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Star Formation in a Complete Spectroscopic Survey of Galaxies
The 15R-North galaxy redshift survey is a uniform spectroscopic survey(S/N~10) covering the range 3650-7400 Å for 3149 galaxies withmedian redshift 0.05. The sample is 90% complete to R=15.4. The medianslit covering fraction is 24% of the galaxy, apparently sufficient tominimize the effects of aperture bias on the EW(Hα). Forty-ninepercent of the galaxies in the survey have one or more emission linesdetected at >=2 σ. In agreement with previous surveys, thefraction of absorption-line galaxies increases steeply with galaxyluminosity. We use Hβ, [O III], Hα, and [N II] todiscriminate between star-forming galaxies and AGNs. At least 20% of thegalaxies are star-forming, at least 17% have AGN-like emission, and 12%have unclassifiable emission. The unclassified 12% may include a``hybrid'' population of galaxies with both star formation and AGNactivity. The AGN fraction increases steeply with luminosity; thefraction of star-forming galaxies decreases. We use the EW(Hα+[NII]) to estimate the Scalo birthrate parameter, b, the ratio of thecurrent star formation rate to the time averaged star formation rate.The median birthrate parameter is inversely correlated with luminosityin agreement with the conclusions based on smaller samples (Kennicutt,Tamblyn, & Congdon). Because our survey is large, we identify 33vigorously star-forming galaxies with b>3. We confirm the conclusionof Jansen, Franx, & Fabricant that EW([O II]) must be used withcaution as a measure of current star formation. Finally, we examine theway galaxies of different spectroscopic type trace the large-scalegalaxy distribution. As expected the absorption-line fraction decreasesand the star-forming emission-line fraction increases as the galaxydensity decreases. The AGN fraction is insensitive to the surroundinggalaxy density; the unclassified fraction declines slowly as the densityincreases. For the star-forming galaxies, the EW(Hα) increasesvery slowly as the galaxy number density decreases. Whether a galaxyforms stars or not is strongly correlated with the surrounding galaxydensity averaged over a scale of a few Mpc. This dependence reflects, inlarge part, the morphology-density relation. However, for galaxiesforming stars, the stellar birthrate parameter is remarkably insensitiveto the galaxy density. This conclusion suggests that the triggering ofstar formation occurs on a smaller spatial scale.
| On the local radio luminosity function of galaxies. II. Environmental dependences among late-type galaxies
Using new extensive radio continuum surveys at 1.4 GHz (FIRST and NVSS),we derive the distribution of the radio/optical and radio/NIR luminosity(RLF) of late-type (Sa-Irr) galaxies (m_p<15.7) in 5 nearby clustersof galaxies: A262, Cancer, A1367, Coma and Virgo. With the aim ofdiscussing possible environmental dependences of the radio properties,we compare these results with those obtained for relatively isolatedobjects in the Coma supercluster. We find that the RLF of Cancer, A262and Virgo are consistent with that of isolated galaxies. Conversely weconfirm earlier claims that galaxies in A1367 and Coma have their radioemissivity enhanced by a factor ~ 5 with respect to isolated objects. Wediscuss this result in the framework of the dynamical pressure sufferedby galaxies in motion through the intra-cluster gas (ram-pressure). Wefind that the radio excess is statistically larger for galaxies in fasttransit motion. This is coherent with the idea that enhanced radiocontinuum activity is associated with magnetic field compression. TheX-ray luminosities and temperatures of Coma and A1367 imply that thesetwo clusters have significantly larger intracluster gas density than theremaining three studied ones, providing a clue for explaining the higherradio continuum luminosities of their galaxies. Multiple systems in theComa supercluster bridge (with projected separations smaller than 300kpc) have radio luminosities significantly larger than isolatedgalaxies. 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/Abstract.html}
| 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.
| Imaging and Spectroscopic Observations of the Case Survey Blue/Emission- Line Galaxies
We present CCD imaging and spectroscopic data for 176 blue and/oremission-line galaxies from Lists I and II of the Case Northern SkySurvey. Our sample consists of all Case galaxies which lie in the regionwhich overlaps the original Slice of the Universe survey. We use theobservational data to investigate the physical properties of thegalaxies selected by the survey, to compare with various parameterspublished in the survey lists, and to investigate the selectioncharacteristics and completeness limit of the survey. The majority ofthe Case galaxies are energized by regions of active star formation;only 5% of the sample are Seyfert galaxies. The dual selectiontechniques used (both UV-excess and emission lines) allow the survey todetect star-forming galaxies with a wide range of properties andevolutionary states. In particular, the Case survey selects galaxieswith lower levels of activity than most previous surveys. The surveyalso includes a larger fraction of intermediate and low-luminositygalaxies than would be present in a purely magnitude- limited sample.Although galaxies as faint as m_B_ = 19 are present in the sample, thecompleteness limit of the UV-excess selected portion of the survey iscloser to m_B_ = 16. The luminosity function of the Case galaxies isderived and compared with that of the "normal" field galaxies in thesame volume of space. The shape of the Case luminosity function issimilar to that for the field sample. A surprising result is that 31% ofthe field galaxy population can be accounted for by galaxies of the typeselected in the Case survey.
| KISO survey for ultraviolet-excess galaxies. XV
The fifteenth list and identification charts of the ultraviolet-excessgalaxies are presented. These galaxies were detected on the multicolorplates taken with the Kiso Schmidt telescope for 10 survey fields. Inthe sky area of 300 square degrees 544 objects are cataloged down to thephotographic magnitude of about 17.5.
| A catalog of Markarian galaxies
A catalog of Markarian galaxies is presented which tabulates redshifts,spectral and morphological classifications, magnitudes, infrared andradio flux densities, and over 600 references to available datapublished before January 1, 1986. Redshifts are now available for 1228objects with strong ultraviolet continua, and follow-up spectroscopicand photometric observations of Markarian galaxies have providedclassifications of 115 Seyfert 1, 43 Seyfert 2, and 137 starburst and HII-type galaxies. After a description of the Markarian survey and thecurrent catalog, a summary of the general results obtained from the datais presented. A preliminary study of the infrared properties ofMarkarian galaxies as measured by IRAS reveals a number of interestingresults, including the existence of a sample of elliptical andlenticular galaxies with appreciable infrared emission.
| On the relation of Markarian galaxies with Zwicky clusters. I - Data
In the area covered by the survey of Markarian et al. (1967-1981) andthe CGCG of Zwicky et al. (1961-1968) there are 1344 Markarian galaxies,of which 597 are positioned inside the contours of Zwicky clusters. Dataon these galaxies and respective clusters are presented in differenttables, according to whether they are galaxies which are members ofclusters, or probable or possible members; projection cases areconsidered separately.
| The case low-dispersion northern sky survey. II
Attention is given to objects, whose blue magnitudes range from 11 to18, which were found on low dispersion objective prism plates taken withthe Burrell Schmidt-type telescope at Kitt Peak. Positions, estimatedmagnitudes, and finding charts are presented for 125 blue and/oremission-line galaxies, 120 blue and/or emission line stellar objects(including QSO candidates), and 38 known and probable blue stars.
| Accurate optical positions for Markarian objects 701-797
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980AJ.....85.1328F&db_key=AST
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