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Optical spectroscopy for a sample of southern binary galaxies
Aims.This work is part of a joint observational program aiming to getphotometric and spectroscopic information on southern pairs of galaxies.We present optical long-slit spectroscopic data on 80 probablecomponents of pairs, 61 of them collected with a spectral resolution of3.4 Å, and 19 with 12 Å. Nevertheless, our analysis takesinto account 53 components of pairs with better spectral resolution, as8 of these target galaxies actually belong to optical pairs. For thesample with better resolution, the covered wavelength range is 5724≤ λ ≤ 7036 Å. The spectroscopic and photometricinformation is gathered for an analysis relating galaxy morphologies totheir spectra. Methods: .We use Hα +[NII] and Hα equivalent widths as star formationtracers for the central region of our sample galaxies, and we classifythe spectra according to the emission lines' relative strength bylooking at their behavior. Results: . Some of our sample galaxiesexhibit high central star formation, most of them belonging to closepairs. However, not all galaxies' components of close pairs show thisbehavior. This may be a clue that besides interaction, other agents canstimulate central emission in binary galaxies. We suggest an enhancementin the number of galaxies with peculiar spectra (probably Seyferts) inour binary sample, when compared to isolated galaxies. Our dataindicates that the morphological types of interacting galaxies arerelated to their spectral characteristics, as almost all early-typegalaxies of our sample do not exhibit central optical emission. We notethat the star formation activity is most likely to take place in bothpairs' components, with a slightly higher mean strength for the lessbright component of the pair. It is interesting to point out that mostspirals exhibiting a strong HII emission line spectra present either abar or a peculiarity, but on a general basis we do not find anenhancement of star formation in our interaction sample.
| Photometric study of a sample of southern binary galaxies
Aims.This work exhibits the basic optical photometric data for a sampleof 50 probable southern binary galaxies. Our sample covers a broad rangeof pair separations, stages of interaction, and morphologies. From theinitial list of selected pairs, using spectroscopic data from theliterature and our own data, we conclude that 84% of these systems aretrue binary galaxies. Methods: .We present residual and asymmetricmaps, R major semi-axis profiles of surface brightness, ellipticity,position-angle, harmonic Fourier coefficients of third and fourth order(b3 and b_4) for 50 probable pairs, and B-R color maps for 47of these pairs. For most galaxies, we present the profiles in twodifferent ways, aiming to verify the influence of random errors onthem. Results: . We note that random errors in position-angleprofiles are at least 2°, but a more significant result must takeinto account a variation larger than 11° for this distribution.Barred galaxies usually show a typical behavior in ellipticity andposition-angle profiles: these profiles display variations when changingfrom a bar to a disk region. In some cases, the variations also occuralong the bar. Some galaxies show distribution profiles that are commonfor their morphological type, and the interaction signature is onlyevidenced by their residual maps. Bars are usually redder and rings arebluer, when compared with the galaxy outskirts. Conclusions: .Ourdata indicates that there is a connection between interaction strengthand morphological distortions in binary galaxies. If we consider theprojected separation of a pair as an indication of interaction strength,distortions such as displaced centers, anomalous shapes of spiral arms,and twistings of external regions are easily detected in some closepairs, although not all components of close pairs show this behavior.Our data suggests that besides interaction, other parameters, likeorbital geometry and internal properties of galaxies, can stimulatebinary galaxies' peculiarities.
| Environmental effects in galaxies. Molecular gas, star formation, and activity
In order to study whether there is any correlation between nuclearactivities, gas content, and the environment where galaxies reside, wehave obtained optical and millimetric spectra for a well-defined sampleof intermediate Hubble type spirals in dense environments and in thefield. We found that these spirals in dense environments have onaverage: less molecular gas per blue luminosity, a higher atomic gasfraction, lower current star formation rate, and the same star formationefficiency as field galaxies. Although none of these results stands outas a single strong diagnostic given their statistical significance,taken together they indicate a trend for diminished gas content andstar-formation activity in galaxies in high-density environments. Ourresults suggest that galaxies in dense environments have either (i)consumed their molecular gas via star formation in the past or (ii) thatdense environments leads to an inhibition of molecular gas from atomicphase. The similarities in star-formation efficiency of the denseenvironments and field galaxies suggest that the physical processescontroling the formation of stars from the molecular gas are localrather than global. We also found that star formation rate per blueluminosity increases linearly as the total amount of gas increases inLINERs. This result, based on a small sample, suggests that LINERs arepowered by star formation rather than an AGN. Based on observations atthe European Southern Observatory at the 15 m Swedish ESO Submillimetretelescope, SEST, and at the the 1.52 m telescope which is operated underthe ESO-ON agreement.
| Environmental effects in galaxies. The data{
We present optical and millimetric data for 47 intermediate Hubble typespiral galaxies located either in dense environments or in the field. Wecompare correlations between global parameters, such as far-infraredluminosity, blue luminosity, and total molecular gas content, with othersamples of galaxies, including normal galaxies, clusters andultraluminous infrared galaxies. We find that overall our sample is awell-defined subset of these other samples of galaxies. Based onobservations at the European Southern Observatory at the 15 m SwedishESO Submillimetre telescope, SEST, and at the the 1.52 m telescope whichis operated under the ESO-ON agreement. Appendix A is only available inelectronic form at http://www.edpsciences.org
| Nearby Optical Galaxies: Selection of the Sample and Identification of Groups
In this paper we describe the Nearby Optical Galaxy (NOG) sample, whichis a complete, distance-limited (cz<=6000 km s-1) andmagnitude-limited (B<=14) sample of ~7000 optical galaxies. Thesample covers 2/3 (8.27 sr) of the sky (|b|>20deg) andappears to have a good completeness in redshift (97%). We select thesample on the basis of homogenized corrected total blue magnitudes inorder to minimize systematic effects in galaxy sampling. We identify thegroups in this sample by means of both the hierarchical and thepercolation ``friends-of-friends'' methods. The resulting catalogs ofloose groups appear to be similar and are among the largest catalogs ofgroups currently available. Most of the NOG galaxies (~60%) are found tobe members of galaxy pairs (~580 pairs for a total of ~15% of objects)or groups with at least three members (~500 groups for a total of ~45%of objects). About 40% of galaxies are left ungrouped (field galaxies).We illustrate the main features of the NOG galaxy distribution. Comparedto previous optical and IRAS galaxy samples, the NOG provides a densersampling of the galaxy distribution in the nearby universe. Given itslarge sky coverage, the identification of groups, and its high-densitysampling, the NOG is suited to the analysis of the galaxy density fieldof the nearby universe, especially on small scales.
| 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
| 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.
| Candidates for a southern extension of the Karachentsev catalogue of isolated pairs of galaxies.
Not Available
| 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.
| 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.
| Galaxy properties in different environments. 1: The sample
This paper presents two galaxy samples, respectively in a high and in alow local density environments, that were generated from the SouthernSky Redshift Survey (SSRS) catalog using objective criteria. Apreliminary comparison of physical properties in these two samplesreveals that galaxies in high-density environments tend to be under ahigher starbursting activity, have a deficiency of the neutral hydrogencontent, present a higher fractional Seyfert population and a higherfraction of barred spirals as well. The present samples are intended tobe used in future spectroscopic observations for more detailedinvestigation.
| CO in paired galaxies: Star formation induced by gas flow
We present CO(1-0) observations of 51 galaxies from anoptically-selected smaple of binaries in the southern hemisphere. Datawere taken with the SEST 15m telescope (44 in beam). CO emission wasdetected from 33 galaxies, corresponding to a 65% detection rate. Thereis a strong correlation between the normalized CO and FIR luminosities.As already noted in other samples, the far infrared luminosity L(FIR)normalized to the blue luminosity and the star formation efficiency, astraced by the L(FIR)/M(H2) ratio, are enhanced, suggesting a tidaltrigger for the star-formation. The FIR luminosity normalized to theoptical surface is also enhanced. The CO luminosity is enhanced intidally perturbed objects, suggesting that the amount of molecular gasis higher in the interacting objetcs. The L(FIR)/L(B), and L(CO)/L(B)ratios correlate, although weakly, with the component separation in thebinaries, while the L(FIR)/M(H2) does not. This suggests that one of themain phenomena triggering star formation is the enhancement in the totalamount of molecular gas. The gas inflow is probably due to gravitationaltorques produced by tidal interaction. Our observations show thatinteracting galaxies have both a higher star formation efficiency and alarger mass of molecular gas available to fuel star formation.
| 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.
| A large sample of southern IRAS galaxies - Spectral classes and superclustering
Results are presented of an extensive spectroscopic survey of IRASgalaxies, in three Southern-Hemisphere fields totaling about 0.5 sr.Spectroscopic observations have been made of 527 galaxies which arecandidates for 474 IRAS sources. Together with published data, there arenow measured redshifts for almost 850 of the 1178 selected IRAS galaxiesin these fields. This measured sample includes nearly all galaxies athigh redshifts, and hense high infrared luminosities, within thesefields. Classification of more than 350 of these galaxies usingemission-line ratios and line widths shows that about 90 percent havestarburst characteristics. Two distinct groups of starburst galaxies inthe sample display forbidden O III-line intensities which significantlyexceed those observed in optically selected starburst galaxies. One ofthese groups, with strong N II forbidden lines, may be related to linersand/or Seyfert galaxies. The other, with weak N II forbidden-lineemission, displays unusually narrow lines; this group is interpreted interms of the youngest phase of starburst activity.
| Southern Sky Redshift Survey - The catalog
The catalog of radial velocities for galaxies which comprise thediameter-limited sample of the Southern Sky Redshift Survey ispresented. It consolidates the data of observations carried out at theLas Campanas Observatory, Observatorio Nacional, and South AfricanAstronomical Observatory. The criteria used for the sample selection aredescribed, as well as the observational procedures and the techniqueutilized to obtain the final radial velocities. The intercomparisonbetween radial velocity measurements from different telescopes indicatesthat the final data base is fairly homogeneous with a typical error ofabout 40 km/s. The sample is at present 90 percent complete, and themissing galaxies are predominantly objects with very low surfacebrightness for which it is very difficult to obtain optical redshifts.
| Mass-to-Light Ratios of Binary Galaxies. III. Analysis
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1987ApJS...64..427S&db_key=AST
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