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

NGC 2842



Upload your image

DSS Images   Other Images

Related articles

The BIMA Survey of Nearby Galaxies (BIMA SONG). II. The CO Data
The BIMA Survey of Nearby Galaxies is a systematic imaging study of the3 mm CO J=1-0 molecular emission within the centers and disks of 44nearby spiral galaxies. The typical spatial resolution of the survey is6" or 360 pc at the average distance (12 Mpc) of the sample. Thevelocity resolution of the CO observations is 4 km s-1,though most maps are smoothed to 10 km s-1 resolution. For 33galaxies, multifield observations ensured that a region >~190"(=10 kpc) in diameter was imaged. For the remaining 11galaxies, which had smaller optical diameters and were on averagefarther away, single-pointing observations imaged a 100" diameter(=11 kpc) region. The sample was not chosen based on CO orinfrared brightness; instead, all spirals were included that met theselection criteria of vsolar<=2000 km s-1,δ>=-20deg, i<=70deg,D25<70', and BT<11.0. Thedetection rate was 41/44 sources or 93%; of the three nondetections, one(M81) is known to have CO emission at locations outside the survey fieldof view. Fully sampled single-dish CO data were incorporated into themaps for 24 galaxies; these single-dish data comprise the most extensivecollection of fully sampled, two-dimensional single-dish CO maps ofexternal galaxies to date. We also tabulate direct measurements of theglobal CO flux densities for these 24 sources. For the remaining 20sources, we collected sensitive single-dish spectra in order to evaluatethe large-scale flux recovery. We demonstrate that the measured ratiosof flux density recovered are a function of the signal-to-noise of theinterferometric data. We examine the degree of central peakedness of themolecular surface density distributions and show that the distributionsexhibit their brightest CO emission within the central 6" in only 20/44or 45% of the sample. We show that all three Local Group spiral galaxieshave CO morphologies that are represented in SONG, though the Milky WayCO luminosity is somewhat below the SONG average, and M31 and M33 arewell below average. This survey provides a unique public database ofintegrated intensity maps, channel maps, spectra, and velocity fields ofmolecular emission in nearby galaxies. It also lays the groundwork forextragalactic surveys by more powerful future millimeter-wavelengthinterferometers like CARMA and ALMA.

A catalog of galaxies behind the Southern Milky Way . I. The Hydra/Antlia extension (l~ 266or - 296or)
A deep optical galaxy search in the southern Milky Way - aimed atreducing the width of the Zone of Avoidance - revealed 3279 galaxycandidates above the diameter limit of D >~ 0.2', of which only 112(3.4%) were previously catalogued. The surveyed region (266o<~ \ell <~ 296o and -10o <~ b <~+8o) lies in the extension of the Hydra and Antlia clusters -where a supercluster is suspected - and in the approximate direction ofthe dipole anisotropy in the Cosmic Microwave Background radiation. Herewe present the optical properties of the unveiled galaxies such aspositions, diameters, magnitudes, morphological types, including adetailed discussion on the quality of these data and the completenesslimits as a function of the foreground dust extinction. For 127 of the227 positional matches in the IRAS PSC, a reliable cross-identificationcould be found. Several distinct overdensities and filaments of galaxiescan be identified that are apparently uncorrelated with the Galacticforeground extinction hence the probable signature of extragalacticlarge-scale structures. This catalog constitutes the first part in aseries of five equally conducted optical searches for galaxies in thesouthern Milky Way (245o <~ \ell <~ 350o).With these surveys, the entire Zone of Avoidance will have been coveredby means of visual inspection. The catalogs build the basis for variousspectroscopic and photometric follow-up programs which eventually willallow a thorough analyse of the galaxy distribution in redshift spaceand the peculiar velocity fields within the Zone of Avoidance, as wellan an improved understanding of the Galactic foreground extinction.Tables 1 and 2 are available in electronic form at the CDS via anonymousftp to cdsarc.u-strasbg.fr ( or viahttp://cdsweb.u-strasbg.fr/Abstract.html

Galaxy coordinates. II. Accurate equatorial coordinates for 17298 galaxies
Using images of the Digitized Sky Survey we measured coodinates for17298 galaxies having poorly defined coordinates. As a control, wemeasured with the same method 1522 galaxies having accurate coordinates.The comparison with our own measurements shows that the accuracy of themethod is about 6 arcsec on each axis (RA and DEC).

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.

Comparative study of fine structure in samples of isolated and paired early-type galaxies
Fine structure in early-type galaxies is considered to be among the morerobust indicators of a past merging or acquisition event, althoughgrowing evidence from numerical simulations suggests that fine structuremay be also interpreted in a `weak interaction' framework. We present amorphological study of a sample composed of 61 `isolated' early-typegalaxies addressed to the detection of fine structure. This sample hasbeen selected in order to be statistically comparable to a set of 54early-type galaxies, members of pairs analysed by Reduzzi & Rampazzowith a similar technique. The rate of occurrence of fine structuredetected in the `isolated' galaxy sample is significantly higher thanthat found for the pairs. In particular, the fraction of isolatedearly-type galaxies exhibiting shells is 16.4 per cent, a percentagesimilar to that found by Malin & Carter for RC2 isolated objects inthe southern sky, while the fraction of early-type galaxies in pairs is~=4 per cent. We discuss the comparison between the two samples in thecontext of the merger versus the weak interaction origin of finestructures. Concerning the formation of shells, although the mergerorigin cannot be ruled out, the observed difference is more naturallyexplained within the weak interaction framework.

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

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.

Total and effective colors of 501 galaxies in the Cousins VRI photometric system
Total color indices (V-R)T, (V-I)T and effectivecolor indices (V-R)e, (V-I)e in the Cousins VRIphotometric system are presented for 501 mostly normal galaxies. Thecolors are computed using a procedure outlined in the Third ReferenceCatalogue of Bright Galaxies (RC3) whereby standard color curvesapproximated by Laplace-Gauss integrals are fitted to observedphotoelectric multiaperture photometry. 11 sources of such photometrywere used for our analysis, each source being assigned an appropriateweight according to a rigorous analysis of residuals of the data fromthe best-fitting standard color curves. Together with the integrated B-Vand U-B colors provided in RC3, our analysis widens the range ofwavelength of homogeneously defined colors of normal galaxies of allHubble types. We present color-color and color-type relations that canbe modeled to understand the star formation history of galaxies.

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.

Southern Galaxy Catalogue.
Not Available

UBVRI photoelectric photometry of 191 southern galaxies
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1984A&AS...58..249L&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:09h15m36.50s
Aparent dimensions:1.738′ × 1.38′

Catalogs and designations:
Proper Names   (Edit)
NGC 2000.0NGC 2842

→ Request more catalogs and designations from VizieR