תוכן
תמונות
הוסף תמונה שלך
DSS Images Other Images
מאמרים קשורים
A Visual Search for Galaxies in a Milky Way Region around the North Supergalactic Pole
We performed a visual systematic search for galaxies on POSS II(B)plates in a Milky Way region between l~=32deg-68° andb~=-4deg to 19°. This region partly contains the LocalVoid, and the north supergalactic pole exists at the central part. Thesurveyed area was about 560 deg2, and a total of 11,310galaxies and galaxy candidates with sizes of 0.1′ or greater wereidentified. Among the detected objects, 152 have been given in galaxycatalogs and 159, including 49 known galaxies, are associated with IRASpoint sources. We made a catalog of the detected objects, in which theposition in (α, δ) and (l, b), the size, and the features ofthe image and multiplicity are given for each object. The surface numberdensities of the detected objects almost depend on the Galacticlatitude. In the surveyed region, there is no nearby cluster and thereis an outstanding concentration of galaxies at l=7deg-12°and 4000-5000 km s-1.
| Arcsecond Positions of UGC Galaxies
We present accurate B1950 and J2000 positions for all confirmed galaxiesin the Uppsala General Catalog (UGC). The positions were measuredvisually from Digitized Sky Survey images with rms uncertaintiesσ<=[(1.2")2+(θ/100)2]1/2,where θ is the major-axis diameter. We compared each galaxymeasured with the original UGC description to ensure high reliability.The full position list is available in the electronic version only.
| 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.
| Large-Scale Structure at Low Galactic Latitude
We have extended the CfA Redshift Survey to low galactic latitudes toinvestigate the relation between the Great Wall in the North GalacticCap and the Perseus-Pisces chain in the South Galactic Cap. We presentredshifts for 2020 galaxies in the Catalogue of Galaxies and of Clustersof Galaxies (Zwicky et al. 1961-68, CGCG) in the following regions: 4^h^<= α <= 8^h^, 17^h^ <= α <= 20^h^, 0^deg^ <=δ <= 45^deg^. In these regions, the redshift catalogue includes1664 galaxies with B(0) <= 15.5 (of which 820 are newly measured) andis 97% complete. We also include redshifts for an additional 356galaxies in these regions with B(O) > 15.5; of these, 148 werepreviously unmeasured. The CGCG samples the galaxy distribution down tob_II_ = 10^deg^. In this paper, we discuss the acquisition and reductionof the spectra, and we examine the qualitative features of the redshiftdistribution. The Great Wall and the Perseus-Pisces chain are not simplyconnected across the Zone of Avoidance. These structures, which at firstappear to be coherent on scales of ~100 h^-1^ Mpc or more, actually formthe boundaries of neighboring voids of considerably smaller scale,approximately 50h^-1^ Mpc. The structures delineated by ouroptically-selected sample are qualitatively similar to those detected bythe far-infrared-selected IRAS 1.2 Jansky Survey (Fisher et al. 1995).Although the IRAS survey probes more deeply into the Zone of Avoidance,our optically-selected survey provides better sampling of structures atb_II_ >= 10^deg^.
| General study of group membership. II - Determination of nearby groups
We present a whole sky catalog of nearby groups of galaxies taken fromthe Lyon-Meudon Extragalactic Database. From the 78,000 objects in thedatabase, we extracted a sample of 6392 galaxies, complete up to thelimiting apparent magnitude B0 = 14.0. Moreover, in order to considersolely the galaxies of the local universe, all the selected galaxieshave a known recession velocity smaller than 5500 km/s. Two methods wereused in group construction: a Huchra-Geller (1982) derived percolationmethod and a Tully (1980) derived hierarchical method. Each method gaveus one catalog. These were then compared and synthesized to obtain asingle catalog containing the most reliable groups. There are 485 groupsof a least three members in the final catalog.
| A catalogue of early-type galaxies with emission lines
Spectroscopic and photometric data on 289 early-type galaxies (E and S0)with optical emission lines are presented and possible correlationsamong properties of the galaxies in the sample are investigated. Theoccurrence of phenomena as radio emission, presence of neutral hydrogenand dust shows an increase in comparison with the occurrence of the samephenomena in these morphological classes as a whole. There is noevidence of a relationship between apparent shape and presence ofionized gas in the central regions.
| An Arecibo survey for extragalactic hydroxyl absorption. I - Presentation of results
Hydroxyl absorption has been detected in a total of 24 galaxies;megamaser emission in six additional galaxies brings the total number ofdetections of extragalactic OH to 30. About 50 percent of theextragalactic absorption lines are asymmetrically skewed toward the red,indicating that the molecular disks could have an unusual velocity orexcitation structure. The hyperfine ratio for the 1667 and 1665 MHztransitions in most galaxies lies within the limits specified by LTEconditions.
| The statistical distribution of the neutral-hydrogen content of S0 galaxies
The distribution of relative global H I content M(H I)/L(B) has beenderived for galaxies of types S0 and S0/a using a data set derived fromrecent H I observations in the literature. The relative H I content ofthese galaxies is found to show transitional properties betweenelliptical and spiral galaxies. The distribution of M(H I)/L(B) forS0/a's resembles that for spirals, and these galaxies may represent'fossil' spirals, i.e., galaxies whose gas has been severely depleted bystar formation. The distribution for S0's, however, resembles that forellipticals. The form of this distribution strongly suggests an externalorigin for most of the H I in S0 galaxies.
| A Determination of Relative Spectrophotometric Gradients of Galaxies - Part Three
Not Available
| Radio observations at 408 MHz of E and SO nearby galaxies
The radio observations of a complete sample of E and SO galaxies fromthe 1956 Humason catalog are presented with an absolute photographicvalue of greater than -20 in the 18 to 60 deg declination range. Thedistribution of the linear dimensions of detected sources and the radioluminosity function in the low radio power range are analyzed. GC 383has an unusual structure, and NGC 507 provides a very steep spectrum.
| A Survey of Elliptical Galaxies at 6 CM
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973A&A....24..247E&db_key=AST
| Radio Observations of E and SO Galaxies
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970AJ.....75..523H&db_key=AST
|
הכנס מאמר חדש
לינקים קשורים
הכנס לינק חדש
משמש של הקבוצה הבאה
|
תצפית ומידע אסטרומטרי
קטלוגים וכינוים:
|
