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A sample of X-ray emitting normal galaxies from the BMW-HRI Catalogue
We obtained a sample of 143 normal galaxies with X-ray luminosity in therange 1038{-}1043 erg s-1 from thecross-correlation of the ROSAT HRI Brera Multi-scale Wavelet (BMW-HRI)Catalogue with the Lyon-Meudon Extragalactic Database (LEDA). We findthat the average X-ray properties of this sample are in good agreementwith those of other samples of galaxies in the literature. We selected acomplete flux limited serendipitous sample of 32 galaxies from which wederived the log N-log S distribution of normal galaxies in the fluxrange 1.1{-} 110 × 10-14 erg cm-2s-1. The resulting distribution is consistent with theEuclidean -1.5 slope. Comparisons with other samples, such as theExtended Medium Sensitivity Survey, the ROSAT All Sky Survey, theXMM-Newton/2dF survey, and the Chandra Deep Field Survey indicate thatthe log N -log S distribution of normal galaxies is consistent with aEuclidean slope over a flux range of about 6 decades.
| 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.
| The Arizona-New Mexico Spectroscopic Survey of Galaxies. I. Data for the Western End of the Perseus Supercluster
We present new optical spectroscopic data for 347 galaxies in the regionof the Perseus supercluster. The new data were obtained using theSteward Observatory 2.3 m telescope and cover the whole optical window.Included are redshifts (for 345 objects), absorption-line equivalentwidths, a continuum index measuring the 4000 Å break, andemission-line flux ratios. After 11 objects are rejected for being toofaint and redshifts for 26 objects are added from the literature, wearrive at a complete sample of 361 galaxies. The distribution ofredshifts for the whole sample is examined, and we show the relationshipof the continuum index to morphology.
| 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.
| Groups of galaxies. III. Some empirical characteristics.
Not Available
| Optical Morphology of Bright Quasars on Images Taken With 1.2 M Schmidt Cameras
The optical morphology of bright extragalactic objects listed by Greenet at. [ApJS, 61,305 (1986)] is determined on Palomar Observatory SkySurvey prints. Morphological types are assigned according to whetherobjects appear resolved or unresolved. These are plotted in the HubbleDiagram. When combined with previous results from the Medium-BrightQuasar Survey (MBQS), objects of redshift z are found to be unresolvedon 1.2 m Schmidt telescopes at apparent magnitudes brighter than B = 21- 3/4z over a large magnitude range 12.5 < B < 18.5. A luminositycutoff for unresolved objects in this range is found to be M_B_ = -24,(H_0_ = 50), in agreement with an earlier estimate. Relevance to thesearch for large, bright, host galaxies, and for "naked quasar"candidates, is noted.
| 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.
| 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.
| The small scale environment of low surface brightness disk galaxies
We use a sample of about 340 low surface brightness (LSB) disk galaxieswith measured redshifts in combination with the Center for Astrophysicsredshift survey to test the hypothesis that LSB galaxies have a deficitof nearby companion galaxies compared to high surface brightness (HSB)disk galaxies. We find a very strong statistical deficit of galaxieslocated within a projected radius of 0.5 Mpc and within a velocity of500 km/s around LSB disk galaxies compared to HSB ones. Further,comparing LSB and HSB disk galaxies which are located in the sameportion of the sky indicates that the average distance to the nearestneighbor is 1.7 times farther for LSB disk galaxies. AKomologorov-Smirnoff test rules out, at greater than the 99 percentconfidence level, the hypothesis that the distribution ofnearest-neighbor distances is the same for HSB and LSB disk galaxies. Wespeculate that LSB disk galaxies have relatively long formation timescales and therefore must form in relative isolation. In addition, thelack of tidal interactions over a Hubble time serves to suppress theoverall star-formation rate as no external trigger is available to helpclump the gas. The observed low surface densities of H I in combinationwith the low probability of tidal interactions effectively preventsthese disk galaxies from evolving very rapidly.
| UBV photometry of galaxies in group and their neighborhood. The Geller-Huchra group GH 3.
Not Available
| 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.
| Optical spectra of narrow emission line Palomar-Green galaxies
Spectra were obtained of 35 of the 36 narrow emission line galaxiesisolated in the Palomar-Green (PG) survey of Green, Schmidt, and Liebert(1986). Of these, three are narrow-line Seyfert 1 galaxies, three moreare Seyfert 1.5 galaxies, and only one, PG 2259 + 157 = NGC 7465 = Mrk313, is a relatively low-ionization active galactic nucleus, a marginalSeyfert 2 with forbidden O III line 5007/H-beta of about 3. The rest areH II region galaxies, as is CSO 177, a candidate Seyfert 2 galaxy notpreviously observed at H-alpha. Redshifts and relative emission-linestrengths are given for all these galaxies. These spectra confirm that asurvey such as the PG, based on ultraviolet excesses, though good forfinding QSOs, is not well suited for finding Seyfert 2 galaxies.However, the PG survey shows that a significant number of Seyfert 1galaxies are 'narrow-line' objects with H I emission-line full widths athalf-maximum equal to or less than 2000 km/s.
| The Palomar-Green catalog of ultraviolet-excess stellar objects
The Palomar-Green Catalog of Ultraviolet Excess Stellar Objects ispresented, with data consisting of positions on the sky accurate toabout 8 arcsec in each coordinate, photographic B-magnitudes accurate to0.29 mag, spectral types, some cross references, and photoelectricbroadband, multichannel, and Stromgren colors when available. Extensivediscussion is given on magnitude calibration using a combination ofphotoelectric measurements and star count modeling, and on thestatistical completeness of the sample based on internal and externaltests. Of the 1874 objects in the catalog, 1715 comprise a statisticallycomplete sample covering 10,714 square degrees from 266 fields taken onthe Palomar 18-inch (46-cm) Schmidt telescope. Limiting magnitudes varyfrom field to field, distributed around B = 16.1 mag, ranging from 15.49to 16.67. The dominant population is that of the hot, hydrogenatmosphere subdwarfs, the sdB stars, which comprise nearly 40 percent ofthe sample. At 16th magnitude, the hot subdwarf (sdB, sdO) number countsare increasing by about a factor of 2 per mag, the hot white dwarfs by 4per mag, and quasars by 8 per mag. The result is a very different mix ofspectral types expected at 18th mag than is found at 16th mag. Thesuggestion is made that the sdB stars are part of the old disk ratherthan a halo population.
| A 21 CM survey of the Pisces-Perseus supercluster. II - The declination zone +21.5 to +27.5 degrees
Neutral-hydrogen 21-cm line spectra and derived parameters are presentedfor a sample of spiral galaxies in the region bounded by an R.A. greaterthan 22 h and less then 0.04 h, and a declination greater than +21 deg30 min and less than +27 deg 30 min, covering the Zwicky fields 470 to488, as the second installment of a survey of the region of thePisces-Perseus supercluster. New H I line observations made with theArecibo 305 m telescope detected 275 galaxies of 318 studied. Atabulation of derived galaxian properties is given. The redshiftdistribution shows gross departures from that expected for a sample withsimilar magnitude characteristics but homogeneously located in space.These new data will be incorporated into the overall survey of thethree-dimensional structure in the Pisces-Perseus region.
| A search for environmental effects on the optical properties of galaxies in groups
Environmental density-related modifications of basic optical properties(luminosities, sizes, axial ratios, and colors) of galaxies belonging toGeller and Huchra's (1983) groups have been investigated. Remarkably, itis found that the broad maxima of the distributions of luminosities anddiameters of spirals and the whole corresponding distributions oflenticulars tend to move to lower values as one goes to groups of highcompactness, whereas the luminosity-diameter relationship of spiralstends to become flatter. No color and axial ratio differences betweengalaxies of high- and low-compactness groups have been detected.
| 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.
| Groups of galaxies. III - The CfA survey
A statistically homogeneous group catalog (CfA) is based on the CfAredshift survey (Huchra et al.) is presented. Groups in the catalog areall density enhancements in redshift space of a factor greater than 20.Group members are identified according to the procedure described in aprevious study (Huchra and Geller) of a shallower whole-sky sample. Allgroups contain at least three members. Of the 176 groups in the CfAcatalog, 102 have been identified in one or more previous studies.Because the utilized algorithm searches for volume rather than surfacedensity enhancements, the groups in a given region generally change onlythrough the addition of fainter members when the magnitude limit of thegalaxy catalog increases. In the region of overlap, agreement betweenthe shallow catalog and the CfA catalog is excellent.
| The south west extension of the Perseus supercluster
The results of a redshift survey of the extreme southwest region of thePerseus supercluster (270 square degrees between R.A. 23 hr 20 min and01 hr 00 min, and between DEC 21 deg 30 min and 33 deg 30 min) arepresented. By studying the velocity distribution of 93 galaxies withmagnitude 14.5, the presence of a population of galaxies with velocity5240 km/sec and radial dispersion of 312 km/sec indicates the furtherextension of the Perseus supercluster. In addition, background galaxieswith a mean velocity of 10,000 km/sec common to this sample areprimarily organized in a structure connected with Abell clusters ofsimilar velocities. Finally, it is shown that the apparent magnitudes ofthe brightest galaxies tend to increase with velocity, implying that atleast a fraction of the velocity dispersion is determined by a Hubbleflow within the supercluster.
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