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Objective Classification of Spiral Galaxies Having Extended Rotation Curves Beyond the Optical Radius
We carry out an objective classification of four samples of spiralgalaxies having extended rotation curves beyond the optical radius. Amultivariate statistical analysis (viz., principal component analysis[PCA]) shows that about 96% of the total variation is due to twocomponents, one being the combination of absolute blue magnitude andmaximum rotational velocity beyond the optical region and the otherbeing the central density of the halo. On the basis of PCA a fundamentalplane has been constructed that reduces the scatter in the Tully-Fisherrelation up to a maximum of 16%. A multiple stepwise regression analysisof the variation of the overall shape of the rotation curves shows thatit is mainly determined by the central surface brightness, while theshape purely in the outer part of the galaxy (beyond the optical radius)is mainly determined by the size of the galactic disk.
| A Catalog of Neighboring Galaxies
We present an all-sky catalog of 451 nearby galaxies, each having anindividual distance estimate D<~10 Mpc or a radial velocityVLG<550 km s-1. The catalog contains data onbasic optical and H I properties of the galaxies, in particular, theirdiameters, absolute magnitudes, morphological types, circumnuclearregion types, optical and H I surface brightnesses, rotationalvelocities, and indicative mass-to-luminosity and H I mass-to-luminosityratios, as well as a so-called tidal index, which quantifies the galaxyenvironment. We expect the catalog completeness to be roughly 70%-80%within 8 Mpc. About 85% of the Local Volume population are dwarf (dIr,dIm, and dSph) galaxies with MB>-17.0, which contributeabout 4% to the local luminosity density, and roughly 10%-15% to thelocal H I mass density. The H I mass-to-luminosity and the H Imass-to-total (indicative) mass ratios increase systematically fromgiant galaxies toward dwarfs, reaching maximum values about 5 in solarunits for the most tiny objects. For the Local Volume disklike galaxies,their H I masses and angular momentum follow Zasov's linear relation,expected for rotating gaseous disks being near the threshold ofgravitational instability, favorable for active star formation. We foundthat the mean local luminosity density exceeds 1.7-2.0 times the globaldensity, in spite of the presence of the Tully void and the absence ofrich clusters in the Local Volume. The mean local H I density is 1.4times its ``global'' value derived from the H I Parkes Sky Survey.However, the mean local baryon densityΩb(<8Mpc)=2.3% consists of only a half of the globalbaryon density, Ωb=(4.7+/-0.6)% (Spergel et al.,published in 2003). The mean-square pairwise difference of radialvelocities is about 100 km s-1 for spatial separations within1 Mpc, increasing to ~300 km s-1 on a scale of ~3 Mpc. alsoWe calculated the integral area of the sky occupied by the neighboringgalaxies. Assuming the H I size of spiral and irregular galaxies to be2.5 times their standard optical diameter and ignoring any evolutioneffect, we obtain the expected number of the line-of-sight intersectionswith the H I galaxy images to be dn/dz~0.4, which does not contradictthe observed number of absorptions in QSO spectra.
| The Hα galaxy survey. I. The galaxy sample, Hα narrow-band observations and star formation parameters for 334 galaxies
We discuss the selection and observations of a large sample of nearbygalaxies, which we are using to quantify the star formation activity inthe local Universe. The sample consists of 334 galaxies across allHubble types from S0/a to Im and with recession velocities of between 0and 3000 km s-1. The basic data for each galaxy are narrowband H\alpha +[NII] and R-band imaging, from which we derive starformation rates, H\alpha +[NII] equivalent widths and surfacebrightnesses, and R-band total magnitudes. A strong correlation is foundbetween total star formation rate and Hubble type, with the strongeststar formation in isolated galaxies occurring in Sc and Sbc types. Moresurprisingly, no significant trend is found between H\alpha +[NII]equivalent width and galaxy R-band luminosity. More detailed analyses ofthe data set presented here will be described in subsequent papers.Based on observations made with the Jacobus Kapteyn Telescope operatedon the island of La Palma by the Isaac Newton Group in the SpanishObservatorio del Roque de los Muchachos of the Instituto deAstrofísica de Canarias.The full version of Table \ref{tab3} is available in electronic form atthe CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/414/23 Reduced image datafor this survey can be downloaded fromhttp://www.astro.livjm.ac.uk/HaGS/
| Distribution of star-forming complexes in dwarf irregular galaxies
We study the distribution of bright star-forming complexes in ahomogeneous sample of 72 late-type (``irregular'') dwarf galaxieslocated within the 10 Mpc volume. Star-forming complexes are identifiedas bright lumps in B-band galaxy images and isolated by means of theunsharp-masking method. For the sample as a whole the radial numberdistribution of bright lumps largely traces the underlyingexponential-disk light profiles, but peaks at a 10 percent smaller scalelength. Moreover, the presence of a tail of star forming regions out toat least six optical scale lengths provides evidence against asystematic star formation truncation within that galaxy extension.Considering these findings, we apply a scale length-independentconcentration index, taking into account the implied non-uniform randomspread of star formation regions throughout the disk. The numberprofiles frequently manifest a second, minor peak at about two scalelengths. Relying on a two-dimensional stochastic self-propagating starformation model, we show these secondary peaks to be consistent withtriggered star formation; for a few of the brighter galaxies a peculiarpeak distribution is observed that is conceivably due to the onset ofshear provided by differential rotation. On scales between 100 and 1000pc, and by taking into account exponential-disk structure, bright lumpsreveal cluster dimensions between 1.3 and 2, with a weak trend to higherdimensions for brighter galaxies. Cluster dimension weaklyanticorrelates with the lumpiness index (the fraction of the totalgalaxy light due to the light contributed by the lumps), the latterindex showing no dependence on luminosity. Lump spreading within thedisk, as measured by the concentration index, and lump clustering, asgiven by the cluster dimension, are not linked to each other.Interpreting cluster dimension in terms of porosity of a self-similarintragalactic medium, we derive a relation between current starformation rate, scale length, and porosity.
| The Westerbork HI survey of spiral and irregular galaxies. II. R-band surface photometry of late-type dwarf galaxies
R-band surface photometry is presented for 171 late-type dwarf andirregular galaxies. For a subsample of 46 galaxies B-band photometry ispresented as well. We present surface brightness profiles as well asisophotal and photometric parameters including magnitudes, diameters andcentral surface brightnesses. Absolute photometry is accurate to 0.1 magor better for 77% of the sample. For over 85% of the galaxies the radialsurface brightness profiles are consistent with published data withinthe measured photometric uncertainty. For most of the galaxies in thesample H I data have been obtained with the Westerbork Synthesis RadioTelescope. The galaxies in our sample are part of the WHISP project(Westerbork H I Survey of Spiral and Irregular Galaxies), which aims atmapping about 500 nearby spiral and irregular galaxies in H I. Theavailability of H I data makes this data set useful for a wide range ofstudies of the structure, dark matter content and kinematics oflate-type dwarf galaxies. Based on observations made with INT operatedon the island of La Palma by the Isaac Newton Group in the SpanishObservatorio del Roque de los Muchachos of the Instituto de Astrofisicade Canarias. The tables in Appendix A are only available in electronicform at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/390/863. Thefigures in Appendix B are only available in electronic formhttp://www.edpsciences.org
| The Westerbork HI survey of spiral and irregular galaxies. I. HI imaging of late-type dwarf galaxies
Neutral hydrogen observations with the Westerbork Synthesis RadioTelescope are presented for a sample of 73 late-type dwarf galaxies.These observations are part of the WHISP project (Westerbork H I Surveyof Spiral and Irregular Galaxies). Here we present H I maps, velocityfields, global profiles and radial surface density profiles of H I, aswell as H I masses, H I radii and line widths. For the late-typegalaxies in our sample, we find that the ratio of H I extent to opticaldiameter, defined as 6.4 disk scale lengths, is on average 1.8 +/- 0.8,similar to that seen in spiral galaxies. Most of the dwarf galaxies inthis sample are rich in H I, with a typical Mion {Hi}/L_B of1.5. The relative H I content M_ion {HI}/L_R increases towards fainterabsolute magnitudes and towards fainter surface brightnesses. Dwarfgalaxies with lower average H I column densities also have lower averageoptical surface brightnesses. We find that lopsidedness is as commonamong dwarf galaxies as it is in spiral galaxies. About half of thedwarf galaxies in our sample have asymmetric global profiles, a thirdhas a lopsided H I distribution, and about half shows signs of kinematiclopsidedness.
| Structure and stellar content of dwarf galaxies. VII. B and R photometry of 25 southern field dwarfs and a disk parameter analysis of the complete sample of nearby irregulars
We present B and R band surface photometry of 25 Southern field dwarfgalaxies within a distance of 10 Mpc. For each galaxy we give theessential model-free photometric parameters and, by fitting exponentialsto the surface brightness profiles, the central extrapolated surfacebrightness and the exponential scale length, in both colour bands.Surface brightness and colour profiles are shown. One of the objects, avery faint dwarf elliptical in the vicinity of NGC 2784, has beendiscovered in the course of this work. Drawing on the data from this andall previous papers of this series, we construct a complete sample of 72late-type (``irregular'') dwarf galaxies in nearby groups and the fieldwithin the 10 Mpc volume, to study the exponential-disk parameterrelations of these galaxies with respect to galaxy environment. Weconfirm our previous finding of statistically lower scale lengths/highercentral surface brightnesses for field and group galaxies as compared tocluster galaxies. However, using a clear-cut definition of ``group''versus ``field'' environment, we find no significant difference in thephotometric structure of group and field irregulars. A difference in thestar formation history may partly account for this structure-environmentrelation: for a given luminosity cluster dwarfs are on average redderthan field and group galaxies. We also report evidence for the colourgradients of dwarf irregulars being roughly inversely proportional tothe disk scale lengths. Supplementing our photometric data withkinematic data from the literature, we study possible relations withkinematic properties of the inner disk. Applying the dark matter scalingrelations for a Burkert halo we show that for field and group galaxiesof a given luminosity faster-than-mean disk rotational velocities at aradius of about two scale lengths are correlated with larger-than-meandisk scale lengths. Based on observations collected at the EuropeanSouthern Observatory, La Silla, Chile. Table 3 containing ``BRphotometry and kinematic data for the 72 irregular dwarf galaxies of ourcomplete sample'' is 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/388/29
| Local Field of Galaxy Velocities
A sample of 145 galaxies having radial velocities relative to thecentroid of the Local Group V LG D H ij , with principal values of81:62:48 in km/sec·Mpc, which have a standard error of 4km/sec·Mpc. The minor axis of the Hubble ellipsoid is orientedalmost along the polar axis of the Local Supercluster, while the majoraxis forms an angle = (29 ± 5)° with the direction toward thecenter of the Virgo Cluster. Such a configuration of thepeculiar-velocity field shows unsatisfactory agreement with the model ofa spherically symmetric flow of galaxies toward the Virgo Cluster.Rotation of the Local Supercluster may be one reason for thisdifference. The peculiar velocities of galaxies within a volume with D V= 74 km/sec, a considerable part of which is due to the virial motionsof galaxies in groups and to distance errors. For field galaxies,located in a layer of 1 < D < 3 Mpc around the Local Group, theradial-velocity dispersion does not exceed 25 km/sec. Thevelocitydistance relation, constructed from the 20 closestgalaxies around the Local Group with D < 3 Mpc and with errorsσ(D) < 0.2 Mpc, exhibits the expected effect of gravitationaldeceleration. Using the estimate of R 0 = (0.96 ± 0.05) Mpc forthe observed radius of the zero-velocity sphere, we determined the totalmass of the Local Group to be (1.2 ± 0.2)·1012 M ȯ,which agrees well with the sum of the virial masses of the subgroups ofgalaxies around the Local Group and M31. The ratio of the Local Group'stotal mass (within R 0) to its luminosity is M/L = (23 ± 4) Mȯ/L ȯ, which does not require the existence of supermassivedark halos around our Galaxy and M31.
| Structure and stellar content of dwarf galaxies. VI. B, V and R photometry of northern field dwarf galaxies
CCD photometry in the Cousins B, V and R bands of 19 northern fielddwarf galaxies is presented. For each galaxy, and for each colour, wedetermined total magnitude, effective radius and effective surfacebrightness, and, by fitting an exponential to the surface brightnessprofile, central surface brightness and exponential scale length.Surface brightness and colour profiles are shown. One of the observedgalaxies (UGC 2689) is probably a background S0 galaxy and belongs tothe cluster Abell 426. All others, with one possible exception (Kar 49),are typical late-type field dwarf galaxies (mostly magellanicirregulars) lying in the distance range 5-10 Mpc. The sample has amedian absolute magnitude M_B = -14.9 and a median colour (B-V) = 0.52.The present late-type dwarfs have higher surface brightness in the meanthan cluster late-type dwarfs, confirming a trend found in our previouswork. However, there is no evidence for a photometric difference betweenfield and group late-type dwarfs. This paper is part of a long-termprogramme to study the environmental differences in the photometricstructure of dwarf galaxies. Based on observations made at Observatoirede Haute Provence (CNRS), France.
| The QDOT all-sky IRAS galaxy redshift survey
We describe the construction of the QDOT survey, which is publiclyavailable from an anonymous FTP account. The catalogue consists ofinfrared properties and redshifts of an all-sky sample of 2387 IRASgalaxies brighter than the IRAS PSC 60-μm completeness limit(S_60>0.6Jy), sparsely sampled at a rate of one-in-six. At |b|>10deg, after removing a small number of Galactic sources, the redshiftcompleteness is better than 98per cent (2086/2127). New redshifts for1401 IRAS sources were obtained to complete the catalogue; themeasurement and reduction of these are described, and the new redshiftstabulated here. We also tabulate all sources at |b|>10 deg with noredshift so far, and sources with conflicting alternative redshiftseither from our own work, or from published velocities. A list of 95ultraluminous galaxies (i.e. with L_60μm>10^12 L_solar) is alsoprovided. Of these, ~20per cent are AGN of some kind; the broad-lineobjects typically show strong Feii emission. Since the publication ofthe first QDOT papers, there have been several hundred velocity changes:some velocities are new, some QDOT velocities have been replaced by moreaccurate values, and some errors have been corrected. We also present anew analysis of the accuracy and linearity of IRAS 60-μm fluxes. Wefind that the flux uncertainties are well described by a combination of0.05-Jy fixed size uncertainty and 8per cent fractional uncertainty.This is not enough to cause the large Malmquist-type errors in the rateof evolution postulated by Fisher et al. We do, however, find marginalevidence for non-linearity in the PSC 60-μm flux scale, in the sensethat faint sources may have fluxes overestimated by about 5per centcompared with bright sources. We update some of the previous scientificanalyses to assess the changes. The main new results are as follows. (1)The luminosity function is very well determined overall but is uncertainby a factor of several at the very highest luminosities(L_60μm>5x10^12L_solar), as this is where the remainingunidentified objects are almost certainly concentrated. (2) Thebest-fitting rate of evolution is somewhat lower than our previousestimate; expressed as pure density evolution with density varying as(1+z)^p, we find p=5.6+/-2.3. Making a rough correction for the possible(but very uncertain) non-linearity of fluxes, we find p=4.5+/-2.3. (3)The dipole amplitude decreases a little, and the implied value of thedensity parameter, assuming that IRAS galaxies trace the mass, isΩ=0.9(+0.45, -0.25). (4) Finally, the estimate of density varianceon large scales changes negligibly, still indicating a significantdiscrepancy from the predictions of simple cold dark matter cosmogonies.
| 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.
| Multi-colour photometry of nearby dwarf galaxies
Observations of 39 nearby, mostly dwarf galaxies are presented. Theobservations were carried out at the 1.2-m telescope of Observatoire deHaute-Provence (France) with B, V and I Cousins filters. Based onsurface and integrated photometry of the obtained images we derivedtotal B, V and I magnitudes and integrated B-V, V-I colours as well asradii and magnitudes at the 25 m isophotal level. Azimuthally averagedsurface brightness profiles were derived for 33 galaxies in eachphotometric band. Most of the profiles can be well fitted by anexponential intensity law of brightness distribution. The best-fittingexponential parameters are also given for the galaxies. Based onobservations made at Observatoire de Haute Provence (CNRS), France.Table 3 is only available in electronic form at the CDS via anonymousftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| HI properties of nearby galaxies from a volume-limited sample
We consider global HI and optical properties of about three hundrednearby galaxies with V_0 < 500 km s(-1) . The majority of them haveindividual photometric distance estimates. The galaxy sample parametersshow some known and some new correlations implying a meaningful dynamicexplanation: 1) In the whole range of diameters, 1 - 40 Kpc, the galaxystandard diameter and rotational velocity follows a nearly linearTully-Fisher relation, lg A25~(0.99+/-0.06)lg V_m. 2) The HImass-to-luminosity ratio and the HI mass-to-``total" mass (inside thestandard optical diameter) ratio increase systematically from giantgalaxies towards dwarfs, reaching maximum values 5 ;M_ȯ/L_ȯand 3, respectively. 3) For all the Local Volume galaxies their totalmass-to-luminosity ratio lies within a range of [0.2-16]M_ȯ/L_ȯ with a median of 3.0 ;M_ȯ/L_ȯ. TheM25/L ratio decreases slightly from giant towards dwarfgalaxies. 4) The M_HI/L and M25/L ratios for the samplegalaxies correlate with their mean optical surface brightness, which maybe caused by star formation activity in the galaxies. 5) The M_HI/L andM25/L ratios are practically independent of the local massdensity of surrounding galaxies within the range of densities of aboutsix orders of magnitude. 6) For the LV galaxies their HI mass andangular momentum follow a nearly linear relation: lgM_HI~(0.99+/-0.04)lg (V_m* A25), expected for rotatinggaseous disks being near the threshold of gravitational instability,favourable for active star formation. Table in the Appendix is availableonly in electronic form at the CDS via anonymous ftp 130.79.128.5 orhttp//cdsweb.u-strasbg.fr/Abstract.html
| CCD imaging of twenty nearby isolated irregular galaxies
We present B, V and I CCD stellar photometry for a sample of 20 fieldirregular dwarf galaxies. Their corrected radial velocity is V_0 <500 km s(-1) . Most of them have been resolved into stars for the firsttime. Based on photometry of their brightest blue stars we have derivedthe following distances: 5.9 Mpc (UGC 685), 5.4 Mpc (UGC 1281), 7.2 Mpc(UGC 3303), 7.0 Mpc (UGC 3476), 7.3: Mpc (UGC 3600), 7.2: Mpc (UGC3698), 7.9 Mpc (NGC 2337), 8.6 Mpc (UGC 3817), 5.7 Mpc (UGC 3860), 5.6Mpc (UGC 4426), >=7.9 Mpc (F 565-v1), 7.4: Mpc (UGC 5086), 7.1 Mpc(UGC 5272), 5.9 Mpc (UGC 5340), 7.1 Mpc (UGC 5427), 2.7: Mpc (UGC 5456),6.6 Mpc (NGC 3274), 9.3 Mpc (UGC 5889), 5.2 Mpc (NGC 5238), and 8.0 Mpc(UGC 9405). Our sample exhibits diverse morphological propertiesevidently caused by their different starburst activity. The galaxysample has a median integral absolute magnitude M_B = -14.6 and a medianintegral colour (B-V)_T = +0.47. One dwarf, UGC 5340, stands out by itsvery blue colour, (B-V)_T = +0.18, and by its high M(HI)/L ratio, asexpected for young galaxies. Four objects of the sample are IRASsources. Being well isolated systems, the considered galaxies may beused to estimate a local value of the Hubble parameter, H = V_0/D. Forhalf of the sample galaxies their individual H- values are concentratedwithin [58-68] km s(-1) /Mpc with a median of 65 km s(-1) /Mpc. Tables2--17 are only available in electronic form at the CDS via anonymous ftpto cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| The Absence of X-Ray Flashes from Nearby Galaxies and the Gamma-Ray Burst Distance Scale
If typical gamma-ray bursts (GRBs) have X-ray counterparts similar tothose detected by Ginga, then sensitive-focusing X-ray telescopes willbe able to detect GRBs 3 orders of magnitude fainter than the detectionlimit of the Burst and Transient Source Experiment (BATSE). If asubstantial portion of the burst population detected by BATSE originatesin a Galactic halo at distances greater than or equal to 150 kpc,existing X-ray telescopes will be able to detect GRBs in externalgalaxies out to a distance of at least 4.5 Mpc. As reported in Gotthelf,Hamilton, & Helfand, the imaging proportional counter (IPC) on boardthe Einstein Observatory detected 42 transient events with pointlikespatial characteristics and timescales of less than 10 s. These eventsare distributed isotropically on the sky; in particular, they are notconcentrated in the directions of nearby external galaxies. For halomodels of the BATSE bursts with radii of 150 kpc or greater, we wouldexpect to see several burst events in observations pointed toward nearbygalaxies. We see none. We therefore conclude that if the Gingadetections are representative of the population of GRBs sampled byBATSE, GRBs cannot originate in a Galactic halo population with limitingradii between 150 and 400 kpc. Inasmuch as halos with limiting radiioutside of this range have been excluded by the BATSE isotropymeasurements, our result indicates that all halo models are excluded.This result is independent of whether the flashes we do detect have anastronomical origin.
| 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^.
| CCD and HI observations of LSB dwarf galaxies in the general field.
CCD B and V observations of 16 low-surface-brightness galaxies and HIdata for a subsample of 4 of them are presented. Both paired andisolated dwarf galaxies are observed to study possible environmentaleffects on their characteristics. Most of the observed galaxies are truedwarfs with -8.0>=M_B_>=-16.0, blue colours(0.16<=B-V<=0.76) and low central surface brightnesses22.2<=μ_B_<=24.0mag/arcsec^2^. Most of them show exponentiallight profiles with a central light depression. About half of them havebright generally blue knots or peculiar loops.
| Nearby galaxies. 3: Gas-to-dust ratio in the interstellar medium of spiral and dwarf irregular galaxies
The gas-to-dust ratio in the interstellar medium of nearby spiralsystems and dwarf irregular galaxies has been obtained by using mainlythe compiled data by Schmidt and Boller (1992). The gas-to-dust ratio ofdwarf irregulars is larger by about one order of magnitude than forspiral galaxies, on the average. A relation between the gas-to-dustratio and the metallicity, represented by the abundance of oxygen, hasbeen detected.
| KISO survey for ultraviolet-excess galaxies. XV
The fifteenth list and identification charts of the ultraviolet-excessgalaxies are presented. These galaxies were detected on the multicolorplates taken with the Kiso Schmidt telescope for 10 survey fields. Inthe sky area of 300 square degrees 544 objects are cataloged down to thephotographic magnitude of about 17.5.
| Nearby galaxies. I - The catalogue
The data of 289 nearby galaxies have been compiled. The inclusion of agalaxy into the catalog depends on its redshift as in the catalogue ofKraan-Korteweg and Tammann (1979) or on the fact that the objects areknown to be certain or probable members of nearby groups. The galaxiesin the sample form the Local Group with 51 certain and probable membersand several additional groups. One third of the galaxies in the catalog(96 objects) does not seem to belong to any group. The main emphasis isto get a distance-limited sample of galaxies, especially of dwarfobjects.
| Properties of the redshift. I - Data and calibrations
Data at 21 cm are presented for 100 galaxies intended to be used forsystem comparisons between the NRAO 140 and 300 foot telescope and the100 m Effelsberg telescope. Data from the 300 foot telescope are alsogiven for galaxies selected for overlap comparisons with older studies.Flux calibrations and measurement uncertainties in flux, redshifts,profile width, and profile shape are discussed.
| A connection between the Perseus-Pisces supercluster and the A 569 cloud?
In order to shed some light on the possibility of a connection betweenthe Perseus-Pisces supercluster and the A 569 cluster through the zoneof avoidance of the Galaxy, H I and optical observations of galaxieshave been carried out in the region. Forty-two redshifts have beenmeasured, among which 21 for the first time in the possible connectionzone. The study of the H I contents of the galaxies detected in the21-cm line shows they are perfectly normal; as a by-product of thisstudy, the UGC magnitudes are found to be high by more than onemagnitude for m/(UGC) greater than or equal to 17.
| Uncertainties in 21 centimeter redshifts. I - Data
High-precision data on the 21-cm redshifts, profile widths, and shapesfor 625 galaxies are presented. Each galaxy is listed in across-identification and morphology table. High-resolution spectra arealso given for each galaxy. Internal redshift consistency is roughly 1km/s for galaxies for which the S/N is above 15. No systematic effectshave been found which might influence the observed redshift quantizationat 72.5 km/s or its submultiples.
| Empirical properties of nearby groups of galaxies
A new list of nearby groups was composed by Vennik (1984) on the basisof radial velocity data of galaxies using the hierarchical clusteringtechnique described by Materne (1978) and Tully (1980). This paperpresents a detailed analysis of empirical properties of groups on thebasis of that list. Various group selection criteria are compared, andthe main parameters of individual groups, possible selection effects,and relationships between various properties of the groups arediscussed. Synthesized groups are composed based on the luminosities ofthe groups and the dominating morphology.
| HI-observations of galaxies in the Kraan-Korteweg - Tammann catalogue of nearby galaxies. I - The data
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1986A&AS...63..323H&db_key=AST
| Irregular galaxies with extended H I emission
The NRAO 43-m telescope has been used to obtain H I 21-cm fluxes of alarge number of irregular galaxies integrated over a 21-arcmin beam,which can be used for determining total gas masses of these systems. Thedata are compared with fluxes obtained by Fisher and Tully (1975, 1981)with a 10-arcmin beam to identify those galaxies which may have extendedH I distributions relative to the optical sizes. Seven good candidatesystems are listed. The presence of extended H I in irregular galaxiesdoes not seem to correlate with basic global galaxian properties.
| The HEAO A-1 X-ray source catalog
The catalog of X-ray sources detected during the NRL Large Area SkySurvey (LASS) with the HEAO 1 satellite is presented. The catalog isderived from the first six months of data from HEAO 1 and includessources detected during one full scan. Positions and intensities for atotal of 842 different sources are included, with a limiting flux of 250nJy at 5 keV. The catalog is more than 90 percent complete at a fluxlevel equivalent to 1.5 microjoules at 5 keV for a Crab-like spectrum.Cross-references with published literature are provided and coincidentalidentifications are proposed for some of the sources which have beennever studied before. A cross-sectional line drawing of the sensormodule of HEAO I is also provided.
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