%...Journal: PASP %R=BibCode %A=Authors %B=Abstract %c=Copyright %D=Date of publication %E=Electronic file %F=Original File %I=Institute and/or Footnotes %J-last page %K=Keywords %T=Title %R 1999PASP..111..919H %F ori/PASPv111n762 %J-945 %T The Distribution of Heavy Elements in Spiral and Elliptical Galaxies. (Invited Review). %A Henry, R.B.C. %I Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019; (henry@mail.nhn.ou.edu) and %A Worthey, Guy %I Department of Physics and Astronomy, St. Ambrose University, Davenport, IA 52803; (gworthey@saunix.sau.edu) %B In large disk and spheroidal galaxies, spatially resolved abundance information can be extracted by analysis of either emission lines, absorption lines, or both, depending on the situation. This review recaps significant results as they apply to nondwarf galaxies, including the Milky Way, spiral disks and bulges, and elliptical and lenticular galaxies. Methods for determining abundances are explained in appendices.\par Conclusions that span the galaxy types treated here are as follows. All galaxies, on average, have heavy-element abundances (metallicities) that systematically decrease outward from their galactic centers while their global metallicities increase with galaxy mass. Abundance gradients are steepest in normal spirals and are seen to be progressively flatter going in order from barred spirals to lenticulars to ellipticals. The distribution of abundances N(Z) versus {\em Z} is strongly peaked compared with simple closed-box model predictions of chemical enrichment in all galaxy types. That is, a ``G dwarf problem'', commonly known in the solar cylinder, exists for all large galaxies.\par For spiral galaxies, local metallicity appears to be correlated with total (disk+bulge) surface density. Examination of N/O versus O/H in spiral disks indicates that production of N is dominated by primary processes at low metallicity and secondary processes at high metallicity. Carbon production increases with increasing metallicity. Abundance ratios Ne/O, S/O, and Ar/O appear to be universally constant and independent of metallicity, which argues either that the initial mass function (IMF) is universally constant or that these ratios are not sensitive to IMF variations. In the Milky Way, there is a rough age-metallicity trend with much scatter, in the sense that older stars are more metal poor.\par In elliptical galaxies, nuclear abundances are in the range [Z/H]=0.0-0.4, but the element mixture is not scaled-solar. In large elliptical galaxies [Mg/Fe] is in the range 0.3-0.5, decreasing to {approx}0 in smaller elliptical galaxies. Other light elements track the Mg enhancement, but the heavier Ca tracks Fe. Velocity dispersion appears to be a key parameter in the modulation of [Mg/Fe], but the cause of the connection is unclear. %K Galaxy: Abundances %K Galaxy: Evolution %K Galaxies: Abundances %K Galaxies: Elliptical and Lenticular, cD %K Galaxies: Evolution %K Galaxies: ISM %K Galaxies: Spiral %K ISM: Abundances %R 1999PASP..111..946E %F ori/PASPv111n762 %J-953 %T KECK HIRES Spectroscopy of APM 08279+5255(1). (Research Note). %A Ellison, Sara L. (2) %A Lewis, Geraint F. (3) %A Pettini, Max (2) %A Sargent, Wallace L.W. (4) %A Chaffee, Frederic H. (5) %A Foltz, Craig B. (6) %A Rauch, Michael (7) %A Irwin, Mike J. (2) %B With an optical {\em R}-band magnitude of 15.2, the recently discovered z=3.911 broad absorption line quasar APM 08279+5255 is an exceptionally bright high-redshift source. Its brightness has allowed us to acquire a high signal-to-noise ratio (~80), high-resolution (~6 km.s^-1^) spectrum using the HIRES echelle spectrograph on the 10 m Keck I telescope. Given the quality of the data, these observations provide an unprecedented view of associated and intervening absorption systems. Here we announce the availability of this spectrum to the general astronomical community and present a brief analysis of some of its main features. %K Galaxies: Quasars: Absorption Lines %K quasars: individual (APM 08279+5255) %I (1) The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. %I (2) Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, England, UK; (sara@ast.cam.ac.uk). %I (3) Fellow of the Pacific Institute of Mathematical Sciences 1998-1999, Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, Victoria, BC V8W 3P6, Canada; and Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195-1580. %I (4) Palomar Observatory, Caltech 105-24, Pasadena, CA 91125. %I (5) W. M. Keck Observatory, 65-1120 Mamalahoa Highway, Kamuela, HI 96743. %I (6) MMT Observatory, University of Arizona, Tucson, AZ 85721. %I (7) European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Munchen, Germany. %R 1999PASP..111..954K %F ori/PASPv111n762 %J-963 %T Broad Absorption Line Quasars and the Radio-Loud/Radio-Quiet Dichotomy. %A Kuncic, Zdenka (1) %I Department of Physics and Astronomy, University of Victoria, Victoria, BC V8W 3P6, Canada %B The observation that the extremely broad, blueshifted absorption troughs which characterize broad absorption line quasars (BALQs) occur exclusively in radio-quiet quasars (RQQs) suggests that this class of active galactic nuclei (AGN) may offer important clues to the radio-loud/radio-quiet (RL/RQ) dichotomy in quasars. Interestingly, there is also substantial observational evidence for similar, but lower velocity, intrinsic absorption outflows in some Seyfert galaxies and radio-loud quasars (RLQs) as well. Theoretically, however, it is difficult to interpret this broad range of mass ejection phenomena in the context of the standard model for BALQs. Thus, a new model is considered here in which the thermal gas producing the blueshifted absorption troughs is associated with a poorly collimated outflow of weakly radio-emitting plasma--in essence, a weak jet. This model provides an appropriate framework not only for assessing the possible connection between the BAL phenomenon in RQQs and related intrinsic absorption outflows in stronger radio sources and in less luminous sources, both of which are known to possess jetlike radio structure, but also for understanding the RL/RQ dichotomy in light of recent observations which indicate that at least some RQQs possess central engines that are capable of producing weak versions of the powerful radio jets characteristic of RLQs. In the context of a weak jet model for BALQs, it is shown that observational constraints on the physical properties of the radio-emitting plasma are consistent with other theoretical arguments suggesting that the differences amongst RL and RQ sources can be attributed to jets with intrinsically different physical properties. Similarly, theoretical constraints on the physical properties of absorbing clouds embedded in weak jets are shown to be consistent with the properties directly inferred from the observed BAL troughs. Most importantly, however, it is argued that a weak jet model provides a successful explanation for the anticorrelation between the terminal velocity of the absorption outflow and the radio power of the quasar. %K Galaxies: Active %K Galaxies: Jets %K Galaxies: Magnetic Fields %K Galaxies: Quasars: General %K Radio Continuum %I (1) (zdenka@uvastro.phys.uvic.ca). %R 1999PASP..111..964M %F ori/PASPv111n762 %J-968 %T The Late-Time Light Curve of SN 1998bw Associated with GRB 980425. %A McKenzie, Eric H. (1) %A Schaefer, Bradley E. (2) %I Department of Physics, Yale University, 260 Whitney Avenue, JWG 463, New Haven, CT 06520-8120 %B We report 139 photometric observations through the {\em B}, {\em V}, and {\em I} filters of the supernova SN 1998bw, an object which is associated with the gamma-ray burst GRB 980425. Detailed light curves of this unique supernova can be compared with theoretical models, so we report here our light curve for 123 days between 1998 June 27 and 1998 October 28. The light curve of SN 1998bw is consistent with those of the Type Ic class. We find that the magnitude versus time relation for this supernova is linear to within 0.05 mag in all colors over the entire duration of our study. Our measured uniform decline rates are 0.0141+/-0.0002, 0.0184+/-0.0003, and 0.0181+/-0.0003 mag per day in the {\em B}, {\em V}, and {\em I} bands. The linear decline and the rate of that decline suggest that the late-time light curve is powered by the radioactive decay of cobalt with some leakage of the gamma rays. %K Gamma Rays %K Stars: Supernovae: General %K supernovae: individual (SN 1998bw) %I (1) (eric.mckenzie@yale.edu). %I (2) (schaefer@grb2.physics.yale.edu). %R 1999PASP..111..969F %F ori/PASPv111n762 %J-979 %T A Black Hole in the X-Ray Nova Velorum 1993. %A Filippenko, Alexei V. %A Leonard, Douglas C. %A Matheson, Thomas %A Li, Weidong %A Moran, Edward C. (1) %A Riess, Adam G. %I Department of Astronomy, University of California, Berkeley, CA 94720-3411; (alex@astro.berkeley.edu), (dleonard@astro.berkeley.edu), (tmatheson@astro.berkeley.edu), (wli@astro.berkeley.edu), (emoran@astro.berkeley.edu), (ariess@astro.berkeley.edu) %B We have obtained 17 moderate-resolution (~2.5 {AA}) optical spectra of the Galactic X-ray Nova Velorum 1993 in quiescence with the Keck II telescope. Cross-correlation with the spectra of late-type dwarfs (especially K7-M0) yields excellent radial velocities for the secondary star. The orbital period ({\em P}) is 0.285206+/-0.0000014 days, and the semiamplitude (K_2_) is 475.4+/-5.9 km.s^-1^. Our derived mass function, f(M_1_)=PK^3^_2_/2{pi}G=3.17+/-0.12 {\em M}_{sun}_, is close to the conventional absolute limiting mass for a neutron star (~3.0-3.2 {\em M}_{sun}_)--but if the orbital inclination i{<~}80{deg} (given the absences of eclipses), then M_1_{>~}4.2-4.4 {\em M}_{sun}_ for nominal secondary-star masses of 0.5 {\em M}_{sun}_ (M0) to 0.65 {\em M}_{sun}_ (K6). Even if the secondary is quite undermassive (e.g., M_2_=0.3 {\em M}_{sun}_), we derive M_1_{>~}3.9 {\em M}_{sun}_. The primary star is therefore almost certainly a black hole rather than a neutron star.\par Fits to the wings of the double-peaked H{alpha} emission line yield approximate radial velocities for the compact primary. The velocity curve has a semiamplitude (K_1_) of 65.3+/-7.0 km.s^-1^, but with a phase offset by 237{deg} (rather than 180{deg}) from that of the secondary star. Under the assumption that the observed semiamplitude reflects the motion of the primary (despite this offset, which is common), the mass ratio q=M_2_/M_1_=K_1_/K_2_=0.137+/-0.015, and hence for M_2_=0.5-0.65 {\em M}_{sun}_ we derive M_1_=3.64-4.74 {\em M}_{sun}_. The constraints from {\em q} and the mass function yield M_1_=4.4 {\em M}_{sun}_ and i{approx}78{deg} if we use a normal K7-K8 secondary (M_2_{approx}0.6 {\em M}_{sun}_). Indeed, consistency cannot be achieved for M_2_{<~}0.59 {\em M}_{sun}_ if the maximum inclination estimate (80{deg}) is correct. An adopted mass M_1_{approx}4.4 {\em M}_{sun}_ is significantly below the typical value of ~7 {\em M}_{sun}_ found for black holes in other low-mass X-ray binaries.\par Keck observations of MXB 1659-29 (V2134 Oph) in quiescence reveal a probable optical counterpart at R=23.6+/-0.4 mag. This object recently went into a new X-ray and optical (R{approx}18 mag) outburst, after about 21 years of inactivity. %K Stars: Binaries: Close %K Stars: Novae, Cataclysmic Variables %K stars: individual (Nova Velorum 1993, MXB 1659-29) %K X-Rays %I (1) Chandra Fellow. %R 1999PASP..111..980S %F ori/PASPv111n762 %J-985 %T Globular Cluster Winds Driven by Main-Sequence Stars. %A Smith, Graeme H. %I University of California Observatories/Lick Observatory, University of California, Santa Cruz, CA 95064; (graeme@ucolick.org) %B If Population II main-sequence stars have winds similar to the solar wind, then these stars could provide a feasible mechanism for expelling red-giant ejecta from globular clusters. For clusters having line-of-sight velocity dispersions less than 22 km.s^-1^, the mass and energy output of main-sequence star winds is found to be sufficient to establish a cluster outflow which is capable of removing all red-giant ejecta. This mechanism provides a natural means for continuously sweeping all or most globular clusters of stellar ejecta. %K Galaxy: Globular Clusters: General %K Stars: Mass Loss %K Stars: Population II %R 1999PASP..111..986R %F ori/PASPv111n762 %J-989 %T {\em BVR} Photometry of Northern Hemisphere Luminous Stars. III. LS and HD Stars(1). %A Reed, B.Cameron %I Department of Physics, Alma College, Alma, MI 48801; (reed@alma.edu) %A Reed, Laureen G. %I Department of Physics, Saginaw Valley State University, University Center, MI 48710; (lgreed@svsu.edu) %B CCD-based {\em BVR} photometry of 48 previously unobserved stars drawn from volumes V and VI of the {\em Luminous Stars in the Northern Milky Way, Luminous Stars in the Southern Milky Way}, and HD catalogs is reported. %K Stars: Early-Type %I (1) This research was performed at the Lowell Observatory 31 inch telescope, which, under an agreement with Northern Arizona University and the NURO consortium, is operated 60% of the time as the National Undergraduate Research Observatory. %R 1999PASP..111..990R %F ori/PASPv111n762 %J-996 %T Filling Factor and Signal-to-Noise Ratios in Optical Interferometric Arrays. %A Roddier, Fran\c{c}ois %I Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822; (roddier@ifa.hawaii.edu) and %A Ridgway, Stephen T. %I National Optical Astronomical Observatories (1) 950 North Cherry Avenue, Tucson, AZ 85726; (ridgway@noao.edu) %B Signal-to-noise ratios are derived for an interferometric array of {\em N} diffraction-limited optical/IR telescopes with a Fizeau-type beam recombination. We consider two types of objects--extended sources and point sources--and three sources of noise--signal photon noise, sky background noise, and detector noise. We compare the results with that of a filled aperture, and also to that of an incoherent array, each with the same total collecting area. Implications are briefly discussed. %K Instrumentation: Interferometers %K Telescopes %I (1) NOAO is operated by the Association of Universities for Research in Astronomy (AURA), under cooperative operating agreement with the National Science Foundation. %R 1999PASP..111..997M %F ori/PASPv111n762 %J-1008 %T NIRIM: A Dual-Purpose Near-Infrared (0.76-2.5 {mu}m) Imaging Camera for Wide-Field and High-Resolution Imaging. %A Meixner, Margaret %A Young Owl, Rolaine %I Department of Astronomy, MC-221, University of Illinois, Urbana, IL 61801; (meixner@astro.uiuc.edu), (rolaine@astro.uiuc.edu) %A Leach, Robert W. %I Department of Astronomy, San Diego State University, San Diego, CA 92182; (leach@mintaka.sdsu.edu) %B We present the design and performance characteristics of the Near-Infrared Imager (NIRIM), which is a near-infrared camera operating in the 0.76-2.5 {mu}m wavelength range. NIRIM is an example of a cost-effective way to expand two telescopes' capabilities to infrared wavelengths. NIRIM has been used for photometry and wide-field (8'.5x8'.5) imaging on our 1 m telescope at the Mount Laguna Observatory since 1995 August. In the future, NIRIM will also be used for high angular resolution imaging with the University of Illinois Seeing Improvement System (UnISIS), which is a laser guided adaptive optics system at the coud\'e focus of the Mount Wilson 2.5 m telescope. %K Instrumentation: Photometers %R 1999PASP..111.1009G %F ori/PASPv111n762 %J-1020 %T Linearity and High Signal-to-Noise Performance of the STIS CCD(1). %A Gilliland, Ronald L. (2) %A Goudfrooij, Paul (2)(3) %A Kimble, Randy A. (4) %B On-orbit data characteristics of the Space Telescope Imaging Spectrograph (STIS) CCD aboard the {\em Hubble Space Telescope} have been explored with early calibrations in a number of limiting conditions. At a gain of 4 {\em e}^-^ DN^-1^, STIS CCD data show excellent linearity at high count levels, even for extreme oversaturation of individual central pixels. At low count levels we interpret a position- and intensity-dependent nonlinearity in terms of charge transfer (in)efficiency in the parallel clocking direction and provide a simple model that accounts for this. A short time series of spectra was acquired at short-exposure times and high signal-to-noise ratio (S/N) on the binary system {alpha} Cen A and B enabling the shutter repeatability to be quantified at 0.0002 s. A direct demonstration of near-Poisson-limited time series with S/N>3000 is shown. %K Instrumentation: Detectors %K Methods: Data Analysis %K Techniques: Photometric %I (1) Based on observations with the NASA/ESA {\em Hubble Space Telescope}, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555. %I (2) Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218; , . %I (3) Affiliated to the Astrophysics Division, Space Science Department, European Space Agency. %I (4) NASA Goddard Space Flight Center, Code 681, Greenbelt, MD 20771, . %R 1999PASP..111.1021S %F ori/PASPv111n762 %J-1024 %T Spectral Gradients and {\em u}-{\em v} Sampling. %A Swain, Mark R. (1) %B I describe a systematic method for characterizing the effects of differences in {\em u}-{\em v} coverage in terms of inferred spectral gradients in interferometric images. This method is directly applicable to optical and radio interferometry; it is useful in situations when observations using scaled arrays are not feasible. %K Techniques: Image Processing %K Techniques: Interferometric %I (1) Jet Propulsion Laboratory, 4800 Oak Grove Drive, MS 171-113, Pasadena, CA 91109-8099; (swain@huey.jpl.nasa.gov). %R 1999PASP..111.1025C %F ori/PASPv111n762 %J-1047 %T The S2 VLBI Correlator: A Correlator for Space VLBI and Geodetic Signal Processing. %A Carlson, B.R. %A Dewdney, P.E. %A Burgess, T.A., %A Casorso, R.V. %I National Research Council of Canada, Herzberg Institute of Astrophysics, Dominion Radio Astrophysical Observatory, Penticton, BC V2A 6K3, Canada; (Brent.Carlson@hia.nrc.ca), (Peter.Dewdney@hia.nrc.ca) %A Petrachenko, W.T. %I Natural Resources Canada, Dominion Radio Astrophysical Observatory, Penticton, BC V2A 6K3, Canada; (Bill.Petrachenko@hia.nrc.ca) and %A Cannon, W.H. %I Space Geodynamics Laboratory, Center for Research in Earth and Space Technology, 4850 Keele Street, North York, ON M3J 3K1, Canada; (wayne@sgl.crestech.ca) %B A unique lag-based VLBI correlator system has been developed for the purpose of supporting S2-based space VLBI observations in both the Japanese-led VSOP mission and the Canadian Geodetic VLBI program. The system architecture has been designed so that replication of a small number of modules can be used to construct systems with a wide range of sizes. Optimized for a large correlator, the design is ``station based'' in the sense that as many hardware and software functions as possible are performed before data are replicated and transmitted for baseline (station pair) processing. As well as delay compensation and generation of phase rotation coefficients, station-based functions include autocorrelation, tone extraction, pulsar gating, signal-statistics accumulation, and digital filtering. Doppler-shift correction (fringe stopping) is performed on a baseline basis {\em at each correlator lag} so that there are no smearing effects (lag-dependent loss of coherence) or frequency shifts that must otherwise be corrected after correlation. This is a key element that simplifies the baseline processing architecture when high accelerations associated with an orbiting antenna must be considered. Flexible, efficient distribution of data from station-based hardware to baseline-based hardware is accomplished by serializing the wide data paths to 1 Gbit.s^-1^ signals and using high-speed switches to route the signals to their final destinations where they are deserialized before cross-correlation. This greatly reduces the size, wiring complexity, and cost of the system. The interval between updates of the delay models, integration times, and other important events is typically 10 ms but can be as short as 1 ms. Within this period, delay and fringe model generation is performed using linear hardware synthesizers. The correlator also contains a number of unique signal processing functions that extend its capability beyond a basic VLBI correlator: flexible Local Oscillator frequency switching for bandwidth synthesis; rapid (1 ms) correlator dump intervals (allowing, for example, the study of some single-pulse pulsar characteristics on VLBI baselines); simple but powerful multirate digital signal-processing techniques to allow correlation of signals at different but related sample rates; and a digital ``zoom'' filter for producing very high resolution cross-power spectra. The correlator software, written almost entirely in C, is highly integrated into the system, supports all of the functions mentioned above, and is reconfigurable to support expansion of the correlator. The software schedules the use of hardware resources to enable correlation of multiple observations concurrently and automatically schedules the correlation of observations that require more than the available number of physical playback terminals. There is also substantial precorrelation consistency checking. The delay model is based on CALC for ground-based antennas and NAIF for space-based antennas. Output data are stored in the UVFITS format. The paper describes the design rationale, architecture, and function of the correlator and also provides specifications for the implemented system. %K Instrumentation: Interferometers %K Techniques: Interferometric %K Techniques: Spectroscopic %R 1999PASP..111.1048W %F ori/PASPv111n762 %J-1048 %T Multicolor Classification in CADIS and the Search for Quasars. (Dissertation Summary). %A Wolf, Chris %I Current address: Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, D-69117 Heidelberg, Germany; (cwolf@mpia-hd.mpg.de)Thesis work conducted at Max-Planck-Institut f\"ur Astronomie, Heidelberg, GermanyPh.D. thesis directed by H.-J. R\"oser; Ph.D. degree awarded 1999 %K Dissertation Summaries %K Cosmology: Early Universe %K Methods: Data Analysis %K Galaxies: Quasars: General %K Surveys %K Techniques: Photometric