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We analyse the sizes, colour gradients, and resolved stellar mass distributions for 36 massive and passive galaxies in the cluster XMMUJ2235-2557 at z=1.39 using optical and near-infrared Hubble Space Telescope imaging. We derive light-weighted S\'ersic fits in five HST bands ($i_{775},z_{850},Y_{105},J_{125},H_{160}$), and find that the size decreases by ~20% going from $i_{775}$ to $H_{160}$ band, consistent with recent studies. We then generate spatially resolved stellar mass maps using an empirical relationship between $M_{*}/L_{H_{160}}$ and $(z_{850}-H_{160})$ and use these to derive mass-weighted S\'ersic fits: the mass-weighted sizes are ~41% smaller than their rest-frame $r$-band counterparts compared with an average of ~12% at z~0. We attribute this evolution to the evolution in the $M_{*}/L_{H_{160}}$ and colour gradient. Indeed, as expected, the ratio of mass-weighted to light-weighted size is correlated with the $M_{*}/L$ gradient, but is also mildly correlated with the mass surface density and mass-weighted size. The colour gradients $(\nabla_{z-H})$ are mostly negative, with a median value of $\sim0.45$ mag dex$^{-1}$, twice the local value. The evolution is caused by an evolution in age gradients along the semi-major axis ($a$), with $\nabla_{age} = d \log(age) / d \log(a)$ $\sim-0.33$, while the survival of weaker colour gradients in old, local galaxies implies that metallicity gradients are also required, with $\nabla_{Z} = d \log(Z) / d \log(a)$ $\sim-0.2$. This is consistent with recent observational evidence for the inside-out growth of passive galaxies at high redshift, and favours a gradual mass growth mechanism, such as minor mergers., Comment: 30 pages, 25 figures, 4 tables, accepted for publication in MNRAS

We present a comparison between the peculiar velocity field measured from the ENEAR all-sky $D_n-\sigma$ catalog and that derived from the galaxy distribution of the IRAS PSCz redshift survey. The analysis is based on a modal expansion of these data in redshift space by means of spherical harmonics and Bessel functions. The effective smoothing scale of the expansion is almost linear with redshift reaching 1500km/s at 3000km/s. The general flow patterns in the filtered ENEAR and PSCz velocity fields agree well within 6000km/s, assuming a linear biasing relation between the mass and the PSCz galaxies. The comparison allows us to determine the parameter $\beta=\Omega^{0.6}/b$, where $\Omega$ is the cosmological density parameter and $b$ is the linear biasing factor. A likelihood analysis of the ENEAR and PSCz modes yields $\beta=0.5 +- 0.1$, in good agreement with values obtained from Tully-Fisher surveys., Comment: Submitted to MNRAS

The disruption of a binary star system by the massive black hole at the Galactic Centre, SgrA*, can lead to the capture of one star around SgrA* and the ejection of its companion as a hypervelocity star (HVS). We consider the possibility that these stars may have planets and study the dynamics of these planets. Using a direct $N$-body integration code, we simulated a large number of different binary orbits around SgrA*. For some orbital parameters, a planet is ejected at a high speed. In other instances, a HVS is ejected with one or more planets orbiting around it. In these cases, it may be possible to observe the planet as it transits the face of the star. A planet may also collide with its host star. In such cases the atmosphere of the star will be enriched with metals. In other cases, a planet is tidally disrupted by SgrA*, leading to a bright flare.

This work aims to study the distribution of luminous and dark matter in Coma early-type galaxies. Dynamical masses obtained under the assumption that mass follows light do not match with the masses of strong gravitational lens systems of similar velocity dispersions. Instead, dynamical fits with dark matter halos are in good agreement with lensing results. We derive mass-to-light ratios of the stellar populations from Lick absorption line indices, reproducing well the observed galaxy colours. Even in dynamical models with dark matter halos the amount of mass that follows the light increases more rapidly with galaxy velocity dispersion than expected for a constant stellar initial mass function (IMF). While galaxies around sigma ~ 200 km/s are consistent with a Kroupa IMF, the same IMF underpredicts luminous dynamical masses of galaxies with sigma ~ 300 km/s by a factor of two and more. A systematic variation of the stellar IMF with galaxy velocity dispersion could explain this trend with a Salpeter IMF for the most massive galaxies. If the IMF is instead constant, then some of the dark matter in high velocity dispersion galaxies must follow a spatial distribution very similar to that of the light. A combination of both, a varying IMF and a component of dark matter that follows the light is possible as well. For a subsample of galaxies with old stellar populations we show that the tilt in the fundamental plane can be explained by systematic variations of the total (stellar + dark) mass inside the effective radius. We tested commonly used mass estimator formulae, finding them accurate at the 20-30% level.

Optical imaging and spectroscopic observations of the z = 0.245 double galaxy cluster Abell 2465 are described. This object appears to be undergoing a major merger. It is a double X-ray source and is detected in the radio at 1.4 GHz. The purpose of this paper is to investigate signatures of the interaction of the two components. Redshifts were measured to determine velocity dispersions and virial radii of each component. The technique of fuzzy clustering was used to assign membership weights to the galaxies in each clump. Using redshifts of 93 cluster members within 1.4 Mpc of the subcluster centres, the virial masses of the north-east (NE) and south-west (SW) components are M v = 4.1 ± 0.8 x 10 14 and 3.8 ± 0.8 x 10 14 M ⊙ , respectively. These agree within the errors with masses from X-ray scaling relations. The projected velocity difference between the two subclusters is 205 ± 149 km s ―1 . The anisotropy parameter, β, is found to be low for both components. Spectra of 37 per cent of the spectroscopically observed galaxies show emission lines and are predominantly star forming in the diagnostic diagram. No strong active galactic nucleus sources were found. The emission-line galaxies tend to lie between the two cluster centres with more near the SW clump. The luminosity functions of the two subclusters differ. The NE component is similar to many rich clusters, while the SW component has more faint galaxies. The NE clump's light profile follows a single Navarro-Frenk-White profile with c = 10 while the SW is better fitted with an extended outer region and a compact inner core, consistent with available X-ray data indicating that the SW clump has a cooling core. The observed differences and properties of the two components of Abell 2465 are interpreted to have been caused by a collision 2―4 Gyr ago, after which they have moved apart and are now near their apocentres, although the start of a merger remains a possibility. The number of emission-line galaxies gives weight to the idea that galaxy cluster collisions trigger star formation.

The origins of the bulge and disc components of galaxies are of primary importance to understanding galaxy formation. Here bulge-disc decomposition is performed simultaneously in B- and R-bands for 922 bright galaxies in 8 nearby (z < 0.06) clusters with deep redshift coverage using photometry from the NOAO Fundamental Plane Survey. The total galaxy colours follow a universal colour-magnitude relation (CMR). The discs of L_* galaxies are 0.24 magnitudes bluer in $B-R$ than bulges. Bulges have a significant CMR slope while the CMR slope of discs is flat. Thus the slope of the CMR of the total light is driven primarily (60%) by the bulge-CMR, and to a lesser extent (40%) by the change in the bulge-to-total ratio as a function of magnitude. The colours of the bulge and disc components do not depend on the bulge-to-total ratio, for galaxies with bulge-to-total ratios greater than 0.2. While the colours of the bulge components do not depend significantly on environment, the median colours of discs vary significantly, with discs in the cluster centre redder by 0.10 magnitudes than those at the virial radius. Thus while star formation in bulges appears to be regulated primarily by mass-dependent, and hence presumably internal, processes, that of discs is affected by the cluster environment.

We use oblate axisymmetric dynamical models including dark halos to determine the orbital structure of intermediate mass to massive Coma early-type galaxies. We find a large variety of orbital compositions. Averaged over all sample galaxies the unordered stellar kinetic energy in the azimuthal and the radial direction are of the same order, but they can differ by up to 40 percent in individual systems. In contrast, both for rotating and non-rotating galaxies the vertical kinetic energy is on average smaller than in the other two directions. This implies that even most of the rotating ellipticals are flattened by an anisotropy in the stellar velocity dispersions. Using three-integral axisymmetric toy models we show that flattening by stellar anisotropy maximises the entropy for a given density distribution. Collisionless disk merger remnants are radially anisotropic. The apparent lack of strong radial anisotropy in observed early-type galaxies implies that they may not have formed from mergers of disks unless the influence of dissipational processes was significant., 14 pages, 8 figures; accepted for publication in MNRAS

We present GALEX near-UV (NUV) and 2MASS J band photometry for red sequence galaxies in local clusters. We define quiescent samples according to a strict emission threshold, removing galaxies with very recent star formation. We analyse the NUV-J colour-magnitude relation (CMR) and find that the intrinsic scatter is an order of magnitude larger than for the analogous optical CMR (~0.35 rather than 0.05 mag), in agreement with previous studies. Comparing the NUV-J colours with spectroscopically-derived stellar population parameters, we find a strong (> 5.5sigma) correlation with metallicity, only a marginal trend with age, and no correlation with the alpha/Fe ratio. We explore the origin of the large scatter and conclude that neither aperture effects nor the UV upturn phenomenon contribute significantly. We show that the scatter could be attributed to simple `frosting' by either a young or a low metallicity subpopulation.

The absolute visual magnitudes, M v , of A-M stars are based on calculated Hipparcos trigonometric parallaxes. The sample used consists of 30986 unreddened and reddened A-M stars in luminosity classes Ia, Iab, Ib, II, III, IV and V. The colour excesses of the reddened stars were calculated using the mean colour indices, according to the SIMBAD data base and the intrinsic B - V values calibrated for the given spectral types and luminosity classes by Schmidt-Kaler. The values of the total-to-selective extinction, R v = A v /E(B-V), for all the reddened stars were calculated from previously published near-infrared photometric measurements. The calculated visual magnitudes, M v , of A-M stars compare with the earlier determinations of Schmidt-Kaler. The mean absolute magnitudes published by Schmidt-Kaler are generally brighter (except for the stars in luminosity classes V and IV) than those determined in this paper.

A new method of determining absolute visual magnitudes of early-type stars, based on averaging Hipparcos parallaxes (ESA 1997) inside samples of the same spectrum and luminosity (Sp/L) classes, is proposed. The used sample consists of 6262 unreddened and reddened OB stars as well as 430 Be stars of luminosity classes Ia, Iab, Ib, II, III, IV and V. The colour excesses of the reddened stars have been calculated using the mean colour indices, according to the SIMBAD data base and the intrinsic (B − V) values calibrated for given Sp/L classes by Papaj, Wegner & Kre� . The values of the total-to-selective extinction RV = AV /E(B − V) for all reddened stars were calculated from the published near-infrared photometric measurements. The calculated visual magnitudes MV of OB and Be stars are compared to those published by Wegner in Paper I, and the earlier determinations of Schmidt-Kaler. Generally, the new values of MV agree well with those given in Paper I, except those for O stars which are systematically brighter than the earlier estimates. The mean absolute magnitudes published by Schmidt-Kaler are generally brighter (except OB stars of luminosity class V) than those determined in this paper.

We present peculiar velocities for 84 clusters of galaxies in two large volumes at distances between 6000 and 15000 km/s in the directions of Hercules-Corona Borealis and Perseus-Pisces-Cetus. These velocities are based on Fundamental Plane (FP) distance estimates for early-type galaxies in each cluster. We fit the FP using a maximum likelihood algorithm which accounts for both selection effects and measurement errors, and yields FP parameters with smaller bias and variance than other fitting procedures. We find a best-fit FP with coefficients consistent with the best existing determinations. We measure the bulk motions of the sample volumes using the 50 clusters with the best-determined peculiar velocities. We find the bulk motions in both regions are small, and consistent with zero at about the 5% level. The EFAR results are in agreement with the small bulk motions found by Dale et al. (1999) on similar scales, but are inconsistent with pure dipole motions having the large amplitudes found by Lauer & Postman (1994) and Hudson et al. (1999). The alignment of the EFAR sample with the Lauer & Postman dipole produces a strong rejection of a large-amplitude bulk motion in that direction, but the rejection of the Hudson et al. result is less certain because their dipole lies at a large angle to the main axis of the EFAR sample. We find the bulk motion of our sample is consistent with most cosmological models that approximately reproduce the shape and normalisation of the observed galaxy power spectrum. We conclude that existing measurements of large-scale bulk motions provide no significant evidence against standard models for the formation of structure., to appear in MNRAS, 27 pages, EFAR paper 7

We present a measurement of the cluster X-ray luminosity-temperature relation out to high redshift (z~0.8). Combined ROSAT PSPC spectra of 91 galaxy clusters detected in the Wide Angle ROSAT Pointed Survey (WARPS) are simultaneously fit in redshift and luminosity bins. The resulting temperature and luminosity measurements of these bins, which occupy a region of the high redshift L-T relation not previously sampled, are compared to existing measurements at low redshift in order to constrain the evolution of the L-T relation. We find a best fit to low redshift (z1 keV, to be L proportional to T^(3.15\pm0.06). Our data are consistent with no evolution in the normalisation of the L-T relation up to z~0.8. Combining our results with ASCA measurements taken from the literature, we find eta=0.19\pm0.38 (for Omega_0=1, with 1 sigma errors) where L_Bol is proportional to (1 + z)^eta T^3.15, or eta=0.60\pm0.38 for Omega_0=0.3. This lack of evolution is considered in terms of the entropy-driven evolution of clusters. Further implications for cosmological constraints are also discussed., 11 pages, 7 figures, accepted for publication in MNRAS

The extinction curves of single clouds, seen towards the stars HD 147165, 179406 and 202904, have been modelled using various mixtures containing both the bare and inhomogeneous (composite and/or multilayer) grains. It has been shown that the models composed of the bare graphite and silicate grains together with the multilayer grains containing silicates, organic refractory and water ice, are more useful in explaining extinction under the reduced cosmic abundances. The models based on Mathis' composite grains or on Greenberg & Li's core-mantle grains can also provide quite good fits of the extinction and the measured scattering parameters, but still require an excessive amount of carbon which results in too large a C/O ratio. The inhomogeneous grains essentially contribute to the extinction in practically the whole wavelength range of our extinction curves. As a rule, such grains have quite wide size distributions, centred at around 100 nm, although graphite grains are mainly of small sizes.

A B STR ACT The extinction curves of single clouds, seen towards the stars HD 147165, 179406 and 202904, have been modelled using various mixtures containing both the bare and inhomogeneous (composite and/or multilayer) grains. It has been shown that the models composed of the bare graphite and silicate grains together with the multilayer grains containing silicates, organic refractory and water ice, are more useful in explaining extinction under the reduced cosmic abundances. The models based on Mathis’ composite grains or on Greenberg & Li’s core-mantle grains can also provide quite good fits of the extinction and the measured scattering parameters, but still require an excessive amount of carbon which results in too large a C/O ratio. The inhomogeneous grains essentially contribute to the extinction in practically the whole wavelength range of our extinction curves. As a rule, such grains have quite wide size distributions, centred at around 100 nm, although graphite grains are mainly of small sizes.

We demonstrate that the method of regularization designed to resolve inverse problems may be successfully applied in analysis of interstellar extinction_ The absolute extinction curves of apparently single clouds, seen towards the stars HD 147165,179406 and 202904, have been derived and modelled using multicomponent bare spherical dust grain mixtures containing graphite, silicates, various types of amorphous carbon, SiC and water ice. We find that the grain size distributions are essentially different from Mathis, Rumpl & Nordsieck's (MRN) power law and may be multimodal. From the recent data about reduced ('" 2/3 solar) cosmic abundances, it has been shown that a mixture of graphite, silicate and ice grains explains quite satisfactorily the extinction towards the stars under analysis whereas a traditional mixture of graphite and silicate grains fails.

The collection of 166 extinction curves derived from the published low-resolution spectra acquired with the aid of the spectrometer on board the TD-1 satellite is presented. The observed variety of extinction laws is apparently due to the varied physical parameters of interstellar clouds; for example, the bright stars, included in the sample of TD-1 material, are very likely to be obscured by single clouds (interstellar or circumstellar). The system of standards (published already by the authors) constructed with the aid of a special procedure allowing the possible effects of spectral mismatch to be avoided and making possible the derivation of extinction curves even in cases of very small E (B−V) s, was applied

Dynamical models for 17 Coma early-type galaxies are presented. The galaxy sample consists of flattened, rotating as well as non-rotating early-types including cD and S0 galaxies with luminosities between M=-18.79 and M=-22.56. Kinematical long-slit observations cover at least the major and minor axis and extend to 1-4 effective radii. Axisymmetric Schwarzschild models are used to derive stellar mass-to-light ratios and dark halo parameters. In every galaxy models with a dark matter halo match the data better than models without. The statistical significance is over 95 percent for 8 galaxies, around 90 percent for 5 galaxies and for four galaxies it is not significant. For the highly significant cases systematic deviations between observed and modelled kinematics are clearly seen; for the remaining galaxies differences are more statistical in nature. Best-fit models contain 10-50 percent dark matter inside the half-light radius. The central dark matter density is at least one order of magnitude lower than the luminous mass density. The central phase-space density of dark matter is often orders of magnitude lower than in the luminous component, especially when the halo core radius is large. The orbital system of the stars along the major-axis is slightly dominated by radial motions. Some galaxies show tangential anisotropy along the minor-axis, which is correlated with the minor-axis Gauss-Hermite coefficient H4. Changing the balance between data-fit and regularisation constraints does not change the reconstructed mass structure significantly. Model anisotropies tend to strengthen if the weight on regularisation is reduced, but the general property of a galaxy to be radially or tangentially anisotropic, respectively, does not change. (abridged), 31 pages, 34 figures; accepted for publication in MNRAS

We present measurements of the clustering properties of bright ($L>L_{*}$) z$\sim$4 Lyman Break Galaxies (LBGs) selected from the Oxford-Dartmouth Thirty Degree Survey (ODT). We describe techniques used to select and evaluate our candidates and calculate the angular correlation function which we find best fitted by a power law, $\omega(\theta)=A_{w}\theta^{-\beta}$ with $A_{w}=15.4$ (with $\theta$ in arcseconds), using a constrained slope of $\beta=0.8$. Using a redshift distribution consistent with photometric models, we deproject this correlation function and find a comoving $r_{0}=11.4_{-1.9}^{+1.7}$ h$_{100}^{-1}$ Mpc in a $\Omega_m=0.3$ flat $\Lambda$ cosmology for $i_{AB}\leq24.5$. This corresponds to a linear bias value of $b=8.1_{-2.6}^{+2.0}$ (assuming $\sigma_{8}=0.9$). These data show a significantly larger $r_{0}$ and $b$ than previous studies at $z\sim4$. We interpret this as evidence that the brightest LBGs have a larger bias than fainter ones, indicating a strong luminosity dependence for the measured bias of an LBG sample. Comparing this against recent results in the literature at fainter (sub-$L_{*}$) limiting magnitudes, and with simple models describing the relationship between LBGs and dark matter haloes, we discuss the implications on the implied environments and nature of LBGs. It seems that the brightest LBGs (in contrast with the majority sub-$L_{*}$ population), have clustering properties, and host dark matter halo masses, that are consistent with them being progenitors of the most massive galaxies today., Comment: Accepted for Publication in MNRAS. 15 Pages, 13 Figures

We have used the EFAR sample of galaxies to study the light distributions of early-type galaxies. We decompose the 2D light distribution of the galaxies in a flattened spheroidal component with a Sersic radial light profile and an inclined disc component with an exponential light profile. We show that the brightest, bulge dominated elliptical galaxies have a fairly broad distribution in the Sersic profile shape parameter n_B, with a median of about 3.7 and a sigma of ~0.9. Other galaxies have smaller n_B values, meaning that spheroids are in general less concentrated than the n_B=4 de Vaucouleurs-law profile. The results of our light decompositions are robust, even though without kinematic information we cannot prove that the spheroids and discs are really pressure- and rotation-supported stellar systems. If we assume that the detected spheroids and discs are indeed separate components, we can draw the following conclusions: 1) the spheroid and disc scale sizes are correlated; 2) bulge-to-total luminosity ratios, bulge effective radii, and bulge n_B values are all positively correlated; 3) the bivariate space density distribution of elliptical galaxies in the (luminosity, scale size)-plane is well described by a Schechter luminosity function in and a log-normal scale-size distribution at a given luminosity; 4) at the brightest luminosities, the scale size distribution of elliptical galaxies is similar to those of bright spiral galaxies; at fainter luminosities the elliptical scale size distribution peaks at distinctly smaller sizes than the spiral galaxy distribution; and 5) bulge components of early-type galaxies are typically a factor 1.5 to 2.5 smaller than the disks of spiral galaxies, while disc components of early-type galaxies are typically twice as large as the discs of spiral galaxies. [abridged], Comment: 16 pages, 18 figures. Accepted for publication in the MNRAS

We present the results of the deepest optically identified X-ray survey yet made. The X-ray survey was obtained with the ROSAT position-sensitive proportional counter (PSPC) and reaches a flux limit of 1.6 × 10-15 erg cm-2 s-1 (0.5-2.0 keV). Above a flux limit of 2 × 10-15 erg cm-2 s-1 we define a complete sample of 70 sources, of which 59 are identified. For a further five sources we have tentative identifications and for a further four the X-ray error boxes are blank to R = 23 mag. At brighter fluxes (≥10-14 erg cm-2 s-1) we confirm the results of previous less deep X-ray surveys, with 84 per cent of our sources being QSOs. However, at the faint flux limit the survey is dominated by a population of galaxies with narrow emission lines (NELGs). In addition, at intermediate fluxes we find a small number of groups and clusters of galaxies at redshifts generally >0.3. Most of these groups are poor systems of low X-ray luminosity and the number that we find is consistent with a zero evolutionary scenario, unlike the situation for high-luminosity clusters at the same redshift. To a flux limit of 2 × 10-15 erg cm-2 s-1, QSOs contribute >31 percent of the cosmic soft X-ray background (XRB), groups/clusters contribute ∼10 per cent and NELGs contribute ∼8 per cent. However, the QSO differential source count slope below 10-14 erg cm-2 s-1 is ∼ -1.4, severely sub-Euclidean, as is the (poorly defined) group/cluster slope, whereas the differential NELG slope is close to Euclidean (∼ -2.4). If the NELG source counts continue to rise at that slope, all of the remaining cosmic soft XRB will be explained by a flux limit of ∼1-2 × 10-16 erg cm-2 s-1, with NELGs contributing about one quarter of the XRB. The average NELG X-ray spectrum is harder than that of the QSOs, and similar to that of the remaining unresolved cosmic XRB, suggesting that NELGs will also be substantial contributors to the XRB at higher energies. The observed NELGs lie in the redshift range 0.1-0.6 and have MR= -20 to -23, approximately 3 mag more luminous than typical field galaxies. They have predominantly blue colours, and some are definitely spirals, but the presence of some ellipticals cannot yet be ruled out. Many are in interacting or disturbed systems. The NELGs have optical spectra similar to those of the majority of the field galaxy population at a similar redshift and may simply be the more luminous members of the emission-line field galaxy population. Based on optical line ratios and X-ray/optical flux ratios, the NELGs, both as a sample and within individual galaxies, appear to be a mixture of starburst galaxies and true active galactic nuclei (AGN)., This work was supported by grants to a number of authors from the UK Science and Engineering Research Council and Particle Physics and Astronomy Research Council. KOM acknowledges support from the Royal Society. FJC acknowledges partial financial support from the DGES under project PB95-0122.

We present R-band CCD photometry for 776 galaxies observed in the EFAR project. The photometry is compared with photoelectric data, showing that a common zero-point good to better than 1 per cent and a precision of 0.03 mag per zero-point have been achieved. We give the circularly averaged surface brightness profiles and the photometric parameters of the 762 programme galaxies, D n diameters (at 20.5 mag arcsec -2), half-luminosity radii R e, total magnitudes m T and average effective surface brightnesses 〈SB e〉. The photometric parameters are derived using the seeing-convolved, R 1/4-plus-exponential fitting algorithm described in Paper IV which optimally combines multiple profiles and corrects for sky subtraction errors. The parameters of the two-component fits are also given. We find that the diameters D n span the range 4.8-90 arcsec, with 〈logD n〉 = 1.30 or 20 arcsec. The run of the effective radii R e is 1.6-71.2 arcsec, with 〈log R e〉 = 0.84 or 6.9 arcsec. The total magnitudes m T extend from 10.57 to 15.97 mag, with a mean of 13.85 mag. The effective surface brightnesses 〈SB e〉 span the range 17.78-22.35 mag arcsec -2 with a mean of 19.89 mag arcsec -2. The mean photometric precisions of D n diameters, magnitudes and surface brightnesses are 0.9 per cent, 0.017 mag and 0.017 mag arcsec -2 respectively. In addition, the fitting scheme quantifies and minimizes the many systematic biases affecting the determination of galaxy photometric parameters. We find simple R 1/4 fits for only 14 per cent of the total, and simple exponential fits for ≉ 1 per cent of the total. The spread in sky values measured from the different profiles of the same object is less than 1 per cent in 85 per cent of the cases. In 80 per cent of the fits a reduced χ 2 of less than 12 is obtained. More than 90 per cent of the galaxies have at least one profile extending to more than 4 half-luminosity radii. More than 90 per cent of the galaxies are well resolved, having at least one profile where R e > 2Γ, where Γ is the FWHM of the point-spread function. More than 80 per cent of the profiles have a global signal-to-noise ratio larger than 300. The extrapolation needed to derive total magnitudes is less than 10 per cent for 80 per cent of the fits. More than 80 per cent of the galaxies have mean effective surface brightness larger than the observed sky brightness. In 90 per cent of the profiles the estimate of the contamination of the sky by the galaxy light is less than 1 per cent. Summarizing, the extensive internal comparisons, together with Monte Carlo simulations (see Paper IV), show that we derive total magnitudes and half-luminosity radii to better than 0.15 mag and 25 per cent respectively for 90 per cent of our sample. In contrast, external comparisons show that data in the literature can be strongly affected by systematic errors due to large extrapolations, small radial range, sky subtraction errors, seeing effects, and the use of a simple R 1/4 fit. The resulting errors can easily amount to more than 0.5 mag in the total magnitudes and 50 per cent in the half-luminosity radii. The errors on the combined quantity FP = log R e - 0.3 〈SB e〉 which enters the Fundamental Plane equation remain, however, always smaller than 0.03 dex. The galaxy type classification, based on all of the information available to us, shows that 31 per cent of the sample objects, visually selected from photographic images to be of early type, are in fact spiral or barred galaxies. The 69 per cent of galaxies classified as early-type can be subdivided into cD (8 per cent), E (12 per cent with a simple R 1/4 law best fit), and E/S0 (48 per cent with a disc-plus-bulge best fit). The photographic diameters D W measured in Paper I correlate with D n diameters or, equivalently, with the Fundamental Plane quantity FP = log R e - 0.3 〈SB e〉, with 23 per cent scatter for the early-type sample. © 1997 RAS.