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|Swift/XRT Detection of the Hard X-ray Sources IGR J18244-5622 and IGR J21178+5139|
Two INTEGRAL sources, IGR J18244-5622 and IGR J21178+5139, have recentlybeen observed and detected with the Swift/XRT X-ray telescope. In thefollowing we report the results of these measurements: IGRJ18244-5622 The XRT observation locates the source at RA = 18 24 19.49,Dec = -56 22 08.72 [J2000] with an error of 4.4", thus confirming aprevious association with the Sey2 galaxy IC 4709 at z=0.017 (seeMasetti et al.
|Unveiling the nature of INTEGRAL objects through optical spectroscopy. V. Identification and properties of 21 southern hard X-ray sources|
Optical spectroscopic identification of the nature of 21 unidentifiedsouthern hard X-ray objects is reported here in the framework of ourcampaign aimed at determining the nature of newly-discovered and/orunidentified sources detected by INTEGRAL. Our results show that 5 ofthese objects are magnetic Cataclysmic Variables (CVs), 4 are High-MassX-ray Binaries (HMXBs; one of which is in the Large Magellanic Cloud)and 12 are Active Galactic Nuclei (AGNs). When feasible, the mainphysical parameters for these hard X-ray sources are also computed usingthe multiwavelength information available in the literature. Theseidentifications further underscore the importance of INTEGRAL in thestudy of the hard X-ray spectrum of AGNs, HMXBs and CVs, and theusefulness of a strategy of catalogues cross-correlation plus opticalspectroscopy to securely pinpoint the actual nature of the X-ray sourcesdetected with INTEGRAL.
|Identification of four RXTE Slew Survey sources with nearby luminous active galactic nuclei|
Based on RXTE scans and observations with the SWIFT/XRT telescope andINTEGRAL observatory, we report the identification of four X-ray sourcesdiscovered during the RXTE Slew Survey of the |b|>10° sky withnearby (z0.017-0.098) luminous (L2-10~keV 5×1042-1044 erg s-1) active galacticnuclei. Two of the objects exhibit heavily intrinsically absorbed X-rayspectra (NH 1023 cm-2).
|Candidates for a southern extension of the Karachentsev catalogue of isolated pairs of galaxies.|
|The Catalog of Southern Ringed Galaxies|
The Catalog of Southern Ringed Galaxies (CSRG) is a comprehensivecompilation of diameters, axis ratios, relative bar position angles, andmorphologies of inner and outer rings, pseudorings, and lenses in 3692galaxies south of declination -17 deg. The purpose of the catalog is toevaluate the idea that these ring phenomena are related to orbitalresonances with a bar or oval in galaxy potentials. The catalog is basedon visual inspection of most of the 606 fields of the Science ResearchCouncil (SRC) IIIa-J southern sky survey, with the ESO-B, ESO-R, andPalomar Sky surveys used as auxiliaries when needed for overexposed coreregions. The catalog is most complete for SRC fields 1-303 (mostly southof declination -42 deg). In addition to ringed galaxies, a list of 859mostly nonringed galaxies intended for comparison with other catalogs isprovided. Other findings from the CSRG that are not based on statisticsare the identification of intrinsic bar/ring misalignment; bars whichunderfill inner rings; dimpling of R'1pseudorings; pointy, rectangular, or hexagonal inner or outer ringshapes; a peculiar polar-ring-related system; and other extreme examplesof spiral structure and ring morphology.
|Dynamics of the Pavo-Indus and Grus clouds of galaxies|
A study of groups of galaxies in the above regions was carried out byselecting a sample extending one magnitude deeper than previous work inthe area, complete down to 15 mag. We report new redshift determinationsfor 58 galaxies in the region and 13 other miscellaneous galaxies, basedon La Silla observations. Using a total of 266 galaxies with measuredredshifts in the Pavo-Indus and Grus clouds, we perform a new analysisof groupings following a well-tested algorithm. A total of 18 groups issingled out, most of them known from previous work, even though a fewadditional members are added. For all the groups, we have calculateddynamical parameters and M/L ratios. All groups are found to be boundaggregates, but only one group can be virialized. For the six mostpopulated examples, having at least five members, we also calculateseveral mass estimators and discuss the wide range of observed M/Lratios, which extends from nine to nearly 500 M(solar)/L(solar). Weintroduce two parameters to measure the presence of either a dominantgalaxy or internal subcondensations, respectively, and test whether anycorrelation with the M/L ratios can be detected. No clear correlationsare found.
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