Главная     Введение     Выжить во Вселенной    
Inhabited Sky
    News@Sky     Астрофотография     Коллекция     Форум     Blog New!     Помощь     Пресса     Войти  

NGC 3244


Оглавление

Изображения

Загрузить ваше изображение

DSS Images   Other Images


Публикации по объекту

Total magnitude, radius, colour indices, colour gradients and photometric type of galaxies
We present a catalogue of aperture photometry of galaxies, in UBVRI,assembled from three different origins: (i) an update of the catalogueof Buta et al. (1995) (ii) published photometric profiles and (iii)aperture photometry performed on CCD images. We explored different setsof growth curves to fit these data: (i) The Sersic law, (ii) The net ofgrowth curves used for the preparation of the RC3 and (iii) A linearinterpolation between the de Vaucouleurs (r(1/4) ) and exponential laws.Finally we adopted the latter solution. Fitting these growth curves, wederive (1) the total magnitude, (2) the effective radius, (3) the colourindices and (4) gradients and (5) the photometric type of 5169 galaxies.The photometric type is defined to statistically match the revisedmorphologic type and parametrizes the shape of the growth curve. It iscoded from -9, for very concentrated galaxies, to +10, for diffusegalaxies. Based in part on observations collected at the Haute-ProvenceObservatory.

Lopsided Spiral Galaxies and a Limit on the Galaxy Accretion Rate
We present a measurement of lopsidedness for the stellar disks of 60field spiral galaxies in terms of the azimuthal m = 1 Fourier amplitude,A1, of the stellar light. We confirm the previous result (Rix &Zaritsky) that ~30% of field spiral galaxies in a magnitude-limitedsample exhibit significant lopsidedness ( >= 0.2) atlarge radii (R > 1.5 disk scalelengths). We conjecture that thislopsidedness is caused by tidal interactions and calculate an upperlimit on the accretion rate of small galaxies. We exploit thecorrelation between lopsidedness and photometric measures of recent starformation (Zaritsky) to obtain two independent estimates of the lifetimeof these m = 1 distortions. First, we show that lopsided galaxies havean excess of blue luminosity relative to that of symmetric galaxies withthe same H I linewidth, which we attribute to a recent star formationepisode that was triggered by an interaction between the galaxy and acompanion. We use stellar population models (Bruzual & Charlot) toestimate the time since that interaction. Second, we use the N-bodysimulation of an infalling satellite by Walker, Mihos, & Hernquistto estimate how fast tidally induced m = 1 distortions are erasedthrough phase mixing. Both approaches indicate that the observations areconsistent with a hypothesized tidal interaction that occurred about 1Gyr ago for galaxies that are lopsided at the 20% level. By combiningthis lifetime estimate for lopsidedness, the observed frequency of suchdistortions, and a correction to the survey volume that depends on theincrease in luminosity during an interaction, we derive an upper limiton the current companion accretion rate of field spiral galaxies (forcompanion masses ~10% parent galaxy mass) that lies in the range0.07--0.25 Gyr-1. The principal uncertainty in this limit arises fromambiguities in the interpretation of the correlation betweenlopsidedness and MB.

The I band Tully-Fisher relation for cluster galaxies: data presentation.
Observational parameters which can be used for redshift-independentdistance determination using the Tully-Fisher (TF) technique are givenfor \ntot spiral galaxies in the fields of 24 clusters or groups. I bandphotometry for the full sample was either obtained by us or compiledfrom published literature. Rotational velocities are derived either from21 cm spectra or optical emission line long-slit spectra, and convertedto a homogeneous scale. In addition to presenting the data, a discussionof the various sources of error on TF parameters is introduced, and thecriteria for the assignment of membership to each cluster are given.

Redshift Distribution of Galaxies in the Southern Milky Way Region 210 degrees < L < 360 degrees and B < 15 degrees
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..107..521V&db_key=AST

Parameters of 2447 Southern Spiral Galaxies for Use in the Tully-Fisher Relation
I-band luminosities, rotational velocities, and redshifts of 1092 spiralgalaxies have been measured by CCD photometry and Hα spectroscopyusing the 1 m and 2.3 m telescopes at Siding Spring Observatory,respectively. The results are tabulated. Luminosity profiles andHα rotation curves are given for the galaxies. When these resultsare combined with similar data for 1355 spiral galaxies publishedpreviously (Mathewson, Ford, & Buchhorn, hereafter Paper I), itprovides a large, uniform, and unique data set with which to measure,via the Tully-Fisher relation, the peculiar velocities of galaxies inthe local universe to a distance of 11,000 km s^-1^ (Mathewson &Ford). Taking advantage of the opportunity for publishing this data inmachine-readable form, in the CD-ROM, we have also included similar datafor the 1355 galaxies in Paper I.

Integrated photoelectric magnitudes and color indices of bright galaxies in the Johnson UBV system
The photoelectric total magnitudes and color indices published in theThird Reference Catalogue of Bright Galaxies (RC3) are based on ananalysis of approximately equals 26,000 B, 25,000 B-V, and 17,000 U-Bmultiaperture measurements available up to mid 1987 from nearly 350sources. This paper provides the full details of the analysis andestimates of internal and external errors in the parameters. Thederivation of the parameters is based on techniques described by theVaucouleurs & Corwin (1977) whereby photoelectric multiaperture dataare fitted by mean Hubble-type-dependent curves which describe theintegral of the B-band flux and the typical B-V and U-B integrated colorgradients. A sophisticated analysis of the residuals of thesemeasurements from the curves was made to allow for the random andsystematic errors that effect such data. The result is a homogeneous setof total magnitudes BTA total colors(B-V)T and (U-B)T, and effective colors(B-V)e and (U-B)e for more than 3000 brightgalaxies in RC3.

A search for IRAS galaxies behind the southern Milky Way
We systematically searched for IRAS galaxies with 60 micrometer fluxdensity larger than 0.6 Jy by using the UK Schmidt Infrared and IIIa-JAtlases in the Milky Way region (absolute value of b less than 15 deg)between l = 210 deg and 360 deg. We first selected about 4000 IRAS pointsources by using our far-infrared criteria, which are optimized for thesearch of IRAS galaxies behind the Milky Way region, and then inspectedvisually the optical counterparts of them on the Schmidt Atlas filmcopies. We found 966 IRAS sources associated with galaxy-like objects.The list of the objects is presented here with the IRAS source name,Galactic coordinates, IRAS flux densities, field number and emulsion ofthe Atlas, type and size of galaxy (-like) image, redshift,multiplicity, and cross-identification. Of these, 423 galaxies arealready cataloged in the Catalog of Galaxies and Quasars Observed in theIRAS Survey, and most of the remaining 543 galaxy candidates are newlyidentified in this search. Although the radial velocities are known foronly 387 galaxies, of which 60 were newly measured by us so far, weinferred the contamination by Galactic objects to be small from the goodcorrelation between the sky distributions of the newly identified galaxycandidates and the previously cataloged galaxies. In the regions wherethe Galactic molecular clouds dominate, almost all the sources were notidentified as galaxies. The detected galaxies are clustered in the threeregions around l = 240 deg, 280 deg, and 315 deg, where the projectednumber densities are higher than the whole-sky average of IRAS galaxiesof the same flux limit.

Observational Data for the Kinematics of the Local Universe - Part Two - Second Set of Radial Velocity Measurements
This paper is the second one in a series dedicated to the study of thekinematics of the local universe. It gives 361 new optical and radioredshifts measured at ESO, OHP and Nancay Observatories.

A southern sky survey of the peculiar velocities of 1355 spiral galaxies
The paper presents data from photometric and spectroscopic observationsof 1355 southern spiral galaxies and uses them to determine theirdistances and peculiar velocities via the Tully-Fisher (TF) relation.I-band CCD surface photometry was carried out using the 1-m and 3.9-mtelescopes at Siding Spring Observatory. H-alpha rotation curves for 965galaxies and 551 H I profiles are presented. The physical parameters,photometric and velocity data, distances, and peculiar velocities of thegalaxies are presented in tabular form. The mean distance, systemicvelocity, and average peculiar velocity of 24 clusters in the sample aregiven. TF diagrams are presented for each cluster.

The distribution of galaxies in the direction of the 'Great Attractor'
A map of about 17,000 galaxies down to B(J) = 17 m in an extended regionof the sky in this direction is presented. The clusters of galaxiesidentified form the map are shown to constitute two distinctconcentrations in redshift. The possibility that the farther of the twoconcentrations, centered near l = 312 deg, b = 31 deg, at a meanredshift of 14,000 km/s, is a major contributor to the peculiar motionof the Local Group is explored. This is unlikely because thecontribution to the dipole anisotropy of extragalactic light due togalaxies in this region, beyond a diameter limit of 1.3 arcmin, is about10 percent of that due to nearer galaxies, and the concentration wouldneed to have an extremely high mass-to-light ratio. Superclusters asmassive as this would cause appreciable anisotropies in the cosmicmicrowave background radiation.

Southern Galaxy Catalogue.
Not Available

The Antlia cluster of galaxies and its environment - The Hydra I-Centaurus supercluster
The small Antlia cluster of galaxies was investigated by measuring manyradial velocities for galaxies from the Lauberts catalog in the Antliaregion. Apart from the Antlia cluster itself, four more small groupswere identified. These five systems form a tiny but not bound Antliamini-supercluster. The mini-supercluster consists of small groups andclusters and of a dispersed component of field galaxies. The five galaxysystems are also part of the large Hydra I-Centaurus supercluster. Thislarge supercluster belongs now to the class of well observed ones. Ithas a chain-like filamentary structure. This supercluster seems to beconnected to the Local Supercluster via two very extended but very loosegroups. The total structure is the triangle-shaped Virgo-HydraI-Centaurus supercluster.

UBV photometry of 262 southern galaxies
Multiaperture photometry of 262 bright southern galaxies in the JohnsonUBV system is given. Most of these are south of -30 deg declination,although some northward to -10 deg are included. A total of 169 objectshave published radial-velocity determinations. These provide distancesand enable construction of color-magnitude diagrams for this subset ofobjects through a physical diameter of 2.0 kpc (with H = 100). Thetwo-color diagrams for the inner regions of the galaxies differ fromthose of integrated galaxies due to the color changes towards theircenters. Comparison with theoretical models of Larson and Tinsley (1978)suggest that the colors of the inner portions of most ellipticals andlenticulars are consistent with their having all stars formed at nearlyone epoch with little subsequent star formation, while for spiralslarger amounts of star formation, either in bursts or continuously, aresuggested. This simple picture is complicated by the presence of certainobjects having peculiar colors indicative of large amounts of recentstar formation.

Добавить новую статью


Внешние ссылки

  • - Внешних ссылок не найдено -
Добавить внешнюю ссылку


Группы:


Наблюдательные данные и астрометрия

Созвездие:Насос
Прямое восхождение:10h25m29.20s
Склонение:-39°49'40.0"
Видимый размер:2.089′ × 1.514′

Каталоги и обозначения:
Собственные имена   (Edit)
NGC 2000.0NGC 3244
HYPERLEDA-IPGC 30594

→ Запросить дополнительные каталоги и обозначения от VizieR