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|Observations of 54 Active Galactic Nuclei with the HEGRA system of Cherenkov telescopes|
A sample of 54 selected Active Galactic Nuclei (AGN) has been observedwith the HEGRA stereoscopic system of Cherenkov Telescopes between 1996and 2002 in the TeV energy regime. The observations were motivated bythe positive results obtained for Mkn 421 and Mkn 501. The distances ofthe selected objects vary over a large range of redshifts between z =0.004 and z = 0.7. Among the observed AGN are the now-establishedTeV-emitting BL Lac type objects H 1426+428 and 1ES 1959+650.Furthermore the BL Lac object 1ES 2344+514 and the radio galaxy M 87show evidence for a signal on a 4 σ level. The observation of 1ES2344+514 together with the Whipple results firmly establishes this AGNas a TeV source. Several objects (PKS 2155-304, BL Lacertae, 3C 066A)that have been claimed as TeV γ-ray emitters by other groups areincluded in this data sample but could not be confirmed using dataanalysed here. The upper limits from several AGN included in thisanalysis are compared with predictions in the frame-work of SSC models.
|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.
|Total magnitude, radius, colour indices, colour gradients and photometric type of galaxies|
We present a catalogue of aperture photometry of galaxies, in UBVRI,assembled from three different origins: (i) an update of the catalogueof Buta et al. (1995) (ii) published photometric profiles and (iii)aperture photometry performed on CCD images. We explored different setsof growth curves to fit these data: (i) The Sersic law, (ii) The net ofgrowth curves used for the preparation of the RC3 and (iii) A linearinterpolation between the de Vaucouleurs (r(1/4) ) and exponential laws.Finally we adopted the latter solution. Fitting these growth curves, wederive (1) the total magnitude, (2) the effective radius, (3) the colourindices and (4) gradients and (5) the photometric type of 5169 galaxies.The photometric type is defined to statistically match the revisedmorphologic type and parametrizes the shape of the growth curve. It iscoded from -9, for very concentrated galaxies, to +10, for diffusegalaxies. Based in part on observations collected at the Haute-ProvenceObservatory.
|A survey of the Pisces-Perseus supercluster. VI - The declination zone +15.5 deg to 21.5 deg|
New results are presented of Arecibo observations in the 21 cm line of765 galaxies with declinations between 15.5 deg and 21.5 deg, in thePisces-Perseus supercluster zone. If considered independently on theneighboring parts of sky, this region, to the South of the superclusterridge, shows significantly less evidence of structure on large scales inexcess of 30 Mpc, contrasting substantially with the characteristics ofthe declination zones immediately to the North.
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