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How large are the bars in barred galaxies?
I present a study of the sizes (semimajor axes) of bars in discgalaxies, combining a detailed R-band study of 65 S0-Sb galaxies withthe B-band measurements of 70 Sb-Sd galaxies from Martin (1995). As hasbeen noted before with smaller samples, bars in early-type (S0-Sb)galaxies are clearly larger than bars in late-type (Sc-Sd) galaxies;this is true both for relative sizes (bar length as fraction ofisophotal radius R25 or exponential disc scalelength h) andabsolute sizes (kpc). S0-Sab bars extend to ~1-10 kpc (mean ~ 3.3 kpc),~0.2-0.8R25 (mean ~ 0.38R25) and ~0.5-2.5h (mean ~1.4h). Late-type bars extend to only ~0.5-3.5 kpc,~0.05-0.35R25 and 0.2-1.5h their mean sizes are ~1.5 kpc, ~0.14R25 and ~0.6h. Sb galaxies resemble earlier-type galaxiesin terms of bar size relative to h; their smallerR25-relative sizes may be a side effect of higher starformation, which increases R25 but not h. Sbc galaxies form atransition between the early- and late-type regimes. For S0-Sbcgalaxies, bar size correlates well with disc size (both R25and h); these correlations are stronger than the known correlation withMB. All correlations appear to be weaker or absent forlate-type galaxies; in particular, there seems to be no correlationbetween bar size and either h or MB for Sc-Sd galaxies.Because bar size scales with disc size and galaxy magnitude for mostHubble types, studies of bar evolution with redshift should selectsamples with similar distributions of disc size or magnitude(extrapolated to present-day values); otherwise, bar frequencies andsizes could be mis-estimated. Because early-type galaxies tend to havelarger bars, resolution-limited studies will preferentially find bars inearly-type galaxies (assuming no significant differential evolution inbar sizes). I show that the bars detected in Hubble Space Telescope(HST) near-infrared(IR) images at z~ 1 by Sheth et al. have absolutesizes consistent with those in bright, nearby S0-Sb galaxies. I alsocompare the sizes of real bars with those produced in simulations anddiscuss some possible implications for scenarios of secular evolutionalong the Hubble sequence. Simulations often produce bars as large as(or larger than) those seen in S0-Sb galaxies, but rarely any as smallas those in Sc-Sd galaxies.
| A Uniform Database of 2.2-16.5 μm Spectra from the ISOCAM CVF Spectrometer
We present all ISOCAM circular variable filter (CVF) spectra that covermore than one-third of the 2.2-16.5 μm spectral range of theinstrument. The 364 spectra have been classified according to theclassification system of Kraemer et al., as modified by Hodge et al. toaccount for the shorter wavelength range. Prior to classification, thespectra were processed and recalibrated to create a uniform database.Aperture photometry was performed at each wavelength centered on thebrightest position in each image field and the various spectral segmentsmerged into a single spectrum. The aperture was the same for all scalesizes of the images. Since this procedure differs fundamentally fromthat used in the initial ISOCAM calibration, a recalibration of thespectral response of the instrument was required for the aperturephotometry. The recalibrated spectra and the software used to createthem are available to the community on-line via the ISO Data Archive.Several new groups were added to the KSPW system to describe spectrawith no counterparts in either the SWS or PHT-S databases: CA, E/SA,UE/SA, and SSA. The zodiacal dust cloud provides the most commonbackground continuum to the spectral features, visible in almost 40% ofthe processed sources. The most characteristic and ubiquitous spectralfeatures observed in the CVF spectral atlas are those of theunidentified infrared bands (UIR), which are typically attributed toultraviolet-excited fluorescence of large molecules containing aromatichydrocarbons. The UIR features commonly occur superimposed on thezodiacal background (18%) but can also appear in conjunction with otherspectral features, such as fine-structure emission lines or silicateabsorption. In at least 13 of the galaxies observed, the pattern of UIRemission features has been noticeably shifted to longer wavelengths.Based on observations with the Infrared Space Observatory, a EuropeanSpace Agency (ESA) project with instruments funded by ESA Member States(especially the Principal Investigator countries: France, Germany, theNetherlands, and the United Kingdom) and with the participation of theInstitute of Space and Astronautical Science (ISAS) and the NationalAeronautics and Space Administration (NASA).
| Catalog of Double Nucleus Disk Galaxies
We have compiled a catalog of disk galaxies that have a double nucleus,through systematic examination of existing catalogs and publications.The Catalog of Double Nucleus Disk Galaxies includes 107 objects,together with their basic data. The aim of the catalog is to provide amore systematic and homogeneous basis for the study of the relevance ofgalaxy interactions and minor mergers in the formation of these doublenuclei. We have also investigated possible correlations betweengeometric and photometric parameters of the double nuclei and their hostgalaxies. The preliminary results indicate the presence of severalsignificant correlations that should be considered in any theoreticalscenario describing minor mergers and disk galaxy evolution.
| Starbursts in barred spiral galaxies. VI. HI observations and the K-band Tully-Fisher relation
This paper reports a study of the effect of a bar on the neutralhydrogen (HI) content of starburst and Seyfert galaxies. We also makecomparisons with a sample of ``normal'' galaxies and investigate howwell starburst and Seyfert galaxies follow the fundamental scalingTully-Fisher (TF) relation defined for normal galaxies. 111 Markarian(Mrk) IRAS galaxies were observed with the Nançay radiotelescope,and HI data were obtained for 80 galaxies, of which 64 are newdetections. We determined the (20 and 50%) linewidths, the maximumvelocity of rotation and total HI flux for each galaxy. Thesemeasurements are complemented by data from the literature to form asample of Mrk IRAS (74% starburst, 23% Seyfert and 3% unknown) galaxiescontaining 105 unbarred and 113 barred ones. Barred galaxies have lowertotal and bias-corrected HI masses than unbarred galaxies, and this istrue for both Mrk IRAS and normal galaxies. This robust result suggeststhat bars funnel the HI gas toward the center of the galaxy where itbecomes molecular before forming new stars. The Mrk IRAS galaxies havehigher bias-corrected HI masses than normal galaxies. They also showsignificant departures from the TF relation, both in the B and K bands.The most deviant points from the TF relation tend to have a strongfar-infrared luminosity and a low oxygen abundance. These resultssuggest that a fraction of our Mrk IRAS galaxies are still in theprocess of formation, and that their neutral HI gas, partly of externalorigin, has not yet reached a stationary state.Based on observations obtained at the large radiotelescope ofObservatoire de Nançay, operated by Observatoire de Paris.Tables 5 and 6 are only (and Table 4 also) available in electronic format the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) orvia http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/416/515
| An Imaging Survey of Early-Type Barred Galaxies
This paper presents the results of a high-resolution imaging survey,using both ground-based and Hubble Space Telescope images, of a completesample of nearby barred S0-Sa galaxies in the field, with a particularemphasis on identifying and measuring central structures within thebars: secondary bars, inner disks, nuclear rings and spirals, andoff-plane dust. A discussion of the frequency and statistical propertiesof the various types of inner structures has already been published.Here we present the data for the individual galaxies and measurements oftheir bars and inner structures. We set out the methods we use to findand measure these structures, and how we discriminate between them. Inparticular, we discuss some of the deficiencies of ellipse fitting ofthe isophotes, which by itself cannot always distinguish between bars,rings, spirals, and dust, and which can produce erroneous measurementsof bar sizes and orientations.
| Redshift-Distance Survey of Early-Type Galaxies: Spectroscopic Data
We present central velocity dispersions and Mg2 line indicesfor an all-sky sample of ~1178 elliptical and S0 galaxies, of which 984had no previous measures. This sample contains the largest set ofhomogeneous spectroscopic data for a uniform sample of ellipticalgalaxies in the nearby universe. These galaxies were observed as part ofthe ENEAR project, designed to study the peculiar motions and internalproperties of the local early-type galaxies. Using 523 repeatedobservations of 317 galaxies obtained during different runs, the dataare brought to a common zero point. These multiple observations, takenduring the many runs and different instrumental setups employed for thisproject, are used to derive statistical corrections to the data and arefound to be relatively small, typically <~5% of the velocitydispersion and 0.01 mag in the Mg2 line strength. Typicalerrors are about 8% in velocity dispersion and 0.01 mag inMg2, in good agreement with values published elsewhere.
| A new catalogue of ISM content of normal galaxies
We have compiled a catalogue of the gas content for a sample of 1916galaxies, considered to be a fair representation of ``normality''. Thedefinition of a ``normal'' galaxy adopted in this work implies that wehave purposely excluded from the catalogue galaxies having distortedmorphology (such as interaction bridges, tails or lopsidedness) and/orany signature of peculiar kinematics (such as polar rings,counterrotating disks or other decoupled components). In contrast, wehave included systems hosting active galactic nuclei (AGN) in thecatalogue. This catalogue revises previous compendia on the ISM contentof galaxies published by \citet{bregman} and \citet{casoli}, andcompiles data available in the literature from several small samples ofgalaxies. Masses for warm dust, atomic and molecular gas, as well asX-ray luminosities have been converted to a uniform distance scale takenfrom the Catalogue of Principal Galaxies (PGC). We have used twodifferent normalization factors to explore the variation of the gascontent along the Hubble sequence: the blue luminosity (LB)and the square of linear diameter (D225). Ourcatalogue significantly improves the statistics of previous referencecatalogues and can be used in future studies to define a template ISMcontent for ``normal'' galaxies along the Hubble sequence. The cataloguecan be accessed on-line and is also available at the Centre desDonnées Stellaires (CDS).The catalogue is available in electronic form athttp://dipastro.pd.astro.it/galletta/ismcat and at the CDS via anonymousftp to\ cdsarc.u-strasbg.fr (130.79.128.5) or via\http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/405/5
| The cold gas properties of Markarian galaxies
A sample of 61 Markarian galaxies detected in the CO line was compiled.Using available HI, element H2, optical and radio continuumdata, the analysis of the gas kinematics and the star formationproperties for this sample of galaxies was performed. The mainconclusion can be summarized as follows: (1) The HI and CO line widthsare well correlated. Interaction between galaxies has no influence onthe CO line broadening. A rapidly rotating nuclear disk in the galaxymight lead to the CO line broadening with less influence on the HI line.(2) The atomic and molecular gas surface densities are well correlatedwith the blue, FIR and radio continuum surface brightness; however, thecorrelation for molecular component is stronger.\ (3) In general, thegalaxies with UV-excess (Markarian galaxies) do not differ in their starformation properties from the non-UV galaxies.
| Double Bars, Inner Disks, and Nuclear Rings in Early-Type Disk Galaxies
We present results from a survey of an unbiased sample of 38 early-type(S0-Sa), low-inclination, optically barred galaxies in the field, usingimages both from the ground and from space. Our goal was to find andcharacterize central stellar and gaseous structures: secondary bars,inner disks, and nuclear rings. We find that bars inside bars aresurprisingly common: at least one-quarter of the sample galaxies(possibly as many as 40%) are double barred, with no preference forHubble type or the strength of the primary bar. A typical secondary baris ~12% of the size of its primary bar and extends to 240-750 pc inradius. Secondary bars are not systematically either parallel orperpendicular to the primary; we see cases where they lead the primarybar in rotation and others where they trail, which supports thehypothesis that the two bars of a double-bar system rotateindependently. We see no significant effect of secondary bars on nuclearactivity: our double-barred galaxies are no more likely to harbor aSeyfert or LINER nucleus than our single-barred galaxies. We findkiloparsec-scale inner disks in at least 20% of our sample; they occuralmost exclusively in S0 galaxies. These disks are on average 20% thesize of their host bar and show a wider range of relative sizes than dosecondary bars. Nuclear rings are present in about a third of oursample. Most of these rings are dusty, sites of current or recent starformation, or both; such rings are preferentially found in Sa galaxies.Three S0 galaxies (8% of the sample, but 15% of the S0's) appear to havepurely stellar nuclear rings, with no evidence for dust or recent starformation. The fact that these central stellar structures are so commonindicates that the inner regions of early-type barred galaxies typicallycontain dynamically cool and disklike structures. This is especiallytrue for S0 galaxies, where secondary bars, inner disks, and/or stellarnuclear rings are present at least two-thirds of the time. If weinterpret nuclear rings, secondary bars, and (possibly) inner disks andnuclear spirals as signs of inner Lindblad resonances (ILRs), thenbetween one and two-thirds of barred S0-Sa galaxies show evidence forILRs.
| 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.
| 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.
| Starbursts in barred spiral galaxies. V. Morphological analysis of bars
We have measured the bar lengths and widths of 125 barred galaxiesobserved with CCDs. The dependence of bar strength (identified with baraxis ratio) on morphological type, nuclear activity, central and mid-barsurface brightness is investigated. The properties of the bars are bestexplained if the sample is divided into early- (< SBbc) and late-typegalaxies, and into active (starburst, Seyfert or LINER) and normalgalaxies. We find that galaxies with very long bars are mostly activeand that normal late-type galaxies have a distinct behavior from thethree other groups of galaxies. We confirm earlier findings that activelate-type galaxies tend to have both stronger and longer bars thannormal ones. An important result of this paper is that early-typegalaxies do not share this behavior: they all tend to have strong bars,whether they are active or not. We also find correlations between barstrength and relative surface brightness in the middle and at the edgeof the bar, which are not followed by normal late-type galaxies. Theseresults are interpreted in the light of recent numerical simulations andparadigms about galaxy evolution. They suggest that normal late-typegalaxies represent the first stage of galaxy evolution, and that bars inearly- and late-type galaxies do not have the same properties becausethey have a different origin. Based on observations obtained at the 2meter telescope of Observatoire du Pic du Midi, operated by INSU (CNRS)
| Starbursts in barred spiral galaxies. III. Definition of a homogeneous sample of starburst nucleus galaxies
This paper presents optical long-slit spectroscopic observations of 105barred Markarian IRAS galaxies. These observations are used to determinethe spectral type (starburst or Seyfert) of emission-line regions in thenucleus and along the bar of the galaxies, in order to define ahomogeneous sample of Starburst Nucleus Galaxies (SBNGs). Our selectioncriteria (ultraviolet excess, far infrared emission and barredmorphology) have been very efficient for selecting star-forminggalaxies, since our sample of 221 emission-line regions includes 82%nuclear or extranuclear starbursts. The contamination by Seyferts is low(9%). The remaining galaxies (9%) are objects with ambiguousclassification (Hii or LINER). The dust content and Hα luminosityincrease towards the nuclei of the galaxies. No significant variation ofthe electron density is found between nuclear and bar Hii regions.However, the mean Hα luminosity and electron density in the barare higher than in typical disk Hii regions. We investigate differentmechanisms for explaining the excess of nitrogen emission observed inour starburst nuclei. There is no evidence for the presence of a weakhidden active galactic nucleus in our starburst galaxies. The cause ofthis excess is probably a selective enrichment of nitrogen in the nucleiof the galaxies, following a succession of short and intense bursts ofstar formation. Our sample of SBNGs, located at a mean redshift of ~0.015, has moderate Hα ( ~ 10(41) erg s(-1) ) and far infrared ( ~10(10) Lsun) luminosities. The types are distributed equallyamong early- and late-type giant spirals with a slight preference forSbc/Sc types because of their barred morphology. The majority (62%) ofSBNGs are isolated with no sign of gravitational interaction. In termsof distance, luminosity and level of interaction, SBNGs are intermediatebetween Hii galaxies and luminous infrared galaxies. Based onobservations obtained at the 1.93 meter telescope of Observatoire deHaute-Provence operated by INSU (CNRS). Tables 1, 3, 4, 5 and 6 are onlyavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| A correlation between CO linewidth and starburst age in barred spiral galaxies.
New CO(1->0) and CO(2->1) profiles complemented by data from theliterature are used to obtain CO linewidths for 29 barred spiralgalaxies with young nuclear starbursts. The ages of the starbursts wereestimated from optical spectroscopy and recent evolutionary synthesismodels. The CO linewidths and the starburst ages are correlated:galaxies with young (4-6Myr) starbursts display narrow (<~100km/s) COline while those with older starbursts show broader CO lines. We discussseveral scenarios of the gas dynamics during the nuclear starbursts'evolution to interpret the correlation.
| 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.
| The Morphology and Kinematics of 16 Markarian Galaxies with Multiple Nuclei. I. Basic Data
Spectra and images are presented for a sample of Markarian galaxieswhich possess multiple "nuclei" yet which show no indication (as seen onthe Palomar Observatory Sky Survey prints) of tidal features resultingfrom mergers. In only two of the eight galaxies imaged is there someindication of faint tails or arms suggesting possible past interactions.Redshifts derived from red and blue long-slit spectra of 16 galaxies areused to examine the relation between radial velocity differences betweenpairs of nuclear sources within a galaxy and projected separation. Theresult of the comparison is to demonstrate a trend toward lower velocitydifferences with smaller pair separations. In addition, a comparison ofabsolute magnitude with projected separation shows the larger the pairseparation the brighter the galaxy. In this paper we present the basicdata and preliminary analysis of the 16 Markarian galaxies.
| A multifrequency radio continuum and IRAS faint source survey of markarian galaxies
Results are presented from a multifrequency radio continumm survey ofMarkarian galaxies (MRKs) and are supplemented by IRAS infrared datafrom the Faint Source Survey. Radio data are presented for 899 MRKsobserved at nu = 4.755 GHz with the National Radio Astronomy Observatory(NRAO)-Green Bank 300 foot (91 m) telescope, including nearly 88% ofthose objects in Markarian lists VI-XIV. In addition, 1.415 GHzmeasurements of 258 MRKs, over 30% of the MRKs accessible from theNational Aeronomy and Ionosphere Center (NAIC)-Arecibo, are reported.Radio continuum observations of smaller numbers of MRKs were made at10.63 GHz and at 23.1 GHz and are also presented. Infrared data from theIRAS Faint Source Survey (Ver. 2) are presented for 944 MRKs, withreasonably secure identifications extracted from the NASA/IPACExtragalactic Database. MRKs exhibit the same canonical infraredcharacteristics as those reported for various other galaxy samples, thatis well-known enhancement of the 25 micrometer/60 micrometer color ratioamong Seyfert MRKs, and a clear tendency for MRKs with warmer 60micrometer/100 micrometer colors to also possess cooler 12 micrometer/25micrometer colors. In addition, non-Seyfert are found to obey thewell-documented infrared/radio luminosity correlation, with the tightestcorrelation seen for starburst MRKs.
| Optical imaging and long-slit spectroscopy of Markarian galaxies with multiple nuclei. I - Basic data
Optical CCD images and long-slit spectroscopic data are presented forover 100 Markarian (UV-excess) galaxies reported in early studies topossess multiple optical nuclei or extreme morphological peculiaritiessuggestive of galaxy collisions and mergers. Stacked broad-band imagesare presented with histogram equalization in order to showsimultaneously the nuclei and features at very low surface-brightnesslevels. Morphological properties, luminosities and colors of theintegral systems are given. Photometric and image properties of over 200individual nuclei and giant H II regions have been measured with respectto the local backgrounds in the galaxies using an objective imagefinding algorithm. Labeled contour plots identify the measuredsubcomponents. Two-dimensional spectral data are presented, in additionto intensity profiles along the slit in the light of H-alpha + forbiddenN II emission lines and adjacent continuum. Nuclear emission-linemeasurements, reddening estimates, monochromatic continuum magnitudes,and colors are given.
| A revised catalog of CfA1 galaxy groups in the Virgo/Great Attractor flow field
A new identification of groups and clusters in the CfA1 Catalog ofHuchra et al. is presented, using a percolation algorithm to identifydensity enhancements. It is shown that in the resulting catalog,contamination by interlopers is significantly reduced. The Schechterluminosity function is redetermined, including the Malmquist bias.
| Radio and infrared emission from Markarian starburst galaxies
Radio and infrared emission were compared for a sample of 58 Markarianstarburst galaxies, chosen to cover a wide range of 60-micron luminositydensity. New radio observations were from the VLA at 6 and 20 cm in theB and A configurations. IRAS data were reanalyzed for 25 of thestarbursts that were previously undetected at either 25 or 100 microns.The correlation between the global radio and IR emission for thestarbursts in the sample is strongest at 25 and 60 microns, wavelengthsin which the warm dust dominates. The radio spectral index steepens awayfrom the center. This indicates that nonthermal emission leaks out ofthe starburst region. The change in the spectral index implies thatwhile nonthermal sources dominate in the entire region, the bulk of theinterior emission at 6 cm is thermal. The radio spectral index does notappear to vary as a function of the infrared luminosity or the infraredcolors, which indicates that the slope of the initial mass function doesnot appear to be a function of either the mass or temperature of thestarburst.
| The far-infrared properties of the CfA galaxy sample. I - The catalog
IRAS flux densities are presented for all galaxies in the Center forAstrophysics magnitude-limited sample (mB not greater than 14.5)detected in the IRAS Faint Source Survey (FSS), a total of 1544galaxies. The detection rate in the FSS is slightly larger than in thePSC for the long-wavelength 60- and 100-micron bands, but improves by afactor of about 3 or more for the short wavelength 12- and 25-micronbands. This optically selected sample consists of galaxies which are, onaverage, much less IR-active than galaxies in IR-selected samples. Itpossesses accurate and complete redshift, morphological, and magnitudeinformation, along with observations at other wavelengths.
| Far-infrared properties of Markarian galaxies with multiple nuclei - Warm dust emission in mergers
An investigation of coadded IRAS data is performed on 187 Markariangalaxies where distinguishing morphological characteristics or multipleoptical nuclei are present. The far-IR properties of Markarian galaxiesare compared to the IRAS Bright Galaxy Sample, and a much higher mediandust temperature is found in the multiple nucleus galaxies, suggestingthat more far-IR luminosity results from active star formation. Bothoptical/UV and far-IR selection techniques are necessary to extractcomplete samples of AGNs since the far-IR two-color plane can miss up to50 percent of the galaxies. A systematic increase in the contribution ofwarm dust emission due to active star formation and AGNs is found in astatistical comparison of merger candidates and other galaxy samples.The assumed nature of precursor galaxies determines the assumedenhancement of far-IR luminosity caused by galaxy collisions. A model ispresented which describes the properties of the Markarian galaxies interms of enhanced OB star formation and different grain sizedistributions. The results of the investigation are shown to beconsistent with a 'subdued' interpretation of merging galaxies with highluminosities.
| Radio-continuum sources in nearby and bright E/S0 galaxies - Active nuclei versus star formation
Results of a sensitive VLA survey of nearby E/S0 galaxies are presented.The 204 galaxies surveyed, plus 12 additional galaxies with existing VLAimages, comprise a volume- and optical magnitude-limited sample. Thediscussion focuses on the relation between radio powers and opticalluminosities, whether the radio emission is driven by an active nucleusor by recent star formation, and what galaxian properties might enhancenuclear activity in an elliptical galaxy. It is suggested that the 67ellipticals in the sample should be targets of sensitive searches forHI, optical emission-line gas, and X-ray emitting gas.
| Radio-continuum sources in nearby and bright E/S0 galaxies - Sample selection and well-studied cases
A volume-limited sample of 216 nearby and optically bright E/S0 galaxieshas been compiled. Twelve of the galaxies are confirmed radio sourcesfor which VLA images are available. Most of the remaining galaxies havepowers less than or of the order of 10 to the 21st-22nd W/Hz, and thisinformation is used to establish the parameters of a new VLA survey ofthese galaxies. The basic optical properties of the galaxies in thesample are tabulated.
| The influence of environment on gas and dust in S0 galaxies
Consideration is given to the effect of local environemnt on the gas anddust content of S0 galaxies relative to other spiral systems in theLocal Supercluster. The optical properties, H I content, and FIRcontinuum properties of a complete sample of Local Supercluster S0galaxies are analyzed. The characteristics of S0 galaxies are comparedwith those of Sa and Sc galaxies. It is concluded that, like otherspiral galaxies, S0's undergo continuing gas removal when they passthrough high-density regions.
| A model for far-IR emission of non-Seyfert Markarian galaxies
The paper presents simple models for the FIR emission from extended H IIregions and from cooler dust heated by the general interstellarradiation field. The models account for a realistic grain-sizedistribution including PAH molecules. In addition, the model explainsthe observed correlation between the FIR to optical luminosity ratio andthe 60-10 micron colors.
| The extragalatic zoo.
The characteristics of various types of extragalactic objects aredescribed. Consideration is given to cD galaxies, D galaxies, Ngalaxies, Markarian galaxies, liners, starburst galaxies, andmegamasers. Emphasis is also placed on the isolated extragalatic H Iregion; the isolated extragalatic H II region; primeval galaxies orphotogalaxies; peculiar galaxies; Arp galaxies; interacting galaxies;ring galaxies; and polar-ring galaxies. Diagrams of these objects areprovided.
| Optical and far-IR luminosity functions of Markarian galaxies
A new optical luminosity function of Markarian galaxies is presentedwhich improves on earlier determinations. The importance of clusteringof Markarian galaxies is checked by applying an alternative methodproposed by Turner (1979) which allows the shape of the luminosityfunction to be derived for an arbitrary space distribution provided thatthe shape is the same in clusters and in the field. A fractionalbivariate function is constructed using IRAS data, and survival analysistechniques are used to exploit the information content of IR upperlimits. The resulting far-IR luminosity function is presented andcompared with previous estimates.
| Uv-Galaxies
Not Available
| Imaging and Spectroscopy of Double-Nucleus Markarian Galaxies: Results for Six Representative Objects
Not Available
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