%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..111.1193C
%F ori/PASPv111n764
%J-1222
%T Very High Energy Gamma-Ray Astronomy. (Invited Review).
%A Catanese, Michael
%I Department of Physics and Astronomy, Iowa State University, Ames, IA 50011-3160;
   (mcatanese@cfa.harvard.edu)
%A Weekes, Trevor C.
%I Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, P.O.
   Box 97, Amado, AZ 85645-0097; (tweekes@cfa.harvard.edu)
%B We present a review of the current status of very high energy {gamma}-ray
   astronomy. The development of the atmospheric Cerenkov imaging technique
   for ground-based {gamma}-ray astronomy has led to a rapid growth in the number
   of observatories. The detection of TeV {gamma}-rays from active galactic
   nuclei was unexpected and is providing new insights into the emission mechanisms
   in the jets. Next-generation telescopes are under construction and will increase
   dramatically the knowledge available at this extreme end of the cosmic electromagnetic spectrum.
%K Galaxies: BL Lacertae Objects: General
%K Galaxies: Active
%K Gamma Rays
%K Galaxies: Intergalactic Medium
%K Stars: Pulsars: General
%K ISM: Supernova Remnants

%R 1999PASP..111.1223N
%F ori/PASPv111n764
%J-1232
%T Two-dimensional Photometric Decomposition of the TeV BL Lacertae Objects
   Markarian 421, Markarian 501, and 1ES 2344+514.
%A Nilsson,  K.
%A Pursimo, T.
%A Takalo, L.O.
%A Sillanp\"a\"a, A.,
%A Pietil\"a, H.
%I Tuorla Observatory, V\"ais\"al\"antie 20, FIN-21500 Piikki\"o, Finland; (kani@astro.utu.fi)
%A Heidt, J.
%I Landessternwarte Heidelberg, K\"onigstuhl, D-69117 Heidelberg, Germany
%B We have obtained high-resolution {\em R}-band images of three BL Lacertae
   objects, Mrk 421, Mrk 501, and 1ES 2344+514, that have been detected at high-energy (TeV)
   {gamma}-rays. Because of their TeV emission, these three objects have been
   targets of intensive optical monitoring during the last few years. We have
   studied the morphology of host galaxies by fitting ellipses and two-dimensional
   galaxy+core models to the observed surface brightness distribution. We find
   the host galaxies to be large (effective radii 7-40 kpc) and bright (M_R_=-23.2
   to -24.6) elliptical galaxies, whose surface brightness distribution can
   be described by a single power law I(r){prop.to}r^-{beta}^ with {beta}=0.10-0.36
   to an accuracy of ~0.2 mag. The isophotes of the host galaxies are found
   to be ellipses with no apparent ``boxyness'' or ``diskyness.'' The host galaxies
   of Mrk 501 and 1ES 2344+514 also exhibit a position angle twist that increases
   linearly with distance from the nucleus.\par Using the two-dimensional photometric
   decomposition we have constructed tables of host galaxy magnitude as a function
   of measuring aperture diameter and seeing. These tables can be used to ``clean''
   photometric data of the host galaxy contribution.
%K BL Lacertae objects: individual (\object{Markarian 421}, \object{Markarian 501}, \objS{1ES 2344+51.4}{1ES 2344+514})
%K Galaxies: Active
%K Galaxies: Structure

%R 1999PASP..111.1233S
%F ori/PASPv111n764
%J-1247
%T Radial Velocities of Giant Stars in Globular Clusters(1).
%A Soderberg, A.M.
%I National Optical Astronomy Observatories;(2) and Bates College, Department
   of Physics and Astronomy, Box 628, Lewiston, ME 04240; (asoderbe@bates.edu)
%A Pilachowski, C.A.
%A Barden, S.C.,
%A Willmarth, D.
%I National Optical Astronomy Observatories (2) P.O. Box 26732, Tucson, AZ 85726-6732;
   (cpilachowski@noao.edu), (sbarden@noao.edu), (dwillmarth@noao.edu)
%A Sneden, C.
%I McDonald Observatory and Department of Astronomy, University of Texas, Austin,
   TX 78712; (chris@verdi.as.utexas.edu)
%B We report radial velocities for 303 giant stars in the globular clusters M3,
   M13, M15, and M92. Spectra were obtained using the 4 m Mayall and 3.5 m WIYN
   telescopes and the Hydra fiber positioner between 1993 and 1997; most spectra
   were provided by the NOAO WIYN Queue Program. Observations spanned times
   from a few days to several months. The uncertainties in the velocity measurements
   are typically 1 km.s^-1^ or less. Several stars show velocity variations
   which may result from binary companions or atmospheric motions. Mean cluster
   velocities were measured to be -147.0+/-0.3, -245.5+/-1.0, -106.2+/-0.3, and -120.3+/-0.3
   km.s^-1^, for M3, M13, M15, and M92, respectively. Radial velocity observations
   for the photometric variable V73 (vZ 1406) in M3 confirm that the star varies
   with a period of 0.67 days.
%K Stars: Binaries: Spectroscopic
%K Stars: Variables: General
%K Galaxy: Globular Clusters: Individual: Messier Number: M3
%K globular clusters: individual (M13, M15)
%K Galaxy: Globular Clusters: Individual: Messier Number: M92
%I (1) The WIYN Observatory is a joint facility of the University of Wisconsin--Madison,
   Indiana University, Yale University, and the National Optical Astronomy Observatories.
%I (2) The National Optical Astronomy Observatories are operated by the Association
   of Universities for Research in Astronomy (AURA), Inc., under cooperative
   agreement with the National Science Foundation.

%R 1999PASP..111.1248V
%F ori/PASPv111n764
%J-1250
%T The Stellar Mass Spectrum in the Young Populous Cluster NGC 1866.
%A van den Bergh, Sidney
%I Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, National Research
   Council of Canada, 5071 West Saanich Road, Victoria, BC V8X 4M6, Canada;
   (vdb@dao.nrc.ca)
%B The young populous cluster NGC 1866 in the Large Magellanic Cloud (LMC),
   which is probably one of the most massive objects formed in the LMC during
   the last ~3 Gyr, appears to have an unexpectedly high mass-to-light ratio.
   From its velocity dispersion Fischer and coworkers find its mass to be (1.35+/-0.25)x10^5^ {\em
   M}_{sun}_. The luminosity of this cluster is M_v_=-8.93+/-0.13, corresponding
   to L_v_=(3.2+/-0.4)x10^5^ L_v,{sun}_. This yields M/L_v_=0.42+/-0.09 in solar units.
   For a cluster of age 0.1 Gyr, such a relatively high mass-to-light ratio
   requires a mass spectrum with an exponent x=1.72+/-0.09, or x=1.75+/-0.09 if
   mass loss by evolving stars is taken into account.

%R 1999PASP..111.1251A
%F ori/PASPv111n764
%J-1257
%T Emission-Line Helium Abundances in Highly Obscured Nebulae.
%A Armour, Mary-Helen
%I Department of Physics and Astronomy, York University, 4700 Keele Street,
   Toronto, ON M3J 1P3, Canada; (armour@aries.phys.yorku.ca) and
%A Ballantyne, David R. (1)
%A Ferland, Gary J. (2)
%A Karr, Jennifer (1)
%A Martin, P.G.
%I Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto,
   ON M5S 3H8, Canada; (ballanty@cita.utoronto.ca), (ferland@cita.utoronto.ca),
   (karr@cita.utoronto.ca), (pgmartin@cita.utoronto.ca)
%B This paper outlines a way to determine the ionization correction factor (ICF)
   using only infrared data. We identify four line pairs, [Ne III] 36 {mu}m/[Ne
   II] 12.8 {mu}m, [Ne III] 15.6 {mu}m /[Ne II] 12.8 {mu}m, [Ar III] 9 {mu}m/[Ar
   II] 6.9 {mu}m, and [Ar III] 21 {mu}m/[Ar II] 6.9 {mu}m, that are sensitive
   to the He ICF. This happens because the ions cover a wide range of ionization,
   the line pairs are not sensitive to electron temperature, they have similar
   critical densities, and they are formed within the He^+^/H^+^ region of the nebula.
   We compute a very wide range of photoionization models appropriate for galactic
   H II regions. The models cover a wide range of densities, ionization parameters,
   and stellar temperatures and use continua from four very different stellar
   atmospheres.\par The results show that each line pair has a critical intensity
   ratio above which the He ICF is always small. Below these values the ICF
   depends very strongly on details of the models for three of the ratios, and
   so other information would be needed to determine the helium abundance. The [Ar
   III] 9 {mu}m/[Ar II] 6.9 {mu}m ratio can indicate the ICF directly as a result
   of the near exact match in the critical densities of the two lines. Finally,
   continua predicted by the latest generation of stellar atmospheres are sufficiently hard
   that they routinely produce significantly negative ICFs.
%K ISM: H II Regions
%K Infrared: General
%K Infrared: Stars
%K Methods: Observational
%K ISM: Planetary Nebulae: General
%K Stars: Fundamental Parameters
%I (1) Also at Department of Astronomy, University of Toronto, Toronto,
   ON M5S 3H8, Canada.
%I (2) Also at Department of Physics, University of Kentucky, Lexington,
   KY 405506-0055.

%R 1999PASP..111.1258T
%F ori/PASPv111n764
%J-1268
%T Ionization of the Local Interstellar Medium.
%A Tat, Hong H. (1)
%A Terzian, Yervant (1)
%I Cornell University, Ithaca, NY 14853; (hong@astrosun.tn.cornell.edu); (terzian@astrosun.tn.cornell.edu)
%B We have determined the distribution of the ionization of the interstellar
   medium within the vicinity of the Sun due to the ultraviolet radiation from
   nearby white dwarf stars. If one assumes steady state conditions, the ionization
   is irregular and does not consist of one large continuous cloud, but instead
   consists of irregular regions of ionization with occasional mergers of the
   Str\"omgren spheres. We also present a compilation of the known white dwarf
   stars within 20 pc of the Sun.
%K ISM: Structure
%K Stars: White Dwarfs
%I (1) Cornell University, Department of Astronomy; and National Astronomy
   and Ionosphere Center.

%R 1999PASP..111.1269G
%F ori/PASPv111n764
%J-1274
%T The Chemical Compositions of the SRd Variable Stars. II. WY Andromedae, VW
   Eridani, and UW Librae.
%A Giridhar, Sunetra
%I Indian Institute of Astrophysics, Bangalore, 560034 India; (giridhar@iiap.ernet.in)
%A Lambert, David L.
%I Department of Astronomy, University of Texas, Austin, TX 78712-1083; (dll@astro.as.utexas.edu)
%A Gonzalez, Guillermo
%I Department of Astronomy, University of Washington, Seattle, WA 98195-1580;
   (gonzalez@astro.washington.edu)
%B Chemical compositions are derived from high-resolution spectra for three
   stars classed as SRd variables in the {\em General Catalogue of Variable
   Stars}. These stars are shown to be metal-poor supergiants: WY And with [Fe/H]=-1.0, VW
   Eri with [Fe/H]=-1.8, and UW Lib with [Fe/H]=-1.2. Their compositions are
   identical to within the measurement errors to the compositions of subdwarfs,
   subgiants, and less evolved giants of the same [Fe/H]. The stars are at the
   tip of the first giant branch or in the early stages of evolution along the
   asymptotic giant branch (AGB). There is no convincing evidence that these
   SRd variables are experiencing thermal pulsing and the third dredge-up on
   the AGB. The SRd variables appear to be at the cool limit of the sequence
   of RV Tauri variables.
%K Stars: Abundances
%K Stars: AGB and Post-AGB
%K Stars: Variables: Other

%R 1999PASP..111.1275F
%F ori/PASPv111n764
%J-1280
%T Superhumps in Cataclysmic Binaries. XVI. DI Ursae Majoris.
%A Fried, Robert E. (1)
%A Kemp, Jonathan (2)(3)
%A Patterson, Joseph (2)(3)
%A Skillman, David R. (4)
%A Retter, Alon (5)(6)
%A Leibowitz, Elia (5)
%A Pavlenko, Elena (7)
%B We report photometry of the dwarf nova DI Ursae Majoris during 1997-1998.
   The star shows an orbital light curve at quiescence with a period of 0.054564(1)
   days. During superoutburst, it flashes superhumps with a period of 0.05529(5)
   days. The superhump period excess of 1.3% is quite low among cataclysmic
   variables, suggesting a weak perturbation on the accretion disk and therefore
   a secondary of very low mass. But other stars of low period excess are rare
   eruptors, whereas DI UMa is extremely active with normal outbursts every
   8 days and superoutbursts every 30-45 days. This is puzzling. We speculate
   that the binary really does have a secondary of anomalously low mass but
   is presently in a high state of a mass-transfer cycle.
%K Stars: Binaries: Close
%K Stars: Novae, Cataclysmic Variables
%K stars: individual (DI Ursae Majoris)
%I (1) Braeside Observatory, P.O. Box 906, Flagstaff, AZ 86002; (captain@braeside.org).
%I (2) Biosphere 2 Center, Columbia University, 32540 South Biosphere Road, Oracle,
   AZ 85623; (jonathan@astro.bio2.edu).
%I (3) Department of Astronomy, Columbia University, 550 West 120th Street,
   New York, NY 10027; (jop@astro.columbia.edu).
%I (4) Center for Backyard Astrophysics (East), 9517 Washington Avenue,
   Laurel, MD 20723; (dskillman@home.com).
%I (5) Wise Observatory and Department of Astronomy, Tel Aviv University,
   Ramat Aviv, Tel Aviv 69978, Israel; (elia@wise.tau.ac.il).
%I (6) Current address: Astrophysics Group, Department of Physics, Keele University,
   Keele, Staffordshire ST5 5BG, England, UK; (ar@astro.keele.ac.uk).
%I (7) Crimean Astrophysical Observatory, P/O Nauchny, 334413 Crimea, Ukraine;
   (pavlenko@crao.crimea.ua).

%R 1999PASP..111.1281S
%F ori/PASPv111n764
%J-1291
%T Superhumps in Cataclysmic Binaries. XVII. AM Canum Venaticorum.
%A Skillman, David R. (1)
%A Patterson, Joseph (2)(3)
%A Kemp, Jonathan (2)(3)(4)
%A Harvey, David A. (5)
%A Fried, Robert E. (6)
%A Retter, Alon (7)(8)
%A Lipkin, Yiftah (7)
%A Vanmunster, Tonny (9)
%B We report new photometry of the cataclysmic variable AM Canum Venaticorum,
   comprising 670 hr over 227 nights during 1992-1999. The data demonstrate
   conclusively that (1) the fundamental period is 1051.2 s, with a well-defined
   waveform which has not changed during the four decades of study; (2) this
   period wanders erratically by ~0.2 s on a timescale of 3-6 months; and (3)
   the light curve contains a rich spectrum of periodic signals, at least 20
   of them. We also report a secure detection of a photometric signal at 1028.7322+/-0.0003
   s, consistent with the orbital period previously hypothesized to explain
   the spectroscopic variations.\par The behavior of the 1051 s signal is consistent
   with the hypothesis of a superhump origin, and the discovery of a signal
   at the presumed {\em P}_orb_ is yet another strong argument for this hypothesis.
   Apparently superhumps can manufacture a very complex spectrum of photometric
   periods, and they can remain stable for many thousands of cycles. But most
   are harmonics and sidebands of the truly fundamental clocks in the binary,
   at {\em P}_orb_ and the disk's two likely periods of precession--at 13.36
   and 16.69 hr. It is plausible that the latter correspond to the periods of
   {\em apsidal advance} and {\em nodal regression}. The former is steadily present,
   evidently producing the well-known superhump. The signatures of nodal regression,
   primarily the 1011.4 s ``negative superhump'', are more variable. The sideband
   structure of the harmonics obeys firm selection rules, which may reveal intricate
   details of structure in the accretion disk. And somehow all these exotic
   clocks manage to coexist and remain relatively stable, despite being putatively
   seated in the relatively sloppy structure of a disk, highly sheared and unsupported
   by pressure!
%K Stars: Binaries: Close
%K Stars: Novae, Cataclysmic Variables
%K stars: individual (AM Canum Venaticorum)
%I (1) Center for Backyard Astrophysics (East), 9517 Washington Avenue,
   Laurel, MD 20723; (dskillman@home.com).
%I (2) Department of Astronomy, Columbia University, 550 West 120th Street,
   New York, NY 10027; (jop@astro.columbia.edu).
%I (3) Biosphere 2 Center, Columbia University, 32540 South Biosphere Road, Oracle,
   AZ 85623; (jonathan@astro.bio2.edu).
%I (4) Visiting Astronomer, Kitt Peak National Observatory, National Optical Astronomy
   Observatories, which is operated by the Association of Universities for Research
   in Astronomy, (AURA) Inc., under cooperative agreement with the National
   Science Foundation.
%I (5) Center for Backyard Astrophysics (West), 1552 West Chapala Drive,
   Tucson, AZ 85704; (dharvey@comsoft-telescope.com).
%I (6) Braeside Observatory, P.O. Box 906, Flagstaff, AZ 86002; (captain@braeside.org).
%I (7) Wise Observatory and Department of Astronomy, Tel Aviv University,
   Ramat Aviv, Tel Aviv 69978, Israel; (yiftah@wise.tau.ac.il).
%I (8) Current address: Astrophysics Group, Department of Physics, Keele University,
   Keele, Staffordshire ST5 5BG, England, UK; (ar@astro.keele.ac.uk).
%I (9) Center for Backyard Astrophysics (Belgium), Walhostraat 1A, B-3401
   Landen, Belgium; (Tonny.Vanmunster@advalvas.be).

%R 1999PASP..111.1292S
%F ori/PASPv111n764
%J-1297
%T A Time-Series {\em IUE} Archival Study of the White Dwarf in the Ultrashort-Period
   Dwarf Nova WZ Sagittae.
%A Slevinsky, R.J. (1)
%A Stys, D. (2)
%A West, S. (3)
%A Sion, E.M. (4)
%A Cheng, F.H. (5)
%I Department of Astronomy and Astrophysics, Villanova University, Villanova,
   PA 19085
%B The {\em IUE} archive offers a series of far-UV spectra of the ultrashort-period
   dwarf nova WZ Sge over a long time baseline and hence the opportunity to
   monitor the ongoing accretion, the cooling of the white dwarf, and temporal
   variations in the line spectra. We have carried out a quantitative analysis
   of these spectra including model atmosphere simulations. We find an indicated
   cooling of the white dwarf by 5140 K from 20,510 to 15,370 K with a thermal
   {\em e}-folding time of 690 days. This cooling rate is well represented by
   heating of the white dwarf by accretion of matter with angular momentum during
   the 1978 December outburst followed by subsequent cooling. We find that the abundance
   of carbon in the white dwarf photosphere is elevated above solar. This finding
   is consistent with the results of recent {\em Hubble Space Telescope} observations.
   We find marginal evidence that the C abundance was 6 times solar close to
   the outburst and 2 times solar in the most recent spectra obtained 13.7 years
   later. However, uncertainties in the abundances do not allow any definitive conclusion
   regarding temporal abundance variations. The origin of the elevated carbon
   abundance is discussed in terms of accretion and diffusion while arguments
   are presented which may rule out ordinary convective dredge-up and dredge-up
   due to forced convection associated with shear mixing.
%I (1) (richs@ast.vill.edu).
%I (2) (stys@stsci.edu).
%I (3) (swest@aol.com).
%I (4) (emsion@ucis.vill.edu).
%I (5) (fhcheng@ucis.vill.edu).

%R 1999PASP..111.1298S
%F ori/PASPv111n764
%J-1315
%T Panoramic Polarimetry Data Analysis.
%A Sparks, William B. (1)
%A Axon, David J. (2)
%B Derivation of accurate polarization information about an astronomical target
   is a vital tool for investigation of astrophysical processes. Use of large
   area detectors for imaging and spectroscopy has become commonplace, and frequently
   such instruments offer a polarization capability. Processing of polarimetric
   data, however, is nontrivial, especially when the polarimeter is far from
   ideal. Here we present an overview of the analysis procedures needed to properly
   process polarimetry data that comprise a series of images of an object taken
   through a given set of polarizers, such as the imaging instruments on the
   {\em Hubble Space Telescope} ({\em HST}). The analysis can also be used for
   other types of polarization data, such as spectra. We consider only linear
   polarization, not circular. The polarizers do not need to be perfect polarizers,
   although it is important that their characteristics be well established.
   From an input data set of {\em n} intensities (or, equivalently, fluxes)
   and their errors, assumed independent between observations, corresponding
   to a set of observations through {\em n} polarizers (not necessarily identical
   or perfect), we show how to derive the Stokes parameters and their covariance
   matrix both for the special case of n=3 and for general {\em n}.\par We then
   discuss how to derive higher level parameters such as polarization degree
   and position angle and their associated uncertainties and indicate ways to
   ``debias'' the positive definite polarization degree. We present tests of our
   analysis using Monte Carlo simulations. Finally, we show the achievable accuracy
   for various levels of polarization and signal-to-noise ratio for typical
   cases, which should be useful for observation design. The techniques allow accurate
   recovery of polarization information from several of the instruments on board
   the {\em HST} as well as estimates of the uncertainties in the results.
%K Methods: Data Analysis
%I (1) Visiting Scholar, Center for Astrophysical Sciences, The Johns Hopkins University,
   3400 North Charles Street, Baltimore, MD 21218; on sabbatical leave from
   Space Telescope Science Institute; (sparks@stsci.edu).
%I (2) Department of Physical Sciences, University of Hertfordshire, Hatfield, Herts,
   AL10 9AB, England, UK; (dja@star.herts.ac.uk).

%R 1999PASP..111.1316O
%F ori/PASPv111n764
%J-1320
%T Calibration of {\em Hubble Space Telescope} WFPC2 Emission-Line Filters(1).
%A O'Dell, C.R.
%I Department of Space Physics and Astronomy, MS-108, Rice University, P.O.
   Box 1892, Houston, TX 77251-1892; (cro@rice.edu)
%A Doi, Takao
%I NASA/Johnson Space Center, MC:CB, Houston, TX 77058; (takao.doi1@jsc.nasa.gov)
%B The results of calibration of the primary emission-line filters of the
   {\em Hubble Space Telescope} WFPC2 are presented in a form which allows observers
   to easily calculate emission-line surface brightnesses for H{alpha}, H{beta},
   [O III] {lambda}5007, and [N II] {lambda}6583. The H{alpha} and [N II] filters
   pass both lines in such a way that observations in both are necessary to
   obtain good isolation of either line. We establish that determination of
   the strength of the underlying continuum can be important, especially in
   H II regions. We express cautionary notes against overly simple interpretations
   of the signal from filters selected to isolate lines at 4363, 6300, and 6717+6731 {AA}.
   Finally, we use this calibration to recommend guidelines for the selection
   of emission-line filters on future {\em HST} instruments.
%K ISM: Lines and Bands
%K ISM: individual (Orion)
%K Methods: Data Analysis
%I (1) Based on observations with the NASA/ESA {\em Hubble Space Telescope},
   obtained at the Space Telescope Science Institute, which is operated by the
   Association of Universities for Research in Astronomy, Inc., under NASA contract
   NAS 5-26555.

%R 1999PASP..111.1321G
%F ori/PASPv111n764
%J-1330
%T The Nulling Stellar Coronagraph: Laboratory Tests and Performance Evaluation.
%A Guyon, Olivier (1)
%A Roddier, Claude
%A Graves, J.Elon
%A Roddier, Fran\c{c}ois
%I Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu,
   HI 96822
%A Cuevas, Salvador
%A Espejo, Carlos
%A Gonzalez, Salustio
%I Instituto de Astronomia UNAM, Mexico
%A Martinez, Andrea
%A Bisiacchi, Gianfranco
%A Vuntesmeri, Valeri
%I Centro de Instrumentos UNAM, Mexico
%B The nulling coronagraph, first proposed by Roddier and Roddier, uses
   a small mask (less than half the size of the central Airy spot) that shifts
   the phase of the incoming light by 180{deg} to strongly attenuate the Airy spot
   as well as the rings. We report on both theoretical and laboratory performance.
   In our laboratory experiment, we reduce the peak intensity of the Airy pattern
   by a factor of 16. We derive estimates of the performance of a nulling coronagraph
   used on a telescope equipped with an adaptive optics system, based upon the
   performance of the University of Hawaii Hokupa'a adaptive optics system.
   On a 3.6 m telescope at 1.65 {mu}m, it is found that a tip/tilt amplitude
   lower than 20 mas is needed for such a coronagraph to yield an extinction
   better than 2 stellar mag.
%K Instrumentation: Adaptive Optics
%K Techniques: Interferometric
%I (1) Ecole Normale Sup\'erieure, 45 rue d'Ulm, 75230 Paris, France; (oguyon@clipper.ens.fr).

%R 1999PASP..111.1331B
%F ori/PASPv111n764
%J-1331
%T Comparative Kinematics of Gas and Stars in Disk Galaxies. (Dissertation Summary).
%A Vega Beltran, Juan Carlos 
%I Current address: Instituto Astrofisico de Canarias (IAC), C. Via Lactea s/n.,
   38200 La Laguna, Tenerife, Spain; (jvega@ll.iac.es)Thesis work conducted
   at Osservatorio Astronomico de Padova and IACPh.D. thesis directed by Francesco
   Bertola and John Beckman; Ph.D. degree awarded 1999
%K Dissertation Summaries
%K Galaxies: Kinematics and Dynamics