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The radial velocities of radio recombination lines from 15 to 20,000 GHz facilitate a kinematic probe of the stellar wind (outflow) from MWC 349A. These data and an earlier fit to the free-free continuum emission determine the radial velocity of the stellar wind out to more than 100 AU. The derived gas flow fits a "beta law" with β = 6 and a terminal velocity of 32 km s-1. The derived mass loss via the wind is about 4 × 10-6 M☉ yr-1 at a radius of 50 AU from the star, comparable to the value derived earlier by Cohen et al. by modeling an image of the 5 GHz emission observed with the Very Large Array. This outflow could also be the evaporation from the circumstellar disk rather than a conventional stellar wind. The stellar recession velocity appears to be about 12 km s-1.

Observations of the H30? (231?GHz) and H35? (147?GHz) recombination lines from MWC 349?we assume from the MWC 349A star?from 1997 May through 2000 June show variations in the intensities and radial velocities of the strongly masing, double-peaked lines on scales of a few weeks to a few months. The data include a few observations of the H40? (99?GHz) line during this period. We examine intensities, widths, and radial velocities of the line components and intensities of the free-free continuum emission. We detect both positive and negative correlations between the variations of some of these parameters, as well as a lack of correlation. We consider these results in terms of a differentially rotating, inhomogeneous disk viewed edge-on, having a considerable radial component of gas motion and surrounding a central object with strong, variable UV emission.

Observations of double-peaked, masing H29α, H30α, and H31α radio recombination lines (RRLs), at 256-210 GHz, from the binary star system MWC 349 show variations over a period of 2 yr. Both the velocity separation of the peaks and the intensity ratio V/R of the violet (V)- and red (R)-shifted components vary similarly to what has been observed in optical and IR lines from Be stars

From observations of seven elliptical galaxies selected by the strength of their far-infrared (FIR) fluxes, the detection of CO (2 - 1) in the central regions of NGC 3265 and NGC 5666, classified as E4 and Ec, respectively, is reported. Observed with the FWHM beam of 17 arcsec of the IRAM telescope, the CO radial velocities and line widths agree well with H I spectra emitted from a much more extended region, caused partly by rigid rotation in their nuclear regions but also implying a contribution from extensive noncircular motions in the interstellar gas. The shapes of the CO profiles indicate velocity structure within the beam. The observational ratios of CO/H I fluxes are similar to those found in early-type galaxies. The data also imply H2 masses of 1.7 {times} 10 to the 8th and 3.8 {times} 10 to the 8th solar masses for the central regions of NGC 3265 and NGC 5666, respectively, giving for those regions H2/H I mass ratios of about three that are comparable to what is observed for the inner region of the Milky Way. 29 refs.

Observations of H36-alpha, He36-alpha, H40-alpha, He40-alpha, H44-beta, He44-beta, H45-beta, H50-beta, H50-gamma, H56-delta, H57-gamma, and H60-epsilon radio recombination lines in the 2 and 3 mm telluric windows made with the IRAM 30 m telescope on Pico Veleta, Spain are presented. Sources observed were the H II regions W3, NGC 1976, NGC 2024, Sgr B2, M17, W49, and DR 21. The observations are consistent with non-LTE models based upon centimeter-wave observations. The millimeter-wave recombination lines show no substantive indication of excitation by Lyman line radiation from nearby exciting stars so that conventional departure coefficients may be used with confidence. However, small departures from the expected line ratios have been found in some cases which merit additional investigation. 32 refs.

Les observations de l'emission du continuum des nuages de poussiere Cep A et Cep B sont presentees a 1300 et 865 μm. Ces donnees, combinees aux densites de flux IRAS et a d'autres observations, definissent le spectre du continuum de l'emission de poussiere integre sur les sources. A partir de ces spectres sont etablis les luminosites, les temperatures, les densites de colonne, les masses, les facteurs de remplissage, les dimensions des agregats, et les densites volumiques et ces resultats sont compares avec les observations des nuages moleculaires au voisinage de Cep A et avec les caracteristiques d'autres nuages de poussiere galactiques

The detection of CO(2 - 1) emission from five positions within the blue elliptical galaxy NGC 3928 (Mrk 190) is reported. The spectra indicate discrete components with a velocity gradient of about 190 km/s over a projected distance of about 2 kpc and a total CO luminosity of 800,000 Jy km/s sq Mpc. The CO emission implies a mass of roughly 5.1 x 10 to the 8th masses of H2. Compared to a H I mass of 2.8 x 10 to the 7th solar masses, the mass ratio of H2/H1 is at least 18 in the inner region of the galaxy, a situation similar to what is seen in the inner regions of spiral galaxies. 17 refs.

The paper presents the continuum spectrum of large, warm interstellar clouds associated with the H II regions W3 Main, M42, NGC 2024, Sgr B2, and M17, supplementing spectra previously published by Gordon (1987) for W3 Main, M42, W49 A, and W 51 A. These clouds appear to be highly fragmented such that the color temperatures derived from their continuum spectra may represent average temperatures within the clouds. Their color temperatures range from 30-110 K. The possibility that the high temperatures of OMC-1 could have evaporated ice mantles from its grains is discussed. 38 references.

Observations of emission at 2.6 mm from /sup 12/CO, /sup 13/CO, and C/sup 18/O from the nearby dark clouds L255, L673, L1471, and L1613 permit calculations of their molecular column densities for both CO and H/sub 2/. Two of these clouds, L1613 and L673, are known to emit continuum radiation at millimeter wavelengths: presumably from embedded heated dust grains. The continuum emission correlates with the spatial distribution of the molecular column densities.

Millimeter-wave continuum and CO spectral line observations of SS 433 and the IRAS-detected infrared objects in the vicinity of SS 433 are reported. The 90 GHz flux from SS 433 was 0.087 + or - 0.037 Jy, consistent with an extrapolation of the lower frequency radio power-law spectrum. A 203 GHz upper limit for SS 433 is determined. Upper limits only were derived for two of the infrared objects at 90 and 203 GHz. The (C-12)O spectral lines from four of the infrared objects to the west of SS 433 were detected in the same velocity range as the western optical filaments and the nearby H II region S74. The masses and H2 column densities derived from the (C-12)O and (C-13)O lines are consistent with dark molecular clouds. It is suggested that the infrared sources and S74 are part of a gas complex in front of SS 433 and W50. 36 references.

High-sensitivity observations of the 2.6 mm spectral line of /sup 12/CO show the detailed distribution of cold interstellar material along the galactic equator in the first longitude quadrant. The fact that /sup 12/CO and /sup 13/CO lines have the same general shape indicates effective optical thinness of the /sup 12/CO lines and thus permits derivation of the galactic distribution of CO volume and surface densities. Relating the CO densities to those of H/sub 2/ on the basis of solar abundances gives the galactic arrangement of H/sub 2/, and, with the distribution of H I, of total interstellar nucleons smoothed over galactic azimuth. The mode of the CO and H/sub 2/ volume density distributions is 5.8 kpc; here the volume densities of CO and H/sub 2/ are respectively 1.2 x 10/sup -4/ cm/sup -3/ and 2.0 cm/sup -3/, and the surface densities projected through the galactic disk are respectively 1.0 x 10/sup -2/ M/sub sun/ pc/sup -2/ and 12 M/sub sun/ pc/sup -2/. Integration of the distributions gives the galactic mass of CO, 2 x 10/sup 6/ M/sub sun/, and of H/sub 2/, 2 x 10/sup 9/ M/sub sun/. At galactic radii >5 kpc, the surface density of gas is approximatelymore » 4 percent of the surface density of total mass predicted by Innanen, implying a uniform efficiency for star formation. (AIP)« less

Observations of the 2.6 mm line of /sup 12/CO, made at l=21degree between b=+2degree and -2degree, are modeled well by a Gaussian distribution in z of dispersion 50 +- 10 pc. The model consists of a stochastic assemblage of dark clouds, each having a diameter of 5 pc, an excitation temperature of 16 K, a representative optical depth of 5, an internal dispersion of 2.5 km s/sup -1/, and a cloud-to-cloud separation of 800 pc at the mode (5.8 kpc) of the previously observed variation with galactocentric radius. Presumably these parameters also describe H/sub 2/ in the Galaxy. Comparison with H I observations clearly show the molecular layer to be thinner and more clumpy than the much more ubiquitous atomic hydrogen. (AIP)

The 2.6-mm line of $sup 12$CO is observed at 5degree longitude intervals along the galactic equator between l=10degree and 200degree with a velocity coverage sufficient to include all velocities expected in terms of differential galactic rotation. CO emission is generally observed at positive velocities (LSR) at l 8 kpc and R R$sub 0$=10 kpc, only a few isolated emission peaks are found, generally associated with known H ii regions. Histograms of abundance as a function of R are given for the distributed CO and H i, and for giant H ii regions. H ii and CO show amore » rather similar large-scale distribution (although that of the H ii is less regular); both are more concentrated than H i to the inner Galaxy as well as more concentrated than H i to the galactic plane. Similar morphological characteristics also distinguish the distribution of OH, supernova remnants, very young stars, pulsars, $gamma$-radiation, and diffuse H ii gas from that of the neutral hydrogen. The relative distributions are amenable to interpretation in terms of compression on a galactic scale associated with density-waves. (AIP)« less

Observations at 14 positions in the direction of the galactic center region show H159 alpha (1.621 GHz) hydrogen rccombination lines over an extended area. The lines do not originate under conditions of LTE. Comparison of one of the spectra with a neutralhydrogen absorption profile taken in the same direction shows a coincidence of features. The data is best interpreted as emission from a region with electron temperature of 20 deg K and an electron density of 3 cm/sup - 3/ lying along the line of sight to the galactic center. This model is also consistent with the observations of diffuse H157 alpha and H166 alpha line emission from the inner regions of the Galaxy. (auth)

An optically invisible giant dust complex has been detected through observations in H/sub 2/CO, OH, and H I. Its distance is about 4400 pc and the dimensions roughly 38 x 13 pc. Derived column densities are 3.8 x 10/sup 13/ for H/sub 2/CO, 1 x 10/sup 14/ for OH, and 2.3 x 10/sup 19/ cm/sup -2/ for H I. The plausibility of these values is discussed. (auth)