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Near-infrared observations of galaxies in Pisces-Perseus. V. On the origin of bulges
We investigate the scaling relations of bulge and disk structuralparameters for a sample of 108 disk galaxies. Structural parameters ofindividual galaxies are obtained from two-dimensional bulge/diskdecomposition of their H-band surface brightness distributions. Bulgesare modelled with a generalized exponential (Sérsic) withvariable integer shape index n. We find that bulge effectivescalelengths reB and luminosity MBincrease with increasing n, but disk properties are independent of bulgeshape. As Hubble type T increases, bulges become less luminous and theirmean effective surface brightness <μeB>gets fainter; disk <μeD> shows a similar,but much weaker, trend. When bulge parameters(<μeB>, reB,MB) are compared with disk ones(<μeD>, reD,MD), they are tightly correlated for n=1 bulges. Thecorrelations gradually worsen with increasing n such that n=4 bulgesappear virtually independent of their disks. The Kormendy relation,<μeB> vs. reB, isshown to depend on bulge shape n; the two parameters are tightlycorrelated in n=4 bulges (r=0.8), and increasingly less so as ndecreases; disk <μeD> andreD are well correlated (r=0.7). Bulge-to-disksize ratios reB/reD areindependent of Hubble type, but smaller for exponential bulges; the meanreB/reD for n=1 bulges is 4times smaller than that for n=4, with a spread which is 9 times smaller.Strongly barred SB galaxies with exponential bulges are more luminousthan their unbarred counterparts. Exponential bulges appear to beclosely related to their underlying disks, while bulges with higher nvalues are less so; n=4 bulges and their disks apparently have norelation. We interpret our results as being most consistent with asecular evolutionary scenario, in which dissipative processes in thedisk are responsible for building up the bulges in most spirals.Based on observations at the TIRGO, NOT, and VATT telescopes. TIRGO(Gornergrat, CH) is operated by IRA-CNR, Arcetri, Firenze. NOT (LaPalma, Canary Islands) is operated by NOTSA, the Nordic ObservatoryScientific Association. VATT (Mt. Graham, AZ) is operated by VORG, theVatican Observatory Research Group.Full Table 1 is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr ( or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/414/905.

A search for Low Surface Brightness galaxies in the near-infrared. I. Selection of the sample
A sample of about 3800 Low Surface Brightness (LSB) galaxies wasselected using the all-sky near-infrared (J, H and Ks-band)2MASS survey. The selected objects have a mean central surfacebrightness within a 5'' radius around their centre fainter than 18 magarcsec-2 in the Ks band, making them the lowestsurface brightness galaxies detected by 2MASS. A description is given ofthe relevant properties of the 2MASS survey and the LSB galaxy selectionprocedure, as well as of basic photometric properties of the selectedobjects. The latter properties are compared to those of other samples ofgalaxies, of both LSBs and ``classical'' high surface brightness (HSB)objects, which were selected in the optical. The 2MASS LSBs have aBT_c-KT colour which is on average 0.9 mag bluerthan that of HSBs from the NGC. The 2MASS sample does not appear tocontain a significant population of red objects.All tables and Figs. 2a-c are only available in electronic form athttp://www.edpsciences.org

Supernovae in isolated galaxies, in pairs and in groups of galaxies
In order to investigate the influence of environment on supernova (SN)production, we have performed a statistical investigation of the SNediscovered in isolated galaxies, in pairs and in groups of galaxies. 22SNe in 18 isolated galaxies, 48 SNe in 40 galaxy members of 37 pairs and211 SNe in 170 galaxy members of 116 groups have been selected andstudied. We found that the radial distributions of core-collapse SNe ingalaxies located in different environments are similar, and consistentwith those reported by Bartunov, Makarova & Tsvetkov. SNe discoveredin pairs do not favour a particular direction with respect to thecompanion galaxy. Also, the azimuthal distributions inside the hostmembers of galaxy groups are consistent with being isotropics. The factthat SNe are more frequent in the brighter components of the pairs andgroups is expected from the dependence of the SN rates on the galaxyluminosity. There is an indication that the SN rate is higher in galaxypairs compared with that in groups. This can be related to the enhancedstar formation rate in strongly interacting systems. It is concludedthat, with the possible exception of strongly interacting systems, theparent galaxy environment has no direct influence on SN production.

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.

The I-Band Tully-Fisher Relation for SC Galaxies: 21 Centimeter H I Line Data
A compilation of 21 cm line spectral parameters specifically designedfor application of the Tully-Fisher (TF) distance method is presentedfor 1201 spiral galaxies, primarily field Sc galaxies, for which opticalI-band photometric imaging is also available. New H I line spectra havebeen obtained for 881 galaxies. For an additional 320 galaxies, spectraavailable in a digital archive have been reexamined to allow applicationof a single algorithm for the derivation of the TF velocity widthparameter. A velocity width algorithm is used that provides a robustmeasurement of rotational velocity and permits an estimate of the erroron that width taking into account the effects of instrumental broadeningand signal-to-noise. The digital data are used to establish regressionrelations between measurements of velocity widths using other commonprescriptions so that comparable widths can be derived throughconversion of values published in the literature. The uniform H I linewidths presented here provide the rotational velocity measurement to beused in deriving peculiar velocities via the TF method.

The I-Band Tully-Fisher Relation for SC Galaxies: Optical Imaging Data
Properties derived from the analysis of photometric I-band imagingobservations are presented for 1727 inclined spiral galaxies, mostly oftypes Sbc and Sc. The reduction, parameter extraction, and errorestimation procedures are discussed in detail. The asymptotic behaviorof the magnitude curve of growth and the radial variation in ellipticityand position angle are used in combination with the linearity of thesurface brightness falloff to fit the disk portion of the profile. TotalI-band magnitudes are calculated by extrapolating the detected surfacebrightness profile to a radius of eight disk scale lengths. Errors inthe magnitudes, typically ~0.04 mag, are dominated by uncertainties inthe sky subtraction and disk-fitting procedures. Comparison is made withthe similar imaging database of Mathewson, Ford, & Buchhorn, both aspresented originally by those authors and after reanalyzing theirdigital reduction files using identical disk-fitting procedures. Directcomparison is made of profile details for 292 galaxies observed incommon. Although some differences occur, good agreement is found,proving that the two data sets can be used in combination with onlyminor accommodation of those differences. The compilation of opticalproperties presented here is optimized for use in applications of theTully-Fisher relation as a secondary distance indicator in studies ofthe local peculiar velocity field.

Near-infrared observations of galaxies in Pisces-Perseus. I. vec H-band surface photometry of 174 spiral
We present near-infrared, H-band (1.65 $() μm), surface photometry of174 spiral galaxies in the area of the Pisces-Perseus supercluster. Theimages, acquired with the ARNICA camera mounted on various telescopes,are used to derive radial profiles of surface brightness, ellipticities,and position angles, together with global parameters such as H-bandmagnitudes and diameters Radial profiles in tabular form and images FITSfiles are also available upon request from gmorio@arcetri.astro.it.}.The mean relation between H-band isophotal diameter D_{21.5} and theB-band D25 implies a B-H color of the outer disk bluer than3.5; moreover, D_{21.5}/D25 depends on (global) color andabsolute luminosity. The correlations among the various photometricparameters suggest a ratio between isophotal radius D_{21.5}/2 and diskscale length of ~ m3.5 and a mean disk central brightness ~ meq 17.5H-mag arcsec^{-2}. We confirm the trend of the concentration indexC31$ with absolute luminosity and, to a lesser degree, withmorphological type. We also assess the influence of non-axisymmetricstructures on the radial profiles and on the derived parameters. Basedon observations at the TIRGO, NOT, and VATT telescopes. TIRGO(Gornergrat, CH) is operated by CAISMI-CNR, Arcetri, Firenze. NOT (LaPalma, Canary Islands) is operated by NOTSA, the Nordic ObservatoryScientific Association. VATT (Mt. Graham, Az) is operated by VORG, theVatican Observatory Research Group Table 3 and Fig. 4 are only availablein electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr( or via http://cdsweb.u-strasbg.fr/Abstract.html.

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

HIPPARCOS calibration of the peak brightness of four SNe IA and the value of H_0
HIPPARCOS geometrical parallaxes allowed us to calibrate the CepheidPeriod-Luminosity relation and to compute the true distance moduli of 17galaxies. Among these 17 galaxies, we selected those which generatedtype Ia Supernovae (SNe Ia). We found NGC 5253, parent galaxy of 1895Band 1972E, IC 4182 and NGC 4536 parents of 1937C and 1981B,respectively. We used the available B-band photometry to determine thepeak brightness of these four SNe Ia. We obtained = -19.65 +/- 0.09. Then, we built a sample of 57SNe Ia in order to plot the Hubble diagram and determine its zero-point.Our result (ZPB = -3.16 +/- 0.10) is in agreement with otherdeterminations and allows us to derive the following Hubble constant:H0 = 50 +/- 3 (internal) km.s(-1}.Mpc({-1)) .

Constraining the Ages of Supernova Progenitors. I. Supernovae and Spiral Arms
We present the first results of a three-part study of supernova (SN)ages using positional age indicators in spiral galaxies. We havemeasured the positions of 90 Spectroscopically identified Type Ia andType II SNs (SNs Ia and SNs II) relative to spiral arms in their hostgalaxies, making a special effort to reduce inhomogeneity in the processof arm tracing for different galaxies. We find that SNs II are moretightly concentrated to the arms than SNs Ia, but both kinds of SNsoccur closer to arms than a random disk population. However, whencompared with the distribution of V and I light relative to the arms,the SNs Ia are no more tightly concentrated than the general stellarpopulation. This indicates that SNs Ia occur in a population old enoughto have diffused away from their formation regions.

Global H I profiles of spiral galaxies.
In this paper we present short H I synthesis observations of 57 galaxieswithout H I information in the RC3. These are a by-product of a largesurvey with the WSRT of the neutral hydrogen gas in spiral and irregulargalaxies. Global profiles and related quantities are given for the 42detected galaxies and upper limits for the remaining 15. A number ofgalaxies have low values of H I mass-to-blue luminosity ratio.

The Hubble Diagram for Supernovae of Type Ia. II. The Effect on the Hubble Constant of a Correlation between Absolute Magnitude and Light Decay Rate
New Hubble diagrams in B and V are derived for supernovae of type Ibased on light curves from the archive literature plus 13 new lightcurves with superior modern photometry observed in the CerroTololo/University of Chile program (Hamuy et al, 1995). The sample isrestricted to SNe Ia whose light curves are defined by photometrybeginning 5 days or less after maximum light and with (B - V)max <0.5 mag. Supernovae of known type Ib or Ic are also excluded. Theresulting Hubble diagrams, extending to redshifts of 30,00 km s^- 1^,have dispersions in absolute magnitude of 0.34 mag in B and 0.33 mag inV, confirming that spectroscopically "normal" (Branch et al. 1993) SNeIa are among the best standard candles known. A solution for the slopeof the Hubble diagram gives n(B) = 0.977 +/- 0.025 and n(V) = 1.020 +/-0.024 for the exponent in ν~D^n^, proving linearity of the expansionfield to a high level. The residuals in magnitude from the ridge line ofthe Hubble diagram are compared with the light decay rate during thefirst 15 days to test the correlation between the two suggested byPskovskii and by Phillips. The strongest possible correlation using theextant data has a slope 3 times smaller than that derived by Phillips,and 2 times smaller than suggested by Hamuy et al., leading to adecrease of less than 10% in the distance scale based on the present(1995) SNe Ia calibration by means of three supernovae whose distancesare known from Cepheids in their parent galaxies. Applying the maximumpossible correction to M(max) for a Psko'vskii- Phillips effect wouldgive Hubble constants of H_0_(B)<= 54 +/- 4 km s^-1^ Mpc^-1^, andH_0_(V) <= 59 +/- 4 km s^-1^ Mpc^-1^, where the errors are internal.It is argued that the absence of measurable bias effects in the Hubblediagrams shows that the three local (nearest) SNe Ia presentlycalibrated via Cepheid distances cannot all be overluminous relative tothe average of more distant SNe. If they are underluminous, which mustbe the case by the statistics of the Malmquist effect if the largedispersion in M(max) for SNe Ia claimed by Hamuy et al. applies to thecalibrators, then the value of H_0_ = 52 km s^-1^ Mpc^-1^ given by Sahaet al. is an upper limit to the Hubble constant.

The blue anbd visual absolute magnitude distributions of Type IA supernovae
Tully-Fisher (TF), surface brightness fluctuation (SBF), and Hubble lawdistances to the parent galaxies of Type Ia supernovae (SNs Ia) are usedin order to study the SN Ia blue and visual peak absolute magnitude(MB and MV) distributions. We propose twoobjective cuts, each of which produces a subsample with small intrinsicdispersion in M. One cut, which can be applied to either band,distinguishes between a subsample of bright events and a smallersubsample of dim events, some of which were extinquished in the parentgalaxy and some of which were intrinsically subluminous. The brightevents are found to be distributed with an observed dispersions of 0.3less than or approximately = Sigmaobs less than orapproximately = 0.4 about a mean absolut magnitude (M-barB orM-barV). Each of the dim SNs was spectroscopically peculiarand/or had a red B-V color; this motivates the adoption of analternative cut that is based on B-V rather than on M. To wit, SNs Iathat are both known to have -0.25 less than B-V less than + 0.25 and notknown to be spectroscopically peculiar show observational dispersion ofonly Sigmaobs(MB) =Sigmaobs(MV) = 0.3. Because characteristicsobservational errors produce Sigmaerr(M) greater than 0.2,theintrinsic dispersion among such SNs Ia is Sigmaint(M) lessthan or approximately = 0.2. The small observational dispersionindicates that SNs Ia, the TF relation, and SBFs all good relativedistances to those galaxies that produce SNs Ia. The conflict betweenthose who use SNs Ia in order to determine the value of the Hubbleconstant (H0) and those who use TF and SBF distances todetermine H0 results from discrepant calibrations.

Distribution of supernovae relative to spiral arms and H II regions
We have studied the association of supernovae in spiral galaxies withsites of recent stars formation -- sprial arms and H II regions. It isshown that supernovae (SNe) of Types Ia, Ib, and II exhibitconcentration to spiral arms and their distributions over the distanceto the nearest spiral arm do not differ significantly. This result isconfirmed by a Kolmogorov-Smirnov test comparison with the distancedistributions, expected if SNe are distributed randomly inside the modelgalaxy. SNe of types Ib and II show a strong concentration towards H IIregions, while distribution of SNe Ia can be explained by chancesuperposition. All studied distributions of SNe Ib and II show strikingsimilarity, which suggests that their progenitors are massive stars withsimilar ages and initial masses. The association of SNe Ia with spiralarms suggests that their progenitors in spiral galaxies are likely to beintermediate mass stars.

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.

Type IA supernovae as standard candles
The distribution of absolute blue magnitudes among Type Ia supernovae(SNs Ia) is studied. Supernovae were used with well determined apparentmagnitudes at maximum light and parent galaxies with relative distancesdetermined by the Tully-Fisher or Dn - sigma techniques. The meanabsolute blue magnitude is given and the observational dispersion isonly sigma(MB) 0.36, comparable to the expected combined errors indistance, apparent magnitude, and extinction. The mean (B-V) color atmaximum light is 0.03 +/- 0.04, with a dispersion sigma(B-V) = 0.20. TheCepheid-based distance to IC 4182, the parent galaxy of the normal andunextinguished Type Ia SN 1937C, leads to a Hubble constant of H(0) + 51+/- 12 km/s Mpc. The existence of a few SNs Ia that appear to have beenreddened and dimmed by dust in their parent galaxies does not seriouslycompromise the use of SNs Ia as distance indicators.

Spectroscopic differences between supernovae of type IA in early-type and in late-type galaxies
Published data are used to derive a uniform set of blueshifts in thelambda 6355 feature of Si II for 33 SNe Ia. All seven SNe Ia withblueshifts at 10 days past maximum of 9500 km/s occurred in early-typegalaxies. The observed dependence of Si II blueshift on parent-galaxytype indicates that differing SNe Ia blueshifts are due to globalphysical differences, rather than to asymmetries in their expansion thatare viewed from different directions. It is speculated that SNe Ia withlow expansion velocities might, in the mean, have older progenitors thanthose with high expansion velocities.

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.

The Local Group Motion Towards Virgo and the Microwave Background
The peculiar motion of the Local Group is determined from 15 clusterswhose relative distances are known with minimum bias. The resultinglocal motion is 745 +/- 106 kms^-1^ towards l = 273^deg^, b = 3^deg^.This 7σ signal is in perfect statistical agreement with the motioninferred from the dipole of the cosmic microwave background. The mediandistance of 6400 km s^-1^ of the 15 clusters sets an upper limit to thecomoving volume. - The three-dimensional peculiar motions of theclusters become 587 km s^-1^, if allowance is made for a 5 percent errorof the cluster distances. The value compares well with the 489 km s^-1^motion of the Virgo complex with respect to the cosmic microwavebackground. - The data imply a local slow-down of the expansion fielddue to the Virgo cluster of v_VC_ = 239 +/- 40 km s^-1^. An almostidentical value, i.e. v_VC_ = 233 +/- 44 km s^-1^, is independentlydetermined using the relative distances of the Virgo, UMa, and Fornaxclusters and of eight nearby supernovae of type Ia. - These results donot require the adoption of any zero-point of the extragalactic distancescale.

The rate of supernovae. I - The data base, the recipe and the uncertainties
Because the determination of SN rates is vulnerable to the small numberstatistics of homogeneous samples, the data bases of two independent SNsearches were merged in order to build up the largest data base everused for SN rate determinations. Using a software specially developedfor the analysis of these materials, the individual control times wereestimated for each galaxy and in turn the SN rates for samples ofgalaxies extracted from different catalogs were estimated. Theuncertainties in the input parameters were quantitatively estimated byseveral tests. It is found that the assumption of the limiting discoverymagnitude is crucial. Contrary to previous belief, it is shown that thedispersion of the absolute SN magnitude at maximum is not particularlyimportant for the SN rates determined from the samples, whereasuncertainties about the shape of the light curve are more serious. Therate of SNe was computed for four galaxy samples extracted fromdifferent catalogs. It is shown that the SNe rate reflects thedifferences among the galaxy parameters reported by different catalogs.

The absolute magnitude at maximum of type IA supernovae in late type galaxies
The color excess data for the best photometrically studied type Iasupernovae (SNIa) which occurred in late type galaxies have beengathered and analyzed. A ratio of the B-band to selective extinction inthe parent galaxies of R(B) = A(B)/E(B-V) = 3.35 +/- 0.25 (1-sigma).This indicates that the extinction curves in late type galaxies havesimilar properties to that of the Galaxy. A new calibration for theabsolute magnitude at maximum of SNIa in late type galaxies of M(B) =-19.24 +/- 0.18 (1-sigma) + 5log(H(0)/75) is obtained, which ismarginally brighter that the recent determinations for type Iasupernovae observed in elliptical (dust-free) galaxies, and appears toconfirm the potential of SNIa as standard candles for distancedeterminations.

Type IA supernovae in late type galaxies - Reddening correction, scale height, and absolute maximum magnitude
The color excess data for the best photometrically studied type Iasupernova (SNIa) which occurred in late-type galaxies are analyzed.These data are used to derive a ratio of the B band to selectiveextinction in the parent galaxies of 3.35 +/-0.25 (1 sigma), whichindicates that the extinction curves in late-type galaxies have similarproperties to that of the Milky Way. A new calibration for the absolutemagnitude at maximum of SNIa in late-type galaxies is obtained; it ismarginally brighter than the recent determinations for type Iasupernovae observed in elliptical (dust-free) galaxies, and confirms thepotential of SNIa as standard candles for distance determinations. It isinferred that SNIa have a considerably broader distribution than thedust disk, and it is confirmed that they are older than old diskpopulation objects, i.e., age greater than 1-2 billion yr. It isconcluded that the total extinction thickness of late-type galaxies isvery similar to that of the Milky Way.

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 Asiago Supernova Catalogue
A Catalogue of Supernovae (SNe) is presented which tabulates the maindata relative to all extragalactic SNe discovered up to 1988 December31, and to their parent galaxies. In total 661 SNe are listed of which267 are classified. For an easier consultation, two lists are givenwhere the SNe are ordered chronologically and by Right Ascension,respectively. The overall distribution of classified supernovae over themorphological types of their parent galaxies is also presented in asummary table.

Photographic and spectroscopic observations of three type IA supernovae - 1982 W, 1983 R, and 1983 U
Three supernovae (1982 W, 1983 R, and 1983 U) have been observed in theframework of the systematic researches on supernovae carried out since1961. Their B and V light curves, colors, distances and absolutemagnitudes are derived by using all the available data. Spectra of thesupernovae obtained near maximum and during the luminosity decline areanalyzed. They show that all three supernovae belong to type Ia, withthe characteristic absorption feature at 6100 A, and that their spectralproperties and evolution are quite normal for this type of object.

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.

Frequency of outbursts and spatial distribution of type I and II supernovae
The frequency of outbursts of type I and II supernovae in galaxies ofdifferent types has been determined on the basis of the observationaldata of the supernova search at the Sternberg Astronomical Institute andAsiago Astrophysical Observatory. For a number of galaxies, the expectedsupernova rate is compared with independent estimates. The probablerange of the mass of supernova progenitors is determined. No differencehas been found in the distributions of type I and II supernovae alongthe radius and z-coordinate in spiral galaxies; the distributionsindicate that supernovae belong to the young population I.

A Checklist of Supernovae in the NGC and IC Galaxies Through 1985
This Checklist of Supernovae in the NGC and IC Galaxies Through 1985 ispresented to assist those interested in undertaking a visual orphotographic search for extragalactic supernovae. Some galaxies appearto have had more than one or two supernovae, and these should bemonitored closely for any new outbursts.

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