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Measured Metallicities at the Sites of Nearby Broad-Lined Type ic Supernovae and Implications for the Supernovae Gamma-Ray Burst Connection
We compare the chemical abundances at the sites of 12 nearby (z <0.14) Type Ic supernovae (SN Ic) that showed broad lines, but had noobserved gamma-ray burst (GRB), with the chemical abundances in fivenearby (z < 0.25) galaxies at the sites of GRBs where broad-lined SNIc were seen after the fireball had faded. It has previously been notedthat GRB hosts are low in luminosity and low in their metal abundances.If low metallicity is sufficient to force the evolution of massive starsto end their lives as GRBs with an accompanying broad-lined SN Ic, thenwe would expect higher metal abundances for the broad-lined SN Ic thathave no detected GRBs. This is what we observe, and this trend isindependent of the choice of metallicity calibration we adopt and themode of SN survey that found the broad-lined SN Ic. A unique feature ofthis analysis is that we present new spectra of the host galaxies andanalyze all measurements of both samples in the same set of methods,using the galaxy emission-line measurements corrected for extinction andstellar absorption, via independent metallicity diagnostics of Kewley& Dopita, McGaugh, and Pettini & Pagel. In our small sample, theboundary between galaxies that have GRBs accompanying their broad-linedSN Ic and those that have broad-lined SN Ic without GRBs lies at anoxygen abundance of 12 + log(O/H)KD02 ~ 8.5, whichcorresponds to 0.2-0.6 Zsun depending on the adoptedmetallicity scale and solar abundance value. Even when we limit thecomparison to SN Ic that were found in untargeted supernova surveys, theenvironment of every broad-lined SN Ic that had no GRB is more metalrich than the site of any broad-lined SN Ic where a GRB was detected.This paper includes data gathered with the MMT Observatory, a jointfacility of the Smithsonian Institution and the University of Arizona,and with the 6.5 m Magellan Telescopes located at Las CampanasObservatory, Chile.
| Star formation in isolated AMIGA galaxies: dynamical influence of bars
Context: Star formation depends strongly on both the local environmentof galaxies and the internal dynamics of the interstellar medium. Todisentangle the two effects, we obtained, in the framework of the AMIGAproject, Hα and Gunn r photometric data for more than 200 spiralgalaxies lying in very low-density regions of the local Universe. Aims:We characterise the Hα emission, tracing current star formation,of the 45 largest and least inclined galaxies observed for which weestimate the torques between the gas and the bulk of the optical matter.We subsequently study the Hα morphological aspect of theseisolated spiral galaxies. Methods: Using Fourier analysis, we focus onthe modes of the spiral arms and also on the strength of the bars,computing the torques between the gas and newly formed stars (Hα),and the bulk of the optical matter (Gunn r). Results: We interpret thevarious bar/spiral morphologies observed in terms of the secularevolution experienced by galaxies in isolation. We also classify thedifferent spatial distributions of star forming regions in barredgalaxies. The observed frequency of particular patterns bringsconstraints on the lifetime of the various evolution phases. We proposean evolutive sequence accounting for the transitions between thedifferent phases we observed. Conclusions: Isolated galaxies do notappear to be preferentially barred or unbarred. Fitting the Hαdistributions using numerical simulations yields constraints on the starformation law, which is likely to differ from a genuine Schmidt law. Inparticular, it is probable that the relative velocity of the gas in thebar also needs to be taken into account.Partially based on observations collected at the CentroAstronómico Hispano Alemán (CAHA) at Calar Alto, operatedjointly by the Max-Planck Institut für Astronomie and the Institutode Astrofísica de Andalucía (CSIC), as well as at theObservatorio de Sierra Nevada (OSN), operated by the IAA/CSIC. Table[see full text] and Figs. [see full text]-[see full text] areonly available in electronic form at http://www.aanda.org
| The AMIGA sample of isolated galaxies. V. Quantification of the isolation
Context: The AMIGA project aims to build a well defined andstatistically significant reference sample of isolated galaxies in orderto estimate the environmental effects on the formation and evolution ofgalaxies. Aims: The goal of this paper is to provide a measure of theenvironment of the isolated galaxies in the AMIGA sample, quantifyingthe influence of the candidate neighbours identified in our previouswork and their potential effects on the evolution of the primarygalaxies. Here we provide a quantification of the isolation degree ofthe galaxies in this sample. Methods: Our starting sample is theCatalogue of Isolated Galaxies (CIG). We used two parameters to estimatethe influence exerted by the neighbour galaxies on the CIG galaxy: thelocal number density of neighbour galaxies and the tidal strengthaffecting the CIG galaxy. We show that both parameters together providea comprehensive picture of the environment. For comparison, thoseparameters have also been derived for galaxies in denser environmentssuch as triplets, groups and clusters. Results: The CIG galaxies show acontinuous spectrum of isolation, as quantified by the two parameters,from very isolated to interacting. The fraction of CIG galaxies whoseproperties are expected to be influenced by the environment is howeverlow (159 out of 950 galaxies). The isolated parameters derived for thecomparison samples gave higher values than for the CIG and we foundclear differences for the average values of the 4 samples considered,proving the sensitivity of these parameters. Conclusions: Theenvironment of the galaxies in the CIG has been characterised, using twocomplementary parameters quantifying the isolation degree, the localnumber density of the neighbour galaxies and the tidal forces affectingthe isolated galaxies. A final catalogue of galaxies has been producedand the most isolated of these galaxies are consequently appropriate toserve as a reference sample for the AMIGA project.Full Tables [see full text], [see full text] and [see full text]-[see full text] are available in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/472/121 and fromhttp://www.iaa.es/AMIGA.html.
| Correlation between the peak spectral energy of gamma-ray bursts and the peak luminosity of the underlying supernovae: implication for the nature of the gamma-ray burst-supernova connection
In this paper, we present a correlation between the peak spectral energyof gamma-ray bursts (GRBs) and the peak bolometric luminosity of theunderlying supernovae (SNe), based on a sample of four pairs of GRBs-SNewith a spectroscopically confirmed connection. Combining it with thewell-known relation between the peak spectral energy and the isotropicequivalent energy of GRBs, we obtain an upper limit on the isotropicenergy of GRBs, which is ~ 1052erg(LSN,peak/1043 ergs-1)10, where LSN,peak is the peakbolometric luminosity of the SNe. Our results suggest that the criticalparameter determining the GRB-SN connection is the peak luminosity ofSNe, rather than the feature of the SN spectra and/or the SN explosionenergy as commonly hypothesized. Because it is generally believed thatthe peak luminosity of SNe powered by radioactive decays is related tothe amount of 56Ni produced in the SN explosion, the mass of56Ni may be a key physical factor for understanding thenature of GRBs and their connection with SNe. Application of ourrelation to Type Ibc SNe with normal peak luminosities indicates that,if those normal SNe have GRBs accompanying them, the GRBs would beextremely soft and subenergetic in gamma-rays and, hence, easier todetect with X-ray or UV detectors than with gamma-ray detectors.
| Absolute Magnitude Distributions and Light Curves of Stripped-Envelope Supernovae
The absolute visual magnitudes of three Type IIb, 11 Type Ib, and 13Type Ic supernovae (collectively known as stripped-envelope supernovae)are studied by collecting data on the apparent magnitude, distance, andinterstellar extinction of each event. Weighted and unweighted meanabsolute magnitudes of the combined sample, as well as various subsetsof the sample, are reported. The limited sample size and theconsiderable uncertainties, especially those associated with extinctionin the host galaxies, prevent firm conclusions regarding differencesbetween the absolute magnitudes of supernovae of Types Ib and Ic, andregarding the existence of separate groups of overluminous andnormal-luminosity stripped-envelope supernovae. The spectroscopiccharacteristics of the events of the sample are considered. Three of thefour overluminous events are known to have had unusual spectra. Most butnot all of the normal-luminosity events have had typical spectra. Thelight curves of stripped-envelope supernovae are collected and compared.Because SN 1994I in M51 was very well observed, it often is regarded asthe prototypical Type Ic supernova, but it has the fastest light curvein the sample. Light curves are modeled by means of a simple analyticaltechnique that, combined with a constraint on E/M from spectroscopy,yields internally consistent values of ejected mass, kinetic energy, andnickel mass.
| The AMIGA sample of isolated galaxies. II. Morphological refinement
We present a refinement of the optical morphologies for galaxies in theCatalog of Isolated Galaxies that forms the basis of the AMIGA (Analysisof the interstellar Medium of Isolated GAlaxies) project. Uniformreclassification using the digitized POSS II data benefited from thehigh resolution and dynamic range of that sky survey. Comparison withindependent classifications made for an SDSS overlap sample of more than200 galaxies confirms the reliability of the early vs. late-typediscrimination and the accuracy of spiral subtypes within Δ T =1-2. CCD images taken at the Observatorio de Sierra Nevada were alsoused to solve ambiguities in early versus late-type classifications. Aconsiderable number of galaxies in the catalog (n = 193) are flagged forthe presence of nearby companions or signs of distortion likely due tointeraction. This most isolated sample of galaxies in the local Universeis dominated by two populations: 1) 82% are spirals (Sa-Sd) with thebulk being luminous systems with small bulges (63% between types Sb-Sc)and 2) a significant population of early-type E-S0 galaxies (14%). Mostof the types later than Sd are low luminosity galaxies concentrated inthe local supercluster where isolation is difficult to evaluate. Thelate-type spiral majority of the sample spans a luminosity rangeMB-corr = -18 to -22 mag. Few of the E/S0 population are moreluminous than -21.0 marking the absence of the often-sought superL* merger (e.g. fossil elliptical) population. The rarity ofhigh luminosity systems results in a fainter derived M* forthis population compared to the spiral optical luminosity function(OLF). The E-S0 population is from 0.2 to 0.6 mag fainter depending onhow the sample is defined. This marks the AMIGA sample as unique amongsamples that compare early and late-type OLFs separately. In othersamples, which always involve galaxies in higher density environments,M^*_E/S0 is almost always 0.3-0.5 mag brighter than M^*_S, presumablyreflecting a stronger correlation between M* andenvironmental density for early-type galaxies.
| Late-Time Radio Observations of 68 Type Ibc Supernovae: Strong Constraints on Off-Axis Gamma-Ray Bursts
We present late-time radio observations of 68 local Type Ibc supernovae,including six events with broad optical absorption lines(``hypernovae''). None of these objects exhibit radio emissionattributable to off-axis gamma-ray burst jets spreading into our line ofsight. Comparison with our afterglow models reveals the followingconclusions. (1) Less than ~10% of Type Ibc supernovae are associatedwith typical gamma-ray bursts initially directed away from our line ofsight; this places an empirical constraint on the GRB beaming factor of<~104, corresponding toan average jet opening angle, θj>~0.8d. (2) Thisholds in particular for the broad-lined supernovae (SNe 1997dq, 1997ef,1998ey, 2002ap, 2002bl, and 2003jd), which have been argued to host GRBjets. Our observations reveal no evidence for typical (or evensubenergetic) GRBs and rule out the scenario in which every broad-linedSN harbors a GRB at the 84% confidence level. Their large photosphericvelocities and asymmetric ejecta (inferred from spectropolarimetry andnebular spectroscopy) appear to be characteristic of the nonrelativisticSN explosion and do not necessarily imply the existence of associatedGRB jets.
| Observations of Supernovae in the Period 1997-1999
We present our photometric observations of the 15 supernovae (SN)discovered in the period 1997-1999; of these, six are type Ia SN, twoare peculiar type Ia SN, three are type Ib/c SN, and four are type IISN. For 11 SN, we constructed reliable light curves and determined theirmaximum brightnesses and absolute magnitudes at maximum. Based on theshapes of the light curves, we improved the classification for threetype II SN. We show that the two peculiar type Ia SN (similar to SN1991T) studied, SN 1998es and SN 1999aa, have enhanced and normalluminosities at maximum, respectively.
| Revised positions for CIG galaxies
We present revised positions for the 1051 galaxies belonging to theKarachentseva Catalog of Isolated Galaxies (CIG). New positions werecalculated by applying SExtractor to the Digitized Sky Survey CIG fieldswith a spatial resolution of 1 arcsper 2. We visually checked theresults and for 118 galaxies had to recompute the assigned positions dueto complex morphologies (e.g. distorted isophotes, undefined nuclei,knotty galaxies) or the presence of bright stars. We found differencesbetween older and newer positions of up to 38 arcsec with a mean valueof 2 arcsper 96 relative to SIMBAD and up to 38 arcsec and 2 arcsper 42respectively relative to UZC. Based on star positions from the APMcatalog we determined that the DSS astrometry of five CIG fields has amean offset in (alpha , delta ) of (-0 arcsper 90, 0 arcsper 93) with adispersion of 0 arcsper 4. These results have been confirmed using the2MASS All-Sky Catalog of Point Sources. The intrinsic errors of ourmethod combined with the astrometric ones are of the order of 0 arcsper5.Full Table 1 is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/411/391
| Rotation curves and metallicity gradients from HII regions in spiral galaxies
In this paper we study long slit spectra in the region of Hαemission line of a sample of 111 spiral galaxies with recognizable andwell defined spiral morphology and with a well determined environmentalstatus, ranging from isolation to non-disruptive interaction withsatellites or companions. The form and properties of the rotation curvesare considered as a function of the isolation degree, morphological typeand luminosity. The line ratios are used to estimate the metallicity ofall the detected HII regions, thus producing a composite metallicityprofile for different types of spirals. We have found that isolatedgalaxies tend to be of later types and lower luminosity than theinteracting galaxies. The outer parts of the rotation curves of isolatedgalaxies tend to be flatter than in interacting galaxies, but they showsimilar relations between global parameters. The scatter of theTully-Fisher relation defined by isolated galaxies is significantlylower than that of interacting galaxies. The [NII]/Hα ratios, usedas a metallicity indicator, show a clear trend between Z andmorphological type, t, with earlier spirals showing higher ratios; thistrend is tighter when instead of t the gradient of the inner rotationcurve, G, is used; no trend is found with the change in interactionstatus. The Z-gradient of the disks depends on the type, being almostflat for early spirals, and increasing for later types. The[NII]/Hα ratios measured for disk HII regions of interactinggalaxies are higher than for normal/isolated objects, even if all thegalaxy families present similar distributions of Hα EquivalentWidth. Tables 3 and 4 and Figs. 6, 7 and 21 are only available inelectronic form at http://www.edpsciences.org. Table 5 is only availablein electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr(130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/393/389 Based on dataobtained Asiago/Ekar Observatory. Also based on observations made withINT operated on the island of La Palma by ING in the SpanishObservatorio del Roque de Los Muchachos of the Instituto deAstrofísica de Canarias.
| The Second Kiso Survey for ultraviolet-excess galaxies. III
The catalogue list and the identification chart of ultraviolet(UV)-excess galaxies which have been detected on two-color Kiso Schmidtplates are presented for 10 Schmidt fields. Catalogued are 710 objects,down to the photographic magnitude ~17.5 in the sky area of some 300square degrees. The total number of KUGs newly detected in the secondsurvey reaches 1,642.
| A Hubble Space Telescope Snapshot Survey of Nearby Supernovae
We present photometry of 13 recent supernovae (SNe) recovered in aHubble Space Telescope Snapshot program and tie the measurements toearlier ground-based observations in order to study the late-timeevolution of the SNe. Many of the ground-based measurements arepreviously unpublished and were made primarily with a robotic telescope,the Katzman Automatic Imaging Telescope. Evidence for circumstellarinteraction is common among the core-collapse SNe. Late-time declinerates for Type IIn SNe are found to span a wide range, perhaps becauseof differences in circumstellar interaction. An extreme case, SN IIn1995N, declined by only 1.2 mag in V over about 4 yr followingdiscovery. Template images of some SNe must therefore be obtained manyyears after the explosion if contamination from the SN itself is to beminimized. Evidence is found against a previous hypothesis that the TypeIIn SN 1997bs was actually a superoutburst of a luminous blue variablestar. The peculiar SN Ic 1997ef, a ``hypernova,'' declined very slowlyat late times. The decline rate of the SN Ia 2000cx decreased at latetimes, but this is unlikely to have been caused by a light echo.Partially based on observations with the NASA/ESA Hubble SpaceTelescope, obtained at the Space Telescope Science Institute, which isoperated by the Association of Universities for Research in Astronomy(AURA), Inc., under NASA contract NAS 5-26555.
| Optical Spectroscopy of Type IB/C Supernovae
We present 84 spectra of Type Ib/c and Type IIb supernovae (SNe),describing the individual SNe in detail. The relative depths of thehelium absorption lines in the spectra of the SNe Ib appear to provide ameasurement of the temporal evolution of the SN, with He I λ5876and He I λ7065 growing in strength relative to He I λ6678over time. Light curves for three of the SNe Ib provide a sequence forcorrelating the helium line strengths. We find that some SNe Ic showevidence for weak helium absorption, but most do not. Aside from thepresence or absence of the helium lines, there are other spectroscopicdifferences between SNe Ib and SNe Ic. On average, the O I λ7774line is stronger in SNe Ic than in SNe Ib. In addition, the SNe Ic havedistinctly broader emission lines at late times, indicating aconsistently larger explosion energy and/or lower envelope mass for SNeIc than for SNe Ib. While SNe Ib appear to be basically homogeneous, theSNe Ic are quite heterogeneous in their spectroscopic characteristics.Three SNe Ic that may have been associated with gamma-ray bursts arealso discussed; two of these have clearly peculiar spectra, while thethird seems fairly typical.
| A Spectroscopic Analysis of the Energetic Type Ic Hypernova SN 1997EF
The properties of the bright and energetic Type Ic SN 1997ef areinvestigated using a Monte Carlo spectrum synthesis code. Analysis ofthe earliest spectra is used to determine the time of outburst. Thechanging features of the spectrum and the light curve are used to probethe ejecta and to determine their composition, verifying the results ofexplosion calculations. Since synthetic spectra computed using our bestexplosion model, CO100, are only moderately good reproductions of theobservations, the inverse approach is adopted, and a density structureis derived by demanding that it gives the best possible fit to theobserved spectrum at every epoch analyzed. It is found that the densitystructure of model CO100 is adequate at intermediate velocities(5000-25,000 km s-1), but that a slower density decline(ρ~r-4) is required to obtain the extensive line blendingat high velocities (25,000-50,000 km s-1) that is thecharacterizing feature of this and other energetic Type Ic Supernovae.Also, the inner ``hole'' in the density predicted by the model is foundnot to be compatible with the observed evolution of the spectrum, whichreaches very low photospheric velocities at epochs of about 2 months.The ``best-fit'' density distribution results in somewhat differentparameters for the SN, namely an ejecta mass of 9.6 Msolar(vs. 7.6 Msolar in CO100) and an explosion kinetic energy of1.75×1052 ergs (vs. 8×1051 ergs inCO100). This revised value of the kinetic energy brings SN 1997ef closerto the value for the ``prototypical'' Type Ic hypernova SN 1998bw. Theabundance distribution of model CO100 is found to hold well. Themodified density structure is used to compute a synthetic light curve,which is found to agree very well with the observed bolometric lightcurve around maximum. The amount of radioactive 56Ni producedby the SN is confirmed at 0.13 Msolar. In the context of anaxisymmetric explosion, a somewhat smaller kinetic energy than that ofSN 1998bw may have resulted from the nonalignment of the symmetry axisof the SN and the line of sight. This might also explain the lack ofevidence for a gamma-ray burst correlated with SN 1997ef.
| The Peculiar Type IC Supernova 1997EF: Another Hypernova
SN 1997ef has been recognized as a peculiar supernova from its lightcurve and spectral properties. The object was classified as a Type Icsupernova (SN Ic) because its spectra were dominated by broad absorptionlines of oxygen and iron, lacking any clear signs of hydrogen or heliumline features. The light curve is very different from that of previouslyknown SNe Ic, showing a very broad peak and a slow tail. The strikinglybroad line features in the spectra of SN 1997ef, which were also seen inthe hypernova SN 1998bw, suggest the interesting possibility that SN1997ef may also be a hypernova. The light curve and spectra of SN 1997efwere modeled first with a standard SN Ic model assuming an ordinarykinetic energy of explosion EK=1051 ergs. Theexplosion of a CO star of mass MCO~6 Msolar givesa reasonably good fit to the light curve but clearly fails to reproducethe broad spectral features. Then, models with larger masses andenergies were explored. Both the light curve and the spectra of SN1997ef are much better reproduced by a C+O star model withEK=8×1051 ergs and MCO=10Msolar. Therefore, we conclude that SN 1997ef is very likelya hypernova on the basis of its kinetic energy of explosion. Finally,implications for the deviation from spherical symmetry are discussed inan effort to improve the fits to the observations.
| 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.
| A hypernova model for the peculiar type Ic supernova 1997ef
There have been an increasing number of candidates for the gamma-raybursts/supernovae connection. Among these, the Type Ic SN 1998bw and theType IIn SN 1997cy are characterized by their extremely large explosionenergy, well in excess of 1052 erg, and thus have been calledhypernovae. Here we suggest that the peculiar Type Ic SN 1997ef isanother hypernova.
| Supernovae
IAUC 6823 available at Central Bureau for Astronomical Telegrams.
| Supernova 1997ef in UGC 4107
IAUC 6820 available at Central Bureau for Astronomical Telegrams.
| Supernovae
IAUC 6803 available at Central Bureau for Astronomical Telegrams.
| Supernova 1997ef in UGC 4107
IAUC 6798 available at Central Bureau for Astronomical Telegrams.
| Supernova 1997ef in UGC 4107.
Not Available
| Possible Supernova in UGC 4107
IAUC 6778 available at Central Bureau for Astronomical Telegrams.
| 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 extended 12 micron galaxy sample
We have selected an all-sky (absolute value of b greater than or equalto 25 deg) 12 micron flux-limited sample of 893 galaxies from the IRASFaint Source Catalog, Version 2 (FSC-2). We have obtained accurate totalfluxes in the IRAS wavebands by using the ADDSCAN procedure for allobjects with FSC-2 12 micron fluxes greater than 0.15 Jy and increasingflux densities from 12 to 60 microns, and defined the sample by imposinga survey limit of 0.22 Jy on the total 12 micron flux. Its completenessis verified, by means of the classical log N - log S andV/Vmax tests, down to 0.30 Jy, below which we have measuredthe incompleteness down to the survey limit, using the log N - log Splot, for our statistical analysis. We have obtained redshifts (mostlyfrom catalogs) for virtually all (98.4%) the galaxies in the sample.Using existing catalogs of active galaxies, we defined a subsample of118 objects consisting of 53 Seyfert 1s and quasars, 63 Seyfert 2s, andtwo blazars (approximately 13% of the full sample), which is the largestunbiased sample of Seyfert galaxies ever assembled. Since the 12 micronflux has been shown to be about one-fifth of the bolometric flux forSeyfert galaxies and quasars, the subsample of Seyferts (includingquasars and blazars) is complete not only to 0.30 Jy at 12 microns butalso with respect to a bolometric flux limit of approximately 2.0 x10-10 ergs/s/sq cm. The average value of V/Vmaxfor the full sample, corrected for incompleteness at low fluxes, is 0.51+/- 0.04, expected for a complete sample of uniformly distributedgalaxies, while the value for the Seyfert galaxy subsample is 0.46 +/-0.10. We have derived 12 microns and far-infrared luminosity functionsfor the AGNs, as well as for the entire sample. We extracted from oursample a complete subsample of 235 galaxies flux-limited (8.3 Jy) at 60microns. The 60 micron luminosity function computed for this subsampleis in satisfactory agreement with the ones derived from the brightgalaxy sample (BGS) and the deep high-galactic latitude sample, bothselected at 60 microns.
| A 21 CM survey of the Pisces-Perseus supercluster. III - The region north of +38 degrees
As part of a comprehensive survey of galaxies in the region of thePisces-Perseus supercluster and its surroundings, 21-cm lineobservations obtained with the NRAO 91-m telescope are presented for 383galaxies in the right ascension range from 22 to 10 hr and north of +38deg declination. Recent improvements to the Green Bank receiver/feedsystem have dramatically raised detection rates at the distance ofPisces-Perseus (cz = +5000 km/s). The present study has contributed todouble the number of known redshifts outside rich clusters in thissection of the sky. The H I content of the current sample, as expressedin terms of the H I mass expected for a galaxy of the same optical sizeand morphology, matches the standard of normalcy established forisolated galaxies.
| A 21 centimeter line survey of a complete sample of interacting and isolated galaxies
The paper presents 21 cm line observations of a complete sample ofinteracting and isolated galaxies made with the National Radio AstronomyObservatory 91 and 43 m telescopes and the Arecibo 3035 m telescope. The21 cm line data are combined with a homogeneous set of optical data onangular diameters, axial ratios, magnitudes, and colors, and integralproperties are calculated for the galaxies in both samples. In thispaper, the sample selection procedures, the method of observation, thedata reduction, and the observational errors are described. Thedetection percentages are presented for both samples.
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