galaxies ◽  
M 31

In this note we report the detection and mapping of neutral hydrogen in two dwarf elliptical galaxies NGC 185 and NGC 205. Both are companions to M 31 and both are classified as peculiar owing to the presence of obscurring dust patches near their nuclei. Both galaxies also contain a small population of blue, presumably young stars (Hodge 1963, 1973).

A Search for HI in Elliptical Galaxies with Nuclear Radio Sources

1982 ◽  
Vol 97 ◽  
pp. 309-310
Author(s):  
L. L. Dressel ◽  
T. M. Bania ◽  
R. W. O'Connell
Keyword(s):  
Neutral Hydrogen ◽  
Large Mass ◽  
Elliptical Galaxies ◽  
Continuum Emission ◽  
Radio Sources ◽  
Upper Limits ◽  
Continuum Radio ◽  
Arecibo Observatory ◽  
Radio Power ◽  
Made In

Many searches have been made in the last few years for 21 cm emission from neutral hydrogen in elliptical galaxies. Emission has been detected in several galaxies, which have 108 to 109 M⊙ of HI (for H○ = 100 km s−1Mpc−1). Upper limits between 106 and 109 M⊙ have been set for the HI mass in about 40 other galaxies. Why most E galaxies have so little gas, and why some few have detectable gas, remains a matter of great interest. Two of the galaxies with large HI mass, NGC 1052 and 4278, are known to have powerful nuclear continuum radio sources (P2380 ∼ 1022 WHz−1). Since both of these attributes are fairly rare among elliptical galaxies, their coexistence in these galaxies is not likely to have occurred by chance. We have therefore observed twelve other elliptical galaxies with nuclear radio power P2380 > 1022 WHz−1 at Arecibo Observatory, to determine whether a large mass of HI is a necessary auxillary to nuclear continuum emission.

Motions of neutral hydrogen at high latitudes

1967 ◽  
Vol 31 ◽  
pp. 265-278 ◽  
Author(s):  
A. Blaauw ◽  
I. Fejes ◽  
C. R. Tolbert ◽  
A. N. M. Hulsbosch ◽  
E. Raimond
Keyword(s):  
Surface Density ◽  
Velocity Dispersion ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
High Latitudes ◽  
Low Velocity

Earlier investigations have shown that there is a preponderance of negative velocities in the hydrogen gas at high latitudes, and that in certain areas very little low-velocity gas occurs. In the region 100° <l< 250°, + 40° <b< + 85°, there appears to be a disturbance, with velocities between - 30 and - 80 km/sec. This ‘streaming’ involves about 3000 (r/100)2solar masses (rin pc). In the same region there is a low surface density at low velocities (|V| < 30 km/sec). About 40% of the gas in the disturbance is in the form of separate concentrations superimposed on a relatively smooth background. The number of these concentrations as a function of velocity remains constant from - 30 to - 60 km/sec but drops rapidly at higher negative velocities. The velocity dispersion in the concentrations varies little about 6·2 km/sec. Concentrations at positive velocities are much less abundant.

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

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