High resolution mapping of galactic \hi in the direction of 3C147
P. M. W. Kalberla, U. J. Schwarz, W. M. Goss;
AaA, 1985, 144, 27
ABSTRACT:In the present high resolution H I emission and absorption data for the field of 3C147, the H I brightness temperature distribution is clumpy and the
absorption features are identifiable with 3-6 arcmin features whose brightness
temperatures lie in the 4-10 K range.
The clumps have excitation temperatures in the
34-74 K range, with H I masses between 0.03 and 0.5 solar masses (assuming a
distance of 500 pc).
The clumps of absorbing H I gas are associated with extended
warm halos which dominate the observed H I emission.
The fact that the
absorbing gas is concentrated in small scale clumps severely constrains the
interpretation of available apparent spin temperatures, since they are not direct
indicators of the excitation temperature of the H I gas.
KEYWORDS: absorption spectra, astronomical maps, hydrogen clouds, neutral gases, radio sources (astronomy), spin temperature, brightness temperature, gas density, mass distribution, microwave emission, microwave spectra
PERSOKEY:h_i, ,
CODE: kalberla85