Contents
Images
Upload your image
DSS Images Other Images
Related articles
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.
| 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.
| 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.
| Galaxy structures in the Hercules region
216 redshifts have been obtained in a region of 981 sq deg south of theHercules supercluster. 172 of these redshifts are of galaxies withmpg less than or equal to 15.1, 110 of which had no previousvelocity measurement. 44 new redshifts are of galaxies fainter thanmpg = 15.1. With these new data we have been able to define asample in a vast region (approximately 1700 sq deg) around Herculeslimited to mpg less than or equal to 15.1 with a velocitycompleteness of 81.5%. 189 galaxies have been morphologically classifiedso that all galaxies in the sample with known velocity now also haveknown morphology. The magnitude limited sample, including 556 galaxies,is then used to identify and describe galaxy structures in the region.We find that the overdense volume is small, that its overall appearanceis that of a coral branch floating in a sea of nothing and that earlyand late type galaxies defined different structures.
| H I observations of binary spiral galaxies
A sample of binary spiral galaxies has been observed with the Areciboand Westerbork radio telescopes in the H I 21 cm line, and these data,in conjunction with optical information, are used to ascertain thespin-vector spatial orientation of the galaxies, as well as to estimatetheir systemic and rotation velocities. A tabulation is given of theresults thus obtained for 23 galaxies.
| H I observations of galaxies in the Hercules supercluster. II - Additional UGC galaxies and galaxies in selected CGCG fields
The second installment of a H I redshift survey in the region of theHercules supercluster is presented. This part of the survey presents 218H I spectra of galaxies selected from the UGC which extends thepreviously begun survey of UGC galaxies in that region. In addition,spectra of 136 galaxies from selected CGCG fields are given. The CGCGfields were chosen to cover the projected position of the Hercules void.Measured H I parameters from the spectra are given. This survey wasconducted for application of the Tully-Fisher relation to search forstreaming motion around the void in front of the supercluster. Theselection effects affecting such a search are discussed in detail.
| 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.
| 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.
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
Catalogs and designations:
|
