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PGC 36774



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Analysis of possible anomalies in the QSO distribution of the Flesch & Hardcastle catalogue
Aims.A recent catalogue by Flesch & Hardcastle presents two majoranomalies in the spatial distribution of QSO candidates: i) an apparentexcess of such objects near bright galaxies, and ii) an excess of verybright QSO candidates compared to random background expectations inseveral regions of the sky. Because anyone of these anomalies would berelevant in a cosmological context, we carried out an extensive analysisof the probabilities quoted in that catalogue. Methods: We determinethe nature and redshift of a subsample of 30 sources in that catalogueby analysing their optical spectra (another 11 candidates wereidentified from existing public databases). These have allowed us tostatistically check the reliability of the probabilities QSO statusquoted by Flesch & Hardcastle for their candidates. Results: Only12 of the 41 candidates turned out QSOs (7 of which have been identifiedhere for the first time). Conclusions: The probabilities of the QSOs'being the candidates given by Flesch & Hardcastle are overestimatedfor mB ≤ 17 and for objects projected near (≤1 arcmin)bright galaxies. This is the cause of the anomalies mentioned above.

The Ursa Major Supercluster of Galaxies: II. The Structure and Peculiar Velocities
Kormendy's relation (mu_e - log R_e) is used to investigate thestructure of the compact Ursa Major supercluster of galaxies (11h30m+55deg, cz = 18000 km/s); this relation allows the distances ofearly-type galaxies to be estimated. The relative distances of 13clusters in the supercluster and their peculiar velocities aredetermined with a mean statistical accuracy of 6%. In general, thesupercluster obeys the Hubble relation between radial velocity anddistance. However, there is reason to suggest that the superclusterconsists of two subsystems with mean radial velocities of 16200 and19700 km/s. For a velocity dispersion in the subsystems of about 1100km/s, the fact that each of them is gravitationally bound is not ruledout.

The Ursa Major Supercluster of Galaxies: I. The Luminosity Function
Catalogs of bright galaxies in the central regions of 11 clusters in theUrsa Major supercluster are presented. Absolute and relative coordinatesand total B and R magnitudes are given for each galaxy. Plates takenwith the 2-m Tautenburg Observatory telescope and CCD images obtainedwith the 6-m and 1-m SAO telescopes are used. The luminosity functions(LFs) for galaxies in the cluster nuclei (3 Mpc x 3 Mpc) and thecomposite LF for the supercluster are constructed. The composite LF iswell fitted by a Schechter function with M_B^* = - 20.91 mag, alpha =-1.02 and with M_R^* = - 22.39 mag, alpha = -1.06. A comparison with theLFs of field galaxies and of various samples of clusters andsuperclusters shows that the Ursa Major supercluster have LF parameterscharacteristic of the field and, thus, differ from those of the CoronaBorealis supercluster, which is apparently at a later stage of dynamicalevolution.

An image database. II. Catalogue between δ=-30deg and δ=70deg.
A preliminary list of 68.040 galaxies was built from extraction of35.841 digitized images of the Palomar Sky Survey (Paper I). For eachgalaxy, the basic parameters are obtained: coordinates, diameter, axisratio, total magnitude, position angle. On this preliminary list, weapply severe selection rules to get a catalog of 28.000 galaxies, wellidentified and well documented. For each parameter, a comparison is madewith standard measurements. The accuracy of the raw photometricparameters is quite good despite of the simplicity of the method.Without any local correction, the standard error on the total magnitudeis about 0.5 magnitude up to a total magnitude of B_T_=17. Significantsecondary effects are detected concerning the magnitudes: distance toplate center effect and air-mass effect.

Properties of nearby clusters of galaxies. II. A 151, A 637, A 646, A 649, A 655, A 1132, A 1314, A 1377, A 1570, A 1589.
We present F band photometry, from digitized 48-inch Palomar plates, of1167 galaxies brighter than m_3_+3 in 10 Abell clusters. For eachgalaxy, absolute coordinates, magnitude, size, ellipticity endorientation are given. For each cluster we provide finding charts andcontour maps of the galaxy surface density.

A catalog of morphological types in 55 rich clusters of galaxies
Data are presented from a study of 55 rich clusters of galaxies. Thedata include positions, morphological types, estimated total magnitudes,bulge sizes, and ellipticities for about 6000 galaxies, as determinedfrom high scale photographic plates. Data reduction procedures aredescribed, and a brief analysis of cluster richness, which indicatesthat Abell richness classes are only rough indicators of total clustermembership, is included.

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Observation and Astrometry data

Constellation:Ursa Major
Right ascension:11h47m21.60s
Aparent dimensions:0.977′ × 0.708′

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