LOW-MASS COLLISIONLESS PARTICLES AND GALAXY FORMATIONMatzner, R. A.
doi: 10.1086/131321pmid: N/A
Collisionless particles with masses ⪉100 eV ("massive neutrinos") would play a substantial role in the early development of density inhomogeneities in the expanding universe. Detailed calculations of 3- and 1-dimensional processes in an initially-slightly inhomogeneous cosmology show 3-d structure similar to the voids/pancake/string nature of the observations of large clusters of galaxies, and 1-d consistency with galaxy formation in neutrino-initiated pancake collapse. The 1-dimensional calculations apparently require a large baryon fraction ≡90% in hot intergalactic gas, in models which are essentially closed by massive neutrinos, and contain baryons at ≡0.1 closure density. These models are consistent, but 'delicately' so, with observations. Condensations based on heavier stable particles (m ⪆ 1 keV) would have typically galaxy - or smaller - sizes. They appear to be excluded because the cluster-of-galaxies correlation function is very much larger than that observed for galaxies. It is difficult to see how this result can be obtained by a dynamical clustering process, as would be required if collapses were initiated on galactic scales by heavy stable collisionless particles.
BRIGHTNESS PROFILES FOR 69 GLOBULAR CLUSTERS DETERMINED BY MEANS OF THE ELECTRONIC CAMERA.Kron, G. E.; Hewitt, A. V.; Wasserman, L. H.
doi: 10.1086/131322pmid: N/A
The present 109 partial profiles are of the surface brightness of 69 globular clusters. All but two were determined by PDS microphotometry of electronic camera recordings. Some objects were recorded through UBV filters, while others were recorded more than once with the same filter (or none) for a check on consistency. For the outer regions (representing most of each cluster), the observed profiles agree well with the theoretical profiles of King (1966). For the core regions, however, there exist some clusters for which there is significant disagreement with the King profiles.
A STUDY OF THE PECULIAR GALAXY VV371 AND A NEARBY COMPANION.Scholl, J. F.; Grayzeck, E. J.
doi: 10.1086/131323pmid: N/A
A study of the peculiar galaxy VV371, and a possible nearby companion is presented. Results from digital imaging techniques are given for blue and visual photographs of VV371. H-alpha photographic data are also presented. Masses, sizes, and distances are then calculated for the two galaxies from 21-cm H I distribution data. Discussions of tidal and dynamical stability concerning the system are presented.
A HIGH-RESOLUTION INFRARED SPECTRUM OF THE WOLF-RAYET STAR HD 193793.Lambert, D. L.; Hinkle, K. H.
doi: 10.1086/131324pmid: N/A
A high-resolution infrared (2.0 - 2.4 μm) spectrum of the WC7 Wolf-Rayet star HD 193793 is presented. A weak He I 2p1P0 - 2s1S absorption line is identified at a velocity of -2650 km s-1. Emission lines are identified with transitions in He I, He II (weak), and C IV. The strongest emission line at about 2.06 μm has previously been assigned to He I 2p1P0 - 2s1S with C IV 3d → 3p as a minor contributor but the authors' spectrum shows that C IV not He I is the dominant contributor. A preliminary analysis of the recombination lines gives an abundance ratio C/He > 0.08.
NIOBIUM AND RUBIDIUM IN THE BARIUM STAR ZETA CAPRICORNI.Smith, V. V.; Lambert, D. L.
doi: 10.1086/131325pmid: N/A
An abundance analysis of the elements Rb to Nb (relative to the G-giant standard ∊ Vir) has been carried out for the barium star ζ Cap using low-noise, high-resolution Digicon and Reticon spectra. Tech's (1971) low abundance of Nb in ζ Cap suggests that the s-process ceased less than about a million years ago. The authors' improved analysis finds a higher Nb abundance consistent with the complete decay of 93Zr to 93Nb; i.e., more than 3×106 years have elapsed since the principal phase of s-processing. The abundance of Rb suggests a neutron density of Nn ≡ 107cm-3 for the s-process site at the close of s-processing.
THE HE I D3 LINE IN G AND K STARS.Wolff, S. C.; Heasley, J. N.
doi: 10.1086/131326pmid: N/A
High-resolution spectra have been obtained of 18 late-type stars in order to search for He I λ5876. This feature is present in main-sequence stars that are known to have active chromospheres, and the line widths, depths, and the ratio λ10830/λ5876 in integrated starlight are similar to what is measured in solar plages. The line λ5876 is also present, with an equivalent width of 35 mÅ, in the RS CVn star λ And. In the remaining giants and supergiants in the present sample, the ratio λ10830/λ5876 is apparently much larger than it is in either solar plages or active dwarfs, and the conditions under which the helium triplet lines are formed may be very different in highly luminous stars. Theoretical analyses of the line-formation process indicate coronal emission may not be the dominant factor in determining the helium level populations in main-sequence stars.
LITHIUM IN THE BARIUM STARS.Pinsonneault, M. H.; Sneden, C.; Smith, V. V.
doi: 10.1086/131327pmid: N/A
New high-resolution spectra of the lithium resonance doublet have provided lithium abundances or upper limits for 26 classical and mild barium stars. The lithium lines always are present in the classical barium stars. Lithium abundances in these stars obey a trend with stellar masses consistent with that previously derived for ordinary K giants. This supports the notion that classical barium stars are post-core-He-flash or core-He-burning stars. Lithium contents in the mild barium stars, however, often are much smaller than those of the classical barium stars; sometimes only upper limits may be determined. The cause for this difference is not easily understood, but may be related to more extensive mass loss by the mild barium stars.
LIGHT CURVE VARIATIONS AND H-ALPHA FLARING OF FK COMAE.Dorren, J. D.; Guinan, E. F.; McCook, G. P.
doi: 10.1086/131329pmid: N/A
Multiband photoelectric observations reveal that the rapidly rotating giant FK Com's light curve is rapidly changing with respect to amplitude, shape, and light minimum phase. Analysis of the light curves indicates that these variations are due to rotational modulation by two large, subluminous regions on the star's surface, which appear to be about 800 + or - 150 K cooler than the star's photosphere. Flaring activity in the H-alpha emission is also noted, but there is no modulation of this emission with the 2.4-day photometric period or with any other period. This behavior is contrasted with the mechanisms suggested in the Walter and Basri (1982) model for the light variations.
ANOMALOUS C IV AND SI IV RESONANCE LINES IN 36 LYNCIS.Sadakane, K.
doi: 10.1086/131330pmid: N/A
Anomalously strong resonance lines of C IV and Si IV are found in the UV spectrum of the chemically peculiar star 36 Lyncis. The C IV resonance lines near 1550 Å are not found in about 40 other middle or late B-type main-sequence stars. The C IV lines (Wλ ≡ 1.0 Å) are stronger than the Si IV lines (Wλ ≡ 0.7 Å) in 36 Lyn and such an intensity ratio is quite exceptional. The continuous energy distribution of 36 Lyn in the UV region fits with those of late B-type stars. The presence of a hot gas (chromosphere or corona) is suggested.