Contents
Images
Upload your image
DSS Images Other Images
Related articles
Supernova 2005M in NGC 2930
IAUC 8474 available at Central Bureau for Astronomical Telegrams.
| Supernovae 2005M and 2005N
IAUC 8470 available at Central Bureau for Astronomical Telegrams.
| 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.
| Galaxy coordinates. II. Accurate equatorial coordinates for 17298 galaxies
Using images of the Digitized Sky Survey we measured coodinates for17298 galaxies having poorly defined coordinates. As a control, wemeasured with the same method 1522 galaxies having accurate coordinates.The comparison with our own measurements shows that the accuracy of themethod is about 6 arcsec on each axis (RA and DEC).
| The H i Mass Function of Galaxies from a Deep Survey in the 21 Centimeter Line
The H I mass function (HIMF) for galaxies in the local universe isconstructed from the results of the Arecibo H I Strip Survey, a blindextragalactic survey in the 21 cm line. The survey, consisting of twostrips covering in total ~65 deg2 of sky, with a depth of cz = 7400 kms-1, was optimized to detect column densities of neutral gas NH I >1018 cm-2 (5 sigma ). The survey yielded 66 significant extragalacticsignals, of which approximately 50% are cataloged galaxies. Nofree-floating H I clouds without stars are found. VLA follow-upobservations of all signals have been used to obtain better measurementsof the positions and fluxes and to allow an alternate determination ofthe achieved survey sensitivity. The resulting HIMF has a shallowfaint-end slope ( alpha ~ 1.2) and is consistent with earlier estimatescomputed for the population of optically selected gas-rich galaxies.This implies that there is not a large population of gas-richlow-luminosity or low-surface brightness galaxies that has goneunnoticed by optical surveys. The influence of large-scale structure onthe determination of the HIMF from the Arecibo H I Strip Survey wastested by numerical experiments and was not found to affect theresulting HIMF significantly. The cosmological mass density of H I atthe present time, determined from the survey, Omega H I(z = 0) = (2.0+/- 0.5) x 10-4 h-1, is in good agreement with earlier estimates. Wedetermine lower limits for the average column densities ofthe galaxies detected in the survey and find that none of the galaxieshave < 1019.7 cm-2, although there are no observationalselection criteria against finding lower density systems. Eight percentof the signals detected in the original survey originated in groups ofgalaxies whose signals chanced to coincide in frequency.
| The Wasilewski sample of emission-line galaxies - Follow-up CCD imaging and spectroscopic and IRAS observations
The results of an extensive imaging and spectroscopic follow-up of theobjective prism-selected emission line galaxy (ELG) sample of Wasilewski(1982) are presented. Fluxes at 12, 25, 60, and 100 microns were alsoobtained from the coadded IRAS survey data. ELGs found by objectiveprism surveys are found to be generally small and underluminous galaxieswhich usually have higher than average optical surface brightness. TheSeyfert detection rate in objective prism surveys is roughly 10 percentand the ratio of the space densities of Seyfert 2 to Seyfert 1 galaxiesis significantly larger than unity. Most of the galaxies selected byobjective prism surveys are star-forming, late-type spirals which oftenshow disturbed morphology. About 25 percent of the galaxies detected bythe surveys are faint, high-excitation metal-poor compact H II regions.
| The space density and spectroscopic properties of a new sample of emission-line galaxies
A 4-deg objective prism survey for low redshift emission line galaxiesconducted over an 825 sq deg region of the sky indicates that a newsample of emission line galaxies is available even in areas which havebeen well searched with the 'excess UV-continuum' technique. Thesegalaxies commonly occur in systems with peculiar morphology, indicatinggravitational interaction with a close companion or other disturbance.The space density of the new galaxies is found to be similar to thespace density of the Markarian galaxies. The present galaxies representabout 8 percent of all nearby galaxies in the -16.5 to -22.5 absolutemagnitude range, and are composed of a population which is completelyindependent of the Markarian sample.
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
Catalogs and designations:
|
