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Radio-induced activity in galaxy pairs
The close proximity of a radio-loud active galactic nucleus (AGN) cantrigger star formation in nearby objects containing gas if they are hitby a radio jet emerging from the active nucleus (as is observed, forexample, in the case of Minkowski’s Object). The predictedfrequency of such events is modest for close pairs of galaxies—ofthe order of several percent of all close (with separations of the orderof several tens of parsec) pairs containing a radio AGN. A statisticalstudy of this effect is carried out using the SDSS and FIRST surveys, bysearching for spatially close pairs (projected separations <150 kpc,relative radial velocities <600 km/s) containing AGNs with radiojets. The frequency of galaxies with bursts of star formation, fSF, and active nuclei f AGN, in pairs eithercontaining or not containing an AGN with radio jets are evaluated asfunctions of the separation of the galaxies in the pair. It is concludedthat (1) the predicted effect should be of the order of 5%, falling offwith increasing separation between the galaxies in the pair; (2) theobserved values of f SF and f AGN and theirdependences on the galaxy separation are consistent withmodelpredictions, but the large uncertainties associated with the limitedsize of the studied sample hinders firm conclusions about the existenceof radio-induced activity in close galaxy pairs; (3) furtherinvestigations using a larger volume of observational material arerequired, for example, using only photometric redshifts.
| The UZC-SSRS2 Group Catalog
We apply a friends-of-friends algorithm to the combined Updated ZwickyCatalog and Southern Sky Redshift Survey to construct a catalog of 1168groups of galaxies; 411 of these groups have five or more members withinthe redshift survey. The group catalog covers 4.69 sr, and all groupsexceed the number density contrast threshold, δρ/ρ=80. Wedemonstrate that the groups catalog is homogeneous across the twounderlying redshift surveys; the catalog of groups and their membersthus provides a basis for other statistical studies of the large-scaledistribution of groups and their physical properties. The medianphysical properties of the groups are similar to those for groupsderived from independent surveys, including the ESO Key Programme andthe Las Campanas Redshift Survey. We include tables of groups and theirmembers.
| The K-Band Galaxy Luminosity Function
We measured the K-band luminosity function using a complete sample of4192 morphologically typed 2MASS galaxies withμKs=20 mag arcsec-2 isophotalmagnitudes 7-0.5) galaxies havesimilarly shaped luminosity functions, αe=-0.92+/-0.10and αl=-0.87+/-0.09. The early-type galaxies arebrighter, MK*e=-23.53+/-0.06 mag compared toMK*l=-22.98+/-0.06 mag, but less numerous,n*e=(0.45+/-0.06)×10-2 h3Mpc-3 compared ton*l=(1.01+/-0.13)×10-2 h3Mpc-3 for H0=100 h km s-1Mpc-1, such that the late-type galaxies slightly dominate theK-band luminosity density,jlate/jearly=1.17+/-0.12. Including a factor of1.20+/-0.04 correction for the conversion of the isophotal surveymagnitudes to total magnitudes, the local K-band luminosity density isj=(7.14+/-0.75)×108 h LsolarMpc-3, which implies a stellar mass density relative tocritical of Ω*h=(1.9+/-0.2)×10-3 for aKennicutt initial mass function (IMF) andΩ*h=(3.4+/-0.4)×10-3 for a SalpeterIMF. Our morphological classifications are internally consistent, areconsistent with previous classifications, and lead to luminosityfunctions unaffected by the estimated uncertainties in theclassifications. These luminosity functions accurately predict theK-band number counts and redshift distributions for K<~18 mag, beyondwhich the results depend on galaxy evolution and merger histories. Thispublication makes use of data products from the Two Micron All SkySurvey (2MASS), which is a joint project of the University ofMassachusetts and the Infrared Processing and Analysis Center/CaliforniaInstitute of Technology, funded by the National Aeronautics and SpaceAdministration and the National Science Foundation.
| 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.
| The Updated Zwicky Catalog (UZC)
The Zwicky Catalog of galaxies (ZC), with m_Zw<=15.5, has been thebasis for the Center for Astrophysics (CfA) redshift surveys. To date,analyses of the ZC and redshift surveys based on it have relied onheterogeneous sets of galaxy coordinates and redshifts. Here we correctsome of the inadequacies of previous catalogs by providing (1)coordinates with <~2" errors for all of the 19,369 catalog galaxies,(2) homogeneously estimated redshifts for the majority (98%) of the datataken at the CfA (14,632 spectra), and (3) an estimate of the remaining``blunder'' rate for both the CfA redshifts and for those compiled fromthe literature. For the reanalyzed CfA data we include a calibrated,uniformly determined error and an indication of the presence of emissionlines in each spectrum. We provide redshifts for 7257 galaxies in theCfA2 redshift survey not previously published; for another 5625 CfAredshifts we list the remeasured or uniformly rereduced value. Among ournew measurements, 1807 are members of UZC ``multiplets'' associated withthe original Zwicky catalog position in the coordinate range where thecatalog is 98% complete. These multiplets provide new candidates forexamination of tidal interactions among galaxies. All of the newredshifts correspond to UZC galaxies with properties recorded in the CfAredshift compilation known as ZCAT. About 1000 of our new measurementswere motivated either by inadequate signal-to-noise in the originalspectrum or by an ambiguous identification of the galaxy associated witha ZCAT redshift. The redshift catalog we include here is ~96% completeto m_Zw<=15.5 and ~98% complete (12,925 galaxies out of a total of13,150) for the right ascension ranges 20^h>=alpha_1950<=4^h and8^h>=alpha_1950<=17^h and declination range-2.5d<=delta_1950<=50^deg. This more complete region includes allof the CfA2 survey as analyzed to date. The Great Wall structurepersists throughout the northern survey region. Dedicated to the memoryof Jim Peters, whose friendship, skill, and dedication were essential tothis work.
| 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.
| 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.
| Integrated photoelectric magnitudes and color indices of bright galaxies in the Johnson UBV system
The photoelectric total magnitudes and color indices published in theThird Reference Catalogue of Bright Galaxies (RC3) are based on ananalysis of approximately equals 26,000 B, 25,000 B-V, and 17,000 U-Bmultiaperture measurements available up to mid 1987 from nearly 350sources. This paper provides the full details of the analysis andestimates of internal and external errors in the parameters. Thederivation of the parameters is based on techniques described by theVaucouleurs & Corwin (1977) whereby photoelectric multiaperture dataare fitted by mean Hubble-type-dependent curves which describe theintegral of the B-band flux and the typical B-V and U-B integrated colorgradients. A sophisticated analysis of the residuals of thesemeasurements from the curves was made to allow for the random andsystematic errors that effect such data. The result is a homogeneous setof total magnitudes BTA total colors(B-V)T and (U-B)T, and effective colors(B-V)e and (U-B)e for more than 3000 brightgalaxies in RC3.
| UGC galaxies stronger than 25 mJy at 4.85 GHz
UGC galaxies in the declination band +5 to +75 deg were identified byposition coincidence with radio sources stronger than 25 mJy on theGreen Bank 4.85 GHz sky maps. Candidate identifications were confirmedor rejected with the aid of published aperture-synthesis maps and new4.86 GHz VLA maps having 15 or 18 arcsec resolution, resulting in asample of 347 nearby radio galaxies plus five new quasar-galaxy pairs.The radio energy sources in UGC galaxies were classified as 'starbursts'or 'monsters' on the basis of their infrared-radio flux ratios, infraredspectral indices, and radio morphologies. The rms scatter in thelogarithmic infrared-radio ratio q is not more than 0.16 for starburstgalaxies selected at 4.85 GHz. Radio spectral indices were obtained fornearly all of the UGC galaxies, and S0 galaxies account for adisproportionate share of the compact flat-spectrum (alpha less than0.5) radio sources. The extended radio jets and lobes produced bymonsters are preferentially, but not exclusively, aligned within about30 deg of the optical minor axes of their host galaxies. The tendencytoward minor-axis ejection appears to be independent of radio-sourcesize and is strongest for elliptical galaxies.
| Statistics of galaxy orientations - Morphology and large-scale structure
Using the Uppsala General Catalog of bright galaxies and the northernand southern maps of the Lick counts of galaxies, statistical evidenceof a morphology-orientation effect is found. Major axes of ellipticalgalaxies are preferentially oriented along the large-scale features ofthe Lick maps. However, the orientations of the major axes of spiral andlenticular galaxies show no clear signs of significant nonrandombehavior at a level of less than about one-fifth of the effect seen forellipticals. The angular scale of the detected alignment effect forUppsala ellipticals extends to at least theta of about 2 deg, which at aredshift of z of about 0.02 corresponds to a linear scale of about 2/hMpc.
| Radio sources in giant E and S0 galaxies
An optically selected sample of 67 giant E and S0 galaxies has beenobserved with radio telescopes of high sensitivity to low-brightnessemission. Correlations between radio emission and galaxy type andbetween radio emission and environment are confirmed, and the fractionof E galaxies with M(B) less than -21.75 that have radio powers Pgreater than 10 to the 23rd W/Hz at 2380 MHz is found to be 0.4 + or -0.1. For all of the 19 sources with P greater than 10 to the 23rd W/Hzthere is evidence on high-resolution maps of continuing centralactivity. Sensitive observations at 151 MHz are used to put limits onthe number of steep-spectrum radio sources, which may be relics of pastactivity in other sample galaxies, more effectively than has previouslybeen possible. Based on the expected lifetime at 151 MHz of radiativelydecaying sources, the time-scale over which typical radio galaxiesremain active is determined to be greater than a few billion yr. This isin conflict with the small linear sizes of many radio sources in thissample, and it is likely that other effects (such as expansion losses inunconfined sources) render the older parts of these objects invisible.
| Mass-to-light ratio of elliptical galaxies
Two virial formulas, which take into account the observed flattening,are established for oblate ellipticals obeying the r to the 1/4th powerlaw and used to derive the mean mass to light ratios in their centralpart. One of them, which requires the knowledge of only one kinematicalparameter, the central (stellar) velocity dispersion, is applied to 197ellipticals. The other one, which uses in addition the maximum stellarrotation velocity, is shown to be less sensitive to the unknown trueflattenings and to possible velocity anisotropies. It is applied to 30ellipticals. Both methods give a mean blue mass to luminosity ratio ofabout 13, without any clear correlation with the absolute luminosity ofthe galaxy.
| A catalog of stellar velocity dispersions. I - Compilation and standard galaxies
A catalog of central stellar velocity dispersion measurements ispresented, current through June 1984. The catalog includes 1096measurements of 725 galaxies. A set of 51 standard galaxies is definedwhich consists of galaxies with at least three reliable, concordantmeasurements. It is suggested that future studies observed some of thesestandard galaxies in the course of their observations so that differentstudies can be normalized to the same system. Previous studies arecompared with the derived standards to determine relative accuracies andto compute scale factors where necessary.
| A survey of galaxy redshifts. IV - The data
The complete list of the best available radial velocities for the 2401galaxies in the merged Zwicky-Nilson catalog brighter than 14.5mz and with b (II) above +40 deg or below -30 deg ispresented. Almost 60 percent of the redshifts are from the CfA surveyand are accurate to typically 35 km/s.
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