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|Structure of Disk-dominated Galaxies. I. Bulge/Disk Parameters, Simulations, and Secular Evolution|
A robust analysis of galaxy structural parameters, based on the modelingof bulge and disk brightnesses in the BVRH bandpasses, is presented for121 face-on and moderately inclined late-type spirals. Each surfacebrightness (SB) profile is decomposed into a sum of a generalizedSérsic bulge and an exponential disk. The reliability andlimitations of our bulge-to-disk (B/D) decompositions are tested withextensive simulations of galaxy brightness profiles (one-dimensional)and images (two-dimensional). We have used repeat observations to testthe consistency of our decompositions. The average systematic modelerrors are <~20% and <~5% for the bulge and disk components,respectively. The final set of galaxy parameters is studied forvariations and correlations in the context of profile type differencesand wavelength dependencies. Galaxy types are divided into three classesaccording to their SB profile shapes: Freeman type I, type II, and athird ``transition'' class for galaxies whose profiles change from typeII in the optical to type I in the infrared. Roughly 43%, 44%, and 13%of type I, type II, and transition galaxies, respectively, comprise oursample. Only type I galaxies, with their fully exponential disks, areadequately modeled by our two-component decompositions, and our mainresults focus on these profiles. We discuss possible interpretations ofFreeman type II profiles. The Sérsic bulge shape parameter fornearby type I late-type spirals shows a range between n=0.1 and 2, but,on average, the underlying surface density profile for the bulge anddisk of these galaxies is adequately described by a double-exponentialdistribution. The distribution of disk scale lengths shows a decreasingtrend with increasing wavelength, consistent with a higher concentrationof old stars or dust (or both) in the central regions relative to theouter disk. We confirm a coupling between the bulge and disk with ascale length ratio =0.22+/-0.09, or=0.13+/-0.06 for late-typespirals, in agreement with recent N-body simulations of disk formation.This ratio increases from ~0.20 for late-type spirals to ~0.24 forearlier types. These observations are consistent with bulges oflate-type spiral galaxies being more deeply embedded in their host diskthan earlier type bulges. Bulges and disks can thus preserve a nearlyconstant re/h but show a great range of SB for any giveneffective radius. The similar scaling relations for early- and late-typespirals suggest comparable formation and/or evolution scenarios for diskgalaxies of all Hubble types. In the spirit of Courteau, de Jong, &Broeils but using our new, more extensive database, we interpret thisresult as further evidence for regulated bulge formation byredistribution of disk material to the galaxy center, in agreement withmodels of secular evolution of the disk.
|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.
|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.
|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.
|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.
|The far-infrared properties of the CfA galaxy sample. I - The catalog|
IRAS flux densities are presented for all galaxies in the Center forAstrophysics magnitude-limited sample (mB not greater than 14.5)detected in the IRAS Faint Source Survey (FSS), a total of 1544galaxies. The detection rate in the FSS is slightly larger than in thePSC for the long-wavelength 60- and 100-micron bands, but improves by afactor of about 3 or more for the short wavelength 12- and 25-micronbands. This optically selected sample consists of galaxies which are, onaverage, much less IR-active than galaxies in IR-selected samples. Itpossesses accurate and complete redshift, morphological, and magnitudeinformation, along with observations at other wavelengths.
|H I survey of face-on galaxies - The frequency of distortions in H I disks|
The full results of an H I survey of face-on galaxies are presented andit is shown that narrow H I profiles are rare in normal spiral galaxies.This is due in part to the wider-than-expected range of the integraldispersion and in part to the frequent occurrence of large-scaledistortions in the H I disk. These factors reduce the number of galaxieswith half-power widths less than 30 km/s to about 24 percent of thosethat would occur if galaxies generally had quiescent, coplanar H Idisks. Two useful subsets may be drawn from this study of 212 face-ongalaxies with axial ratios greater than 0.87. Fifty-two spirals of allmorphological types have half-power widths smaller than 100 km/s and maybe used for studies that benefit from a small velocity spread and anenhanced beam-filling factor. About 40 galaxies have velocity widthsmuch larger than expected and are of interest in studies of dynamicallypeculiar systems.
|Linear clusters of galaxies - A999 and A1016|
Redshifts have been measured for galaxies in two of the 'linear'clusters of the sample of Adams, Strom, and Strom (1980), including 44redshifts in A999 and 40 in A1016. From the data, it is concluded thatthe galaxies in A999 are probably drawn from a spherically symmetricdistribution, while those in A1016 probably are not. Both A999 and A1016have mass-to-light ratios lower than typical of other clusters. Theeffect of anisotropy on the determination of cluster masses from thevirial theorem is examined, and it is found that if the shortest axes ofthese clusters are close to the line of sight, the mass-to-light ratiomay be underestimated by about 50 percent. No significant evidence isfound for alignments of individual cluster members with the cluster axisin the convincing linear cluster A1016. There is similarly no evidenceof segregation by luminosity morphological type in A1016.
|A survey of galaxy redshifts. IV - The data|
The complete list of the best available radial velocities for the 2401galaxies in the merged Zwicky-Nilson catalog brighter than 14.5mz and with b (II) above +40 deg or below -30 deg ispresented. Almost 60 percent of the redshifts are from the CfA surveyand are accurate to typically 35 km/s.
|An Isophotometric and Photographic Atlas of Peculiar Galaxies|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973ApJS...26..115S&db_key=AST
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