Galactic H II Regions. II. Observations of Their Hydrogen 109α Recombination-Line Radiation at the Frequency 5009 MHz

1967 ◽  
Vol 147 ◽  
pp. 490 ◽  
Author(s):  
P. G. Mezger ◽  
B. Hoglund
Keyword(s):  
H Ii Regions ◽  
Recombination Line ◽  
Line Radiation

Recombination-line and continuum observations of compact H II regions at 10.5 GHz

1976 ◽  
Vol 81 ◽  
pp. 512 ◽  
Author(s):  
M. R. Viner ◽  
J. N. Clarke ◽  
V. A. Hughes
Keyword(s):  
H Ii Regions ◽  
Recombination Line

scholarly journals A Survey of Recombination-line Abundances in Planetary Nebulae and H II Regions

2003 ◽  
Vol 209 ◽  
pp. 383-384 ◽  
Author(s):  
Y. G. Tsamis ◽  
M. J. Barlow ◽  
X.-W. Liu ◽  
I. J. Danziger
Keyword(s):  
Planetary Nebulae ◽  
Magellanic Cloud ◽  
H Ii Regions ◽  
Recombination Line ◽  
Large Aperture

We have derived C, N and O abundances, relative to H, using optical recombination lines (ORLs), for a number of galactic planetary nebulae and for three Magellanic Cloud PNe (LMC N66, N141, SMC N87) and compared them with the corresponding abundances derived from collisionally-excited lines (CELs). Our goal was to investigate the fact that PNe ORL abundances are in most cases larger than those obtained from CELs. Our scanning, long-slit observations were combined with large-aperture IUE, IRAS and ISO data to yield integrated abundances for more than half of our target objects.

scholarly journals Maser Sources in H ii Regions

1974 ◽  
Vol 60 ◽  
pp. 267-273 ◽  
Author(s):  
B. F. Burke
Keyword(s):  
Background Radiation ◽  
Formation Rate ◽  
Infrared Emission ◽  
Radio Continuum ◽  
H Ii Regions ◽  
Line Radiation ◽  
Compact Source ◽  
Stellar Formation ◽  
Exciting Star ◽  
Compact Sources

When OH and H2O sources are found in Hii regions, a compact source of radio continuum and infrared emission is usually, perhaps always, found nearby, < 1017 cm away (approximately the conjectured size of a prestellar condensation). Whether the masers are self-excited, are amplifying the background radiation, or are themselves associated with an exciting star is clearly model-dependent, and observations have not yet given the answer. H2O masers occur less frequently than OH masers. When they occur together they appear as a cluster of compact sources of line radiation, exhibiting the same range of radial velocities, The OH sources nearly always are strongly polarized, while the H2O maser is not. Both classes of maser are probably saturated, and some care is needed in inferring the maser geometry from the observations. The period of stability of neither OH nor H2O can be much more than 103 yr, and this fact can be used as an estimator of stellar formation rate.

scholarly journals Recombination Line Survey of Galactic H II Regions.

1967 ◽  
Vol 72 ◽  
pp. 824
Author(s):  
E. C., III Reifenstein ◽  
T. L. Wilson ◽  
B. F. Burke ◽  
P. G. Gomez
Keyword(s):  
H Ii Regions ◽  
Recombination Line ◽  
Line Survey

A hydrogen and helium radio recombination-line survey of galactic H II regions at 10 GHz

1979 ◽  
Vol 229 ◽  
pp. 524 ◽  
Author(s):  
S. M. Lichten ◽  
L. F. Rodriguez ◽  
E. J. Chaisson
Keyword(s):  
H Ii Regions ◽  
Recombination Line ◽  
Radio Recombination Line ◽  
Line Survey

scholarly journals UNTANGLING THE RECOMBINATION LINE EMISSION FROM H ii REGIONS WITH MULTIPLE VELOCITY COMPONENTS

2015 ◽  
Vol 810 (1) ◽  
pp. 42 ◽  
Author(s):  
L. D. Anderson ◽  
L. A. Hough ◽  
TREY V. Wenger ◽  
T. M. Bania ◽  
Dana S. Balser
Keyword(s):  
Line Emission ◽  
H Ii Regions ◽  
Recombination Line

A survey of recombination-line radiation from galactic H 11 regions

1967 ◽  
Vol 31 ◽  
pp. 229-231
Author(s):  
P. G. Mezger
Keyword(s):  
Recombination Line ◽  
Line Radiation

This paper summarizes the results of observations of the hydrogen 109 α line at 5009 MHz in galactic H 11 regions.

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