Principal     Comenzar     To Survive in the Universe    
Inhabited Sky
    News@Sky     Astrofotografía     La Colección     Foro     Blog New!     FAQ     Prensa     Login  

NGC 811


Contenidos

Imágenes

Subir su imagen

DSS Images   Other Images


Artículos relacionados

Kinematics of the local universe . XII. 21-cm line measurements of 586 galaxies with the new Nançay receiver
This paper presents 586 new 21-cm neutral hydrogen line measurementscarried out with the FORT receiver of the meridian transit Nançayradiotelescope in the period July 2000-March 2003. This observationalprogramme is part of a larger project aiming at collecting an exhaustiveand magnitude-complete HI extragalactic catalogue for Tully-Fisherapplications. It is associated with the building of the MIGALEspectroscopic archive and database.Tables 2, 3 and HI-profiles and corresponding comments are onlyavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/430/373, or directly atour web site http://klun.obs-nancay.fr

Properties of Spiral-Peculiar Type of Kiso Ultraviolet-Excess Galaxies
We investigated the optical spectroscopic properties of 44KisoUltraviolet-excess Galaxies (KUG), which is one of the most well-knowncatalogs of blue galaxies. All of our sample galaxies belong to thespiral-peculiar (Sp) type, the morphological class of spiral galaxy witha peculiar bar and/or a nucleus in KUGs. Since the Sp type is consideredto be the most peculiar group among KUGs, and about 45% of the KUGs havethe Sp type, a detailed study of the Sp type is crucial to understandthe characteristics of the KUG. The sample galaxies have luminosities inthe B-band of about 108 to less than 1010 in solarunit, and a median physical size of 13kpc. From the nuclear spectra, wedetermined line excitation sources in 39 galaxies. Among them, wedetected four AGNs reliably: two Seyfert1s, one Seyfert2, and one LINER.Other sample galaxies show moderately star-forming activity. For thiscategory of ordinary KUG group, the mode of the Hα equivalentwidth at the nuclear region is a bin of 40 to 60Å. Three galaxieshave extreme starburst nuclei with an Hα equivalent width of morethan 200Å. The internal extinction of AV is about0.8mag, which suggests that the star-forming nuclei are not heavilyenshrouded by dust.

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.

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 Montreal Blue Galaxy survey. 2: Second list of UV-bright candidates
We present and discuss the second list of the Montreal Blue Galaxysurvey. Following the inspection of 71 plates, we found 237 newcandidates with B less than 15.5. 73 percent of them are also detectedby Infrared Astronomy Satellite (IRAS). Spectrophotometry was carriedout, at medium resolution, for a subset of 40 objects leading to theidentification of three new AGNs and producing 13 new radial velocities.Spectral classification of our candidates confirms our previous findingthat the majority of our candidates are starburst nucleus galaxiessimilar to the objects studied by Balzano in 1983. Our survey is biasedagainst the high excitation starburst H II galaxies and the LINERgalaxies. Metallicities of our galaxies are found to be from log(O/H)=8.4 to 9.0, which suggests galaxies in advanced stages of chemicalevolution.

KISO survey for ultraviolet-excess galaxies. II.
Not Available

A morphological study of ultraviolet-excess galaxies
A number of ultraviolet-excess galaxies have been detected during thecourse of surveys using the Kiso Schmidt telescope. In this paper, aclassification scheme is proposed for 142 selected objects on the basisof their morphological features, and the relation between themorphological type and the degree of ultraviolet excess is presented. Ingeneral, irregular galaxies with conspicuous H II regions and pairgalaxies tend to show higher degree of ultraviolet excess, while thedegree in spiral galaxies appears to range widely.

Enviar un nuevo artículo


Enlaces relacionados

  • - No se han encontrado enlaces -
En viar un nuevo enlace


Miembro de los siguientes grupos:


Datos observacionales y astrométricos

Constelación:Ballena
Ascensión Recta:02h04m34.80s
Declinación:-10°06'30.0"
Dimensión Aparente:0.955′ × 0.49′

Catálogos y designaciones:
Nombres Propios   (Edit)
NGC 2000.0NGC 811
HYPERLEDA-IPGC 7905

→ Solicitar más catálogos y designaciones a VizieR