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|Dust Temperatures in the Infrared Space Observatory Atlas of Bright Spiral Galaxies|
We examine far-infrared and submillimeter spectral energy distributionsfor galaxies in the Infrared Space Observatory Atlas of Bright SpiralGalaxies. For the 71 galaxies where we had complete 60-180 μm data,we fitted blackbodies with λ-1 emissivities andaverage temperatures of 31 K or λ-2 emissivities andaverage temperatures of 22 K. Except for high temperatures determined insome early-type galaxies, the temperatures show no dependence on anygalaxy characteristic. For the 60-850 μm range in eight galaxies, wefitted blackbodies with λ-1, λ-2,and λ-β (with β variable) emissivities tothe data. The best results were with the λ-βemissivities, where the temperatures were ~30 K and the emissivitycoefficient β ranged from 0.9 to 1.9. These results producedgas-to-dust ratios that ranged from 150 to 580, which were consistentwith the ratio for the Milky Way and which exhibited relatively littledispersion compared with fits with fixed emissivities.Based on observations with Infrared Space Observatory, an ESA projectwith instruments funded by ESA Member States (especially the PIcountries: France, Germany, the Netherlands, and the United Kingdom) andwith the participation of ISAS and NASA.
|Redshift-Distance Survey of Early-Type Galaxies: Circular-Aperture Photometry|
We present R-band CCD photometry for 1332 early-type galaxies, observedas part of the ENEAR survey of peculiar motions using early-typegalaxies in the nearby universe. Circular apertures are used to tracethe surface brightness profiles, which are then fitted by atwo-component bulge-disk model. From the fits, we obtain the structuralparameters required to estimate galaxy distances using theDn-σ and fundamental plane relations. We find thatabout 12% of the galaxies are well represented by a pure r1/4law, while 87% are best fitted by a two-component model. There are 356repeated observations of 257 galaxies obtained during different runsthat are used to derive statistical corrections and bring the data to acommon system. We also use these repeated observations to estimate ourinternal errors. The accuracy of our measurements are tested by thecomparison of 354 galaxies in common with other authors. Typical errorsin our measurements are 0.011 dex for logDn, 0.064 dex forlogre, 0.086 mag arcsec-2 for<μe>, and 0.09 for mRC,comparable to those estimated by other authors. The photometric datareported here represent one of the largest high-quality and uniformall-sky samples currently available for early-type galaxies in thenearby universe, especially suitable for peculiar motion studies.Based on observations at Cerro Tololo Inter-American Observatory (CTIO),National Optical Astronomy Observatory, which is operated by theAssociation of Universities for Research in Astronomy, Inc., undercooperative agreement with the National Science Foundation (NSF);European Southern Observatory (ESO); Fred Lawrence Whipple Observatory(FLWO); and the MDM Observatory on Kitt Peak.
|The globular cluster systems of NGC 3258 and NGC 3268 in the Antlia cluster|
The Antlia galaxy cluster is the third nearest galaxy cluster afterVirgo and Fornax. We used the wide-field MOSAIC camera of the 4-m CTIOtelescope to search in the brightest cluster galaxies for globularcluster systems, which were detected in the two larger ellipticals - NGC3258 and NGC 3268. These galaxies each contain several thousandclusters; NGC 3258 more than NGC 3268. The color distributions of theglobular cluster systems are clearly bimodal. The peak colors agree withthose of other ellipticals. The radial number density profiles of theglobular cluster systems are indistinguishable for the two galaxies andno difference in the distribution of red and blue clusters - as observedin other elliptical galaxies - can be seen. The light profile of NGC3268 appears to be similar to that of NGC 1399, the central galaxy ofthe Fornax cluster. NGC 3258 has a light profile which is steeper atlarge radii. Both galaxies exhibit color gradients, becoming blueroutwards. In NGC 3268, the color and morphology in the inner 3 arcsecindicate the presence of an inner dusty disk. The globular clustersystems closely trace the galaxy light in the studied radial regime. Theelongation of the cluster systems of both galaxies is approximatelyaligned at large radii with the connecting axis of the two galaxies. Wefind specific frequencies within a radial range of 4 arcmin ofSN=3.0+/-2.0 for NGC 3268 and SN=6.0+/-2.5 for NGC3258.As a byproduct resulting from surveying our wide-field frames, wedescribe a strange absorption feature in the Antlia spiral galaxy NGC3269, which we argue might be a tiny galactic dust cloud projected ontoNGC 3269.Based on observations collected at the Cerro Tololo Inter-AmericanObservatory (CTIO).
|A study of neutral hydrogen in five small galaxy groups|
High-resolution Hi imaging observations of a heterogeneous sample ofsmall galaxy groups are presented. The five galaxy groups studied show abroad range of individual Hi properties: e.g. loose groups surroundingLGG 138 and the genuinely compact LGG 455 are identified; a massive ringof neutral gas is discovered encircling two luminous galaxies in the LGG138 group; a galaxy-sized mass of Hi is found in LGG 455 confined to anextragalactic cloud which exceeds the threshold density for starformation, yet is optically invisible; and the CCG 1 group is argued tobe a chance alignment of Centaurus cluster galaxies. Global results ofthe study are that the deficit of Hi flux in synthesis imaging datacompared with single-dish data is put forward as a quantitative measureof the diffuseness of neutral gas in galaxy groups; several groupscontain gas-poor galaxies that ordinarily would contain detectablequantities of Hi - this is interpreted as being caused by an increasedchance of gas-sweeping collisions in the group environment; and someevidence is found to support previous findings that compact groupspreferentially occur in loose systems.
|ASCA Observations of a Near-by Cluster in Antlia|
The Antlia cluster is a near-by poor cluster which has a redshift of z =0.0087. X-ray observations with ASCA have revealed that the cluster isalmost isothermal in the X-ray with a temperature of kT ~ 2.0 keV. Themetal abundance is Z ~ 0.35\ ZSolar , and the 0.5-10.0 keVcluster luminosity is ~ 3.4 x 1042\h75-2 erg s-1 within r < 250\h-175 kpc. There was no X-ray central excessbrightness and little central cool component, which are frequently seenin near-by poor clusters. The Antlia cluster is the nearest poor clusterwithout these central features.
|Galaxy coordinates. II. Accurate equatorial coordinates for 17298 galaxies|
Using images of the Digitized Sky Survey we measured coodinates for17298 galaxies having poorly defined coordinates. As a control, wemeasured with the same method 1522 galaxies having accurate coordinates.The comparison with our own measurements shows that the accuracy of themethod is about 6 arcsec on each axis (RA and DEC).
|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.
|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.
|Compact groups of galaxies in the nearby universe|
We have searched for compact groups of galaxies among the largestcatalog of nearby groups (LGG catalog). 21 new compact groups of atleast 3 members were found. Their surface brightnesses are generallylower than those of Hickson compact groups (HCGs), and theircharacteristics are close to those of loose groups. We have alsoretrieved all HCGs of the nearby universe. These are all embedded ingroups, forming the cores or substructures of loose groups. Theseresults suggest that compact groups may form as core or substructureswithin loose groups (like the HCGs), or form from loose groups when theystart collapsing (like those of the LGG).
|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.
|Groups of galaxies within 80 Mpc. II - The catalogue of groups and group members|
This paper gives a catalog of the groups and associations obtained bymeans of a revised hierarchical algorithm applied to a sample of 4143galaxies with diameters larger than 100 arcsec and redshifts smallerthan 6000 km/s. The 264 groups of galaxies obtained in this way (andwhich contain at least three sample galaxies) are listed, with the looseassociations surrounding them and the individual members of eachaggregate as well; moreover, the location of every entity among 13regions corresponding roughly to superclusters is specified. Finally,1729 galaxies belong to the groups, and 466 to the associations, i.e.,the total fraction of galaxies within the various aggregates amounts to53 percent.
|Molecular gas in galaxies|
Recent studies of molecular gas in galaxies are reviewed. CO isdiscussed as a tracer of the mass in spiral galaxies, including newevidence that global H2 masses for luminous spirals are generallyaccurate to +/- 50 percent. The radial distribution of gas and starformation, spiral structure, molecular properties of galaxies in theLocal Group, global gas content, star formation rates and efficiencies,effects of galactic interactions, and nuclear gas concentrations isexamined.
|Population studies in groups and clusters of galaxies. III - A catalog of galaxies in five nearby groups|
Five nearby groups of galaxies have been surveyed using large-scaleplates from the 2.5 m duPont Telescope at Las Campanas Observatory.Catalogs of galaxies brighter than B(T) = 20 are presented for the Leo,Dorado, NGC 1400, NGC 5044, and Antlia groups. A total of 1044 galaxiesare included, from visual inspection of 14 plates, covering 31 degsquare. Galaxies have been classified in the extended Hubble system, andgroup memberships have been assigned based on velocity (where available)and morphology. About half the galaxies listed are likely members of oneof the nearby groups. The catalogs are complete to B(T) = 18, althoughthe completeness limits vary slightly from group to group. Based on Kingmodel fits to the surface density profiles, the core radii of the groupsrange from 0.3 to 1 Mpc, and central densities range from 120 to 1900galaxies Mpc exp-3 brighter than M(BT) = -12.5. Dynamical analysisindicates that all of the groups are likely to be gravitationally bound.
|Southern Galaxy Catalogue.|
|Studies of the Virgo cluster. IV - an Atlas of Virgo cluster spiral galaxies: The luminosity range within a given spiral type|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1985AJ.....90..395S&db_key=AST
|The Antlia cluster of galaxies and its environment - The Hydra I-Centaurus supercluster|
The small Antlia cluster of galaxies was investigated by measuring manyradial velocities for galaxies from the Lauberts catalog in the Antliaregion. Apart from the Antlia cluster itself, four more small groupswere identified. These five systems form a tiny but not bound Antliamini-supercluster. The mini-supercluster consists of small groups andclusters and of a dispersed component of field galaxies. The five galaxysystems are also part of the large Hydra I-Centaurus supercluster. Thislarge supercluster belongs now to the class of well observed ones. Ithas a chain-like filamentary structure. This supercluster seems to beconnected to the Local Supercluster via two very extended but very loosegroups. The total structure is the triangle-shaped Virgo-HydraI-Centaurus supercluster.
|UBV photometry of 262 southern galaxies|
Multiaperture photometry of 262 bright southern galaxies in the JohnsonUBV system is given. Most of these are south of -30 deg declination,although some northward to -10 deg are included. A total of 169 objectshave published radial-velocity determinations. These provide distancesand enable construction of color-magnitude diagrams for this subset ofobjects through a physical diameter of 2.0 kpc (with H = 100). Thetwo-color diagrams for the inner regions of the galaxies differ fromthose of integrated galaxies due to the color changes towards theircenters. Comparison with theoretical models of Larson and Tinsley (1978)suggest that the colors of the inner portions of most ellipticals andlenticulars are consistent with their having all stars formed at nearlyone epoch with little subsequent star formation, while for spiralslarger amounts of star formation, either in bursts or continuously, aresuggested. This simple picture is complicated by the presence of certainobjects having peculiar colors indicative of large amounts of recentstar formation.
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