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The Halo Mass Distribution of Field and Cluster Early-Type Galaxies
We describe an ongoing program to study the halo kinematics of a broadsample of early-type galaxies using integrated light measurementsobtained with the Hobby-Eberly and Gemini Telescopes.The Hobby-Eberly Telescope is operated by McDonald Observatory on behalfof the University of Texas at Austin, The Pennsylvania State University,Stanford University, Ludwid-Maximilians-Universit at Munchen, andGeorg-August-Universitat Gottingen.Part of this project is based on observations obtained at the GeminiObservatory, which is operated by AURA, INC., under a cooperativeagreement with the NSF on behalf of the Gemini Partnership: The NSF(USA), PPARC (UK), NRC (Canada), CONICYT (Chile), ARC (Australia), CNPq(Brazil) and CONICET (Argentina ).
| FLASH redshift survey - I. Observations and catalogue
The FLAIR Shapley-Hydra (FLASH) redshift survey catalogue consists of4613 galaxies brighter than bJ= 16.7 (corrected for Galacticextinction) over a 700-deg2 region of sky in the generaldirection of the Local Group motion. The survey region is a70°× 10° strip spanning the sky from the ShapleySupercluster to the Hydra cluster, and contains 3141 galaxies withmeasured redshifts. Designed to explore the effect of the galaxyconcentrations in this direction (in particular the Supergalactic planeand the Shapley Supercluster) upon the Local Group motion, the 68 percent completeness allows us to sample the large-scale structure betterthan similar sparsely-sampled surveys. The survey region does notoverlap with the areas covered by ongoing wide-angle (Sloan or 2dF)complete redshift surveys. In this paper, the first in a series, wedescribe the observation and data reduction procedures, the analysis forthe redshift errors and survey completeness, and present the surveydata.
| 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 (130.79.128.5) or via\http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/405/5
| Early-type galaxies in low-density environments
We describe the construction and study of an objectively defined sampleof early-type galaxies in low-density environments. The sample galaxiesare selected from a recently completed redshift survey using uniform andreadily quantified isolation criteria, and are drawn from a sky area of~700 deg2, to a depth of 7000 km s-1 and anapparent magnitude limit of bJ<= 16.1. Their early-type(E/S0) morphologies are confirmed by subsequent CCD imaging. Five out ofthe nine sample galaxies show signs of morphological peculiarity such astidal debris or blue circumnuclear rings. We confirm that E/S0 galaxiesare rare in low-density regions, accounting for only ~8 per cent of thetotal galaxy population in such environments. We present spectroscopicobservations of nine galaxies in the sample, which are used, inconjunction with updated stellar population models, to investigate starformation histories. Our line-strength analysis is conducted at therelatively high spectral resolution of 4.1 Å. Environmentaleffects on early-type galaxy evolution are investigated by comparisonwith a sample of Fornax cluster E/S0s (identically analysed). Resultsfrom both samples are compared with predictions from semi-analyticgalaxy formation models. From the strength of [OII]λ3727 emissionwe infer only a low level of ongoing star formation (<0.15Msolar yr-1). Relative to the Fornax sample, alarger fraction of the galaxies exhibit [OIII]λ5007 nebularemission and, where present, these lines are slightly stronger thantypical for cluster E/S0s. The Mg-σ relation of E/S0s inlow-density regions is shown to be indistinguishable from that of theFornax sample. Luminosity-weighted stellar ages and metallicities aredetermined by considering various combinations of line-indices; inparticular the HγF versus Fe5015 diagram cleanlyresolves the age-metallicity degeneracy at the spectral resolution ofour analysis. At a given luminosity, the E/S0 galaxies in low-densityregions are younger than the E/S0s in clusters (by ~2-3 Gyr), and alsomore metal-rich (by ~0.2 dex). We infer that an anti-correlation of ageand metallicity effects is responsible for maintaining the zero-point ofthe Mg-σ relation. The youngest galaxies in our sample show clearmorphological signs of interaction. The lower mean age of our sample,relative to cluster samples, confirms, at least qualitatively, a robustprediction of hierarchical galaxy formation models. By contrast, theenhanced metallicity in the field is contrary to the predictions andhighlights shortcomings in the detailed treatment of star formationprocesses in current models. The [Mg/Fe] abundance ratio appears to spana similar, mostly super-solar, range both in low-density regions and inFornax cluster galaxies. This result is quite unexpected in simplehierarchical models.
| A catalogue and analysis of X-ray luminosities of early-type galaxies
We present a catalogue of X-ray luminosities for 401 early-typegalaxies, of which 136 are based on newly analysed ROSAT PSPC pointedobservations. The remaining luminosities are taken from the literatureand converted to a common energy band, spectral model and distancescale. Using this sample we fit the LX:LB relationfor early-type galaxies and find a best-fit slope for the catalogue of~2.2. We demonstrate the influence of group-dominant galaxies on the fitand present evidence that the relation is not well modelled by a singlepower-law fit. We also derive estimates of the contribution to galaxyX-ray luminosities from discrete-sources and conclude that they provideLdscr/LB~=29.5ergs-1LBsolar-1. Wecompare this result with luminosities from our catalogue. Lastly, weexamine the influence of environment on galaxy X-ray luminosity and onthe form of the LX:LB relation. We conclude thatalthough environment undoubtedly affects the X-ray properties ofindividual galaxies, particularly those in the centres of groups andclusters, it does not change the nature of whole populations.
| A synthesis of data from fundamental plane and surface brightness fluctuation surveys
We perform a series of comparisons between distance-independentphotometric and spectroscopic properties used in the surface brightnessfluctuation (SBF) and fundamental plane (FP) methods of early-typegalaxy distance estimation. The data are taken from two recent surveys:the SBF Survey of Galaxy Distances and the Streaming Motions of AbellClusters (SMAC) FP survey. We derive a relation between(V-I)0 colour and Mg2 index using nearly 200galaxies and discuss implications for Galactic extinction estimates andearly-type galaxy stellar populations. We find that the reddenings fromSchlegel et al. for galaxies with E(B-V)>~0.2mag appear to beoverestimated by 5-10 per cent, but we do not find significant evidencefor large-scale dipole errors in the extinction map. In comparison withstellar population models having solar elemental abundance ratios, thegalaxies in our sample are generally too blue at a given Mg2;we ascribe this to the well-known enhancement of the α-elements inluminous early-type galaxies. We confirm a tight relation betweenstellar velocity dispersion σ and the SBF `fluctuation count'parameter N, which is a luminosity-weighted measure of the total numberof stars in a galaxy. The correlation between N and σ is eventighter than that between Mg2 and σ. Finally, we deriveFP photometric parameters for 280 galaxies from the SBF survey data set.Comparisons with external sources allow us to estimate the errors onthese parameters and derive the correction necessary to bring them on tothe SMAC system. The data are used in a forthcoming paper, whichcompares the distances derived from the FP and SBF methods.
| Southern Isolated Galaxy Triplets
Seventy-six isolated triple systems of galaxies with declinatiosnδ<-3° were selected using ESO/SERC and POSS-I sky surveydata. The equatorial coordinates, configuration types, angular sizes,component angular separations, component morphological types, totalmagnitudes, and other parameters are reported for each triplet.Radial-velocity estimates are available for all components in 33 of the76 triplets. The median values of the main dynamicalparametersradial-velocity dispersion, mean harmonic radius,absolute magnitudes of member galaxies, and mass-to-luminosityratiosare similar to those obtained earlier for 83 isolatedtriple systems with δ>-3°.
| Line-of-sight velocity distributions of 53 early-type galaxies
55 long-slit spectra of 53 early-type galaxies were observed at LaSilla/ESO and reduced using standard methods. The line-of-sight velocitydistributions (LOSVDs) were measured using the fourier quotient methodand the fourier fitting method as described by van der Marel et al.(\cite{vdmarel93}). 32% of the examined galaxies contain kinematicallydecoupled stellar omponents, the size of these cores was 0.40 +/- 0.28kpc, in each case the core was smaller than 1 kpc. Analysis of thekinematics reveals in 49% of the sample galaxies the signature of astellar disk component, in 15% this is uncertain. There is evidence thatthe phenomenon of kinematically decoupled components is present in thewhole class of early-type galaxies. Several correlations betweenphotometric and kinematic parameters like the (v/sigma )* vs.epsilon diagram, the anisotropy - luminosity correlation or kappa -spacewere as well examined using measurement results for spectroscopic dataand photometric data out of literature. It is also shown that thosesample galaxies with kinematically decoupled components are more likelyto be found in groups of high density, strengthening the assumption thatsuch components are remnants of merging events. Full Fig. 6 is onlyavailable at http://www.edpsciences.org
| X-ray luminosities for a magnitude-limited sample of early-type galaxies from the ROSAT All-Sky Survey
For a magnitude-limited optical sample (B_T <= 13.5 mag) ofearly-type galaxies, we have derived X-ray luminosities from the ROSATAll-Sky Survey. The results are 101 detections and 192 useful upperlimits in the range from 10^36 to 10^44 erg s^-1. For most of thegalaxies no X-ray data have been available until now. On the basis ofthis sample with its full sky coverage, we find no galaxy with anunusually low flux from discrete emitters. Below log (L_B) ~ 9.2L_⊗ the X-ray emission is compatible with being entirely due todiscrete sources. Above log (L_B) ~ 11.2 L_osolar no galaxy with onlydiscrete emission is found. We further confirm earlier findings that L_xis strongly correlated with L_B. Over the entire data range the slope isfound to be 2.23 (+/- 0.12). We also find a luminosity dependence ofthis correlation. Below log L_x = 40.5 erg s^-1 it is consistent with aslope of 1, as expected from discrete emission. Above this value theslope is close to 2, as expected from gaseous emission. Comparing thedistribution of X-ray luminosities with the models of Ciotti et al.leads to the conclusion that the vast majority of early-type galaxiesare in the wind or outflow phase. Some of the galaxies may have alreadyexperienced the transition to the inflow phase. They show X-rayluminosities in excess of the value predicted by cooling flow modelswith the largest plausible standard supernova rates. A possibleexplanation for these super X-ray-luminous galaxies is suggested by thesmooth transition in the L_x--L_B plane from galaxies to clusters ofgalaxies. Gas connected to the group environment might cause the X-rayoverluminosity.
| 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).
| 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 130.79.128.5. 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.
| 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.
| A Catalog of Stellar Velocity Dispersions. II. 1994 Update
A catalog of central velocity dispersion measurements is presented,current through 1993 September. The catalog includes 2474 measurementsof 1563 galaxies. A standard set of 86 galaxies is defined, consistingof galaxies with at least three reliable, concordant measurements. It issuggested that future studies observe some of these standard galaxies sothat different studies can be normalized to a consistent system. Allmeasurements are reduced to a normalized system using these standards.
| 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.
| Low-luminosity early-type galaxies. I - Photometry and morphology
New multiaperture photoelectric photometry in U, B, V, R, and I for 50southern low-luminosity early-type galaxies (LLEs) is presented.Asymptotic magnitude and mean surface brightness within the effectiveaperture are derived from fits to r exp 1/4 growth curves, and colorsare reduced at an effective radius for 154 galaxies. Morphological andstructural analysis of the LLE sample, based on the ESO-LV image database, shows that the average flattening of these galaxies is high. Thesample can be divided into four main categories. There is no correlationbetween the morphological type for t of not greater than -3 and any ofthe structural and geometrical properties investigated. Only a fewgalaxies show a boxy isophote shape, while a greater fraction showsdisky isophotes.
| A southern redshift survey. I - Accurate redshifts for 500 galaxies observed at SAAO
Radial velocities are presented for about 500 galaxies observed with anintensified Reticon photon-counting detector attached to the 1.9 mtelescope at the Sutherland field station of SAAO. The velocities weredetermined by cross correlation with standard velocity templates, fromthe measured wavelengths of emission lines, or from both techniques,with spectra covering the wavelength range from 3700 to 5400 A. Thefinal velocities appear to have the same zero point as H I radiovelocities, and have standard deviations of the order of 35 km/s, thoughcross-correlation velocities on their own may have significantly largererrors.
| A wide angle redshift survey of the Hydra-Centaurus region
Spectroscopic observations of 266 galaxies in the Hya-Cen region arereported. Redshift data obtained at 350-700 nm with dispersion 21 nm/mmusing the UNIT spectrograph and RPCS detector on the 1.9-m RadcliffeReflector telescope at SAO during March 1985, May 1986, and March 1987are presented in tables and graphs and briefly characterized. It isshown that the Hya supercluster is separated from the Cen superclusterby a large void at right ascension 11 h 40 min, declination -35 deg, andradial velocity 5200 km/sec; a bridge of galaxies at velocity about 3200km/sec connects the two superclusters.
| Spectroscopy and photometry of elliptical galaxies. III - UBV aperture photometry, CCD photometry, and magnitude-related parameters
Photoelectric aperture photometry of nearly 2000 individual observationsof 449 elliptical galaxies combined with published measurements usingthe self-consistent UVB color catalog developed by Burstein et al.(1987) are presented. The data are placed on a standard magnitude andcolor system, and 'total' magnitudes and effective diameters are derivedby comparison with the standard elliptical magnitude growth curve. Agraphical representation of the standard growth curve and the residualsfrom it for each galaxy are given, and a new diameter measurement Dn ispresented which can be measured reliably for elliptical galaxies andserves as an accurate distance indicator when combined with centralvelocity dispersion. Individual magnitudes, surface brightnesses,effective diameters, and values of Dn are summarized for each galaxy incatalog form.
| Spectroscopy and photometry of elliptical galaxies. II - The spectroscopic parameters
Radial velocities, velocity dispersions, and Mg line-strength indicesare measured for 469 elliptical galaxies using four telescope/detectorconfigurations. The data have been put on a common scale; the scatter ofrepeat measurements indicates an uncertainty of + or - 10 percent and +or - 0.01 mag for single determinations of sigma and Mg2, respectively.A correction for the change in linear aperture size as a function ofdistance has been derived, and mean corrected values of sigma and Mg2are adopted. The galaxies have been assigned to groups by combining thepresent velocities with those in the redshift catalog of Huchra et al.(1983) and using the algorithm of Huchra and Geller (1982).
| 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
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