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Публикации по объекту
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.
| Galaxy coordinates. II. Accurate equatorial coordinates for 17298 galaxies
Using images of the Digitized Sky Survey we measured coodinates for17298 galaxies having poorly defined coordinates. As a control, wemeasured with the same method 1522 galaxies having accurate coordinates.The comparison with our own measurements shows that the accuracy of themethod is about 6 arcsec on each axis (RA and DEC).
| Galaxies with f12 > f25
We have compiled a sample of galaxies whose flux density is higher at 12microns (f12) than at 25 microns (f25). It is argued thatf12 >f25effectively selects quiescent galaxies which are less active ininfrared, radio, and optical bands than other types of normal galaxies.Moreover galaxies withf12 >f25 do not exhibit the well-knownrelations that normal galaxies show between far-infrared parameters, forexample, the negative correlation betweenf12/f25 andf60/f100. Thesegalaxies also show different far-infrared and radio properties. In ouropinion this sample of quiescent galaxies is suitable for use as acontrol sample when properties of more active galaxies are discussed. Itmay also be used in modeling galaxies with active star formation or anactive nucleus.
| 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.
| The velocity-distance relation for galaxies on a bubble
The characteristic diameter of the most prominent void in the redshiftsurvey of de Lapparent et al. (1986) is measured. Distances and peculiarvelocities to individual galaxies are derived, and it is shown that thevoid is approximately a 'Hubble Bubble' in which the near and far edgesare separating with the general expansion of the universe. At the 3sigma level, infall toward the Coma cluster is detected for a portion ofthe bubble wall. Limits on the net outflow from the void and infall intoComa are used to estimate Omega.
| 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.
| High-luminosity IRAS galaxies. II - Optical spectroscopy, modelling of starburst regions and comparison with structure
Moderate-resolution spectrophotometry was used to obtain variousemission-line ratios and emission-line luminosities for a completesample of predominantly high-luminosity IRAS galaxies. Most of theobjects exhibit H II region-like spectra, while about 12 percent areSeyferts or LINERs. The results show the IRAS galaxies to be of lowerionization than an optically selected sample of H II region-likegalaxies, possibly due to either high metallicities or to their highdust content. Although the estimated number of O stars present isconsistent with the observed emission-line flux, the IR to emission-lineluminosity ratio of all the IRAS galaxies is very high. The presentobservations can be reconciled using a model with two types of regions,type I clouds (with extinctions of about 20) representing very recentstar formation, and type II clouds (with extinctions of about 1)representing older starburst and/or general disk star formation.
| High-luminosity IRAS galaxies. I - The proportion of IRAS galaxies in interacting systems
An analysis of CCD images of a sample of 60 high-luminosity IRASgalaxies from the redshift survey of Lawrence et al. (1986) and of acontrol sample of 87 optically selected galaxies from the Durhamredshift survey (Peterson et al., 1986) is presented. It is found that18 + or - 5 percent of the optically selected galaxies are interactingor merging systems, and that 11 + or - 8 percent of the low-luminosityIRAS galaxies are interacting or merging. At high luminosities, theproportion is shown to be 46 + or - 12 percent. The results suggest thatalthough galaxy interaction is a common causal factor in luminous IRactivity, it is far from being the ubiquitous factor suggested in recentreports.
| Study of a field in the Coma supercluster. I - Automated galaxies count
A IIIaJ Palomar Schmidt plate of the eastern end of a filament ofgalaxies found by Fontanelli (1984) in the Coma cluster region has beenexamined. The galaxy selection was performed using a classical Bayesianclassification based on the diagram of integrated density versus thearea, allowing all the nonstellar objects to be identified. Coordinates,amplitudes, areas in pixels, and morphological types are given for 7582galaxies. A real-time reduction technique for image segmentation is usedto identify galaxy condensations, and estimations of the parameters,position, axis, and orientation of these condensations are presented.
| A study of a flux-limited sample of IRAS galaxies
Redshift data and accurate four-color infrared photometry are presentedfor a complete IRAS sample of galaxies brighter than 2 Jy at 60 microns.A simple power law provides a good fit to the distribution forluminosities from 10 to the 10th to 10 to the 12th solar. There is noindication of an exponential dropoff in the luminosity function at highenergies. A flattening of the luminosity function occurs at L less than10 to the 20th solar. The highest luminosity galaxies typically arefound in multiple, possibly interacting, systems and exhibit marginallynarrower infrared spectral energy distributions than the isolatedspirals which predominate at low luminosities. Infrared-bright galaxiescome from a different population than the majority of optically brightgalaxies. In particular, galaxies of low blue luminosity are not stronginfrared emitters.
| KISO survey for ultraviolet-excess galaxies. VI.
Not Available
| The optical luminosity function of a 60-micron flux-limited sample of IRAS galaxies
A determination is made of the optical luminosity function (OPLF) of aninfrared flux-limited sample of IRAS galaxies. The sample includes 92objects; among these are an infrared-loud quasar and two previouslyknown Seyferts. The OPLF of the IRAS galaxies in the sample shows thatin the magnitude range between -22 and 18, IRAS galaxies represent about15 percent of field galaxies. At low luminosities, Mj greater than -19mag, there may be a deficiency of IRAS galaxies relative to the fieldgalaxies. The far-IR luminosity function of the sample is also derived;it agrees well with other determinations.
| 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.
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