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The ISOPHOT 170 μm Serendipity Survey II. The catalog of optically identified galaxies%
The ISOPHOT Serendipity Sky Survey strip-scanning measurements covering≈15% of the far-infrared (FIR) sky at 170 μm were searched forcompact sources associated with optically identified galaxies. CompactSerendipity Survey sources with a high signal-to-noise ratio in at leasttwo ISOPHOT C200 detector pixels were selected that have a positionalassociation with a galaxy identification in the NED and/or Simbaddatabases and a galaxy counterpart visible on the Digitized Sky Surveyplates. A catalog with 170 μm fluxes for more than 1900 galaxies hasbeen established, 200 of which were measured several times. The faintest170 μm fluxes reach values just below 0.5 Jy, while the brightest,already somewhat extended galaxies have fluxes up to ≈600 Jy. For thevast majority of listed galaxies, the 170 μm fluxes were measured forthe first time. While most of the galaxies are spirals, about 70 of thesources are classified as ellipticals or lenticulars. This is the onlycurrently available large-scale galaxy catalog containing a sufficientnumber of sources with 170 μm fluxes to allow further statisticalstudies of various FIR properties.Based on observations with ISO, an ESA project with instruments fundedby ESA Member States (especially the PI countries: France, Germany, TheNetherlands and the UK) and with the participation of ISAS and NASA.Members of the Consortium on the ISOPHOT Serendipity Survey (CISS) areMPIA Heidelberg, ESA ISO SOC Villafranca, AIP Potsdam, IPAC Pasadena,Imperial College London.Full Table 4 and Table 6 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/422/39
| 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
| 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
| 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.
| Radio Structures of Seyfert Galaxies. VIII. A Distance- and Magnitude-Limited Sample of Early-Type Galaxies
The VLA has been used at 3.6 and 20 cm to image a sample of about 50early-type Seyfert galaxies with recessional velocities less than 7000km s^-1 and total visual magnitude less than 14.5. Emission-line ([OIII] and Hα+[N II]) and continuum (green and red) imaging of thissample has been presented in a previous paper. In this paper, we presentthe radio results, discuss statistical relationships between the radioand other properties, and investigate these relationships within thecontext of unified models of Seyferts. The mean radio luminosities ofearly-type Seyfert 1's (i.e., Seyfert 1.0's, 1.2's, and 1.5's) and 2.0'sare found to be similar (consistent with the unified scheme), and theradio luminosity is independent of morphological type within thissample. The fraction of resolved radio sources is larger in the Seyfert2.0's (93%) than in the Seyfert 1's (64%). However, the mean radioextents of Seyfert 2.0's and 1's are not significantly different,although this result is limited by the small number of resolved Seyfert1's. The nuclear radio structures of Seyfert 2.0's in the early-typesample tend to be aligned with the [O III] and Hα+[N II]structures, even though the radio extents are smaller than the [O III]and Hα+[N II] extents by a factor of ~2 to more than 5. Thisalignment, previously known for individual Seyferts with ``linear''radio sources, is here shown to be characteristic of early-type Seyfertgalaxies as a class. Seyfert 2.0's in the early-type sample also show asignificant alignment between the emission-line ([O III] and Hα+[NII]) axes and the major axis of the host galaxy. These alignments areconsistent with a picture in which the ionized gas represents ambientgas predominantly coplanar with the galaxy stellar disk. This ambientgas is ionized by nuclear radiation that may escape preferentially alongand around the radio axis, and is compressed in shocks driven by theradio ejecta. We use this alignment to constrain the product of thevelocity of the radio ejecta and the period of any large-angleprecession of the inner accretion disk and jet: V_ejectaxP>=2 kpc. Aninvestigation of a larger sample of Seyferts reveals the unexpectedresult that the Seyfert 1's with the largest radio extent (>=1.5 kpc)are all of type Seyfert 1.2. It appears that classification as this typeof intermediate Seyfert depends on some factor other than the relativeorientation of the nuclear-obscuring torus to the line of sight. Amongall the other Seyferts, the distribution of radio extent with Seyfertintermediate type is consistent with the expectations of the unifiedscheme.
| Groups of galaxies. III. Some empirical characteristics.
Not Available
| Catalogue of HI maps of galaxies. I.
A catalogue is presented of galaxies having large-scale observations inthe HI line. This catalogue collects from the literature the informationthat characterizes the observations in the 21-cm line and the way thatthese data were presented by means of maps, graphics and tables, forshowing the distribution and kinematics of the gas. It containsfurthermore a measure of the HI extension that is detected at the levelof the maximum sensitivity reached in the observations. This catalogueis intended as a guide for references on the HI maps published in theliterature from 1953 to 1995 and is the basis for the analysis of thedata presented in Paper II. The catalogue is only available inelectronic form at the CDS via anonymous ftp 130.79.128.5 orhttp://cdsweb.u-strasbg.fr/Abstract.html
| 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 Survey for H 2O Megamasers in Active Galactic Nuclei. II. A Comparison of Detected and Undetected Galaxies
A survey for H2O megamaser emission from 354 active galaxies hasresulted in the detection of 10 new sources, making 16 known altogether.The galaxies surveyed include a distance-limited sample (coveringSeyferts and LINERs with recession velocities less than 7000 km s-1) anda magnitude-limited sample (covering Seyferts and LINERs with mB <=14.5). In order to determine whether the H2O-detected galaxies are"typical" active galactic nuclei (AGNs) or have special properties thatfacilitate the production of powerful masers, we have accumulated adatabase of physical, morphological, and spectroscopic properties of theobserved galaxies. The most significant finding is that H2O megamasersare detected only in Seyfert 2 and LINER galaxies, not Seyfert 1's. Thislack of detection in Seyfert 1's indicates either that they do not havemolecular gas in their nuclei with physical conditions appropriate toproduce 1.3 cm H2O masers or that the masers are beamed away from Earth,presumably in the plane of the putative molecular torus that hides theSeyfert 1 nucleus in Seyfert 2's. LINERs are detected at a similar rateto Seyfert 2's, which constitutes a strong argument that at least somenuclear LINERs are AGNs rather than starbursts, since starbursts havenot been detected as H2O megamasers. We preferentially detect H2Oemission from the nearer galaxies and from those that are apparentlybrighter at mid- and far-infrared and centimeter radio wavelengths.There is also a possible trend for the H2O-detected galaxies to be moreintrinsically luminous in nuclear 6 cm radio emission than theundetected ones, though these data are incomplete. We find evidence thatSeyfert 2's with very high (NH > 1024 cm-2) X-ray--absorbing columnsof gas are more often detected as H2O maser emitters than Seyfert 2'swith lower columns. It may be that the probability of detecting H2Omaser emission in Seyfert galaxies increases with increasing column ofcool gas to the nucleus, from Seyfert 1's through narrow-line X-raygalaxies to Seyfert 2's.
| A Survey for H 2O Megamasers in Active Galactic Nuclei. I. Observations
We report an extensive search for 22 GHz H_2_O maser emission fromnearby active galaxies. Our sample includes all Seyfert and LINERgalaxies listed in the Huchra catalog or the Veron-Cetty & Veroncatalog with recessional velocities less than 7000 km s^-1^, and allSeyfert galaxies and LINERs in Huchra's catalog with m_b_ <= 14. Inaddition to these distance- and magnitude-limited samples, we have alsoobserved a number of active galaxies, including radio galaxies, athigher redshift; In all, some 354 galaxies have been surveyed. Ten newH_2_O megamaser sources have been detected, resulting in 16 galaxiesthat are currently known to contain H_2_O masers with isotropicluminosities greater than 20 L_sun_. Of the observed active galaxieswith cz < 7000 km s^-1^, 5.4% have detectable H_2_O megamaseremission. This fraction increases to 11% for those sources with cz <2000 km s^-1^. The newly discovered megamaser sources were monitored onsubsequent observing runs. The strength of the maser features varies forthese sources, as they do for Galactic masers. Three of the galaxieshave sufficient data to test for velocity changes of narrow masercomponents comparable in magnitude to those of the well-studied systemicfeatures in NGC 4258. The maser line in one of these galaxies-NGC2639-is found to have a systematic redward velocity drift of 6.6 +/- 0.4km s^-1^ yr^-1^. No systematic velocity drifts are found for the othertwo sources. We also report large apparent velocity changes in theunusual broad H_2_O emission feature in NGC 1052.
| An Emission-Line Imaging Survey of Early-Type Seyfert Galaxies. I. The Observations
Flux-calibrated images in the lines of [O III] λ5007 and Hα+ [N II] λλ6548, 6583 and the nearby continuum arepresented for 57 Seyfert galaxies of early morphological type. Thissample includes all known Seyfert galaxies with apparent magnitude m_v_<= 14.5 and recessional velocity cz < 7000 km s^-1^ in Hubbletypes E, S0, and S0/a. Images are also presented for an additional 26galaxies with m_v_ > 14.5, cz > 7000 km s^-1^, and/or an uncertainclassification as a Seyfert galaxy. The ratio of the [O III]λ5007 to the Hα + [N II] image has been obtained for eachgalaxy with extended emission to study the spatial variation of thegaseous excitation. Maps of the V - R color distributions over thegalaxies are also presented.
| A Minnesota Automated Plate Scanner Catalog of Galaxies behind the Virgo Cluster and toward Its Antipode
We present a catalog of 1268 galaxies, essentially complete to B <=17.0, found by scanning glass copies of several fields of the originalPalomar Sky Survey using the Minnesota Automated Plate Scanner in itsisodensitometric mode (as opposed to the threshold densitometric modeused in the APS Catalog of the POSS I). In addition to the differentscanning mode, we have employed a different star-galaxy separationmethod and have visually inspected POSS prints to verify that each imageremaining in the catalog is nonstellar. The scanned fields aredistributed generally in two areas, one around the outskirts of theVirgo Cluster, the other toward the antipode of the cluster (but stillin the northern celestial hemisphere). The catalog gives the position ofthe center of each galaxy; estimates of the blue and red magnitudeswithin the outermost threshold crossing and of the blue magnitudeextrapolated to zero surface brightness; and the blue and red diametersof four ellipses fitted to the four threshold crossings (approximately23.8,23.6,23.2, and 22.7 mag arcsec 2 in blue, and 22.5,22.4,21.5, and21.2 mag arcsec^-2^ in red), and the ellipticities of those fourellipses. The catalog has served as a base from which to draw targetsfor a Tully-Fisher study of the Virgocentric infall velocity of theLocal Group.
| 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 fundamental plane of early-type galaxies: stellar populations and mass-to-light ratio.
We analyse the residuals to the fundamental plane (FP) of ellipticalgalaxies as a function of stellar-population indicators; these are basedon the line-strength parameter Mg_2_ and on UBVRI broad-band colors, andare partly derived from new observations. The effect of the stellarpopulations accounts for approximately half the observed variation ofthe mass-to-light ratio responsible for the FP tilt. The residual tiltcan be explained by the contribution of two additional effects: thedependence of the rotational support, and possibly that of the spatialstructure, on the luminosity. We conclude to a constancy of thedynamical-to-stellar mass ratio. This probably extends to globularclusters as well, but the dominant factor would be here the luminositydependence of the structure rather than that of the stellar population.This result also implies a constancy of the fraction of dark matter overall the scalelength covered by stellar systems. Our compilation ofinternal stellar kinematics of galaxies is appended.
| A Catalog of Stellar Velocity Dispersions. II. 1994 Update
A catalog of central velocity dispersion measurements is presented,current through 1993 September. The catalog includes 2474 measurementsof 1563 galaxies. A standard set of 86 galaxies is defined, consistingof galaxies with at least three reliable, concordant measurements. It issuggested that future studies observe some of these standard galaxies sothat different studies can be normalized to a consistent system. Allmeasurements are reduced to a normalized system using these standards.
| 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.
| 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.
| Star formation in the disks of H I-rich S0 galaxies
We present the results of a H-alpha emission-line imaging survey of asample of neutral-gas-rich S galaxies. We find evidence of disk H IIregions in 14 of our sample of 32 galaxies, detect nuclear or faintdiffuse circumnuclear H-alpha + forbidden N II emission in another 11galaxies without disk H II regions, and obtain upper limits for 8galaxies. We find a striking dichotomy between Ss with and without H IIregions; either a galaxy has a number of H II regions, most oftendistributed into distinct rings or ringlike structures, or there arenone down to detection limits equivalent to a single unreddened H IIregion ionized by single O stars. We find that the S0s without disk H IIregions have a lower median MH I/L(B) than those with disk HII regions, but the distributions have a large range of dispersion. Ourdata suggest that S0s may lie in a regime where local threshold effects,perhaps primarily kinematic in origin, are more important in determiningthe star formation in these galaxies than the global stabilitymechanisms that recent empirical models for large-scale star formationhave suggested prevail in later-type spirals.
| Pairing properties of Markarian starburst Galaxies
The environmental parameters of 516 non-Seyfert Markarian galaxies werestudied in a redshift-bounded sample, supplemented by new spectra andredshift measures for possible companions, in order to evaluate theiroccurrence in galaxy pairs, defined through quantitative criteria. Itwas found that one-third of these galaxies occur in pairs (while only 6to 10 percent of optically-selected galaxies are known to be paired). Acomparison of various optical and IR properties of paired and nonpairedMarkarian galaxies showed no differences in the shape of the optical,far-IR, or H-alpha luminosity functions. It was found, however, that theMarkarian component is brighter than the other galaxy in each pair by0.66 magnitude in the mean at B.
| Groups of galaxies within 80 Mpc. II - The catalogue of groups and group members
This paper gives a catalog of the groups and associations obtained bymeans of a revised hierarchical algorithm applied to a sample of 4143galaxies with diameters larger than 100 arcsec and redshifts smallerthan 6000 km/s. The 264 groups of galaxies obtained in this way (andwhich contain at least three sample galaxies) are listed, with the looseassociations surrounding them and the individual members of eachaggregate as well; moreover, the location of every entity among 13regions corresponding roughly to superclusters is specified. Finally,1729 galaxies belong to the groups, and 466 to the associations, i.e.,the total fraction of galaxies within the various aggregates amounts to53 percent.
| 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.
| The neutral hydrogen content of early type disk galaxies
This paper presents the results of a sensitive 21-cm survey of massiveearly type galaxies made with the Arecibo radio telescope. Of the 81galaxies observed, the detections comprise 48 percent of the S0s, 73percent of the S0a's, and 96 percent of the Sa's. The values of thehybrid, distance-independent H I surface densities of the S0 galaxies inthe sample ranged continuously from amounts comparable to the mostgas-rich Sa galaxies to low estimated upper limts of the H I content.CCD images of most of the gas-rich S0s revealed either faint spiralfeatures or patchy structure in the disks. While no firm correlationbetween H I content and environmental density is apparent for thegalaxies in the sample, two-sample statistics suggest a differencebetween the highest and the lowest density bins. Early-type diskgalaxies within low density environments tend to have higher gas surfacedensities than those within high-density environments.
| H I content and FIR emission of S0 galaxies
A sample of 252 S0 galaxies is used to study the relationship between HI content and far-IR emission. Logarithms of the H I content versus thefar-IR emission are employed statistically to develop a best-fit linearregression line which is compared to a slope of approximately unity. Theslopes are different for S0 and SB0 galaxies versus S0/a and SB0/agalaxies. The distribution of the 60-100 micron flux ratio is notsignificantly affected by the presence or absence of bars nor by thedifferences between the S0 and S0/a systems. The flux ratio is higherthan the critical value of Helou in 34 percent of the cases, and thevalue holds when nuclear emission is taken into account. In cases wherethe critical value is exceeded, most far-IR emissions are expected to bedue to star formation. S0 galaxies are generally found to have a normalISM, except where the systems have accreted their H I gas. Systems withdisproportionate FIR emission can be considered galaxies that areexperiencing enhanced star formation or that have had their H I gasswept away.
| A survey of northern Seyfert galaxies
A medium-resolution spectroscopic study of a complete sample of brightnorthern Seyfert galaxies was conducted. A correlation of the linewidthswith the critical density and the ionization potential is found for NGC1358 and NGC 3660. After correcting for the instrumental profile and thecontributions of H II regions, several linewidths are shown to notexceed 250 km/sec. The line ratios are typical for Seyfert 2 objects forall the galaxies considered. Results suggest that locally Seyfert 2galaxies are about 3.5 times more abundant than Seyfert 1 objects, andthat they suffer from a more rapid drop-off in detection probabilitythan Seyfert 1s.
| 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.
| Warm IRAS sources. I. A. Catalogue of AGN candidates from the point source catalog
It was previously shown that a blue (warm) 60 to 25 micron infraredcolor provides a powerful parameter for discriminating between AGNs andnormal galaxies, and that the far-IR spectrum is therefore an efficienttool for finding new AGNs. A list of such AGN candidates based on warmIR sources from the IRAS Point Source Catalogue (PSC) is presented here.Identification data and finding charts are also given. In addition, thelist of warm IRAS sources is supplemented by a compendium of data fromthe IRAS PSC on detected sources identified with previously known AGNswhose infrared spectra do not bring them within this color selectioncriterion.
| H I observations of lenticular and early type galaxies
High sensitivity H I observations of 56 galaxies, mostly S0's (47objects), carried out with the Arecibo radio telescope are presented.Twelve S0's and four S0/a spirals have been detected, among which 12 forthe first time, and nine of them have been mapped. In addition,absorption lines have been found in two S0's. A detailed discussion ofthe results of the mapping has made it possible to solve several casesof confusion and to find out two possible cases of H I ring structuresor flat rotation curves in S0's. Finally for six mapped galaxies, asimple deconvolution procedure has led to the derivation of the total HI fluxes and of the H I diameters; on the average, the ratio of the H Idiameter to the optical one is found to be 30 percent higher for theS0's than for the spirals.
| A catalogue of early-type galaxies with emission lines
Spectroscopic and photometric data on 289 early-type galaxies (E and S0)with optical emission lines are presented and possible correlationsamong properties of the galaxies in the sample are investigated. Theoccurrence of phenomena as radio emission, presence of neutral hydrogenand dust shows an increase in comparison with the occurrence of the samephenomena in these morphological classes as a whole. There is noevidence of a relationship between apparent shape and presence ofionized gas in the central regions.
| A catalog of Markarian galaxies
A catalog of Markarian galaxies is presented which tabulates redshifts,spectral and morphological classifications, magnitudes, infrared andradio flux densities, and over 600 references to available datapublished before January 1, 1986. Redshifts are now available for 1228objects with strong ultraviolet continua, and follow-up spectroscopicand photometric observations of Markarian galaxies have providedclassifications of 115 Seyfert 1, 43 Seyfert 2, and 137 starburst and HII-type galaxies. After a description of the Markarian survey and thecurrent catalog, a summary of the general results obtained from the datais presented. A preliminary study of the infrared properties ofMarkarian galaxies as measured by IRAS reveals a number of interestingresults, including the existence of a sample of elliptical andlenticular galaxies with appreciable infrared emission.
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