Home     Getting Started     To Survive in the Universe    
Inhabited Sky
    News@Sky     Astro Photo     The Collection     Forum     Blog New!     FAQ     Press     Login  

NGC 3100



Upload your image

DSS Images   Other Images

Related articles

Redshift-Distance Survey of Early-Type Galaxies: Spectroscopic Data
We present central velocity dispersions and Mg2 line indicesfor an all-sky sample of ~1178 elliptical and S0 galaxies, of which 984had no previous measures. This sample contains the largest set ofhomogeneous spectroscopic data for a uniform sample of ellipticalgalaxies in the nearby universe. These galaxies were observed as part ofthe ENEAR project, designed to study the peculiar motions and internalproperties of the local early-type galaxies. Using 523 repeatedobservations of 317 galaxies obtained during different runs, the dataare brought to a common zero point. These multiple observations, takenduring the many runs and different instrumental setups employed for thisproject, are used to derive statistical corrections to the data and arefound to be relatively small, typically <~5% of the velocitydispersion and 0.01 mag in the Mg2 line strength. Typicalerrors are about 8% in velocity dispersion and 0.01 mag inMg2, in good agreement with values published elsewhere.

Redshift-Distance Survey of Early-Type Galaxies: Circular-Aperture Photometry
We present R-band CCD photometry for 1332 early-type galaxies, observedas part of the ENEAR survey of peculiar motions using early-typegalaxies in the nearby universe. Circular apertures are used to tracethe surface brightness profiles, which are then fitted by atwo-component bulge-disk model. From the fits, we obtain the structuralparameters required to estimate galaxy distances using theDn-σ and fundamental plane relations. We find thatabout 12% of the galaxies are well represented by a pure r1/4law, while 87% are best fitted by a two-component model. There are 356repeated observations of 257 galaxies obtained during different runsthat are used to derive statistical corrections and bring the data to acommon system. We also use these repeated observations to estimate ourinternal errors. The accuracy of our measurements are tested by thecomparison of 354 galaxies in common with other authors. Typical errorsin our measurements are 0.011 dex for logDn, 0.064 dex forlogre, 0.086 mag arcsec-2 for<μe>, and 0.09 for mRC,comparable to those estimated by other authors. The photometric datareported here represent one of the largest high-quality and uniformall-sky samples currently available for early-type galaxies in thenearby universe, especially suitable for peculiar motion studies.Based on observations at Cerro Tololo Inter-American Observatory (CTIO),National Optical Astronomy Observatory, which is operated by theAssociation of Universities for Research in Astronomy, Inc., undercooperative agreement with the National Science Foundation (NSF);European Southern Observatory (ESO); Fred Lawrence Whipple Observatory(FLWO); and the MDM Observatory on Kitt Peak.

A new catalogue of ISM content of normal galaxies
We have compiled a catalogue of the gas content for a sample of 1916galaxies, considered to be a fair representation of ``normality''. Thedefinition of a ``normal'' galaxy adopted in this work implies that wehave purposely excluded from the catalogue galaxies having distortedmorphology (such as interaction bridges, tails or lopsidedness) and/orany signature of peculiar kinematics (such as polar rings,counterrotating disks or other decoupled components). In contrast, wehave included systems hosting active galactic nuclei (AGN) in thecatalogue. This catalogue revises previous compendia on the ISM contentof galaxies published by \citet{bregman} and \citet{casoli}, andcompiles data available in the literature from several small samples ofgalaxies. Masses for warm dust, atomic and molecular gas, as well asX-ray luminosities have been converted to a uniform distance scale takenfrom the Catalogue of Principal Galaxies (PGC). We have used twodifferent normalization factors to explore the variation of the gascontent along the Hubble sequence: the blue luminosity (LB)and the square of linear diameter (D225). Ourcatalogue significantly improves the statistics of previous referencecatalogues and can be used in future studies to define a template ISMcontent for ``normal'' galaxies along the Hubble sequence. The cataloguecan be accessed on-line and is also available at the Centre desDonnées Stellaires (CDS).The catalogue is available in electronic form athttp://dipastro.pd.astro.it/galletta/ismcat and at the CDS via anonymousftp to\ cdsarc.u-strasbg.fr ( or via\http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/405/5

The Parkes quarter-Jansky flat-spectrum sample. I. Sample selection and source identifications
We present a new sample of quarter-Jansky flat-spectrum radio sourcesselected to search for high-redshift quasars and to study the evolutionof the flat-spectrum quasar population. The sample comprises 878 radiosources selected from the Parkes catalogues with spectral indices alpha5 GHz_2.7 GHz >=-0.4 where Snu ~ nu alpha. The sample covers all right ascensions and the declination rangefrom -80fdg0 to +2fdg5 , excluding low galactic latitudes (mid b mid< 10deg) and the Magellanic Cloud regions. We haveobtained improved radio source positions, firstly to reconfirm themajority of the existing identifications, and secondly, using digitizedsky-survey data and deep B, Gunn-i and Gunn-z CCD-imaging, to findoptical identifications for 223 previously-unidentified sources. Wepresent the final catalogue of 878 flat-spectrum sources: 827 arecompact radio sources identified with galaxies, quasars and BL Lacobjects, 38 have either extended radio structure or are identified withGalactic objects (PN, HII or non-compact radio source), 4 are obscuredby Galactic stars, and 9 (1 per cent of the total sample) remainunidentified. Full Appendices A-D are only available in electronic format http://www.edpsciences.org

A catalogue of Mg_2 indices of galaxies and globular clusters
We present a catalogue of published absorption-line Mg_2 indices ofgalaxies and globular clusters. The catalogue is maintained up-to-datein the HYPERCAT database. The measurements are listed together with thereferences to the articles where the data were published. A codeddescription of the observations is provided. The catalogue gathers 3541measurements for 1491 objects (galaxies or globular clusters) from 55datasets. Compiled raw data for 1060 galaxies are zero-point correctedand transformed to a homogeneous system. Tables 1, 3, and 4 areavailable in electronic form only at the CDS, Strasbourg, via anonymousftp Table 2 is available both in text and electronic form.

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.

A catalogue of spatially resolved kinematics of galaxies: Bibliography
We present a catalogue of galaxies for which spatially resolved data ontheir internal kinematics have been published; there is no a priorirestriction regarding their morphological type. The catalogue lists thereferences to the articles where the data are published, as well as acoded description of these data: observed emission or absorption lines,velocity or velocity dispersion, radial profile or 2D field, positionangle. Tables 1, 2, and 3 are proposed in electronic form only, and areavailable from the CDS, via anonymous ftp to cdsarc.u-strasbg.fr (to130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

The fundamental plane of early-type galaxies: stellar populations and mass-to-light ratio.
We analyse the residuals to the fundamental plane (FP) of ellipticalgalaxies as a function of stellar-population indicators; these are basedon the line-strength parameter Mg_2_ and on UBVRI broad-band colors, andare partly derived from new observations. The effect of the stellarpopulations accounts for approximately half the observed variation ofthe mass-to-light ratio responsible for the FP tilt. The residual tiltcan be explained by the contribution of two additional effects: thedependence of the rotational support, and possibly that of the spatialstructure, on the luminosity. We conclude to a constancy of thedynamical-to-stellar mass ratio. This probably extends to globularclusters as well, but the dominant factor would be here the luminositydependence of the structure rather than that of the stellar population.This result also implies a constancy of the fraction of dark matter overall the scalelength covered by stellar systems. Our compilation ofinternal stellar kinematics of galaxies is appended.

The Catalog of Southern Ringed Galaxies
The Catalog of Southern Ringed Galaxies (CSRG) is a comprehensivecompilation of diameters, axis ratios, relative bar position angles, andmorphologies of inner and outer rings, pseudorings, and lenses in 3692galaxies south of declination -17 deg. The purpose of the catalog is toevaluate the idea that these ring phenomena are related to orbitalresonances with a bar or oval in galaxy potentials. The catalog is basedon visual inspection of most of the 606 fields of the Science ResearchCouncil (SRC) IIIa-J southern sky survey, with the ESO-B, ESO-R, andPalomar Sky surveys used as auxiliaries when needed for overexposed coreregions. The catalog is most complete for SRC fields 1-303 (mostly southof declination -42 deg). In addition to ringed galaxies, a list of 859mostly nonringed galaxies intended for comparison with other catalogs isprovided. Other findings from the CSRG that are not based on statisticsare the identification of intrinsic bar/ring misalignment; bars whichunderfill inner rings; dimpling of R'1pseudorings; pointy, rectangular, or hexagonal inner or outer ringshapes; a peculiar polar-ring-related system; and other extreme examplesof spiral structure and ring morphology.

Line-strength gradients in the bulge components of NGC 3190 and 1023.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1994MNRAS.271...39S&db_key=AST

Parsecscale Radio Cores in Early Type Galaxies
We find compact (<0.03 arcsec) radio-continuum cores in about 70 percent of radio-emitting elliptical and S0 galaxies over a wide range intotal radio power (10^21^-,10^26^ W Hz^-1^ at 5 GHz). The cores usuallyhave a flat or rising spectrum between 2.3 and 8.4 GHz, with a medianspectral index of + 0.3. Even at low luminosities, the radio emissionfrom most elliptical galaxies appears to be powered by a parsec-scale`engine' like those in classical radio galaxies and quasars. The coreand total radio power are related (P_core_ is proportional toP_total_^0.7^ on average), and the parsec-scale cores of radio galaxiesare typically one hundred times more powerful than those in `normal'giant elliptical galaxies.

UBVRI photoelectric photometry of bright southern early-type galaxies
UBVRI multi-aperture photometry of 207 bright southern galaxies and of72 objects of an additional list is presented. These observations weremade for obtaining the magnitude scale zero-point as an accuratedetermination of the sky background for a two-dimensional photometryprogram concerning these galaxies. We have also inferred the asymptoticmagnitudes, color indices and effective apertures of these objects. Ourresults are in good agreement with those of others authors.

Metallicity Gradients in Early Type Galaxies
Long-slit spectra in the range 4500-6500 A have been obtained for asample of 42 galaxies. Rotation velocities and velocity dispersions,together with radial line strength gradients of Mg_2_, Mg_1_, Hβ,NaD, TiO_1_, TiO_2_ and Fe_5270_, have been measured to, on average,half an effective radius. To a high level of significance, Mg_2_gradients positively correlate with those of Mg_1_ and Na D, but nocorrelation is observed with the other indices. In addition,correlations of Mg_2_ gradients with various physical parameters arestudied. For galaxies smaller than about 10^11^ M_sun_, the Mg_2_gradient increases with increasing mass, but more massive objects showno correlation. In low- mass galaxies, the correlation of Mg_2_gradients with mass suggests dissipative collapse as the mechanismacting during the initial star formation episode. Different formationmechanisms, such as, for example, a less dissipative collapse and/ormerging of smaller systems, are discussed as a means of explaining thelack of correlation at higher masses. Even at low masses, the galacticmass seems not to influence either the position or the slope on theFe_5270_-Mg_2_ plane, abundance ratios within galaxies depending onstill-unidentified parameters.

Millimeter and submillimeter observations of nearby radio galaxies
Radio galaxies are often observed to be strong long wavelength infraredsources. Twenty-six radio galaxies with strong compact cores wereobserved at wavelengths near 1 mm with the James Clerk Maxwell Telescopeon Mauna Kea, Hawaii. The detections and upper limits establish thepresence of excess infrared emission for almost all of the galaxies inthe sample. The exceptions are the BL Lac objects, which have smoothcontinuous spectra from radio to infrared wavelengths. The spectralenergy distributions of the infrared emission from the radio galaxiesfavor a thermal origin due to emission from cool interstellar dust. Theamounts of dust inferred to be present approach those observed in largespirals.

Infrared properties of nearby radio galaxies
The IRAS data for a sample of nearby radio galaxies (z less than 0.13)are analyzed. Comparison of the infrared, radio, and optical datasuggests that most of the long-wavelength infrared emission comes fromcool interstellar dust for almost all of the galaxies; these galaxiesmay contain large amounts (10 to the 8th - 10 to the 10th solar massesof interstelar matter. About 15 percent of the galaxies show evidencefor a hotter thermal component emitting at the shorter IRAS wavelengths;this could be due to dust in the inner regions of the galaxy heated bythe active galactic nucleus.

A complete sample of radio galaxies. I - The radio data
The selection of a complete sample of 91 radio galaxies from the Parkes2.7 GHz survey in the declination range -17 to -40 deg is described, andVLA observations of all sample members are presented together with datafor several from other radio observatories. The sample is intermediatein radio luminosity, with an optical limit of mv = 17.0 magand a radio limit of 0.25 Jy at 2.7 GHz.

H I absorption in radio elliptical galaxies - Evidence for infall
A complete sample of 29 radio galaxies with compact cores has beenobserved by the VLA in the H I line to an almost uniform optical-depthsensitivity of about 0.01 at a velocity resolution of 40 km/s. Thesegalaxies were selected using continuum observations of an almostcomplete sample of 49 radio galaxies; 21-cm core flux densities aregiven for these galaxies. H I absorption was detected in four galaxies,NGC 3894, NGC 5363, 3C 236, and 4C 31.06, bringing to eight the numberof radio ellipticals in which H I absorption has been detected. In allcases, absorption is seen redshifted wiht respect to the galaxy'ssystemic velocity, or close to the systemic velocity, or both. Noblueshifted absorption components are seen. These observationsdemonstrate the infall of H I to the inner regions of radio ellipticalgalaxies. The estimated infall rates (a few hundredths of a solar massper year) are more than adequate to fuel the nuclear activity.

The radio and optical axes of radio elliptical galaxies
New VLA and CCD data are incorporated with previous observations toinvestigate the alignment of radio and optical axes of radio-emittingearly-type galaxies. A comparison of observations with simulationsmodeling the random projection effects of different geometries on thesky shows that there is no strong physical relation of radio axis with aparticular stellar axis. This result is true for both triaxial andaxially symmetric galaxies.

Stellar Dynamics of Radio Elliptical Galaxies
Not Available

Southern Galaxy Catalogue.
Not Available

A catalog of dusty elliptical galaxies
A catalog of about 100 dusty elliptical galaxies and some relatedobjects is presented. A morphological classification system is proposed,and the observed dust lane characteristics of some of the individualgalaxies are described. The properties of the galaxies are discussed,including the distribution of morphological types, their radioproperties, radio source orientation, neutral hydrogen, kinematics anddynamics, and relationship to other types of peculiar galaxies.

JHK colours of 'ordinary' galaxies
Accurate JHK photometry is presented for 19 elliptical, 10 lenticular,29 'ordinary' spiral galaxies, and 1 Im type on the SAAO photometricsystem which has well-defined transformations to the Caltech/CTIO andAAO systems. The groups having the highest degree of color uniformityare the ellipticals and lenticulars. 'Ordinary', or inactive spirals,show slightly more scatter; late types are bluer than average in J-H andemission-line galaxies are redder in H-K. In general, the infrared andV-K colors determined here agree well with previous work. However, noevidence for significant change of infrared color with radius has beenseen, in contrast to the results of some other workers.

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.

The UHURU catalog of X-ray souces.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972ApJ...178..281G&db_key=AST

Submit a new article

Related links

  • - No Links Found -
Submit a new link

Member of following groups:

Observation and Astrometry data

Right ascension:10h00m41.20s
Aparent dimensions:3.631′ × 2.291′

Catalogs and designations:
Proper Names   (Edit)
NGC 2000.0NGC 3100

→ Request more catalogs and designations from VizieR