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Ultraluminous X-Ray Sources in Nearby Galaxies from ROSAT High Resolution Imager Observations I. Data Analysis
X-ray observations have revealed in other galaxies a class ofextranuclear X-ray point sources with X-ray luminosities of1039-1041 ergs s-1, exceeding theEddington luminosity for stellar mass X-ray binaries. Theseultraluminous X-ray sources (ULXs) may be powered by intermediate-massblack holes of a few thousand Msolar or stellar mass blackholes with special radiation processes. In this paper, we present asurvey of ULXs in 313 nearby galaxies withD25>1' within 40 Mpc with 467 ROSAT HighResolution Imager (HRI) archival observations. The HRI observations arereduced with uniform procedures, refined by simulations that help definethe point source detection algorithm employed in this survey. A sampleof 562 extragalactic X-ray point sources withLX=1038-1043 ergs s-1 isextracted from 173 survey galaxies, including 106 ULX candidates withinthe D25 isophotes of 63 galaxies and 110 ULX candidatesbetween 1D25 and 2D25 of 64 galaxies, from which aclean sample of 109 ULXs is constructed to minimize the contaminationfrom foreground or background objects. The strong connection betweenULXs and star formation is confirmed based on the striking preference ofULXs to occur in late-type galaxies, especially in star-forming regionssuch as spiral arms. ULXs are variable on timescales over days to yearsand exhibit a variety of long term variability patterns. Theidentifications of ULXs in the clean sample show some ULXs identified assupernovae (remnants), H II regions/nebulae, or young massive stars instar-forming regions, and a few other ULXs identified as old globularclusters. In a subsequent paper, the statistic properties of the surveywill be studied to calculate the occurrence frequencies and luminosityfunctions for ULXs in different types of galaxies to shed light on thenature of these enigmatic sources.
| Optical Identification of Infrared Space Observatory Far-Infrared Sources in the Lockman Hole Using a Deep Very Large Array 1.4 GHz Continuum Survey
By exploiting the far-infrared (FIR) and radio correlation, we haveperformed a likelihood-ratio analysis to identify optical counterpartsto the FIR sources that have been found in an area of ~0.9deg2 during the Infrared Space Observatory (ISO) deep FIRsurvey in the Lockman Hole. New ground-based observations have beenconducted to build up the catalogs of radio and optical objects, whichinclude a deep Very Large Array (VLA) observation at 1.4 GHz, optical R-and I-band imaging with the Subaru 8 m and University of Hawaii 2.2 mtelescopes, and optical spectroscopy with the Keck II 10 m and WIYN 3.5m telescopes. This work is based on FIR samples consisting of 116 and 20sources selected with the criteria of FC(90 μm)>=43 mJyand FC(170 μm)>=102 mJy, respectively, whereFC is the bias-corrected flux. Using the likelihood ratioanalysis and the associated reliability, 44 FIR sources have beenidentified with radio sources. Optical confirmation of the 44 FIR/radioassociations was then conducted using accurate radio positions.Redshifts have been obtained for 29 out of the 44 identified sources.One hyperluminous infrared galaxy (HyLIRG) withLFIR>1013 Lsolar and fourultraluminous infrared galaxies (ULIRGs) withLFIR=1012-1013 Lsolar areidentified in our sample, while the remaining 24 FIR galaxies haveLFIR<1012 Lsolar. The space densityof the FIR sources at z=0.3-0.6 is 4.6×10-5Mpc-3, which is 460 times larger than the local value,implying a rapid evolution of the ULIRG population. Most ISO FIR sourceshave L(1.4 GHz)/L(90 μm) similar to the star-forming galaxies Arp 220and M82, indicating that star formation is the dominant mechanism fortheir FIR and radio luminosity.At least seven of our FIR sources show evidence for the presence of anactive galactic nucleus (AGN) in optical emission lines, radio continuumexcess, or X-ray activity. Three out of five (60%) of the ULIRGs/HyLIRGsare AGN galaxies, suggesting that the AGN fraction among theULIRG/HyLIRG population may not change significantly between z~0.5 andthe present epoch. Five of the seven AGN galaxies are within the ROSATX-ray survey field, and two are within the XMM-Newton survey fields.X-ray emission has been detected in only one source, 1EX030, which isoptically classified as a quasar. The nondetection in the XMM-Newton2-10 keV band suggests a very thick absorption column density of3×1024 cm-2 or AV~1200 magobscuring the central source of the two AGN galaxies. Several sourceshave an extreme FIR luminosity relative to the optical R band, L(90μm)/L(R)>500, which is rare even among the local ULIRG population.While source confusion or blending might offer an explanation in somecases, these observations may represent a new population of galaxieswith an extreme amount of star formation in an undeveloped stellarsystem, i.e., formation of bulges or young elliptical galaxies.
| ISOPHOT 95 μm observations in the Lockman Hole. The catalogue and an assessment of the source counts
We report results from a new analysis of a deep 95 μm imaging surveywith ISOPHOT on board the Infrared Space Observatory, over a 1deg2 area within the Lockman Hole, which extends thestatistics of our previous study (Rodighiero et al.\cite{Rodighiero03}). Within the survey area we detect sixty-foursources with S/N>3 (roughly corresponding to a flux limit of 16 mJy).Extensive simulations indicate that the sample is almost complete atS95 μm ≥ 100 mJy, while the incompleteness can bequantified down to 30 mJy. The 95 μm galaxy counts reveal asteep slope at S95 μm ≤100 mJy (α≃ 1.6),in excess of that expected for a non-evolving source population. Inagreement with counts data from ISO at 15 and 175 μm, this favours amodel where the IR populations evolve both in number and luminositydensities. We finally comment on some differences found with other ISOresults in this area.Based on observations obtained with the Infrared Space Observatory, anESA science missions with instruments and contributions funded by ESAMember States and the USA (NASA).
| ISO deep far-infrared survey in the ``Lockman Hole''. III. Catalogs and source counts at 90 & 170 μm
We present the catalogs and source counts for the C90(reference wavelength of 90 μm) and C160 (170 μm)bands, which were extracted from our analysis of an ISO deepfar-infrared survey conducted as part of the Japan/UH ISO cosmologyproject. The total survey area is 0.9 deg2 in two fieldswithin the Lockman Hole. The analysis consists of source extractionusing the IRAF DAOPHOT package and simulations carried out by addingartificial sources to the maps to estimate the detection rate, the fluxbias, the positional accuracy, and the noise. The flux calibration wasperformed using the Sb galaxy UGC 06009 - the photometric error wasestimated to be 50% at C90 and 65% atC160. The total noise estimated from the simulation isdominated by the confusion noise due to the high source density. Theconfusion noise is 20 mJy at C90 and 35 mJy atC160, which is much larger than the instrumental noise whichis at the level of a few mJy or less. The catalogs were constructed byselecting 223 C90 sources and 72 C160 sources witha Signal to Noise Ratio (SNR) of three or greater. The distribution ofthe observed associations between C90 and C160sources indicates that the 1 σ positional errors are 20arcsec and 35 arcsec at C90 and C160,respectively. The corrections for the detection rate and the flux biasare significant for sources fainter than 200 mJy at C90 and250 mJy at C160. Most of the sources detected both atC90 and C160 have aF(C160)/F(C90) color redder than the Sb galaxy UGC06009. Such a red color could result from reddening due to the flux biasor a K-correction brightening due to the effect of redshift. Red sourcesbrighter than 200 mJy at C160 may be very luminous galaxieslike Arp 220 at moderate redshift. The source counts are derived byapplying the corrections for the detection rate and flux bias. Theresultant counts are quite consistent with the constraints derived fromthe fluctuation analysis performed in Paper II. The C160counts are also consistent with the results from the FIRBACK project.Our C90 survey, which is 2-3 times deeper than thosepreviously published, reveals an upturn in the count slope at around 200mJy. While recent models give a reasonable fit to the C160counts, none of them are successful in accounting for the upturn in theC90 counts. If the upturn is caused by ultraluminous IRgalaxies, their redshifts would need to be at z 0.5, implying amajor event in galaxy evolution at moderate redshift.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.
| A far-infrared view of the Lockman Hole from ISO 95-μm observations - I. A new data reduction method
We report results from a new analysis of a deep 95-μm imaging surveywith the photopolarimeter ISOPHOT on-board the Infrared SpaceObservatory, over a 40 × 40 arcmin2 area within theLockman Hole. To this end we exploit a newly developed parametricalgorithm able to identify and clean spurious signals induced by cosmicrays impacts and by transient effects and non-linearities in thedetectors. These results provide us with the currently deepest - to ourknowledge - far-infrared (far-IR) image of the extragalactic sky. Withinthe survey area, we detect 36 sources with signal-to-noise ratio S/N> 3 (corresponding to a flux of 16 mJy), making up a completeflux-limited sample for S95μm>= 100 mJy. Reliablesources are detected, with decreasing but well-controlled completeness,down to S95μm~= 20 mJy. The source extraction process andthe completeness, the photometric and astrometric accuracies of thiscatalogue have been tested by us with extensive simulations accountingfor all the details of the procedure. We estimate source counts down toa flux of ~30 mJy, at which limit we evaluate that 10-20 per cent of thecosmic IR background (CIRB) has been resolved into sources (contributingto the CIRB intensity ~=2.0 × 10-9 W m-2sr-1).The 95-μm galaxy counts reveal a steep slope atS95μm<= 100 mJy (α~= 1.6), in excess of thatexpected for a non-evolving source population. The shape of these countsagrees with those determined by ISO at 15 and 175 μm, and startssetting strong constraints on the evolution models for the far-IR galaxypopulations.
| Compact groups in the UZC galaxy sample
Applying an automatic neighbour search algorithm to the 3D UZC galaxycatalogue (Falco et al. \cite{Falco}) we have identified 291 compactgroups (CGs) with radial velocity between 1000 and 10 000 kms-1. The sample is analysed to investigate whether Tripletsdisplay kinematical and morphological characteristics similar to higherorder CGs (Multiplets). It is found that Triplets constitute lowvelocity dispersion structures, have a gas-rich galaxy population andare typically retrieved in sparse environments. Conversely Multipletsshow higher velocity dispersion, include few gas-rich members and aregenerally embedded structures. Evidence hence emerges indicating thatTriplets and Multiplets, though sharing a common scale, correspond todifferent galaxy systems. Triplets are typically field structures whilstMultiplets are mainly subclumps (either temporarily projected orcollapsing) within larger structures. Simulations show that selectioneffects can only partially account for differences, but significantcontamination of Triplets by field galaxy interlopers could eventuallyinduce the observed dependences on multiplicity. Tables 1 and 2 are onlyavailable in electronic at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.125.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/391/35
| 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.
| Box- and peanut-shaped bulges. I. Statistics
We present a classification for bulges of a complete sample of ~ 1350edge-on disk galaxies derived from the RC3 (Third Reference Catalogue ofBright Galaxies, de Vaucouleurs et al. \cite{rc3}). A visualclassification of the bulges using the Digitized Sky Survey (DSS) inthree types of b/p bulges or as an elliptical type is presented andsupported by CCD images. NIR observations reveal that dust extinctiondoes almost not influence the shape of bulges. There is no substantialdifference between the shape of bulges in the optical and in the NIR.Our analysis reveals that 45% of all bulges are box- and peanut-shaped(b/p). The frequency of b/p bulges for all morphological types from S0to Sd is > 40%. In particular, this is for the first time that such alarge frequency of b/p bulges is reported for galaxies as late as Sd.The fraction of the observed b/p bulges is large enough to explain theb/p bulges by bars. Partly based on observations collected at ESO/LaSilla (Chile), DSAZ/Calar Alto (Spain), and Lowell Observatory/Flagstaff(AZ/U.S.A.). Tables 6 and 7 are only available in electronic form at CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| ISO deep far-infrared survey in the ``Lockman Hole". II. Power spectrum analysis: evidence of a strong evolution in number counts
We investigate the characteristics of FIR brightness fluctuations at 90mu m and 170 mu m in the Lockman Hole, which were surveyed with ISOPHOTaboard the Infrared Space Observatory (ISO). We first calculated theangular correlation function of each field and then its Fouriertransform (the angular Power Spectral Density: PSD) over the spatialfrequency range of f=0.05-1 arcmin-1. The PSDs are found tobe rather flat at low spatial frequencies (f <= 0.1arcmin-1), slowly decreasing toward higher frequencies. Thesespectra are unlike the power-law ones seen in the IR cirrusfluctuations, and are well explained by randomly distributed pointsources. Furthermore, point-to-point comparison between 90 mu m and 170mu m brightness shows a linear correlation between them, and the slopeof the linear fit is much shallower than that expected from the IRcirrus color, and is consistent with the color of galaxies at low ormoderate redshift (z<1). We conclude that the brightness fluctuationsin the Lockman Hole are not caused by the IR cirrus, but are most likelydue to faint star-forming galaxies. We also give the constraints on thegalaxy number counts down to 35 mJy at 90 mu m and 60 mJy at 170 mu m,which indicate the existence of a strong evolution down to these fluxesin the counts. The galaxies responsible for the fluctuations alsosignificantly contribute to the cosmic infrared background radiation.Based on observations with ISO, an ESA project with instruments fundedby ESA member states (especially the PI countries: France, Germany, theNetherlands, and the United Kingdom) and with the participation of ISASand NASA. The ISOPHOT data presented in this paper was reduced usingPIA, which is a joint development by ESA Astrophysics Division and theISOPHOT consortium.
| Deep far infrared ISOPHOT survey in ``Selected Area 57". I. Observations and source counts
We present here the results of a deep survey in a 0.4 deg2blank field in Selected Area 57 conducted with the ISOPHOT instrumentaboard ESAs Infrared Space Observatory (ISO at both 60 mu m and 90 mu m.The resulting sky maps have a spatial resolution of 15 x 23arcsec2 per pixel which is much higher than the 90 x 90arcsec2 pixels of the IRAS All Sky Survey. We describe themain instrumental effects encountered in our data, outline our datareduction and analysis scheme and present astrometry and photometry ofthe detected point sources. With a formal signal to noise ratio of 6.75we have source detection limits of 90 mJy at 60 μm and 50 mJy at 90μm. To these limits we find cumulated number densities of 5+/- 3.5deg-2 at 60 μm and 14.8+/- 5.0 deg-2 at 90μm. These number densities of sources are found to be lower thanpreviously reported results from ISO but the data do not allow us todiscriminate between no-evolution scenarios and various evolutionarymodels. Based on observations with ISO, an ESA project with instrumentsfunded by ESA member states (especially the PI countries: France,Germany, the Netherlands, and the United Kingdom) and with theparticipation of ISAS and NASA.
| Identification of Faint Markarian Galaxies with IRAS Sources
The identification of IRAS sources with Faint Markarian galaxies on thebase of the Second Byurakan Survey were made. It is shown that about 30%of SBS galaxies are also IRAS sources.The list of newly identifiedobjects are presented.
| 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.
| Investigation of Barred Galaxies. V. Surroundings of SB and SA Galaxies
Not Available
| ISO Far-Infrared Deep Survey of the Lockman Hole
Not Available
| Groups of galaxies. III. Some empirical characteristics.
Not Available
| Kinematics of the local universe. VII. New 21-cm line measurements of 2112 galaxies
This paper presents 2112 new 21-cm neutral hydrogen line measurementscarried out with the meridian transit Nan\c cay radiotelescope. Amongthese data we give also 213 new radial velocities which complement thoselisted in three previous papers of this series. These new measurements,together with the HI data collected in LEDA, put to 6 700 the number ofgalaxies with 21-cm line width, radial velocity, and apparent diameterin the so-called KLUN sample. Figure 5 and Appendices A and B forcorresponding comments are available in electronic form at thehttp://www.edpsciences.com
| ISO deep far-infrared survey in the ``Lockman Hole''. A search for obscured objects at high redshift. I. Observations
Two 44arcmin x 44arcmin fields in the Lockman Hole were mapped at 95 mum and 175 mu m using ISOPHOT. A simple program code combined with PIAworks well to correct for drift in the detector responsivity. The numberdensity of 175 mu m sources is 3-10 times higher than expected from theno-evolution model. Based on observations with ISO, an ESA project withinstruments funded by ESA member states (especially the PI countries:France, Germany, the Netherlands, and the United Kingdom) and with theparticipation of ISAS and NASA. The ISOPHOT data presented in this paperwas reduced using PIA, which is a joint development by the ESAAstrophysics Division and the ISOPHOT consortium led by the Max PlankInstitute for Astronomy (MPIA), Heidelberg.
| 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 UV properties of normal galaxies. III. Standard luminosity profiles and total magnitudes.
In the previous papers of this series we collected and reduced to thesame system all the available photometric data obtained in theultraviolet (UV) range for normal (i.e. non active) galaxies. Here weuse these data to derive standard UV luminosity profiles for threemorphological bins (E/S0; Sa/Sb; Sc/Sd) and extrapolated totalmagnitudes for almost 400 galaxies. We find that: 1) the UV growthcurves are well matched by the B-band revised standard luminosityprofiles, once a proper shift in the effective radius is applied, and 2)the UV light in early-type galaxies is more centrally concentrated thanthe visible light.
| The UV properties of normal galaxies. II. The ``non-IUE'' data.
In the last decade several satellite and balloon borne experiments havecollected a large number of ultraviolet fluxes of normal galaxiesmeasured through apertures of various sizes and shapes. We havehomogenized this data set by deriving scale corrections with respect toIUE. In a forthcoming paper these data will be used to derive standardluminosity profiles and total magnitudes.
| Compact groups of galaxies in the nearby universe
We have searched for compact groups of galaxies among the largestcatalog of nearby groups (LGG catalog). 21 new compact groups of atleast 3 members were found. Their surface brightnesses are generallylower than those of Hickson compact groups (HCGs), and theircharacteristics are close to those of loose groups. We have alsoretrieved all HCGs of the nearby universe. These are all embedded ingroups, forming the cores or substructures of loose groups. Theseresults suggest that compact groups may form as core or substructureswithin loose groups (like the HCGs), or form from loose groups when theystart collapsing (like those of the LGG).
| 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.
| General study of group membership. II - Determination of nearby groups
We present a whole sky catalog of nearby groups of galaxies taken fromthe Lyon-Meudon Extragalactic Database. From the 78,000 objects in thedatabase, we extracted a sample of 6392 galaxies, complete up to thelimiting apparent magnitude B0 = 14.0. Moreover, in order to considersolely the galaxies of the local universe, all the selected galaxieshave a known recession velocity smaller than 5500 km/s. Two methods wereused in group construction: a Huchra-Geller (1982) derived percolationmethod and a Tully (1980) derived hierarchical method. Each method gaveus one catalog. These were then compared and synthesized to obtain asingle catalog containing the most reliable groups. There are 485 groupsof a least three members in the final catalog.
| 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.
| Neutral hydrogen observations of galaxies in superclusters
Neutral hydrogen observations of spiral galaxies in the Uppsala GeneralCatalog were made with the 91 m telescope in Green Bank. Results of theH I observations are presented for 309 objects north of declination +38deg in the right ascension range between 10 h and 22 h and for a sampleof 46 objects just south of the equator in the region around R.A.between 0 h and 3 h. Many of these objects are outlying members ofsuperclusters and may be useful in the study of deviations from Hubbleflow on supercluster scales. Velocity widths as measured by fivedifferent algorithms are presented along with a profile quality index.
| HI observations of galaxies in nearby Zwicky clusters
The results of a long term project of H I observations of galaxieswithin the boundaries of nearby Zwicky clusters are presented. Thedetection rate is rather low (233 out of 618, i.e., 38 percent) ascompared to other surveys carried out recently. Most of the radialvelocities of the detected galaxies are new determinations. The largespread in radial velocities for many of these clusters is a strongindication for the presence of several foreground and/or backgroundgalaxies.
| Cosmology from a galaxy group catalog. I - Binaries
A new, completely objective group-finding algorithm is described andapplied to the CfA redshift catalog. The binary galaxies are isolatedfor analysis. The assumptions underlying the analysis are (1) that lighttraces mass, (2) that our binary galaxy subsets are representative lighttracers, and (3) that the binary orbits are circular. The primary resultof the work is that the resulting bias-free binary catalogs are afunction of the assumed cosmological model. For virtually any inputvalue of Omega(0) in the range 0.01-5.00, there is a reasonablyconsistent interpretation of the CfA survey such that the specifiedvalue of Omega(0) can be derived from the binary sample obtained underthat interpretation. A secondary result is that the higher the inputvalue of Omega(0), the broader the intrinsic distribution in M/L, andhence the less valid the assumption that light traces mass.
| 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.
| A catalog of hierarchical subclustering in the Turner-Gott groups
Information on the substructure, to four levels of hierarchy, ispresented for the 103 groups listed by Turner and Gott (TG) in theircatalog of groups of galaxies. All galaxies brighter than Mpg= 14.0 in the region delta is 0 deg or greater and b(II) is 40 deg orgreater that have been assigned group memberships by TG are included.Also listed is the local environmental information for each of thegalaxies, giving the surface density enhancement beta in the galaxy'sneighborhood, calculated at 15 levels in the range beta = 4.6 to 10,000.
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