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|The UZC-SSRS2 Group Catalog|
We apply a friends-of-friends algorithm to the combined Updated ZwickyCatalog and Southern Sky Redshift Survey to construct a catalog of 1168groups of galaxies; 411 of these groups have five or more members withinthe redshift survey. The group catalog covers 4.69 sr, and all groupsexceed the number density contrast threshold, δρ/ρ=80. Wedemonstrate that the groups catalog is homogeneous across the twounderlying redshift surveys; the catalog of groups and their membersthus provides a basis for other statistical studies of the large-scaledistribution of groups and their physical properties. The medianphysical properties of the groups are similar to those for groupsderived from independent surveys, including the ESO Key Programme andthe Las Campanas Redshift Survey. We include tables of groups and theirmembers.
|Arcsecond Positions of UGC Galaxies|
We present accurate B1950 and J2000 positions for all confirmed galaxiesin the Uppsala General Catalog (UGC). The positions were measuredvisually from Digitized Sky Survey images with rms uncertaintiesσ<=[(1.2")2+(θ/100)2]1/2,where θ is the major-axis diameter. We compared each galaxymeasured with the original UGC description to ensure high reliability.The full position list is available in the electronic version only.
|The structure of spiral galaxies - II. Near-infrared properties of spiral arms|
We have imaged a sample of 45 face-on spiral galaxies in the K band, todetermine the morphology of the old stellar population, which dominatesthe mass in the disc. The K-band images of the spiral galaxies have beenused to calculate different characteristics of the underlying densityperturbation such as arm strengths, profiles and cross-sections, andspiral pitch angles. Contrary to expectations, no correlation was foundbetween arm pitch angle and Hubble type, and combined with previousresults this leads us to conclude that the morphology of the old stellarpopulation bears little resemblance to the optical morphology used toclassify galaxies. The arm properties of our galaxies seem inconsistentwith predictions from the simplest density wave theories, and someobservations, such as variations in pitch angle within galaxies, seemhard to reconcile even with more complex modal theories. Bars have nodetectable effect on arm strengths for the present sample. We have alsoobtained B-band images of three of the galaxies. For these galaxies wehave measured arm cross-sections and strengths, to investigate theeffects of disc density perturbations on star formation in spiral discs.We find that B-band arms lead K-band arms and are narrower than K-bandarms, apparently supporting predictions made by the large-scale shockscenario, although the effects of dust on B-band images may contributetowards these results.
|The structure of spiral galaxies - I. Near-infrared properties of bulges, discs and bars|
We present data for a sample of 45 spiral galaxies over a range ofHubble types, imaged in the near-IR JK bands. Parameters are calculateddescribing the bulge, disc and bar K-band light distributions, and welook for correlations showing the interrelation between thesecomponents. We find that bulge profiles are not well-fitted by theclassic de Vaucouleurs profile, and that exponential or R^1/2 fits arepreferred. The bulge-to-disc ratio correlates only weakly with Hubbletype. Many of the galaxies show central reddening of their J-K colours,which we interpret as due to nuclear starbursts or dusty AGN. We definea new method for measuring the strength of bars, which we call`equivalent angle'. We stress that this is better than the traditionalbar-interbar contrast, as it is not subject to seeing and resolutioneffects. Bars are found in 40 of the 45 galaxies, nine of which had beenpreviously classified as unbarred. Bar strengths are found not tocorrelate with disc surface brightness or the presence of nearneighbours, but a tendency is found for the most strongly barredgalaxies to lie within a restricted, intermediate range of bulge-to-discratio. Bar light profiles are found to be either flat or exponentiallydecreasing along their long axes, with profile type not correlatingstrongly with Hubble type. Bar short axis profiles are significantlyasymmetric, with the steeper profile being generally on the leadingedge, assuming trailing arms. In the K band we find bars with higheraxial ratios than have been found previously in optical studies.
|21 CM H1 Line Spectra of Galaxies in Nearby Clusters|
A compilation of HI line fluxes, systemic velocities and line widths ispresented for \Ndet detected galaxies, mostly in the vicinities of 30nearby rich clusters out to a redshift of z ~ .04, specifically for usein applications of the Tully-Fisher distance method. New 21 cm HI lineprofiles have been obtained for ~ 500 galaxies in 27 Abell clustersvisible from Arecibo. Upper limits are also presented for \Nnod galaxiesfor which HI emission was not detected. In order to provide ahomogeneous line width determination optimized for Tully-Fisher studies,these new data are supplemented by the reanalysis of previouslypublished spectra obtained both at Arecibo and Green Bank that areavailable in a digital archive. Corrections for instrumental broadening,smoothing, signal-to-noise and profile shape are applied, and anestimate of the error on the width is given. When corrected forturbulent broadening and viewing angle, the corrected velocity widthspresented here will provide the appropriate line width parameter neededto derive distances via the Tully-Fisher relation.
|Large-Scale Structures in the Zone of Avoidance: The Galactic Anticenter Region|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995ApJ...449..527L&db_key=AST
|A study of the large-scale structure in the distribution of galaxies in a region centered about the Cancer cluster. I - Initial observational results. II - Further observational results|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1986AJ.....91..705B&db_key=AST
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