Contents
Images
Upload your image
DSS Images Other Images
Related articles
Mass Models for Spiral Galaxies from Two-dimensional Velocity Maps
We model the mass distributions of 40 high surface brightness spiralgalaxies inside their optical radii, deriving parameters of mass modelsby matching the predicted velocities to observed velocity maps. We useconstant mass-to-light disk and bulge models, and we have tried fitswith no halo and with three different halo density profiles. The datarequire a halo in most, but not all, cases, while in others the best fitoccurs with negligible mass in the luminous component, which we regardas unphysical. All three adopted halo profiles lead to fits of about thesame quality, and our data therefore do not constrain the functionalform of the halo profile. The halo parameters display large degeneraciesfor two of the three adopted halo functions, but the separate luminousand dark masses are better constrained. However, the fitted disk andhalo masses vary substantially between the adopted halo models,indicating that even high-quality two-dimensional optical velocity mapsdo not provide significant constraints on the dark matter content of agalaxy. We demonstrate that data from long-slit observations are likelyto provide still weaker constraints. We conclude that additionalinformation is needed in order to constrain the separate disk and halomasses in a galaxy.
| The H I Line Width/Linear Diameter Relationship as an Independent Test of the Hubble Constant
The relationship between corrected H I line widths and linear diameters(LW/LD) for spiral galaxies is used as an independent check on the valueof the Hubble constant. After calibrating the Tully-Fisher (TF) relationin both the B and I bands, the B-band relation is used for galaxies ofmorphological/luminosity types Sc I, Sc I.2, Sc I.3, Sab, Sb, Sb I-II,and Sb II to derive the LW/LD relation. We find that for this sample thescatter in the LW/LD is smallest with a Hubble constant of 90-95 kms-1 Mpc-1. Lower values of the Hubble constantproduce a separation in the LW/LD relation that is a function ofmorphological type. Since a Hubble constant of 90-95 is significantlylarger than the final Key Project value of 72 km s-1Mpc-1, a comparison of TF, surface brightness fluctuation(SBF), and fundamental plane (FP) is made. This comparison indicatesthat the Key Project TF distances to 21 clusters may be too large. For asample of 11 clusters, the Key Project TF distances provide anunweighted mean Hubble constant of 77 km s-1Mpc-1, while a combination of the FP, SBF, and our TFdistances for the same 11 clusters gives H0=91 kms-1 Mpc-1. A more subtle result in our data is amorphological dichotomy in the Hubble constant. The data suggest that ScI galaxies follow a Hubble constant of 90-95 while Sb galaxies follow aHubble constant closer to 75 km s-1 Mpc-1.Possible explanations for this result are considered, but it is shownthat this Sb/Sc I Hubble flow discrepancy is also present in the VirgoCluster and is consistent with previous investigations that indicatethat some galaxies carry a component of age-related intrinsic redshift.
| Precision Velocity Fields in Spiral Galaxies. II. Rotation Curves
Imaging Fabry-Perot data has been acquired for a sample of sevenlate-type spiral galaxies from which two-dimensional velocity fieldshave been constructed on a subkiloparsec resolution scale. The kinematicdisk (i.e., tilted ring) modeling procedure is used to fit the velocityfield and recover its rotational structure. From this fit, differentschemes are used to extract the major-axis rotation curve, as well asvelocity profiles along the minor axis. Rotation curves found fromdeprojection of the velocity field using mean geometric parametersinvariably produce small-scale ``bumps and wiggles,'' which are areflection of the inclusion of noncircular motions. In the best-rotationcurve method, the rotation curve is derived from the best fit to theentire velocity field. This method is shown to minimize the effects ofnoncircular motions. The kinematic center of the velocity field isallowed to vary, and those results are directly compared with caseswhere the kinematic center is held fixed. In virtually all cases, wefind that the variable center model produces the smoothest and mostsymmetric rotation curves and minor-axis velocity profiles. Our resultsindicate that the kinematic center of mass is moving around in thesedisk systems with an amplitude of plus or minus ~300 pc. Finally, weinvestigate the effects of small, systematic errors in centering andfind that small minor-axis displacements can artificially producespurious slopes in the rotation curve at large radius, includingproducing rotation curves that are apparently falling.
| Distances to Galaxies from the Correlation between Luminosities and Line Widths. III. Cluster Template and Global Measurement of H0
The correlation between the luminosities and rotation velocities ofgalaxies can be used to estimate distances to late-type galaxies. It isan appropriate moment to reevaluate this method given the great deal ofnew information available. The major improvements described hereinclude: (1) the template relations can now be defined by large,complete samples, (2) the samples are drawn from a wide range ofenvironments, (3) the relations are defined by photometric informationat the B, R, I, and K' bands, (4) the multiband information clarifiesproblems associated with internal reddening, (5) the template zeropoints are defined by 24 galaxies with accurately known distances, and(6) the relations are applied to 12 clusters scattered across the skyand out to velocities of 8000 km s-1. The biggest change fromearlier calibrations are associated with point 5. Roughly a 15% increasein the distance scale has come about with the fivefold increase in thenumber of zero-point calibrators. The overall increase in the distancescale from the luminosity-line width methodology is about 10% afterconsideration of all factors. Modulo an assumed distance to the LargeMagellanic Cloud of 50 kpc and no metallicity corrections to the Cepheidcalibration, the resulting value of the Hubble constant isH0=77+/-8 km s-1 Mpc-1, where the erroris the 95% probable statistical error. Cumulative systematic errorsinternal to this analysis should not exceed 10%. Uncertainties in thedistance scale ladder external to this analysis are estimated at ~10%.If the Cepheid calibration is shifted from the LMC to NGC 4258 with adistance established by observations of circumnuclear masers, thenH0 is larger by 12%.
| Maximum Disk Mass Models for Spiral Galaxies
We present axisymmetric maximum disk mass models for a sample of 74spiral galaxies taken from the southern sky Fabry-Perot Tully-Fishersurvey by Schommer et al. The sample contains galaxies spanning a largerange of morphologies and having rotation widths from 180 km s-1 to 680 km s -1. For each galaxy we have an I-bandimage and a two-dimensional Hα velocity field. We decompose thedisk and bulge by fitting models directly to the I-band image. Thismethod utilizes both the distinct surface brightness profiles and shapesof the projected disk and bulge in the galaxy images. The luminosityprofiles and rotation curves are derived using consistent centers,position angles, and inclinations derived from the photometry andvelocity maps. The distribution of mass is modeled as a sum of disk andbulge components with distinct, constant mass-to-light ratios. No darkmatter halo is included in the fits. The models reproduce the overallstructure of the rotation curves in the majority of galaxies, providinggood fits to galaxies that exhibit pronounced structural differences intheir surface brightness profiles. Of galaxies for which the rotationcurve is measured to R23.5 or beyond 75% are well fitted by amass-traces-light model for the entire region within R23.5.The models for about 20% of the galaxies do not fit well; the failure ofmost of these models is traced directly to nonaxisymmetric structures,primarily bars but also strong spiral arms. The median I-band M/L of thedisk plus bulge is 2.4+/-0.9 h75 in solar units, consistentwith normal stellar populations. These results require either that themass of dark matter within the optical disk of spiral galaxies is smallor that its distribution is very precisely coupled to the distributionof luminous matter.
| Precision Velocity Fields in Spiral Galaxies. I. Noncircular Motions and rms Noise in Disks
Investigation of the symmetry of the major- and minor-axis rotationcurves reveals strong evidence of nonconcentric gas orbits with themaximum center shift of ~300 pc. Comparisons between kinematic andphotometric structure (e.g., position angles, inclinations, centers)show considerable noise on small scales. Although large-scale averagesare in agreement, this noise is a matter of some concern in theapplication of the Tully-Fisher method to disk galaxies. Moreover, casesof significant misalignment in position angle between the inner andouter disks are seen in two of the sample galaxies and may indicate thetransition between luminous and dark-matter-dominated regions (i.e.,where the maximum-disk hypothesis begins to fail). The kinematic diskmodels are used to find the residual velocity fields, and typicalresiduals are found to be 10-15 km s-1 over regions 0.5-1.5kpc in diameter. Correlations are shown to exist between the residualvelocity fields and both the Hα intensity and the velocitydispersion images. This suggests that kinematic feedback to the gas fromstar formation is an important source of noncircular motion. However,the relative quiescence of the large-scale velocity field indicates thatthe effect does not cause a significant deviation from circularsymmetry, kinematically indicating that star formation is not a hiddenparameter in the Tully-Fisher relation. Finally, the residual velocityfields are examined for signs of noncircular orbits by looking forazimuthal angular harmonics that would be present if disk galaxies areembedded in a triaxial dark matter potential. For our sample we find theellipticity of the gas orbits to be <~0.08, which implies thepotential is relatively round. This is consistent with disks beingmaximal.
| 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).
| Kinematics of the local universe. VII. New 21-cm line measurements of 2112 galaxies
This paper presents 2112 new 21-cm neutral hydrogen line measurementscarried out with the meridian transit Nan\c cay radiotelescope. Amongthese data we give also 213 new radial velocities which complement thoselisted in three previous papers of this series. These new measurements,together with the HI data collected in LEDA, put to 6 700 the number ofgalaxies with 21-cm line width, radial velocity, and apparent diameterin the so-called KLUN sample. Figure 5 and Appendices A and B forcorresponding comments are available in electronic form at thehttp://www.edpsciences.com
| 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 catalogue of spatially resolved kinematics of galaxies: Bibliography
We present a catalogue of galaxies for which spatially resolved data ontheir internal kinematics have been published; there is no a priorirestriction regarding their morphological type. The catalogue lists thereferences to the articles where the data are published, as well as acoded description of these data: observed emission or absorption lines,velocity or velocity dispersion, radial profile or 2D field, positionangle. Tables 1, 2, and 3 are proposed in electronic form only, and areavailable from the CDS, via anonymous ftp to cdsarc.u-strasbg.fr (to130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html
| Homogeneous Velocity-Distance Data for Peculiar Velocity Analysis. III. The Mark III Catalog of Galaxy Peculiar Velocities
This is the third in a series of papers in which we assemble and analyzea homogeneous catalog of peculiar velocity data. In Papers I and II, wedescribed the Tully-Fisher (TF) redshift-distance samples thatconstitute the bulk of the catalog and our methodology for obtainingmutually consistent TF calibrations for these samples. In this paper, wesupply further technical details of the treatment of the data andpresent a subset of the catalog in tabular form. The full catalog, knownas the Mark III Catalog of Galaxy Peculiar Velocities, is available inaccessible on-line databases, as described herein. The electroniccatalog incorporates not only the TF samples discussed in Papers I andII but also elliptical galaxy Dn- sigma samples originally presentedelsewhere. The relative zero pointing of the elliptical and spiral datasets is discussed here. The basic elements of the Mark III Catalog arethe observables for each object (redshift, magnitude, velocity width,etc.) and inferred distances derived from the TF or Dn- sigma relations.Distances obtained from both the forward and inverse TF relations aretabulated for the spirals. Malmquist bias--corrected distances arecomputed for each catalog object using density fields obtained from theIRAS 1.2 Jy redshift survey. Distances for both individual objects andgroups are provided. A variety of auxiliary data, including distancesand local densities predicted from the IRAS redshift surveyreconstruction method, are tabulated as well. We study the distributionsof TF residuals for three of our samples and conclude that they are wellapproximated as Gaussian. However, for the Mathewson et al. sample wedemonstrate a significant decrease in TF scatter with increasingvelocity width. We test for, but find no evidence of, a correlationbetween TF residuals and galaxy morphology. Finally, we derivetransformations that map the apparent magnitude and velocity width datafor each spiral sample onto a common system. This permits theapplication of analysis methods that assume that a unique TF relationdescribes the entire sample.
| Optical Rotation Curves and Linewidths for Tully-Fisher Applications
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.2402C&db_key=AST
| The I band Tully-Fisher relation for cluster galaxies: data presentation.
Observational parameters which can be used for redshift-independentdistance determination using the Tully-Fisher (TF) technique are givenfor \ntot spiral galaxies in the fields of 24 clusters or groups. I bandphotometry for the full sample was either obtained by us or compiledfrom published literature. Rotational velocities are derived either from21 cm spectra or optical emission line long-slit spectra, and convertedto a homogeneous scale. In addition to presenting the data, a discussionof the various sources of error on TF parameters is introduced, and thecriteria for the assignment of membership to each cluster are given.
| Parameters of 2447 Southern Spiral Galaxies for Use in the Tully-Fisher Relation
I-band luminosities, rotational velocities, and redshifts of 1092 spiralgalaxies have been measured by CCD photometry and Hα spectroscopyusing the 1 m and 2.3 m telescopes at Siding Spring Observatory,respectively. The results are tabulated. Luminosity profiles andHα rotation curves are given for the galaxies. When these resultsare combined with similar data for 1355 spiral galaxies publishedpreviously (Mathewson, Ford, & Buchhorn, hereafter Paper I), itprovides a large, uniform, and unique data set with which to measure,via the Tully-Fisher relation, the peculiar velocities of galaxies inthe local universe to a distance of 11,000 km s^-1^ (Mathewson &Ford). Taking advantage of the opportunity for publishing this data inmachine-readable form, in the CD-ROM, we have also included similar datafor the 1355 galaxies in Paper I.
| Rotation Curves of 967 Spiral Galaxies
We present the rotation curves of 967 southern spiral galaxies, obtainedby deprojecting and folding the raw Hα data originally publishedby Mathewson, Ford, & Buchhorn (1992). For 900 objects, we alsopresent, in figures and tables, the rotation curves smoothed on scalescorresponding to 5%-20% of the optical size; of these, 80 meet objectiveexcellence criteria and are suitable for individual detailed massmodeling, while 820, individually less compelling mainly because of themoderate statistics and/or limited extension, are suitable forstatistical studies. The remaining 67 curves suffer from severeasymmetries, small statistics, and large internal scatter that maylargely limit their use in galaxy structure studies. The deprojectedfolded curves, the smoothed curves, and various related quantities areavailable via anonymous ftp at galileo.sissa.it in the directory/users/ftp/pub/psrot.
| Recalibration of the H-0.5 magnitudes of spiral galaxies
The H-magnitude aperture data published by the Aaronson et al.collaboration over a 10 year period is collected into a homogeneous dataset of 1731 observations of 665 galaxies. Ninety-six percent of thesegalaxies have isophotal diameters and axial ratios determined by theThird Reference Cataloque of Bright Galaxies (RC3; de Vaucouleurs et al.1991), the most self-consistent set of optical data currently available.The precepts governing the optical data in the RC3 are systematicallydifferent from those of the Second Reference Catalogue (de Vaucouleurs,de Vaucouleurs, & Corwin 1976), which were used by Aaronson et al.for their original analyses of galaxy peculiar motions. This in turnleads to systematic differences in growth curves and fiducialH-magnitudes, prompting the present recalibration of the near-infraredTully-Fisher relationship. New optically normalized H-magnitude growthcurves are defined for galaxies of types SO to Im, from which new valuesof fiducial H-magnitudes, Hg-0.5, are measured forthe 665 galaxies. A series of internal tests show that these fourstandard growth curves are defined to an accuracy of 0.05 mag over theinterval -1.5 less than or equal to log (A/Dg) less than orequal to -0.2. Comparisons with the Aaronson et al. values of diameters,axial ratios, and fiducial H-magnitudes show the expected differences,given the different definitions of these parameters. The values ofHg-0.5 are assigned quality indices: a qualityvalue of 1 indicates an accuracy of less than 0.2 mag, quality 2indicates an accuracy of 0.2-0.35 mag, and quality 3 indicates anaccuracy of more than 0.35 mag. Revised values of corrected H I velocitywidths are also given, based on the new set of axial ratios defiend bythe RC3.
| Measuring galaxy distances from optical rotation curves
A distance indicator for spiral galaxies is described using detailedrotation curves derived from H-alpha velocities fields and I band CCDphotometry. Two-dimensional velocity fields are obtained with an imagingFabry-Perot spectrometer, with a velocity accuracy of better than 10km/s. Rotation curves, based upon rotating disks geometries, are fit tothese velocity fields. The I band photometry profiles, and theindividual rotation curves for 75 galaxies are presented. The extractedcircular velocity is combined with I band magnitudes to form aTully-Fisher relation, with a scatter of about 0.25-0.3 mag. As anexample, the data are used to derive the relative distance modulusbetween the Hydra and Antlia clusters, which yields a peculiar motionfor Antlia of 900 +/- 100 km/s. This confirms previous detections oflarge peculiar motions in the Hydra-Centaurus region.
| 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 southern sky survey of the peculiar velocities of 1355 spiral galaxies
The paper presents data from photometric and spectroscopic observationsof 1355 southern spiral galaxies and uses them to determine theirdistances and peculiar velocities via the Tully-Fisher (TF) relation.I-band CCD surface photometry was carried out using the 1-m and 3.9-mtelescopes at Siding Spring Observatory. H-alpha rotation curves for 965galaxies and 551 H I profiles are presented. The physical parameters,photometric and velocity data, distances, and peculiar velocities of thegalaxies are presented in tabular form. The mean distance, systemicvelocity, and average peculiar velocity of 24 clusters in the sample aregiven. TF diagrams are presented for each cluster.
| I-band CCD surface photometry of spiral galaxies in 16 nearby clusters
Results of I-band CCD surface photometry for 284 spiral galaxies in 16clusters in the redshift range from 3000 to 11,000 km/s are presented.Various effects on surface photometry are discussed, and the relevantcorrections are outlined.
| 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.
| Large peculiar velocities in the Hydra-Centaurus supercluster
Distances from the infrared Tully-Fisher relation have been obtainedwith the Parkes radio telescope for six clusters of galaxies in theHydra-Centaurus supercluster. Three of these clusters show significantpositive peculiar velocities of order 500 km/s in a comoving referenceframe in which the observer is at rest with respect to the cosmicmicrowave background radiation. The net peculiar velocity of the samplesuggests that Hydra-Centaurus tends to share the motion of the LocalGroup in this reference frame. The data also fit a model in which twomass concentrations, one at Virgo and one just beyond the centroid ofthe Parkes sample, perturb the Hubble flow.
| Southern Galaxy Catalogue.
Not Available
| 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.
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
Catalogs and designations:
|
