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Gas and Stars in an H I-Selected Galaxy Sample
We present the results of a J-band study of the H I-selected AreciboDual-Beam Survey and Arecibo Slice Survey galaxy samples using TwoMicron All Sky Survey data. We find that these galaxies span a widerange of stellar and gas properties. However, despite the diversitywithin the samples, we find a very tight correlation between luminosityand size in the J band, similar to that found in a previous paper byRosenberg & Schneider between the H I mass and size. We also findthat the correlation between the baryonic mass and the J-band diameteris even tighter than that between the baryonic mass and the rotationalvelocity.
| Completing H I observations of galaxies in the Virgo cluster
High sensitivity (rms noise 0.5 mJy) 21-cm H I line observationswere made of 33 galaxies in the Virgo cluster, using the refurbishedArecibo telescope, which resulted in the detection of 12 objects. Thesedata, combined with the measurements available from the literature,provide the first set of H I data that is complete for all 355 late-type(Sa-Im-BCD) galaxies in the Virgo cluster with mp ≤ 18.0mag. The Virgo cluster H I mass function (HIMF) that was derived forthis optically selected galaxy sample is in agreement with the HIMFderived for the Virgo cluster from the blind HIJASS H I survey and isinconsistent with the Field HIMF. This indicates that both in this richcluster and in the general field, neutral hydrogen is primarilyassociated with late-type galaxies, with marginal contributions fromearly-type galaxies and isolated H I clouds. The inconsistency betweenthe cluster and the field HIMF derives primarily from the difference inthe optical luminosity function of late-type galaxies in the twoenvironments, combined with the HI deficiency that is known to occur ingalaxies in rich clusters.Tables \ref{t1, \ref{sample_dat} and Appendix A are only available inelectronic form at http://www.edpsciences.org
| Spectrophotometry of galaxies in the Virgo cluster. II. The data
Drift-scan mode (3600-6800 Å) spectra with 500
| Intracluster Planetary Nebulae in the Virgo Cluster. II. Imaging Catalog
Intracluster stars-stars outside of individual galaxies-are a sensitivemeasure of the poorly understood processes of galactic mergers, clusteraccretion, and tidal stripping that occur in galaxy clusters. Inparticular, intracluster planetary nebulae are a useful probe ofintracluster light as a whole. We present a catalog of 318 intraclusterplanetary nebula candidates in the nearby Virgo Cluster of galaxies,taken with the Kitt Peak National Observatory 4 m telescope. We detailthe automated detection routines developed to search for thesecandidates and discuss the routines' strengths and weaknesses. Wediscuss the importance of contamination in the catalog, and the likelycauses. We present magnitudes and positions of these candidates,suitable for spectroscopic follow-up observations. Analyses of thesecandidates are presented in other papers of this series.
| UV to radio centimetric spectral energy distributions of optically-selected late-type galaxies in the Virgo cluster
We present a multifrequency dataset for an optically-selected,volume-limited, complete sample of 118 late-type galaxies (>=S0a) inthe Virgo cluster. The database includes UV, visible, near-IR, mid-IR,far-IR, radio continuum photometric data as well as spectroscopic dataof Hα , CO and HI lines, homogeneously reduced, obtained from ourown observations or compiled from the literature. Assuming the energybalance between the absorbed stellar light and that radiated in the IRby dust, we calibarte an empirical attenuation law suitable forcorrecting photometric and spectroscopic data of normal galaxies. Thedata, corrected for internal extinction, are used to construct thespectral energy distribution (SED) of each individual galaxy, andcombined to trace the median SED of galaxies in various classes ofmorphological type and luminosity. Low-luminosity, dwarf galaxies haveon average bluer stellar continua and higher far-IR luminosities perunit galaxy mass than giant, early-type spirals. If compared to nearbystarburst galaxies such as M 82 and Arp 220, normal spirals haverelatively similar observed stellar spectra but 10-100 times lower IRluminosities. The temperature of the cold dust component increases withthe far-IR luminosity, from giant spirals to dwarf irregulars. The SEDare used to separate the stellar emission from the dust emission in themid-IR regime. We show that the contribution of the stellar emission at6.75 mu m to the total emission of galaxies is generally important, from~ 80% in Sa to ~ 20% in Sc.Tables 2-5, 7, 8, and Fig. 2 are only available in electronic form athttp://www.edpsciences.orgTables 10-12 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/402/37
| The Three-dimensional Structure of the Virgo Cluster Region from Tully-Fisher and H I Data
The distances and H I contents of 161 spiral galaxies in the region ofthe Virgo cluster are used to gain insight into the complicatedstructure of this galaxy system. Special attention has been paid to theinvestigation of the suggestion presented in an earlier work that someperipheral Virgo groups may contain strongly gas-deficient spiralgalaxies. The three-dimensional galaxy distribution has been inferredfrom quality distance estimates obtained by averaging distance modulibased on the Tully-Fisher relationship taken from eight published datasets previously homogenized, resulting in a relation with a dispersionof 0.41 mag. Previous findings that the spiral distribution issubstantially more elongated along the line of sight than in the planeof the sky are confirmed by the current data. In addition, an importanteast-west disparity in this effect has been detected. The overallwidth-to-depth ratio of the Virgo cluster region is about 1:4, with themost distant objects concentrated in the western half. The filamentarystructure of the spiral population and its orientation are alsoreflected by the H I-deficient objects alone. The H I deficiency patternshows a central enhancement extending from ~16 to 22 Mpc inline-of-sight distance; most of this enhancement arises from galaxiesthat belong to the Virgo cluster proper. However, significant gasdeficiencies are also detected outside the main body of the cluster in aprobable group of galaxies at line-of-sight distances ~25-30 Mpc, lyingin the region dominated by the southern edge of the M49 subcluster andclouds W' and W, as well as in various foreground galaxies. In the Virgoregion, the H I content of the galaxies then is not a straightforwardindicator of cluster membership.
| 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.
| Hα surface photometry of galaxies in the Virgo cluster. IV. The current star formation in nearby clusters of galaxies
Hα +[NII] imaging observations of 369 late-type (spiral) galaxiesin the Virgo cluster and in the Coma/A1367 supercluster are analyzed,covering 3 rich nearby clusters (A1367, Coma and Virgo) and nearlyisolated galaxies in the Great-Wall. They constitute an opticallyselected sample (mp<16.0) observed with ~ 60 %completeness. These observations provide us with the current(T<107 yrs) star formation properties of galaxies that westudy as a function of the clustercentric projected distances (Theta ).The expected decrease of the star formation rate (SFR), as traced by theHα EW, with decreasing Theta is found only when galaxies brighterthan Mp ~ -19.5 are considered. Fainter objects show no orreverse trends. We also include in our analysis Near Infrared data,providing information on the old (T>109 yrs) stars. Puttogether, the young and the old stellar indicators give the ratio ofcurrently formed stars over the stars formed in the past, or``birthrate'' parameter b. For the considered galaxies we also determinethe ``global gas content'' combining HI with CO observations. We definethe ``gas deficiency'' parameter as the logarithmic difference betweenthe gas content of isolated galaxies of a given Hubble type and themeasured gas content. For the isolated objects we find that b decreaseswith increasing NIR luminosity. In other words less massive galaxies arecurrently forming stars at a higher rate than their giant counterpartswhich experienced most of their star formation activity at earliercosmological epochs. The gas-deficient objects, primarily members of theVirgo cluster, have a birthrate significantly lower than the isolatedobjects with normal gas content and of similar NIR luminosity. Thisindicates that the current star formation is regulated by the gaseouscontent of spirals. Whatever mechanism (most plausibly ram-pressurestripping) is responsible for the pattern of gas deficiency observed inspiral galaxies members of rich clusters, it also produces the observedquenching of the current star formation. A significant fraction of gas``healthy'' (i.e. with a gas deficiency parameter less than 0.4) andcurrently star forming galaxies is unexpectedly found projected near thecenter of the Virgo cluster. Their average Tully-Fisher distance isfound approximately one magnitude further away (muo = 31.77)than the distance of their gas-deficient counterparts (muo =30.85), suggesting that the gas healthy objects belong to a cloudprojected onto the cluster center, but in fact lying a few Mpc behindVirgo, thus unaffected by the dense IGM of the cluster. Based onobservations taken at the Observatorio Astronómico Nacional(Mexico), the OHP (France), Calar Alto and NOT (Spain) observatories.Table \ref{tab4} is only available in electronic form athttp://www.edpsciences.org
| Hα surface photometry of galaxies in the Virgo cluster I. Observations with the San Pedro Martir 2.1 m telescope
Hα imaging observations of 125 galaxies obtained with the 2.1 mtelescope of the San Pedro Martir Observatory (SPM) (Baja California,Mexico) are presented. The observed galaxies are mostly Virgo clustermembers (77), with 36 objects in the Coma/A1367 supercluster and 12 inthe clusters A2197 and A2199 taken as fillers. Hα +[NII] fluxesand equivalent widths, as well as images of the detected targets arepresented. The observatory of San Pedro Martir (Mexico) belongs to theObservatorio Astronómico Nacional, UNAM. Figure 4 is onlyavailable in electronic form at http://www.edpsciences.org
| Total Magnitudes of Virgo Galaxies. II. An Investigation into the mp Scale of Volume I of Zwicky et al.'s Catalogue of Galaxies and of Clusters of Galaxies
We investigate the photographic-magnitude (mp) scale ofVolume I of the Catalogue of Galaxies and of Clusters of Galaxies forgalaxies in the Virgo direction. It is found that for 11.5 <= Bt <14 5, the mp values listed correspond very closely (with ascatter of only 0.16 magnitude) to blue magnitudes measured to theμB = 24 4 isophote. If mp values need to beused as estimates of total blue magnitude the scatter is 0.27 magnitudeover the same range in Bt and the mean offset ismp-Bt=0 28 magnitude. However, a serious scaleerror at the bright end causes both the isophotal and total luminositiesof galaxies brighter than Bt~11.5 to be severelyunderestimated. At the faint end there also appears to be a significantscale error. This causes galaxy luminosities to be seriouslyoverestimated faintward of Bt ~ 14.5. We demonstrate thatthis is a real effect based on a detailed galaxy-by-galaxy study of thecatalogue's completeness down to Bt= 17.0. The catalogue isfound only to be complete to Bt ~ 14.7 whilst its degree ofincompleteness is found to be relatively constant at the 30% level overthe range 14.75 <= Bt < 15.75. Most of the missingobjects are found to be elliptical galaxies and so late-type objects areover-represented at the faint end.
| The Arecibo Dual-Beam Survey: Arecibo and VLA Observations
The Arecibo Dual-Beam Survey is a ``blind'' 21 cm search for galaxiescovering ~430 deg2 of sky. We present the data from thedetection survey as well as from the follow-up observations to confirmdetections and improve positions and flux measurements. We find 265galaxies, many of which are extremely low surface brightness. Some ofthese previously uncataloged galaxies lie within the zone of avoidance,where they are obscured by the gas and dust in our Galaxy. Eighty-one ofthese sources are not previously cataloged optically, and there are 11galaxies that have no associated optical counterpart or are onlytentatively associated with faint wisps of nebulosity on the DigitizedSky Survey images. We discuss the properties of the survey, and inparticular we make direct determinations of the completeness andreliability of the sample. The behavior of the completeness and itsdependencies is essential for determining the H I mass function. Weleave the discussion of the mass function for a later paper, but do notethat we find many low surface brightness galaxies and seven sources withMHI<108 Msolar. The AreciboObservatory is part of the National Astronomy and Ionosphere Center,which is operated by Cornell University under cooperative agreement withthe National Science Foundation. in Puerto Rico.
| Luminosity versus Phase-Space-Density Relation of Galaxies Revisited
We reexamined the correlation between the BTmagnitude and the phase-space-density parameterw=(D225vc)-1 of galaxies forthe Virgo, the Coma, the Fornax, and the Perseus clusters in an effortto better understand the physical underpinning of the fundamental plane.A tight correlation (BT=alog w+b) common to differentmorphological types of galaxies (E, S0, S) was found for the Virgo andthe Coma clusters, with a=1.87+/-0.10 and 1.33+/-0.11, respectively. Aninvestigation using only E galaxies was made for the four clusters. Theresults indicated that the empirical linear relation might be commonamong the Coma, the Fornax, and the Perseus clusters, with the VirgoCluster showing deviation. This relation, which is another way toproject the fundamental plane, has an expression insensitive to themorphology and may be suitable for treating galaxies of differentmorphological types collectively.
| 1.65 μm (H-band) surface photometry of galaxies. V. Profile decomposition of 1157 galaxies
We present near-infrared H-band (1.65 μm) surface brightness profiledecomposition for 1157 galaxies in five nearby clusters of galaxies:Coma, A1367, Virgo, A262 and Cancer, and in the bridge between Coma andA1367 in the ``Great Wall". The optically selected (mpg≤16.0) sample is representative of all Hubble types, from E to Irr+BCD,except dE and of significantly different environments, spanning fromisolated regions to rich clusters of galaxies. We model the surfacebrightness profiles with a de Vaucouleurs r1/4 law (dV), withan exponential disk law (E), or with a combination of the two (B+D).From the fitted quantities we derive the H band effective surfacebrightness (μe) and radius (re) of each component, theasymptotic magnitude HT and the light concentration indexC31. We find that: i) Less than 50% of the Ellipticalgalaxies have pure dV profiles. The majority of E to Sb galaxies is bestrepresented by a B+D profile. All Scd to BCD galaxies have pureexponential profiles. ii) The type of decomposition is a strong functionof the total H band luminosity (mass), independent of the Hubbleclassification: the fraction of pure exponential decompositionsdecreases with increasing luminosity, that of B+D increases withluminosity. Pure dV profiles are absent in the low luminosity rangeLH<1010 L\odot and become dominantabove 1011 L\odot . Based on observations taken atTIRGO, Gornergrat, Switzerland (operated by CAISMI-CNR, Arcetri,Firenze, Italy) and at the Calar Alto Observatory (operated by theMax-Planck-Institut für Astronomie (Heidelberg) jointly with theSpanish National Commission for Astronomy). Table 2 and Figs. 2, 3, 4are available in their entirety only in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| 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.
| Internal extinction, population incompleteness bias and the faint-end of the B-band Tully-Fisher relation
We analyse the distribution of three different samples of spiralgalaxies of the Local Universe in the B-band luminosity-maximumrotational velocity (L_B-VMax) plane, i.e. the B-magnitudeTully-Fisher (TF) relation. The first sample comprises 25+31 late-type(from Sa to Im-BCD) galaxies, selected from, respectively, the Virgo andthe Ursa Major clusters. In addition, a sample of 20 group extremelate-type (ELT) spiral (from Sd to Sm) galaxies and a sample of 13 dwarflate-type galaxies are selected. First, we analyse the influence ofthree different corrections for internal extinction (IE) on both theslope and the zero-point of the relation. These recipes reflect eitheri) the morphological type dependence of the IE or ii) the assumption ofa ``sandwich-model'' for the distribution of the dust and the stellarcomponents within the disk or iii) the existence of the metallicity-massrelation. As a first result we find that the latter recipe of IEcorrection systematically makes Sa-Sc galaxies brighter than laterspirals. Since the former galaxies mainly populate the region of thebright, fast rotators, the slope of the corresponding TF relationbecomes much steeper than in the other two cases. Under the hypothesisthat the ELT spiral galaxies in clusters and in groups share the sameLF, we show that the claimed skew of the group ELT spiral galaxies withrespect to the extrapolated TF relation of more luminous systems (i.e.the local TF calibrators) is due both to the population incompletenessbias affecting such a template and to the type segregation. Finally, weconfirm that the distribution of dwarf galaxies with comparablerotational and random velocities in the L_B-VMax plane isconsistent with the relation of more luminous systems, while therotationally supported dwarf galaxies are underluminous with respect tothe ELT galaxies of the same VMax. However, the latterresults may suffer from the heterogeneous methods of measurement ofdwarf galaxy distances that were adopted.
| A linear near-IR Tully-Fisher relation for giant and dwarf late-type galaxies
We present the near-IR (K(') -band, i.e.: lambda = 2.1 ^mu m)Tully-Fisher (TF) relation for a sample of 50 giant and dwarf late-typegalaxies, selected from the Virgo Cluster Catalogue. We find that L ~VMax(4) along a range of 8 K(') -mag for galaxies withdifferent Hubble types (from Sa to Im-BCD), phenomenologies, structures,star-formation histories, masses, dark-to-luminous mass ratios,metallicities and, perhaps, ages. The linearity of the near-IR TFrelation is in contrast with recent determinations of the optical TFrelations for samples of extreme late-type and dwarf galaxies. Thenear-IR TF law is in agreement both with the expectation from theFundamental Plane for disk systems and with the scenario ofself-regulating star-formation in disks. The previous results suggestthat the TF relation reflects the connection between thestructural/dynamical properties and the star-formation process of bothgiant and dwarf late-type galaxies, through a gas supply forstar-formation regulated by the gravitational potential of the galaxy.
| 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 ``Virgo photometry catalogue''; a catalogue of 1180 galaxies in the direction of the Virgo Cluster's core
We present a new catalogue of galaxies in the direction of the VirgoCluster's core: the Virgo Photometry Catalogue (VPC)*. This cataloguecontains 1180 galaxies (including background objects) within a 23square-degree area of the sky centred on R.A._{1950.0} = 12h 26m anddec._{1950.0} = 13(deg) 08'. The VPC galaxy sample comprises ofnon-stellar objects brighter than B_J25 = 19.0; thecompleteness limits being B_J25 ~18.5 for the northern halfof the survey area and B_J25 ~18.0 for the southern half.Independently-calibrated photographic surface photometry is presentedfor over 1000 galaxies in the U, B_J and R_C bands. Parameters listedfor catalogued galaxies include: equatorial coordinates, morphologicaltypes, surface-brightness profile parameters (which preserve themajority of the original surface photometry information), U, B_J &R_C isophotal magnitudes, B_J and [transformed] B total magnitudes,(U-B_J) and (B_J-R_C) equal-area and total colours, apparent angularradii, ellipticities, position angles, heliocentric radial velocitiesand alternative designations. All total magnitudes and total colours areextrapolated according to a new system denoted t in order to distinguishit from the T system already in use. The VPC is based primarily on four(one U, two B_J and one R_C) UK-Schmidt plates, all of which weredigitised using the Royal Observatory Edinburgh's (ROE) COSMOS measuringmachine. All magnitudes, colours and surface-brightness parameters arederived from numerical integrations of segmented plate-scan data, exceptfor (in 109 cases) saturated or (in 51 cases) inextricably-mergedimages; our segmentation software being able to cope with the vastmajority of image mergers. * Appendices B, C and E, which contain thesurface photometry, the main catalogue and the summary cataloguerespectively, are only available in electronic form. They can beobtained from La Centre des Donees astronomiques de Strasbourg (CDS) viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html.
| 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
| Study of the Virgo Cluster Using the B-Band Tully-Fisher Relation
The distances to spiral galaxies of the Virgo cluster are estimatedusing the B-band Tully-Fisher (TF) relation, and the three-dimensionalstructure of the cluster is studied. The analysis is made for a completespiral sample taken from the Virgo Cluster catalog of Binggeli, Sandage,& Tammann. The sample contains virtually all spiral galaxies down toM_{BT}=-15 mag at 40 Mpc. A careful examination is made ofthe selection effect and errors of the data. We estimate distance to 181galaxies, among which distances to 89 galaxies are reasonably accurate.We compare these distances to those obtained by other authors on agalaxy-by-galaxy basis. We find reasonable consistency of theTully-Fisher distance among various authors. In particular, it is foundthat the discrepancy in the distance among the different analyses withdifferent data is about 15%, when good H I and photometric data areavailable. We clarify that the different results on the Virgo distanceamong authors arise from the choice of the sample and interpretation ofthe data. We confirm that the Tully-Fisher relation for the Virgocluster shows an unusually large scatter sigma = 0.67 mag, compared tothat for other clusters. We conclude that this scatter is not due to theintrinsic dispersion of the Tully-Fisher relation, but due to a largedepth effect of the Virgo cluster, which we estimate to be extended from12 Mpc to 30 Mpc. The distribution of H I--deficient galaxies isconcentrated at around 14--20 Mpc, indicating the presence of a core atthis distance, and this agrees with the distance estimated for M87 andother elliptical galaxies with other methods. We show also that thespatial number density of spiral galaxies takes a peak at this distance,while a simple average of all spiral galaxy distances gives 20 Mpc. Thefact that the velocity dispersion of galaxies takes a maximum at 14--18Mpc lends an additional support for the distance to the core. Thesefeatures cannot be understood if the large scatter of the TF relation ismerely due to the intrinsic dispersion. The structure of the VirgoCluster we infer from the Tully-Fisher analysis looks like a filamentwhich is familiar to us in a late phase of structure formation in thepancake collapse in hierarchical clustering simulations. This Virgofilament lies almost along the line of sight, and this is the originthat has led a number of authors to much confusion in the Virgo distancedeterminations. We show that the M87 subcluster is located around 15--18Mpc, and it consists mainly of early-type type spiral galaxies inaddition to elliptical and S0 galaxies. There are very few late-typespiral galaxies in this subcluster. The spiral rich M49 subclusterconsists of a mixture of all types of spiral galaxies and is located atabout 22 Mpc. The two other known clouds, W and M, are located at about30--40 Mpc and undergo infall toward the core. The M cloud contains fewearly type spirals. We cannot discriminate, however, whether thesesubclusters or clouds are isolated aggregates or merely parts offilamentary structure. Finally, we infer the Hubble constant to be 82+/- 10 km s-1 Mpc-1.
| Near infrared surface photometry of late-type Virgo cluster galaxies
Near Infrared (K' band) surface photometry has been obtained for 102 (88late-type) Virgo cluster galaxies. A subset of 20 galaxies was alsoimaged in the H band. Magnitudes and diameters within the 21.5 and 22.0mag arcsec$^{-2}$ isophote, concentration indices and total H and K'magnitudes are derived. Basic statistical properties of a completesample of spiral galaxies spanning the range 6.3 < K'_T < 13.5 aregiven. Tables 3, 5 and 6 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html} Based on observations taken atthe Calar Alto Observatory, operated by the Max-Planck-Institut furAstronomie (Heidelberg) jointly with the Spanish National Commission forAstronomy.
| Arecibo H i Mapping of a Large Sample of Dwarf Irregular Galaxies
Neutral hydrogen mapping of 70 dwarf irregular (Sm, Im, and BCD)galaxies is reported, with position-velocity contour maps (and a fewcontour maps in R.A. and decl.) presented for those resolved by theArecibo beam. The galaxies were selected either from the Virgo ClusterCatalog, from similarly identified field galaxies, or from a distance-limited sample within the Arecibo declination range. We do not find anyisolated dwarfs with a larger H I to optical radius ratio than DDO 154;the "protogalaxy" H I 1225+01 of Giovanelli & Haynes continues to bea unique object among dwarfs that have been mapped in H I. For alldwarfs with significant rotation, we are able to determine the sense ofthe spin. For a number of better resolved dwarfs, we are able todetermine rotation curves, in most cases extending well beyond the lastmeasured point in available synthesis array maps. Correlations among theseveral measures of galaxy size and mass are studied; in a companionpaper we combine these data with those for the set of all availablemapped dwarf irregular galaxies and for mapped spirals spanning asimilar range of redshifts to investigate variations in Tully-Fisherrelations and in surface densities as functions of galaxy size andluminosity or mass.
| On the Size and Formation Mechanism of Star Complexes in Sm, Im, and BCD Galaxies
The diameters D_c_ of the largest star-forming complexes in 67Magellanic spiral and irregular galaxies and 16 blue compact dwarf (BCD)galaxies are found to scale approximately with the square root of thegalaxy luminosity for each type, i.e., smaller galaxies haveproportionately smaller star-forming regions. This is the same relationas for the largest complexes in bright spiral galaxies found previously,although Sm/Im galaxies have complexes that, on average, are a factor of2 larger than the extrapolation for spiral galaxies at the same absolutemagnitude, and the BCD galaxies have complexes that are ~2 times largerthan those typical of the Sm/Im galaxies at the same absolute magnitude.These results are consistent with the interpretation that the largestcomplexes form at the gravitational length scale in a marginally stableinterstellar medium with a nearly constant velocity dispersion c ~ 5-10km s^-1^. The luminosity scaling is then the result of higher averagetotal densities in smaller galaxies compared with the outer regions ofgiant spirals. This total density correlation is shown using published HI line widths and optical galaxy sizes. The implication of these resultsis that star formation begins when the ratio of the gas density ρ tothe total density (gas + stars + dark matter) exceeds several tenths. Ifstar formation lasts for a time scaling with (Grho_)^-1/2^ ~D_c_/c, then the main morphological differences between star formationin galaxies of various sizes can be explained: large galaxies have largestar complexes that form groups of OB associations slowly for up to 50Myr; small galaxies have small complexes (in terms of absolute size)that form dense associations quickly, in bursts spanning less than 5Myr.
| New aperture photometry for 217 galaxies in the Virgo and Fornax clusters.
We present photo electric multi-aperture photometry in UBVRI of 171 and46 galaxies in the Virgo and Fornax clusters, respectively. Many of thegalaxies have not been observed in at least one of these passbandsbefore. We discuss the reduction and transformation into the Cousinsphotometric system as well as the extinction coefficients obtainedbetween 1990 and 1993.
| Kinematics of the local universe. III. Neutral hydrogen observations of southern galaxies.
This paper is the third one in a series dedicated to the study of thekinematics of the local universe. It gives 52 new 21-cm neutral hydrogenmeasurements, made with the 64-m Parkes radio telescope. These newmeasurements are used to built a complete sample of 5,219 galaxies with21-cm line widths, radial velocity and apparent diameter. This sample iscomplete down to a diameter limit of 1.6 arcmin.
| An image database. II. Catalogue between δ=-30deg and δ=70deg.
A preliminary list of 68.040 galaxies was built from extraction of35.841 digitized images of the Palomar Sky Survey (Paper I). For eachgalaxy, the basic parameters are obtained: coordinates, diameter, axisratio, total magnitude, position angle. On this preliminary list, weapply severe selection rules to get a catalog of 28.000 galaxies, wellidentified and well documented. For each parameter, a comparison is madewith standard measurements. The accuracy of the raw photometricparameters is quite good despite of the simplicity of the method.Without any local correction, the standard error on the total magnitudeis about 0.5 magnitude up to a total magnitude of B_T_=17. Significantsecondary effects are detected concerning the magnitudes: distance toplate center effect and air-mass effect.
| Surface photometry of spiral galaxies in the Virgo cluster region
Photographic surface photometry is carried out for 246 spiral galaxiesin the Virgo cluster region north of declination + 5 deg. The samplecontains all spiral galaxies of 'certain' and 'possible' Virgo membersin the Virgo Cluster Catalogue of Binggeli, Sandage, & Tammann. Thesample also includes those galaxies which were used in the Tully-Fisheranalyses of the Virgo cluster given in the literature. A catalog ispresented for positions, B-band total magnitudes and inclinations forthese galaxies, and they are compared with the data given in previousstudies.
| A Very Large Array search for emission from HI associated with nearby Lyman alpha absorbers
We present a sensitive Very Large Array (VLA) search for H I emissionfrom the vicinity of the Lyman alpha clouds in the Virgo Cluster, whichwere recently discovered with Hubble Space Telescope (HST) in absorptiontoward the nearest quasar 3C273. We searched an area of 40 by 40 arcmincentered on 3C273, covering a velocity range from 840 to 1840 km/s. Thebandpass was self-calibrated on 3C273 leading to a spectral dynamicrange of better than 105 to 1. No H I was detected. The rmsnoise in the final images corresponds to a 3 sigma column densitysensitivity of 2.8 x 1019 sq cm on scales of a few kpc. SmallH I clouds could have been detected down to a few times 106solar mass. Our failure to detect H I emission at the higher columndensities sets a lower limit to the radius of the Lyman alpha clouds of3.9 kpc, assuming a spherical geometry.
| Distribution of the spin vectors of the disk galaxies of the Virgo cluster. I. The catalogue of 310 disk galaxies in the Virgo area.
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