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.