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The 1000 Brightest HIPASS Galaxies: H I Properties
We present the HIPASS Bright Galaxy Catalog (BGC), which contains the1000 H I brightest galaxies in the southern sky as obtained from the H IParkes All-Sky Survey (HIPASS). The selection of the brightest sourcesis based on their H I peak flux density (Speak>~116 mJy)as measured from the spatially integrated HIPASS spectrum. The derived HI masses range from ~107 to 4×1010Msolar. While the BGC (z<0.03) is complete inSpeak, only a subset of ~500 sources can be consideredcomplete in integrated H I flux density (FHI>~25 Jy kms-1). The HIPASS BGC contains a total of 158 new redshifts.These belong to 91 new sources for which no optical or infraredcounterparts have previously been cataloged, an additional 51 galaxiesfor which no redshifts were previously known, and 16 galaxies for whichthe cataloged optical velocities disagree. Of the 91 newly cataloged BGCsources, only four are definite H I clouds: while three are likelyMagellanic debris with velocities around 400 km s-1, one is atidal cloud associated with the NGC 2442 galaxy group. The remaining 87new BGC sources, the majority of which lie in the zone of avoidance,appear to be galaxies. We identified optical counterparts to all but oneof the 30 new galaxies at Galactic latitudes |b|>10deg.Therefore, the BGC yields no evidence for a population of``free-floating'' intergalactic H I clouds without associated opticalcounterparts. HIPASS provides a clear view of the local large-scalestructure. The dominant features in the sky distribution of the BGC arethe Supergalactic Plane and the Local Void. In addition, one can clearlysee the Centaurus Wall, which connects via the Hydra and Antlia Clustersto the Puppis Filament. Some previously hardly noticable galaxy groupsstand out quite distinctly in the H I sky distribution. Several newstructures, including some not behind the Milky Way, are seen for thefirst time.
| The gas content of peculiar galaxies: Strongly interacting systems
A study of the gas content in 1038 interacting galaxies, essentiallyselected from Arp, Arp & Madore, Vorontsov-Velyaminov catalogues andsome of the published literature, is presented here. The data on theinterstellar medium have been extracted from a number of sources in theliterature and compared with a sample of 1916 normal galaxies. The meanvalues for each of the different ISM tracers (FIR, 21 cm, CO lines,X-ray) have been estimated by means of survival analysis techniques, inorder to take into account the presence of upper limits. From the datait appears that interacting galaxies have a higher gas content thannormal ones. Galaxies classified as ellipticals have both a dust and gascontent one order of magnitude higher than normal. Spirals have in mostpart a normal dust and HI content but an higher molecular gas mass. TheX-ray luminosity also appears higher than that of normal galaxies ofsame morphological type, both including or excluding AGNs. We consideredthe alternative possibilities that the molecular gas excess may derivefrom the existence of tidal torques which produce gas infall from thesurrounding regions or from a different metallicity which affects the Xconversion factor between the observed CO line luminosity and the H_2calculated mass. According to our tests, it appears that interactinggalaxies possess a higher molecular mass than normal galaxies but with asimilar star formation efficiency.Table 1 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/cgi-bin/qcat?J/A+A/422/941
| First Results from the COLA Project: The Radio-Far-Infrared Correlation and Compact Radio Cores in Southern COLA Galaxies
We present the first results from the COLA (compact objects in low-powerAGNs) project, which aims to determine the relationship between onefacet of AGN activity, the compact radio core, and star formation in thecircumnuclear region of the host galaxy. This will be accomplished bythe comparison of the multiwavelength properties of a sample of AGNswith compact radio cores to those of a sample of AGNs without compactcores and a matched sample of galaxies without AGNs. In this paper wediscuss the selection criteria for our galaxy samples and present theinitial radio observations of the 107 southern(δ<0deg) galaxies in our sample. Low-resolution ATCAobservations at 4.8, 2.5, and 1.4 GHz and high-resolution,single-baseline snapshots at 2.3 GHz with the Australian Long BaselineArray (LBA) are presented. We find that for the majority of the galaxiesin our sample, the radio luminosity is correlated with the far-infrared(FIR) luminosity. However, a small number of galaxies exhibit a radioexcess causing them to depart from the FIR-radio correlation. Compactradio cores are detected at fluxes greater than 1.5 mJy in nine of the105 galaxies observed with the LBA. The majority (8/9) of these galaxiesexhibit a radio excess, and 50% (7/14) of the galaxies that lie abovethe radio-FIR correlation by more than 1 σ have compact radiocores. The emission from the compact cores is too weak to account forthis radio excess, implying that there are radio structures associatedwith the compact cores that extend farther than the 0.05" resolution(corresponding to a linear scale 11-22 pc) of the LBA. There is noevidence that the radio luminosity of the compact cores is correlatedwith the FIR galaxy luminosity, indicating that the core contributeslittle to the overall FIR emission of the galaxy. The galaxies withcompact cores tend to be classified optically as AGNs, with two-thirds(6/9) exhibiting Seyfert-like optical emission line ratios, and theremaining galaxies classified either as composite objects (2/9) orstarburst (1/9). The galaxies classified optically as AGNs also exhibitthe largest radio excesses, and we therefore conclude that a large radioexcess on the radio-FIR correlation is a strong indication of an AGNwith a compact radio core.
| A Catalog of H I-Selected Galaxies from the South Celestial Cap Region of Sky
The first deep catalog of the H I Parkes All Sky Survey (HIPASS) ispresented, covering the south celestial cap (SCC) region. The SCC areais ~2400 deg2 and covers δ<-62°. The average rmsnoise for the survey is 13 mJy beam-1. Five hundredthirty-six galaxies have been cataloged according to their neutralhydrogen content, including 114 galaxies that have no previous catalogedoptical counterpart. This is the largest sample of galaxies from a blindH I survey to date. Most galaxies in optically unobscured regions of skyhave a visible optical counterpart; however, there is a small populationof low-velocity H I clouds without visible optical counterparts whoseorigins and significance are unclear. The rms accuracy of the HIPASSpositions is found to be 1.9′. The H I mass range of galaxiesdetected is from ~106 to ~1011 Msolar.There are a large number of late-type spiral galaxies in the SCC sample(66%), compared with 30% for optically selected galaxies from the sameregion in the NASA Extragalactic Database. The average ratio of H I massto B luminosity of the sample increases according to optical type, from1.8 Msolar/Lsolar for early types to 3.2Msolar/Lsolar for late-type galaxies. The HI-detected galaxies tend to follow the large-scale structure traced bygalaxies found in optical surveys. From the number of galaxies detectedin this region of sky, we predict the full HIPASS catalog will contain~5000 galaxies, to a peak flux density limit of ~39 mJy (3 σ),although this may be a conservative estimate as two large voids arepresent in the region. The H I mass function for this catalog ispresented in a subsequent paper.
| Unveiling a connection between large-scale structures behind the southern Milky Way
A redshift survey of galaxies located in the direction of the southernMilky Way has been carried out using the FLAIR multi-objects system onthe 1.2-m UK Schmidt Telescope (UKST) at the Anglo-AustralianObservatory in Australia. The galaxy sample was extracted from the LEDAand COSMOS data bases, but essentially by scanning by eye four plates ofthe UKST/SERC Survey in the region between the Centaurus complex and thePavo-Indus (PI) wall. The galaxies selected have high central surfacebrightnesses and are distributed evenly over the whole search area. Themajority of the galaxies have apparent magnitudes in the range11.5
| Redshift Distribution of Galaxies in the Southern Milky Way Region 210 degrees < L < 360 degrees and B < 15 degrees
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..107..521V&db_key=AST
| 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.
| A search for IRAS galaxies behind the southern Milky Way
We systematically searched for IRAS galaxies with 60 micrometer fluxdensity larger than 0.6 Jy by using the UK Schmidt Infrared and IIIa-JAtlases in the Milky Way region (absolute value of b less than 15 deg)between l = 210 deg and 360 deg. We first selected about 4000 IRAS pointsources by using our far-infrared criteria, which are optimized for thesearch of IRAS galaxies behind the Milky Way region, and then inspectedvisually the optical counterparts of them on the Schmidt Atlas filmcopies. We found 966 IRAS sources associated with galaxy-like objects.The list of the objects is presented here with the IRAS source name,Galactic coordinates, IRAS flux densities, field number and emulsion ofthe Atlas, type and size of galaxy (-like) image, redshift,multiplicity, and cross-identification. Of these, 423 galaxies arealready cataloged in the Catalog of Galaxies and Quasars Observed in theIRAS Survey, and most of the remaining 543 galaxy candidates are newlyidentified in this search. Although the radial velocities are known foronly 387 galaxies, of which 60 were newly measured by us so far, weinferred the contamination by Galactic objects to be small from the goodcorrelation between the sky distributions of the newly identified galaxycandidates and the previously cataloged galaxies. In the regions wherethe Galactic molecular clouds dominate, almost all the sources were notidentified as galaxies. The detected galaxies are clustered in the threeregions around l = 240 deg, 280 deg, and 315 deg, where the projectednumber densities are higher than the whole-sky average of IRAS galaxiesof the same flux limit.
| Spectroscopic observations of Arp-Madore interacting galaxies. I - Pairs of comparably sized galaxies
Nuclear spectra of 129 galaxies from a sample of 71 pairs of interactingdoubles of comparably sized galaxies have been analyzed on the basis ofIRAS observations. Data obtained include radial velocities, relativeemission-line intensity measurements, and optical classifications. It isconfirmed that a large number of these objects are indeed showing H IIregion type spectra. It is suggested that a low LINER detection ratecould be due to the IR criteria which favor a strong H II region typeactivity and make it difficult to detect low-level LINER activity whichmay be present. The excess of Seyfert-type nuclei was not found, and thereason remains unclear. A high-frequency of one-sided enhancedstar-formation activity, suggested by the far-infrared study of the samesample of galaxies, also was not found. The enhancement of thestar-formation activity more likely to take place in both galaxies, butthe strength and/or time-scale and phase of the activity in each of thetwo galaxies of the pair may differ substantially.
| The supergalactic plane redshift survey
Redshift measurements, about 1000 of which are new, are presented for1314 galaxies in a survey toward the apex of the large-scale streamingflow for ellipticals. The velocity histogram shows that the excess ingalaxy number counts in this area is due to a substantial concentrationof galaxies with discrete peaks at V about 3000 km/s and V about 4500km/s. After correction for the sampling function, the centroid of thedensity distribution is found to be near V about 4500 km/s.Normalization to the more extensive SSRS survey, which was selected bythe same criteria, shows that the region studied contains a considerableoverdensity of galaxies from 2000 to 6000 km/s. This result is in goodagreement with the 'great attractor' model suggested by Lynden-Bell etal. (1988) which attributes the peculiar motions of elliptical galaxiesover a large region of space to an extensive mass overdensity whichincludes the Hydra-Centaurus and Pavo-Indus superclusters. The centroidof the density enhancement is also consistent with new data by Dresslerand Faber (1990) of peculiar motions of elliptical and spiral galaxies,both of which show a zero crossing of the Hubble line at approximately4500-5000 km/s.
| A deep redshift survey of IRAS galaxies towards the Bootes void
Redshifts were measured for a complete sample of galaxies detected bythe IRAS within 11.5 deg of the center of the void in Bootes discoveredby Kirshner et al (1981). There are 12 IRAS galaxies within the void asdefined by the above authors, seven of which were discovered in thissurvey. One of these has a companion at the same redshift. The resultingdensity of IRAS galaxies in the void is measured to be between 1/6 and1/3 of the average density; the uncertainty is dominated by Poissonstatistics. Good agreement is found between the selection function andnumber density derived from the present sample and those derived fromthe all-sky sample of Strauss (1989). The optical spectra of the newlyfound galaxies in the void are typical of IRAS galaxies in the field.
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