תוכן
תמונות
הוסף תמונה שלך
DSS Images Other Images
מאמרים קשורים
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.
| CCD galaxy photometry and the calibration of photographic surveys
We present CCD UBVRI aperture photometry and total B-band magnitudes fora sample of 155 galaxies with B<~18 covering 14UK Schmidt fields. The data, taken on a variety of telescopes, have beenacquired in order to calibrate photographic photometry on these fields.Using these data, we discuss the calibration of photographic galaxysurveys at these magnitudes, and show that the accuracy of suchphotometry is potentially better than +/-0.05 mag. However, data fromboth the COSMOS and APM automatic plate measuring machines show strongsurface-brightness-dependent systematic errors, which primarily manifestthemselves as a much increased scatter (~+/-0.25 mag). The cause ofthese effects is almost certainly related to the limited dynamic rangeof the automated machines. They have the potential to introduce scaleerrors of up to ~0.1 mag per magnitude into the photographic magnitudes,and we discuss the implications of this for bright galaxynumber-magnitude counts. We show evidence for a scale error in the APMgalaxy survey magnitudes. Our revised APM magnitudes allow a standard,non-evolving cosmological model to fit the APM galaxy counts in therange 17<B<20, although this model continuesto overpredict the galaxy count at brighter magnitudes.
| Galaxy structures in the Hercules region
216 redshifts have been obtained in a region of 981 sq deg south of theHercules supercluster. 172 of these redshifts are of galaxies withmpg less than or equal to 15.1, 110 of which had no previousvelocity measurement. 44 new redshifts are of galaxies fainter thanmpg = 15.1. With these new data we have been able to define asample in a vast region (approximately 1700 sq deg) around Herculeslimited to mpg less than or equal to 15.1 with a velocitycompleteness of 81.5%. 189 galaxies have been morphologically classifiedso that all galaxies in the sample with known velocity now also haveknown morphology. The magnitude limited sample, including 556 galaxies,is then used to identify and describe galaxy structures in the region.We find that the overdense volume is small, that its overall appearanceis that of a coral branch floating in a sea of nothing and that earlyand late type galaxies defined different structures.
| An extended galaxy redshift survey. I - The catalogue
Redshifts and blue magnitudes are presented for a sample of 264 'field'galaxies virtually complete to a limiting magnitude of 16.80 mag. Thegalaxies were selected by sampling one galaxy in every three in order ofapparent magnitude on each of nine high-latitude UK Schmidt (UKST)fields. The spectral data came from observations with the 1.9-mtelescope at the South African Astronomical Observatory (SAAO), and theresulting radial velocities have a precision of 130 + or - km/s. Thissurvey augments substantially the Durham/AAT redshift survey. Theobservational techniques and reduction procedures are discussed.
| Isolated Triplets of Galaxies - a Complete Summary of Radial Velocities and Reduced Data
Not Available
|
הכנס מאמר חדש
לינקים קשורים
הכנס לינק חדש
משמש של הקבוצה הבאה
|
תצפית ומידע אסטרומטרי
קטלוגים וכינוים:
|
