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Dust-penetrated arm classes: insights from rising and falling rotation curves
In the last decade, near-infrared imaging has highlighted the decouplingof gaseous and old stellar discs: the morphologies of optical(Population I) tracers compared to the old stellar disc morphology, canbe radically different. Galaxies which appear multi-armed and evenflocculent in the optical may show significant grand-design spirals inthe near-infrared. Furthermore, the optically determined Hubbleclassification scheme does not provide a sound way of classifyingdust-penetrated stellar discs: spiral arm pitch angles (when measured inthe near-infrared) do not correlate with Hubble type. Thedust-penetrated classification scheme of Block & Puerari provides analternative classification based on near-infrared morphology, which isthus more closely linked to the dominant stellar mass component. Here wepresent near-infrared K-band images of 14 galaxies, on which we haveperformed a Fourier analysis of the spiral structure in order todetermine their near-infrared pitch angles and dust-penetrated armclasses. We have also used the rotation curve data of Mathewson et al.to calculate the rates of shear in the stellar discs of these galaxies.We find a correlation between near-infrared pitch angle and rate ofshear: galaxies with wide open arms (the γ class) are found tohave rising rotation curves, while those with falling rotation curvesbelong to the tightly wound α bin. The major determinant ofnear-infrared spiral arm pitch angle is the distribution of matterwithin the galaxy concerned. The correlation reported in this studyprovides the physical basis underpinning spiral arm classes in thedust-penetrated regime and underscores earlier spectroscopic findings byBurstein and Rubin that Hubble type and mass distributions areunrelated.
| Near-infrared constraints on the driving mechanisms for spiral structure
We have imaged a sample of 17 inclined spiral galaxies with measuredHα rotation curves in the K band, in order to determine themorphology of the old stellar population that dominates the mass in thedisc. The K-band images of the galaxies have been used to determine theradial extent of grand-design spiral structure and compare this with theturnover radius in their rotation curves, where the rotation curvetransforms from solid-body rotation to differential rotation. If thearms do not extend past this radius, the winding problem is solved. Wefind in all 17 cases that the arms extend past this radius, with theradius of grand-design spiral structure being a factor of 1.3-9.6 timeslarger than the rotation curve turnover radius. Of these galaxies, fourhave near neighbours and central bars and a further seven have a centralbar. These bars or near neighbours may be the cause of the driving ofthe spiral potential in the discs of these galaxies. Of the remainingsix galaxies, five show some evidence for a bar or oval distortion intheir K-band images. The remaining galaxy (UGC 14) shows no evidence fora central bar and has no near neighbours.Finally, we also find that the spiral structure of these galaxies in thenear-infrared is extremely regular, although some range in theregularity of spiral structure is found. To quantify this range inspiral structure, we introduce the dust-penetrated arm class, which isanalogous to the dust-penetrated classification scheme of Block &Puerari and is based on the optical arm class of Elmegreen &Elmegreen.
| The I-Band Tully-Fisher Relation for SC Galaxies: Optical Imaging Data
Properties derived from the analysis of photometric I-band imagingobservations are presented for 1727 inclined spiral galaxies, mostly oftypes Sbc and Sc. The reduction, parameter extraction, and errorestimation procedures are discussed in detail. The asymptotic behaviorof the magnitude curve of growth and the radial variation in ellipticityand position angle are used in combination with the linearity of thesurface brightness falloff to fit the disk portion of the profile. TotalI-band magnitudes are calculated by extrapolating the detected surfacebrightness profile to a radius of eight disk scale lengths. Errors inthe magnitudes, typically ~0.04 mag, are dominated by uncertainties inthe sky subtraction and disk-fitting procedures. Comparison is made withthe similar imaging database of Mathewson, Ford, & Buchhorn, both aspresented originally by those authors and after reanalyzing theirdigital reduction files using identical disk-fitting procedures. Directcomparison is made of profile details for 292 galaxies observed incommon. Although some differences occur, good agreement is found,proving that the two data sets can be used in combination with onlyminor accommodation of those differences. The compilation of opticalproperties presented here is optimized for use in applications of theTully-Fisher relation as a secondary distance indicator in studies ofthe local peculiar velocity field.
| 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
| Optical Rotation Curves and Linewidths for Tully-Fisher Applications
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.2402C&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.
| Rotation Curves of 967 Spiral Galaxies
We present the rotation curves of 967 southern spiral galaxies, obtainedby deprojecting and folding the raw Hα data originally publishedby Mathewson, Ford, & Buchhorn (1992). For 900 objects, we alsopresent, in figures and tables, the rotation curves smoothed on scalescorresponding to 5%-20% of the optical size; of these, 80 meet objectiveexcellence criteria and are suitable for individual detailed massmodeling, while 820, individually less compelling mainly because of themoderate statistics and/or limited extension, are suitable forstatistical studies. The remaining 67 curves suffer from severeasymmetries, small statistics, and large internal scatter that maylargely limit their use in galaxy structure studies. The deprojectedfolded curves, the smoothed curves, and various related quantities areavailable via anonymous ftp at galileo.sissa.it in the directory/users/ftp/pub/psrot.
| 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.
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