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מאמרים קשורים
A Digital Archive of H I 21 Centimeter Line Spectra of Optically Targeted Galaxies
We present a homogeneous compilation of H I spectral parametersextracted from global 21 cm line spectra for some 9000 galaxies in thelocal universe (heliocentric velocity-200
| 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 QDOT all-sky IRAS galaxy redshift survey
We describe the construction of the QDOT survey, which is publiclyavailable from an anonymous FTP account. The catalogue consists ofinfrared properties and redshifts of an all-sky sample of 2387 IRASgalaxies brighter than the IRAS PSC 60-μm completeness limit(S_60>0.6Jy), sparsely sampled at a rate of one-in-six. At |b|>10deg, after removing a small number of Galactic sources, the redshiftcompleteness is better than 98per cent (2086/2127). New redshifts for1401 IRAS sources were obtained to complete the catalogue; themeasurement and reduction of these are described, and the new redshiftstabulated here. We also tabulate all sources at |b|>10 deg with noredshift so far, and sources with conflicting alternative redshiftseither from our own work, or from published velocities. A list of 95ultraluminous galaxies (i.e. with L_60μm>10^12 L_solar) is alsoprovided. Of these, ~20per cent are AGN of some kind; the broad-lineobjects typically show strong Feii emission. Since the publication ofthe first QDOT papers, there have been several hundred velocity changes:some velocities are new, some QDOT velocities have been replaced by moreaccurate values, and some errors have been corrected. We also present anew analysis of the accuracy and linearity of IRAS 60-μm fluxes. Wefind that the flux uncertainties are well described by a combination of0.05-Jy fixed size uncertainty and 8per cent fractional uncertainty.This is not enough to cause the large Malmquist-type errors in the rateof evolution postulated by Fisher et al. We do, however, find marginalevidence for non-linearity in the PSC 60-μm flux scale, in the sensethat faint sources may have fluxes overestimated by about 5per centcompared with bright sources. We update some of the previous scientificanalyses to assess the changes. The main new results are as follows. (1)The luminosity function is very well determined overall but is uncertainby a factor of several at the very highest luminosities(L_60μm>5x10^12L_solar), as this is where the remainingunidentified objects are almost certainly concentrated. (2) Thebest-fitting rate of evolution is somewhat lower than our previousestimate; expressed as pure density evolution with density varying as(1+z)^p, we find p=5.6+/-2.3. Making a rough correction for the possible(but very uncertain) non-linearity of fluxes, we find p=4.5+/-2.3. (3)The dipole amplitude decreases a little, and the implied value of thedensity parameter, assuming that IRAS galaxies trace the mass, isΩ=0.9(+0.45, -0.25). (4) Finally, the estimate of density varianceon large scales changes negligibly, still indicating a significantdiscrepancy from the predictions of simple cold dark matter cosmogonies.
| Large-Scale Structure at Low Galactic Latitude
We have extended the CfA Redshift Survey to low galactic latitudes toinvestigate the relation between the Great Wall in the North GalacticCap and the Perseus-Pisces chain in the South Galactic Cap. We presentredshifts for 2020 galaxies in the Catalogue of Galaxies and of Clustersof Galaxies (Zwicky et al. 1961-68, CGCG) in the following regions: 4^h^<= α <= 8^h^, 17^h^ <= α <= 20^h^, 0^deg^ <=δ <= 45^deg^. In these regions, the redshift catalogue includes1664 galaxies with B(0) <= 15.5 (of which 820 are newly measured) andis 97% complete. We also include redshifts for an additional 356galaxies in these regions with B(O) > 15.5; of these, 148 werepreviously unmeasured. The CGCG samples the galaxy distribution down tob_II_ = 10^deg^. In this paper, we discuss the acquisition and reductionof the spectra, and we examine the qualitative features of the redshiftdistribution. The Great Wall and the Perseus-Pisces chain are not simplyconnected across the Zone of Avoidance. These structures, which at firstappear to be coherent on scales of ~100 h^-1^ Mpc or more, actually formthe boundaries of neighboring voids of considerably smaller scale,approximately 50h^-1^ Mpc. The structures delineated by ouroptically-selected sample are qualitatively similar to those detected bythe far-infrared-selected IRAS 1.2 Jansky Survey (Fisher et al. 1995).Although the IRAS survey probes more deeply into the Zone of Avoidance,our optically-selected survey provides better sampling of structures atb_II_ >= 10^deg^.
| 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.
| Large-Scale Structures in the Zone of Avoidance: The Galactic Anticenter Region
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995ApJ...449..527L&db_key=AST
| The Tully-Fisher relation of the IRAS minisurvey galaxies
We investigated the possible influence on the Tully-Fisher relation ofactive massive star formation in IRAS galaxies, in order to estimate thecontribution of star formation to their near-infrared luminosity. Weobserved 60 galaxies from the infrared complete so- called IRASMinisurvey sample in the 21 cm H1 line at Arecibo, determined thenear-infrared (H-band) Tully-Fisher relation for the 36 objects in thesample we judged to be usable for this purpose, and compared thisrelation with that of optically selected normal galaxies. The resultsshow no significant enhancement of the near- infrared luminosities ofthe IRAS Minisurvey galaxies compared to those of the optically selectednormal glaxies. From these results we inferred that in the minisurveygalaxies the average contribution of the active massive star formationto the total near-infrared luminosity is less and that exponential decaytimes for the starbursts occurring in the Minisurvey galaxies are of theorder of 10 Myr. The Tully-Fisher relation shows one exceptional galaxy(IRAS 03565+2139) with an about 25 times higher luminosity than averagefor its rotational velocity.
| 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 radio properties of galaxies with high far-infrared luminosities
Observations have been made with the Very Large Array, mainly at 5 GHz,of a sample of galaxies with high far-infrared luminosities selectedfrom the Infrared Astronomical Satellite (IRAS) minisurvey. The surfacebrightnesses of the minisurvey sources are greater than those of thedisks of normal galaxies but are similar to those of the central radiosources in these galaxies; the minisurvey sources, however, have muchlarger luminosities and physical sizes than these central sources. Onthe basis of the available data at all wavelengths, it is concluded thatthe far-infrared and radio emission from the minisurvey galaxies iscaused by star formation, not by active nuclei. It is found that thesize of the radio source is inversely correlated with the 60-100 microncolor temperature but is independent of the far-infrared luminosity.
| A further study of the relation of the radio-far-infrared in galaxies. I - Observations and data processing
The radio luminosities of 99 galaxies at 6.3 cm (and of 31 of them at2.8 cm) are determined on the basis of observations obtained with the100-m Effelsberg radio telescope during March-August 1984 and comparedto the IRAS color-corrected FIR luminosities, extending the survey of deJong et al. (1985). The data-reduction procedures are described, and theresults are presented in extensive tables and maps and brieflycharacterized. The correlation of radio to FIR luminosity is confirmedover about four decades in both parameters, and the dispersion of logP(6.3 cm)/L(FIR) is found to be about 0.2, which is significantlysmaller than the dispersion found by de Jong et al. The improvement isattributed to color correction, integration over the 100-60-micronrange, and the exclusion of ambiguous identifications.
| H I survey of face-on galaxies - The frequency of distortions in H I disks
The full results of an H I survey of face-on galaxies are presented andit is shown that narrow H I profiles are rare in normal spiral galaxies.This is due in part to the wider-than-expected range of the integraldispersion and in part to the frequent occurrence of large-scaledistortions in the H I disk. These factors reduce the number of galaxieswith half-power widths less than 30 km/s to about 24 percent of thosethat would occur if galaxies generally had quiescent, coplanar H Idisks. Two useful subsets may be drawn from this study of 212 face-ongalaxies with axial ratios greater than 0.87. Fifty-two spirals of allmorphological types have half-power widths smaller than 100 km/s and maybe used for studies that benefit from a small velocity spread and anenhanced beam-filling factor. About 40 galaxies have velocity widthsmuch larger than expected and are of interest in studies of dynamicallypeculiar systems.
| Near-infrared observations of IRAS minisurvey galaxies
Near-infrared photometry was obtained for 82 galaxies from the InfraredAstronomy Satellite (IRAS) minisurvey, a sample of infrared selectedgalaxies. The near-infrared colors of these galaxies are similar tothose of normal field spiral galaxies, but cover a larger range in J - Hand H - K. There is evidence of a tighter correlation between the nearand far infrared emission than exists between far-infrared and thevisible emission. These results suggest that hot dust emissioncontributes to the 2.2 micron luminosity, and extinction by dust affectsboth the near-infrared colors and the visible luminosities. In addition,there is an indication that the far-infrared emission in many of theminisurvey galaxies is coming from a strong nuclear component.
| A study of the large-scale structure in the distribution of galaxies in a region centered about the Cancer cluster. I - Initial observational results. II - Further observational results
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1986AJ.....91..705B&db_key=AST
| Properties of IRAS galaxies with B(0)T not greater than approximately 14.5
The optical and infrared properties of 86 galaxies from IRAS circulars1-15, identified with optically bright galaxies in RC-2 and UGC havebeen studied. It is seen that B(0)T, the face-on integratedblue magnitude, is correlated with the far-infrared (FIR) flux. For asubsample of 61 galaxies for which distances are available, it is foundthat the color temperature of FIR emitting dust is correlated with theFIR luminosity, but not with the blue band luminosity. This along withthe observed ratio of L(FIR)/L(B) implies that the observed blueluminosity is unlikely to be associated with young star formationactivity. Associating FIR luminosity with young star formation activityin molecular clouds and the blue luminosity to the mass of the galaxy, avalue of 5-10 solar luminosity/solar mass is estimated for the meanratio of total FIR luminosity to the mass of the gas in these galaxies.
| Sense of rotation in 109 spirals, and the leading arms in the interacting galaxies NGC 3786 and NGC 5426
From analysis of 132 spiral galaxies, designed to determine the sense ofwinding of the arms, 107 are reliably found to have trailing arms, buttwo others, NGC 3786 (paired with the spiral NGC 3788) and NGC 5426(paired with NGC 5427), have leading arms. The sample of galaxies havinga well-established sense of spiral rotation now totals 190; the arms areleading in only four of these, all objects interacting dynamically withcompanion galaxies. A mechanism that might have induced such leadingspiral patterns is suggested and discussed.
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