We present the optical spectra and simple statistical analysis for a complete sample of 110 soft X-ray-selected AGNs. About half of the sources are narrow-line Seyfert 1 galaxies (NLS1's), which have the steepest X-ray spectra, the strongest Fe ii emission, and slightly weaker [O iii] k5007 emission than broad-line Seyfert 1's (BLS1's). Kolmogorov-Smirnov tests show that NLS1's and BLS1's have clearly different distributions of the X-ray spectral slope X , X-ray short-term variability, and Fe ii equivalent widths and luminosity and Fe ii/H ratios. The differences in the [O iii]/H and [O iii] equivalent widths are only marginal. We found no significant differences between NLS1's and BLS1's in their rest-frame 0.2-2.0 X-ray luminosities, rest-frame 5100 monochromatic luminosities, bolometric luminosities, redshifts, and their H equivalent widths.

Aims. The study of the ensemble properties of the UV/optical broadband variability of quasars is hampered by the combined effects of the dependence of variability on timescale, rest-frame wavelength, and luminosity. Here, we present a new approach to analysing the dependence of quasar variability on rest-frame wavelengths. Methods. We exploited the spectral archive of the Sloan Digital Sky Survey (SDSS) to create a sample of over 9000 quasars in the Stripe 82. The quasar catalogue was matched with the Light Motion Curve Catalogue for SDSS Stripe 82 and first-order structure functions were computed from the lightcurves. The structure functions are used to create a variability indicator that is related to the same intrinsic timescales for all quasars (about 1 to 2 yr in the rest-frame). We study the variability ratios for adjacent SDSS filter bands as a function of redshift. A quantitative interpretation of these relations is provided by comparing with the results of simple Monte Carlo simulations of variable quasar spectra. Results. We confirm the well-known dependence of variability on time-lag; the best power-law fit of the sample-averaged structure function has a slope β = 0.31 ± 0.03. We also confirm that anti-correlations exist with luminosity, wavelength, and redshift, where the latter can be fully explained as a consequence of the former two dependencies. The variability ratios as a function of redshift resemble the corresponding colour index-redshift relations. While variability is almost always stronger in the bluer passband than in the redder, the variability ratio depends on whether strong emission lines contribute to either one band or the other. We find that the observed variability ratio-redshift relations are described well assuming that (a) the r.m.s. fluctuation of the quasar continuum flux follows a power law σ( f λ ) ∝ λ −2 (i.e., is bluer when brighter) and (b) the variability of the emission line flux is only ∼10% of that of the underlying continuum. These results, based upon the photometry of more than 8000 quasars, confirm the previous findings by Wilhite and collaborators for 315 quasars with repeated SDSS spectroscopy. Finally, we find that quasars with unusual spectra and weak emission lines tend to have less variability than conventional quasars. This trend is the opposite of that expected from the dilution effect of variability due to line emission and may be indicative of high Eddington ratios in these unusual quasars.

Distance estimates based on low-resolution spectroscopy and Two Micron All Sky Survey (2MASS) J magnitudes are presented for a large sample of 322 nearby candidates from Luyten's NLTT catalogue. Mainly relatively bright (typically 7 < K s < 11) and red high proper motion stars have been selected according to their 2MASS magnitudes and optical-to-infrared colours (+1 < R − K s < +7). Some LHS stars previously lacking spectroscopy have also been included. We have classified the majority of the objects as early-M dwarfs (M 2−M 5). More than 70% of our targets turned out to lie within the 25 pc horizon of the catalogue of nearby stars, with 50 objects placed within 15 pc and 8 objects being closer than 10 pc. Three objects in the 10 pc sample have no previously published spectral type: LP 876-10 (M 4), LP 870-65 (M 4.5), and LP 869-26 (M 5). A large fraction of the objects in our sample (57%) have independent distance estimates, mainly by the recent efforts of Reid and collaborators. Our distance determinations are generally in good agreement with theirs. 11 rather distant (d > 100 pc) objects have also been identified, including a probable halo, but relatively hot (T eff ∼ 13 000 K) white dwarf (LHS 1200) and 10 red dwarfs with extremely large tangential velocities (250 < v t < 1150 km s −1 ). Altogether, there are 11 red dwarfs (including one within 70 pc) with tangential velocities larger than about 250 km s −1 . All these objects are suspected to be in fact subdwarfs, if so, their distances would be only about half of our original estimates. The three most extreme objects in that respect are the K and early M dwarfs LP 323-168, LHS 5343 and LP 552-21 with corrected distances between 180 pc and 400 pc and resulting tangential velocities still larger than about 400 km s −1 .

Abstract. We present a homogeneous catalogue of galaxies in the field of the nearby galaxy cluster A 426 (Perseus) based on a survey of digitised Schmidt plates taken with the Tautenburg 2 m telescope in the B band. Accurate positions, morphological types, B 25 isophotal magnitudes, angular radii and position angles are given for 660 galaxies within a field of about 10 square-degrees, centred on α = 3 h 21 min , δ = 41• 33 (J2000). When available, the radial velocity and the most common name taken from NED or PGC are included. The catalogue comprises galaxies brighter than B 25 ≈ 19.5. The estimated limit of completeness is B 25 ≈ 18. Two thirds of the galaxies are published for the first time. The galaxy positions are measured with a mean accuracy of 0. 5, the photometric accuracy is of the order of 0.1 to 0.2 mag depending on image crowding and galaxy shape. Morphological properties were evaluated from the visual inspections of both deep images obtained from the digital co-addition of a large number of plates and higher-resolution images from single plates taken under good seeing conditions. The superimposed images unveil faint structures down to µ B ≈ 27 mag arcsec −2 . The catalogue is applied to a study of statistical properties of the galaxies in A 426: projected distribution of morphological types, segregation of morphological types, position of the cluster centre, distribution of galaxy position angles, type-dependent luminosity functions, and total B-luminosity of the the cluster. In agreement withThe catalogue is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html Based on observations made with the 2 m telescope of the Thüringer Landessternwarte Tautenburg, Germany, and with the 2.2 m telescope of the German-Spanish Astronomical Centre, Calar Alto, Spain.Visiting Astronomer, German-Spanish Astronomical Centre, Calar Alto, operated by the Max-Planck-Institute for Astronomy, Heidelberg, jointly with the Spanish National Comission for Astronomy.previous studies, we find a relative spiral-deficiency in the central region (r < ∼ 30 ). The percentage of identified S+Irr increases, however, increases from 30% in the centre to more than 50% in the outer parts. The projected distributions of early-and late-type galaxies are not co-centred. The total luminosity of all supposed member galaxies in the surveyed area is estimated to (6.5 ± 0.9) 10 12 × h −2 50 blue solar luminosities. We do not analyse in detail possible substructures in the projected distribution of galaxies. However, we found a pronounced clump of galaxies at α(J2000.0) = 3 h 20. m 4, δ(J2000.0) = 43 • 4 , which is shown to be a background cluster at z ≈ 0.050.

Context. Large spectroscopic surveys have discovered very peculiar and hitherto unknown types of active galactic nuclei (AGN). Such rare objects may hold clues to the accretion history of the supermassive black holes at the centres of galaxies. Aims. We aim to create a sizeable sample of unusual quasars from the unprecedented spectroscopic database of the Sloan Digital Sky Survey (SDSS). Methods. We exploit the spectral archive of the SDSS Data Release 7 to select unusual quasar spectra. The selection method is based on a combination of the power of self-organising maps and the visual inspection of a huge number of spectra. Self-organising maps were applied to nearly 10 5 spectra classified as quasars at redshifts from z = 0.6 to 4.3 by the SDSS pipeline. Particular attention was paid to minimise possible contamination by rare peculiar stellar spectral types. All selected quasar spectra were individually studied to determine the object type and the redshift.Results. We present a catalogue of 1005 quasars with unusual spectra. These spectra are dominated by either broad absorption lines (BALs; 42%), unusual red continua (27%), weak emission lines (18%), or conspicuously strong optical and/or UV iron emission (11%). This large sample provides a useful resource for both studying properties and relations of/between different types of unusual quasars and selecting particularly interesting objects, even though the compilation is not aimed at completeness in a quantifiable sense. The spectra are grouped into six types for which composite spectra are constructed and mean properties are computed. Remarkably, all these types turn out to be on average more luminous than comparison samples of normal quasars after a statistical correction is made for intrinsic reddening (E(B − V) ≈ 0 to 0.4 for SMC-like extinction). Both the unusual BAL quasars and the strong iron emitters have significantly lower radio luminosities than normal quasars. We also confirm that strong BALs avoid the most radioluminous quasars. For 32 particularly interesting objects, individual spectra are presented. Among these objects are quasars with many narrow BAL troughs and one quasar where the continuum is strongly suppressed by overlapping BAL troughs across nearly the whole SDSS spectrum. Finally, we create a sample of quasars similar to the two "mysterious" objects discovered by Hall et al. (2002, ApJS, 141, 267) and briefly discuss the quasar properties and possible explanations of their highly peculiar spectra.

We carry out a large program to classify newly discovered star clusters from Froebrich, Scholz & Raftery in the inner Galaxy. Here, we present a first analysis of a new high-priority globular cluster candidate, FSR 1735 at l = 339.1879; b = −1.8534, based on new deep, near-infrared observations from Sofi at the ESO New Technology Telescope (NTT). A significant peak in the K-band luminosity function is found, which is interpreted as the clump of post-He-flash stars. The distance and the reddening of the cluster are determined to 9.1 kpc and A K = 0.5 mag, respectively, the metallicity is estimated to be [M/H] = −0.8. Radial star density profiles are used to measure the core radius and the tidal radius of the cluster. The lack of signs for ongoing star formation and the position in the Galaxy pose strong arguments against the interpretation of this object as a young or old open cluster. All the observational evidence is in agreement with the interpretation that FSR 1735 is a so far unknown globular cluster in the inner Galaxy.

Aims. Although the variability in the ultraviolet and optical domain is one of the major characteristics of quasars, the dominant underlying mechanisms are still poorly understood. There is a broad consensus on the relationship between the strength of the variability and such quantities as time-lag, wavelength, luminosity, and redshift. However, evidence on a dependence on the fundamental parameters of the accretion process is still inconclusive. This paper is focused on the correlation between the ultraviolet quasar long-term variability and the accretion rate. Methods. We compiled a catalogue of about 4000 quasars including individual estimators for the variability strength derived from the multi-epoch photometry in the SDSS Stripe 82, virial black hole masses M derived from the Mg  line, and mass accretion ratesṀ from the Davis-Laor scaling relation. Several statistical tests were applied to evaluate the correlations of the variability with luminosity, mass, Eddington ratio, and accretion rate. Results. We confirm the existence of significant anti-correlations between the variability estimator V and the accretion rateṀ, the Eddington ratio ε, and the bolometric luminosity L bol , respectively. The Eddington ratio is tightly correlated withṀ. A weak, statistically not significant positive trend is indicated for the dependence of V on M. As a side product, we find a strong correlation of the radiative efficiency η with M in our sample. We show via numerical simulations that this trend is most likely produced by selection effects in combination with the mass errors and the use of the scaling relation forṀ. The anti-correlations of V withṀ, ε, and L bol cannot be explained in such a way. The strongest anti-correlation is found between V andṀ. However, it is difficult to decide which of the quantities L, ε, andṀ is intrinsically correlated with V and which of the observed correlations of V are produced by the L − ε −Ṁ relation. A V −Ṁ anti-correlation is qualitatively expected for the strongly inhomogeneous accretion disks. We argue that the observed amplitudes of the variability at far-UV wavelengths, the stochastic nature of variability, and the variability time-scales are not adequately explained by the simple multi-temperature black-body model of a standard disk and suggest to check whether the strongly inhomogeneous disk model is capable of reproducing these observations better.

Accretion is a fundamental process which establishes the dynamics of the protoplanetary disk and the final properties of the forming star. In solar-type stars, the star-disk coupling is determined by the magnetic field structure, which is responsible for funneling material from the disk midplane to higher latitudes on the star. Here, we use pan-chromatic data for the Herbig Ae star MWC 480 to address whether similar processes occur in intermediatemass stars. MWC 480 has X-ray emission typical of actively accreting Herbig Ae stars, but with ∼10× more photoelectric absorption than expected from optical and FUV data. We consider three sources for the absorption: the disk, absorption in a wind or jet, and accretion. While we detect the disk in scattered light in a re-analysis of archival Hubble Space Telescope data, the data are consistent with grazing illumination of the dust disk. We find that MWC 480's disk is stratified, geometrically thin, and is not responsible for the observed photoelectric absorption. MWC 480 drives a bipolar jet, but with a mass-loss rate that is low compared to other Herbig Ae stars, where the outflow is more favorably oriented and enhanced photoelectric absorption is not seen. This excludes a jet or wind origin for the enhanced photoelectric absorption. We compare MWC 480's O vi emission with other Herbig Ae stars. The distribution of the emission in inclination, and lack of a correlation of profile shape and system inclination excludes equatorially confined accretion for the FUSE Herbig Ae stars. The photoelectric absorption data further suggest that the accretion footprint on MWC 480 and other Herbig Ae stars is located at high-temperate, rather than polar, latitudes. These findings support the presence of funneled accretion in MWC 480 and Herbig Ae stars, strengthening the parallel to T Tauri stars.