bluuebunny/crossref_metadata_2025 huggingface dataset:
Distant Radio Galaxies: Probes of the Formation of Massive Galaxies
Authors: Röttgering Huub , Best Philip , Pentericci Laura , Miley George
Published: July 2016

In this paper we review some of the evidence that the hosts of powerful high redshift (1 ≲ z ≲ 5) radio galaxies (HzRGs) are the progenitors of present day brightest cluster galaxies (BCGs). On the basis of HST imaging we argue that the scenario describing the formation of BCGs consists of at least two important stages. At z > 2 a significant fraction of the stellar mass of a BCG is formed during a massive burst of star-formation. By z ~ 1, well developed massive ellipticals are already observed and from then until the present epoch, the total mass in stars of the BCG will further grow by a factor of order 3, mainly through the accretion of cluster ellipticals.
Metal Enrichment of Ly Alpha Clouds and the Intergalactic Medium
Authors: Murakami I. , Yamashita K.
Published: July 2016

We have considered the metal enrichment of the intergalactic medium (IGM) and Lyα clouds at high redshifts. The CIV absorption lines associated with the Lyα forest have been observed (e.g. Songaila & Cowie 1996) and the metallicity is estimated as ~0.01Z⊙. Here, based on a galactic wind model, we have examined how the IGM is metal-enriched by the outflows driven by supernova explosions in primeval galaxies and minihalos.
The Formation of Galaxy Disks and Bulges
Authors: Williams P.R. , Nelson A.H.
Published: July 2016

Using a TREESPH code modified to run on a parallel computer and a new algorithm for modeling star formation, we have investigated the formation of disk galaxies from idealized cosmological perturbations.
Hubble Sequence as a Temporal Evolution Sequence
Authors: Zhang Xiaolei
Published: July 2016

The results from Hubble Space Telescope's Medium Deep Survey and Deep Fields indicate that there exists far more blue spiral galaxies at the intermediate and high redshifts than at the present epoch. A natural question therefore is: what have become of these excess late type galaxies as the Universe aged?
Global Evolution of the Stars, Gas, Metals, and Dust in Galaxies
Authors: Fall S. Michael
Published: July 2016

We outline a method to infer the global history of star formation in galaxies from absorption-line observations of quasars. The application to existing data leads to the conclusion that most stars formed at relatively low redshifts (z ≲ 2). The results obtained by this absorption-based method are consistent with those obtained subsequently by emission-based methods.
Theory of Flares and MHD Jets
Authors: Shibata Kazunari
Published: July 2016

Recent development on the theory and numerical modeling of solar flares and jets is reviewed with emphasis on the magnetic reconnection model. Application to protostellar flares and jets is also discussed.
ASCA Observations of Distant Clusters of Galaxies
Authors: Tsuru Takeshi Go
Published: July 2016

Investigation of evolution of X-ray properties of clusters of galaxies is a key study of cosmology. The most important result in this field before ROSAT and ASCA observatories is the detection of the negative evolution of the X-ray luminosity function at red-shift lower than 0.6 (Gioia et al., 1990). Following it, many groups have been investigating evolution of X-ray luminosity function from various surveys with ROSAT observatory (eg. Collins et al., 1997). Many of them indicate no negative evolution at the red-shift lower than 0.7, which is against the Einstein result.
ABRIXAS
Authors: Hasinger G. , Trümper J. , Staubert R.
Published: July 2016

All Sky Surveys are very useful for several reasons: Firstly, their unbiased view provides the potential for new discoveries. Secondly, they yield large unbiased samples of a variety of objects which can be used for statistical investigations. And thirdly, the unlimited field of view of telescopic sky surveys allows to study extended objects and large scale structures.
The INTEGRAL Mission
Authors: Hermsen W. , Winkler C.
Published: July 2016

The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) is dedicated to the fine spectroscopy (ΔE: 2 keV FWHM @ 1 MeV) and fine imaging (angular resolution: 12' FWHM) of celestial gamma-ray sources in the energy range 15 keV to 10 MeV. INTEGRAL was selected in 1993 as the next ESA medium-size scientific mission (M2) to be launched in 2001. ESA has the overall spacecraft and mission resposibilities, Russia will provide a PROTON launcher and launch facilities, and NASA will provide ground station support through the Deep Space Network. The scientific payload complement and the INTEGRAL Science Data Centre (ISDC) will be provided by large collaborations led by Principal Investigators (PI).
Binary Stucture of Accreting Neutron Stars
Authors: Leahy D.A.
Published: July 2016

The study of X-ray binaries has made great progress with the advent in the past few years of a number of very capable X-ray astronomy missions. These are reviewed, for example, by Bradt et al 1992, and a set of recent relevant papers in Makino and Mitsuda, 1997. For example, ASCA has allowed a significant increase in sensitivity and spectral resolution in 0.5-10 keV X-rays (Tanaka et al 1994). Many recent Compton/GRO results on X-ray binaries are reviewed in the proceedings of the Second Compton Symposium (Fichtel et al 1994). Another source of recent results from analysis of data from several satellite missions is the proceedings of the Evolution of X-ray Binaries (Holt & Day, 1994). In this short paper, the emphasis is on guiding the reader to some relevant literature.
Evidence for Strong Gravity in the AGN Plasmas
Authors: Iwasawa K.
Published: July 2016

X-ray spectroscopy of the broad iron line has revealed some relativistic effects caused by strong gravity about a black hole in active galactic nuclei (AGN). Recent results from ASCA observations of AGNs are reviewed.
The Properties of Blazars Detected by EGRET
Authors: Mattox J.R.
Published: July 2016

One of the most exciting recent developments in astrophysics is the detection of members of the blazar class of AGN at ~1 GeV by the EGRET instrument aboard the Compton Observatory. Although a weak detection of 3C 273 was obtained by the COS B mission, the very strong detection of 3C 279 by EGRET (Hartman et al. 1992) two months after launch was not anticipated.
A Review of GRB Counterpart Searches
Authors: Kouveliotou C.
Published: July 2016

Gamma-Ray Burst (GRB) research has been recently revitalized with exciting new results that have effectively started a new era in this thirty year old field, marked by the launch of the Italian-Dutch satellite BeppoSAX on April 1996.
X-Ray Observations of the Hot Intergalactic Medium
Authors: Wang Q. Daniel
Published: July 2016

A definite prediction from recent N-body/hydro simulations of the structure formation of the universe is the presence of a diffuse hot intergalactic medium (HIGM; e.g., Ostriker & Cen 1996). The filamentary structure of the today's universe, as seen in various galaxies surveys, is thought to be a result of the gravitational collapse of materials from a more-or-less uniform and isotropic early universe. During the collapse, shock-heating can naturally raise gas temperature to a range of 105 – 107 K. Feedbacks from stars may also be an important heating source and may chemically enrich the HIGM. The understanding of the heating and chemical enrichment of the IGM is critical for studying the structure and evolution of clusters of galaxies, which are nearly virialized systems (e.g., Kaiser 1991; David, Jones, & Forman 1996). Most importantly, the HIGM may explain much of the missing baryon content required by the Big Bang nucleosynthesis theories (e.g., Copi, Schramm, & Turner 1995); the total visible mass in galaxies and in the hot intracluster medium together is known to account for ≲ 10% of the baryon content (e.g., Persic & Salucci 1992).
MHD Simulation of Chromospheric Evaporation in a Solar Flare Based on Magnetic Reconnection Model
Authors: Yokoyama T. , Shibata K.
Published: July 2016

Two-dimensional magnetohydrodynamic simulation of a solar flare is performed using a newly developed MHD code including nonlinear anisotropic heat conduction effect (Fig. 1; Yokoyama & Shibata 1997a). The numerical simulation starts with a vertical current sheet which is line-tied at one end to a dense chromosphere. The flare energy is released by the magnetic reconnection mechanism stimulated initially by the resistivity perturbation in the corona. The released thermal energy is transported into the chromosphere by heat conduction and drives chromospheric evaporation. Owing to the heat conduction effect, the adiabatic slow-mode MHD shocks emanated from the neutral point are dissociated into conduction fronts and isothermal shocks (Yokoyama & Shibata 1997b). Temperature and derived soft X-ray distributions are similar to the cusp-like structure of long-duration-event (LDE) flares observed by the soft X-ray telescope aboard Yohkoh satellite. On the other hand density and radio maps show a simple loop configuration which is consistent with the observation with Nobeyama Radio Heliograph. Two interesting new features are found. One is a pair of high density humps on the evaporated plasma loops formed at the collision site between the reconnection jet and the evaporation flow. The other is the loop-top blob behind the fast-mode MHD shock.
Variable High Velocity Jets in the Symbiotic Star CH Cygni
Authors: Iijima T.
Published: July 2016

Highly blue or red shifted broad emission components of H I lines have been noticed in some recent spectra of the symbiotic star CH Cyg. Their intensities, profiles, and displacements from the narrow component have changed with time scale of days. For example, a blue-shifted (-1545 km s−1) intense emission component and a red-shifted weak (+757 km s−1) emission were seen on 1994 September 9. One day after, the blue-shift and red-shift became −2076 km s−1 and +1285 km s−1, respectively.
X-Ray Coronae from Single Late-Type Dwarf Stars
Authors: Singh K.P. , Drake S.A. , White N.E.
Published: July 2016

Study of X-ray coronae from late-type stars with moderate resolution X-ray spectroscopy with ASCA, has led to the characterization of temperatures and measurements of elemental abundances in their coronae. Several RS CVn and Algol-type binary systems, and single late-type stars have been observed. We present here the results obtained from X-ray spectroscopy of recently observed single F-G-K-M type dwarfs. The sample observed with ASCA contains αCen (Mewe et al. 1997), π1UMa (Drake et al. 1994), YY Gem, Speedy Mic, GJ 890 (Singh et al. 1997), EK Dra, HN Peg, κ1Cet (Guedel et al. 1997), AB Dor (Mewe et al. 1996) and HD 35850 (Tagliaferri et al. 1997).
Neutrino Transport in Type II Supernovae: Boltzmann Solver vs Monte Carlo Method
Authors: Yamada Shoichi , Janka Hans-Thomas , Suzuki Hideyuki
Published: July 2016

In this paper we discuss the results of extensive comparison of the Boltzmann solver recently developed by us and the Monte Carlo method coded by Janka. The aim of our project is to improve the treatment of the neutrino transfer and to study the neutrino reactions systematically, since the numerical treatment of neutrino transfer and neutrino reaction rates in the hot dense medium are two of the greatest uncertainties in the supernova simulations.
Radio Emission from Extended Shell-Like SNRs
Authors: Asvarov A.I.
Published: July 2016

Observations of the soft X-Ray background and interstellar UV absorption lines have indicated that a large fraction of interstellar space is filled with a high temperature low density “coronal” gas. In such low density environments SNRs will expand up to 200 pc in radius without thin shell formation which occurs due to radiative cooling effects. Such SNRs can occupy a large fraction of volume of Galaxy and can be the main source of background emissions. In the present work we examine the evolution of the radio emission of shell-like SNR evolving in the hot ISM.
Discovery of X-Ray Emission from the Radio SNR G352.7-0.1
Authors: Kinugasa K. , Torii K. , Tsunemi H. , Yamauchi S. , Koyama K. , Dotani T.
Published: July 2016

One major objective of our ASCA Galactic Plane Survey Project (AGPSP) is, utilizing the wide and high energy band (up to 10 keV) X-ray imaging capability and the high spectral resolving power of ASCA, to search possible X-ray SNRs in the Galactic inner disk. The observation of the field including G352.7-0.1 reported in this paper, was performed on 1996 March 14 during the first AO4 survey. We report on the X-ray SNR G352.7-0.1 found in AGPSP. G352.7-0.1 is one of the radio SNRs (Green 1996), and is classified as a shell-like SNR with the size of 8' x 6'.
Thermal and Non-Thermal X-Rays from SN 1006 and IC 443
Authors: Ozaki M. , Koyama K.
Published: July 2016

From many Galactic supernova remnants (SNRs), X-ray emissions consisting of non-equilibrium ionization (NEI) plasma and additional hard component are detected. The hard emission have been usually interpreted as a high temperature plasma of = 10 keV. However, the recent observation with ASCA made it clear that the hard components of some SNRs are of non-thermal origin. Here we report the ASCA results of SN 1006 and IC 443 observations as an example of such SNRs.
The AD393 Guest Star and the SNR RX J1713.7-3946
Authors: Wang Z. R. , Qu Q. Y. , Chen Y.
Published: July 2016

RX J1713.7-3946 is a new and bright supernova remnant (SNR) in soft X-rays discovered by Pfeffermann & Aschenbach (1996, hereafter PA 1996). Its visual position as shown on its name is within the asterism Wei where the AD393 guest star occured (Wang et al. 1997).
A Circulation Hypothesis of Spiral Galaxies
Authors: Linfei Chen
Published: July 2016

A circulation hypothesis of spiral galaxies is proposed here to explain their spiral structure: the spiral arm material is going to the galactic center along a spiral orbit and then ejects from the galactic center in the form of two-way jets in opposite directions and finally, the ejected jets return to the galaxy in the form of spiral arms again, thereby forming a closed circulatory system.
The Supply of Magnetic Fields from a cD Galaxy to Intra-Cluster Space
Authors: Hirashita H. , Mineshige S. , Shibata K. , Matsumoto R.
Published: July 2016

Intra-cluster spaces are filled with intra-cluster medium (ICM), whose typical temperature and density are TICM ~ 107.5 K and nICM ~ 10−3 cm−3, respectively (e.g., Sarazin 1988). Recent Faraday rotation measurements have revealed the existence of magnetic fields in ICM with few − 10 μG (e.g., Ge & Owen 1993). In ICM, the plasma β (the ratio of gas pressure to magnetic pressure) is almost “equipartition” value as follows:
Constraints on the Matter Fluctuation Spectrum from X-Ray Cluster Number Counts
Authors: Kitayama Tetsu , Suto Yasushi
Published: July 2016

We find that the observed logN-logS relation of X-ray clusters (Ebeling et al. 1997; Rosati et al. 1997) can be reproduced remarkably well with a certain range of values for the fluctuation amplitude σ8 and the cosmological density parameter Ω0 in cold dark matter (CDM) universes (Kitayama & Suto 1997). The 1σ confidence limits on σ8 in the CDM models with n = 1 and h = 0.7 are expressed as (0.54 ± 0.02)Ω−0.35-0.82Ω0+0.55Ω200 (λ0 = 1 - Ω0) and (0.54 ± 0.02) Ω−0.28-0.91Ω0+0.68Ω200 (λ0 = 0), where n is the primordial spectral index, and h and λ0 are the dimensionless Hubble and cosmological constants. The errors quoted above indicate the statistical ones from the observed logN-logS only, and the systematic uncertainty from our theoretical modelling of X-ray flux in the best-fit value of σ8 is about 15%. In the case of n = 1, we find that the CDM models with (Ω0, λ0, h, σ8) ≃ (0.3, 0.7, 0.7, 1) and (0.45, 0, 0.7, 0.8) simultaneously account for the cluster logN-logS, X-ray temperature functions, and the normalization from the COBE 4 year data. The derived values assume the observations are without systematic errors, and we discuss in details other theoretical uncertainties which may change the limits on Ω0 and σ8 from the logN-logS relation. We have shown the power of this new approach which will become a strong tool as the observations attain more precision.
Evolution of X-Ray Clusters of Galaxies with Active Protogalaxies
Authors: Saga H. , Yachi S. , Habe A.
Published: July 2016

We consider heating due to proto galaxies in the formation process of clusters of galaxies, since much metal is observed in the intracluster gas which must be ejected from protogalaxies vir strong galactic winds and the metal abundance in the intracluster gas correlates with the fraction of early type galaxies in clusters (Arnaud 1993). We also consider radiative cooling. From the difference between the observed LX - TX relation of X-ray cluster (Hatsukade 1989), LX ∝ T2.7-3.3X, and the prediction from the self-similar model (Kaiser 1986), LX ∝ T2X, it is pointed out that physical processes which are not taken into account in the self-similar model, e.g., effect of radiative cooling, and/or effect of proto galaxy heating, play a important role in the formation process (Evrard and Henry 1991, Kaiser 1991).
ASCA Observation of A1674
Authors: Takai T. , Hayashida K. , Hashimotodani K. , Kawasaki W.
Published: July 2016

A cluster of galaxies Abell 1674 is a nearby cluster(z=0.106) and an unique sample among Briel & Henry's(1993, A&A 278,379) catalogue. Although it has the largest number of galaxies within the Abell radius, 165, its X-ray luminosity measured in the ROSAT all-sky survey is 5 × 1043erg/s (in 0.5-2.5keV), about one order of magnitude lower than the brightest one.
Direct Measurement of the CCD with a Subpixel Resolution by Using a New Technique
Authors: Yoshita K. , Kitamoto S. , Miyata E. , Tsunemi H. , Gendreau K. C.
Published: July 2016

The response function of the front-illuminated CCD, like SIS on ASCA, can be devided into three parts: the gate structure transmission, the absorption efficiency in the depletion region and the charge spreading after the photo-absorption. These effect depend on both the incident X-ray energy and the landing posion of the X-ray inside the CCD pixel. Then, the measurement of the X-ray efficiency within the pixel is important for the response function of the CCD. By using a new technique, we performed an experiment using the SIS CCD chip in the GSFC in order to measure how the various types of events are formed.
The ASCA Results of GRO J1744-28
Authors: Nishiuchi Mamiko , Maeda Yoshitomo , Koyama Katsuji , Yokogawa Jun , Dotani Tadayasu , Asai Kazumi , Ueda Yoshihiro , Mitsuda Kazuhisa , Inoue Hajime , Nagase Fumiaki , Kouveliotou Cherissa
Published: July 2016

We present the ASCA/GIS results of the transient source GRO J1744-28, the bursting X-ray pulsar, for the two times observations about one year apart. (the first and the second observations are on Feb.27th 1996 and Mar.16th 1997 respectively.) Since the discovery of GRO J1744-28 on Dec. 2 1995 with the BATSE observatory (Fishman et al. 1995; Kouveliotou et al.), thousands of Type II X-ray bursts, and sinusoidal pulsations have been observed in the X-ray band. No other source has ever been found to exhibit such unusual characteristics. Following each burst the flux decreases below, and recovers to the pre-burst persistent level (here after the dip) within a few seconds to a few minutes, depending on the total flux of the burst. We examined the spectrum of GRO J1744-28 during each persistent, dip, burst phases at the two observations. This is the first detail study of the spectra (1-10keV band) of GRO J1744-28.
Structure and Time-Dependent Behavior of Be Star Disks in Be/X-Ray Binaries
Authors: Okazaki A.T.
Published: July 2016

We consider the structure and time dependent behavior of the outflow in disks of Be stars in Be/X-ray binaries, based on the viscous decretion disk scenario (Lee et al. 1991). In this scenario, the matter ejected from the star with the Keplerian velocity at the equatorial surface of the star drifts outward because of the effects of viscosity, and forms the disk.
VRI Light Curve Analysis of SS 433
Authors: Okugami Masamitsu , Obana Yoshimi , Fukue Jun
Published: July 2016

In the light curves of SS 433, in addition to a binary modulation with a period of 13.1 d, there is a precessional one with a period of 162.5 d (Kemp et al. 1986). In the current studies, however, the attention was focused mainly on the light curves during eclipse (see, however, e.g., Antokhina, Cherepashchuk 1987). Thus, in this paper we examine light curves during precession and compare them with observational ones (Fukue et al. 1997b).
Bright X-Ray Stars near the Galactic Center
Authors: Sakano Masaaki , Nishiuchi Mamiko , Maeda Yoshitomo , Koyama Katsuji , Yokogawa Jun
Published: July 2016

This paper report the ASCA observations of the three brightest persistent X-ray stars near the Galactic Center: an X-ray burster A1742-294, black hole candidate 1E 1740.7-2942, and unclassified source 1E 1743.1-2843. Emission mechanism is briefly discussed based on the new ASCA results.
Discovery of QPO from X Persei with RXTE
Authors: Takeshima Toshiaki
Published: July 2016

X Persei is a Be X-ray binary pulsar with ~835-sec pulsation period. Different from most other Be X-ray binaries, X Persei does not exhibit X-ray outbursts. A binary period of ~580 days has been suggested, but is not confirmed the by follow-up observations.
X-Ray Determination of the Black-Hole Mass in Cygnus X-1
Authors: Kubota A. , Makishima K. , Dotani T. , Inoue H. , Mitsuda K. , Nagase F. , Negoro H. , Ueda Y. , Ebisawa K. , Kitamoto S. , Tanaka Y.
Published: July 2016

About 10 X-ray binaries in our Galaxy and LMC/SMC are considered to contain black hole candidates (BHCs). Among these objects, Cyg X-1 was identified as the first BHC, and it has led BHCs for more than 25 years(Oda 1977, Liang and Nolan 1984). It is a binary system composed of normal blue supergiant star and the X-ray emitting compact object. The orbital kinematics derived from optical observations indicates that the compact object is heavier than ~ 4.8 M⊙ (Herrero 1995), which well exceeds the upper limit mass for a neutron star(Kalogora 1996), where we assume the system consists of only two bodies. This has been the basis for BHC of Cyg X-1.
Accretion-Disk Corona Advected by External Radiation Drag
Authors: Watanabe Y. , Fukue J.
Published: July 2016

Accretion-disk corona (ADC) is required from observational as well as theoretical reasons. In almost all of traditional studies, however, a stationary corona has been assumed; i.e., the corona gas corotates with the underlying (Keplerian) accretion disk, and the radial motion is ignored. Recently, in the theory of accretion disks a radiative interaction between the gas and the external radiation field has attracted the attention of researchers. In particular the radiation drag between the gas and the external radiation field becomes important from the viewpoint of the angular-momentum removal. We thus examine the effect of radiation drag on the accretion-disk corona above/below the accretion disk (Watanabe, Fukue 1996a, b). We suppose that an accretion disk can be described by the standard disk, and that radiation fields are produced by the central luminous source and the accretion disk, itself. In general an accretion-disk corona under the influence of strong radiation fields dynamically infalls (advected) toward the center.
Reverberation Mapping Analysis of the Broad-Line Region in Seyfert Galaxy NGC 4151
Authors: Xue S.J. , Cheng F.Z.
Published: July 2016

One of the primary goals of AGN variability studies has been to determine the size of broad-line region (BLR) through the reverberation mapping technique. In a recent international multiwavelength spectroscopic monitoring campaign, NGC 4151 has been observed intensively by ground-based telescopes for a period of over 2 months, with a typical temporal resolution of 1 day. The main result from this optical campaign is that finding the variation in the emission line flux (Hβ or Hα) lagging the continuum by 0-3 days (1993 campaign: Kaspi et al. 1996). This is in contrast to the past results in which a time lag of 9±2 days was found for the same emission line (1988 campaign: Maoz et al. 1991). Such a BLR “size problem” may be caused by a different variability timescale of the ionizing continuum or a real change in BLR gas distribution in the 5.5 yr interval between the two watch campaigns. In order to clarify which of the two possibilities is most likely the real case, we performed further reverberation analysis on both optical datasets.
A Model of the Broad-Band Continuum of NGC 5548
Authors: Magdziarz P. , Blaes O.
Published: July 2016

We discuss a model of the central source in Seyfert 1 galaxy NGC 5548. The model assumes a three phase disk structure consisting of a cold outer disk, a hot central disk constituting a Comptonizing X/γ source, and an intermediate unstable and complex phase emitting a soft excess component. The model qualitatively explains broad-band spectrum and variability behavior assuming that the soft excess contributes significantly to the continuum emission and drives variability by geometrical changes of the intermediate disk zone.
Possible X-Ray Counterparts to Gamma-Ray Bursts, GRB930131 and GRB940217
Authors: Shibata R. , Murakami T. , Ueda Y. , Yoshida A. , Tokanai F. , Otani C. , Kawai N. , Hurley K.
Published: July 2016

We made a search of quiescent X-ray counterparts of two Gamma-Ray Bursts (GRBs), GRB930131 and GRB940217. These GRBs were detected with BATSE, EGRET, COMPTEL on board CGRO together with the GRB detector on Ulysses spacecraft, then they were localized in small error regions. These observations showed that the bursts were remarkably bright accompanying delayed high energy gamma-rays. ASCA observations have found a single X-ray source for each GRB on the possible location determined with the above instruments.
Recent Report on the ASCA GIS Source Catalog Project
Authors: Ishisaki Y. , Ohashi T. , Ueda Y. , Takahashi T. , Makishima K. ,   The GIS Team
Published: July 2016

We are constructing the ASCA GIS source catalog from the ASCA public archive, mainly for extra-galactic sky. The large field of view and the low-background characteristics of the GIS make it suitable for a search for serendipitous sources in a wide energy band of 0.7-10 keV. Sources to be detected by the project will provide valuable information on the log N-log S relation over the entire sensitivity band, which has never been available before. About this project, also refer to Ishisaki et al. (1995), Ueda et al. (1997) and Takahashi et al. (1997). There is the SIS source catalog project, too (Gotthelf et al., 1996). These catalogs are going to appear on the WEB.
Review of CCD parallax measurements
Authors: Dahn C.C.
Published: July 2016

Several groups, using 1-m to 2-m telescopes on ‘visitor’ arrangements, have employed CCDs to measure stellar trigonometric parallaxes with precisions in the range ± 2–5 mas. More intensive observing efforts now routinely achieve sub-mas results with the best obtained to date in the ± 0.3–0.5 mas range. Selective dimming of bright target stars using neutral density spots now permit CCD parallax measures of stars as bright as R ~ 4.
The ISO-SWS flux standard stars: synthetic spectra and observations
Authors: van der Bliek N.S. , Morris P.W. , Vandenbussche B. , Waters L.B.F.M. , Zaal P. , Bell R.A. , Gustafsson B. , Eriksson K. , de Graauw Th.
Published: July 2016

We present flux-calibrated, synthetic spectra for the calibration stars of the Short Wavelength Spectrometer of the Infrared Space Observatory ISO-SWS (cf. Kessler et al. 1996). ISO-SWS covers a wavelength range of 2.4 to 45 μm (cf. de Graauw et al. 1996), and although in the NIR the flux calibration of Vega can be used, at longer wavelengths the flux calibration has to be extrapolated by other means, because (i) Vega has at λ ≥ 25 μm an IR excess due to circumstellar dust and (ii) there is an, as yet, unresolved controversy about Vega's flux at 10 μm (cf. Rieke et al. 1985). The majority of the standard stars of SWS are of MK class G and K III, as cool giants are amongst the brightest objects in the IR, and model atmospheres for cool giants are available and well-studied (cf. Jørgensen and Gustafsson 1994).
Interferometric measurements of binaries
Authors: McAlister H.A.
Published: July 2016

This paper is a brief overview of the past performance and future promise of interferometry as applied to the study of binary stars. For the sake of brevity, the important results from infrared techniques in recent years are regretfully omitted here. It is probably unnecessary to remind the reader that the analysis of binary star orbital motions is the only direct means for the determination of stellar masses. Historically, stellar masses have resulted primarily from orbits that are sufficiently wide in angular separation to permit the astrometric determination of the motions of the individual components about the center of mass as well as the parallax of the system or from short-period spectroscopic/eclipsing binaries. The advent of long baseline optical interferometers holds the promise of a wealth of new stellar mass data through the direct resolution of spectroscopic binaries.
Cool star empirical temperature scales
Authors: Bessell Michael S.
Published: July 2016

The empirical temperatures scale for cool stars is generally well established. Temperatures are now known with reasonable precision for stars covering the range of spectral types from A to M. In the historical paper by Code, Davis, Bless and Hanbury Brown (Code et al. 1976), six stars between 10000K and 6500K had radii measured by the intensity interferometer and these six, together with the sun formed the basis of the empirical temperature calibration at the time. Since then, many temperatures have been derived for A-K stars (Blackwell & Lynas-Gray 1994; Alonso et al. 1996a) using the Infra-Red Flux Method (see Megessier 1994,5 and this volume), while lunar occultations (Ridgway et al. 1980) and more recently Michelson interferometry (Di Benedetto & Rabbia 1987; Dyck et al. 1996), have been used to measure the radii of K and M giants. It is a tribute to Hanbury Brown's Intensity Interferometer that temperature scales based on its measurements are essentially unchanged by the new data.
Stellar effective temperatures through the infrared flux method
Authors: Megessier C.
Published: July 2016

The principle of the method and its advantages are recalled, as well as the works giving such Teff. Although the method is almost model independent, the monochromatic red fluxes play an important part. The resulting Teff depends on the blanketing in the models. The stellar metallicity and gravity have to be known to avoid uncertainties of about 1%. In principle an accuracy around 1% on Teff could be obtained, but the uncertainty on the absolute red flux calibration, due to the unsolved problem of the Vega red flux, prevents this from being achieved.
What do we do when models don't fit? On model atmospheres and real stellar spectra
Authors: Gustafsson Bengt
Published: July 2016

Developments in the modelling of stellar atmospheres and results from the confrontation between calculated and observed fluxes and spectra are discussed. It is argued that, although impressive advances in the study of O-type, WR and cool star spectra have recently occurred, significant improvements should be possible with already existing methods in the analysis of, e.g., solar-type stars.
Observing solar-like oscillations
Authors: Kjeldsen Hans , Bedding Timothy R.
Published: July 2016

We review techniques for measuring stellar oscillations in solar-type stars. Despite great efforts, no unambiguous detections have been made. A new method, based on monitoring the equivalent widths of strong lines, shows promise but is yet to be confirmed. We also discuss several subtleties, such as the need to correct for CCD non-linearities and the importance of data weighting.
Properties of Cepheids and long-period variables
Authors: Wood P.R.
Published: July 2016

Some recent theoretical results concerning Cepheids and long-period variables are presented and compared with observations. Nonlinear pulsation calculations for select bump Cepheids are shown capable of yielding very accurate fundamental properties of these stars. The implications of the derived parameters are discussed. For the long-period variables, recent observational and theoretical results pertaining to the long-standing problem of the mode of pulsation are presented. The conflicting results point to some fundamental problem with current interpretations.
Evolution of intermediate mass stars
Authors: Chiosi Cesare
Published: July 2016

We summarize the evolution of intermediate-mass stars, calling attention to the uncertainties related to mixing in convectively unstable regions, and to recent developments in the theory of AGB stars with envelope burning. Finally, we briefly report on the distribution of C-stars of the Large Magellanic Cloud in the Mbol-log(age) plane.
Rotation: a fundamental parameter of massive stars
Authors: Langer N. , Heger A. , Fliegner J.
Published: July 2016

Massive stars are rapid rotators. Equatorial rotation velocities span the range vrot = 100–400 km s−1, with B stars rotating closest to their break-up speed vcrit (Howarth et al. 1997). During the last decade, many observations have revealed unusual surface abundances that may require additional internal mixing (beyond that of simple convection and overshooting) for their explanation, most important helium and nitrogen enrichment in main sequence O and B stars (Gies & Lambert 1992), in the SN 1987A progenitor (Fransson et al. 1989), and boron depletions in main sequence B stars (Venn et al. 1996). In particular the latter observations clearly point towards internal mixing and rule out a close binary origin of the abundance peculiarities (Fliegner et al. 1996). Altogether, the occurrence of some form of additional mixing responsible for altering the surface abundances in a large fraction, if not all massive stars appears to be beyond reasonable doubt, and mixing processes due to rotation are the most natural explanation.
Deep Wide-field Hα Images of the Magellanic Clouds
Authors: Morgan D. H. , Parker Q. A. , Phillipps S.
Published: July 2016

A new Hα survey of the Magellanic Clouds which is being carried out on fine-grained Tech-Pan emulsion with the UK 1.2m Schmidt Telescope will have the best combination of depth and resolution of any that cover such a wide area in and around the Magellanic Clouds. Preliminary results show that the films will provide identifications of new emission-line stars and nebulae.
A Wide-Angle Hα Image of the LMC
Authors: Gaustad John E. , Rosing Wayne , Mccullough Peter R. , Van Buren Dave
Published: July 2016

We are conducting a wide-angle Hα survey of the southern sky at CTIO using a robotic CCD camera. The survey consists of 283 fields covering the sky from δ = −90° to δ = +10°, with the same centers as those in the IRAS Sky Survey Atlas. As of July 1, 1998, it was about 45% complete. When all the images are obtained and fully processed, the survey will be made available to the scientific community on the web and on CD-ROM.
An HI Aperture Synthesis Mosaic Survey of the Large Magellanic Cloud
Authors: Kim Sungeun , Staveley-Smith L. , Sault R. J. , Dopita M. A. , Freeman K. C. , Kesteven M. J. , McConnell D.
Published: July 2016

We present the results of an HI aperture synthesis mosaic of the Large Magellanic Cloud (LMC), made by combining data from 1344 separate pointing centers using the Australia Telescope Compact Array (ATCA). The resolution of the mosaiced image is 1′ (15 pc, using a distance to the LMC of 50 kpc).
Fractal Structure in the Interstellar Medium of the Small Magellanic Cloud?
Authors: Stanimirović Snezana , Staveley-Smith L. , Sault R. J. , Dickey J. M. , Snowden S. L.
Published: July 2016

We use the spatial power spectrum for a statistical study of HI in the SMC in order to probe the intrinsic topology of the ISM. A remarkable power-law fit to the spatial power spectrum was found, supporting an alternative ISM model having a fractal nature resulting from interstellar turbulence.
Molecular Cloud Structure in the Magellanic Clouds: CO-to-H2 Conversion Factor
Authors: Pak Soojong , Jaffe D. T.
Published: July 2016

In the Milky Way, the 12CO J = 1 → 0 line traces the molecular gas content. The conversion factor, XGAL, between the H2 column density, N(H2), and the velocity integrated intensity of CO, I(CO), has been measured via the virial theorem or via γ-ray emission (Solomon et al. 1987; Bloemen et al. 1986; Digel et al. 1997; and references therein).

How can we apply XGAL to other galaxies where the metallicities are different from that of our Galaxy? The metallicity dependence of the conversion factor has been an issue. Cohen et al. (1988), Wilson (1995), and Arimoto, Sofue, & Tsujimoto (1996) argued that the value of X increases as the metallicity of the individual galaxy decreases. In contrast, Taylor, Kobulnicky, & Skillman (1996) showed that some low abundance galaxies have lower X.
Formation of Ring Nebulae around Massive Stars in LMC HII Regions
Authors: Weis Kerstin , Duschl Wolfgang J.
Published: July 2016

Massive stars have strong stellar winds and consequently a high mass loss during their lifetimes. Therefore they can form ring nebulae by stellar winds sweeping up the ambient medium in the main sequence phase or through wind-wind interaction or eruptions in the evolved state. We present preliminary results of a search for single bubbles and ring-nebulae around massive stars in the Large Magellanic Cloud (LMC).
N63A: A Supernova Remnant in a Cloudy Medium
Authors: Chu You-Hua , Caulet Adeline , Dickel John , Points Sean , Williams Rosa , Arias-Montaño Lorena , Rosado Margarita , Ambrocio-Cruz Patricia , Laval Annie , Bomans Dominik J.
Published: July 2016

Our recently obtained HST WFPC2 images of N63A reveal shocked cloudlets in the SNR interior. The study of N63A helps us understand the structure and evolution of SNRs in a cloudy medium.
The IRAS Vela Shell: a “Super Shell” in the Making?
Authors: Rajagopal Jayadev , Srinivasan G.
Published: July 2016

The IRAS Vela shell was first seen as a ring of infrared emission in the IRAS maps of the Gum-Vela region coincident with the Gum Nebula. We have studied the kinematics of the molecular material (12CO) associated with the IRAS point sources and Southern Dark Clouds seen in this region and established the presence of a giant expanding shell of molecular gas. The estimated mass, size and expansion velocity of the shell lead us to conclude that it is the remnant of a GMC, in the process of disintegration through the influence of a central OB association. We conjecture that the IRAS Vela shell is a nearby example of a “super shell” in its early stages of evolution and as such is an ideal opportunity to study these objects now widely seen both in our Galaxy and in new observations of the Magellanic Clouds.
The New 30 Doradus
Authors: Walborn Nolan R. , Barbá Rodolfo H.
Published: July 2016

Recent optical and infrared studies of 30 Doradus have revealed a more complex and diverse star-formation history than previously recognized. Five spatially and/or temporally distinct populations have been identified, including a new generation currently being triggered by the R136 cluster in its surroundings. HST/NICMOS observations of the latter provide insights into the phenomena of triggered massive-star formation, as well as the global structure and evolution of the starburst region.
Hot Gas and Physical Structure of 30 Dor
Authors: Wang Q. Daniel
Published: July 2016

Recent ROSAT and ASCA X-ray observations as well as HST images have provided new insights into the structure and evolution of the 30 Dor nebula. I review hot gas properties of the nebula and discuss related physical processes. The structure of the nebula can be understood as outflows of hot and HII gases from the parent giant molecular cloud of R136. The dynamic mixing between the two gas phases is likely a key mass loading process of the hot gas, providing a natural explanation of both temperature and density structure of the nebula.
Discovery of a Stellar Association Surrounding the Massive Binary Sk–67°105 in the Large Magellanic Cloud
Authors: Ostrov P. G. , Niemela V. S. , Morrell N. I.
Published: July 2016

Sk–67°105, a luminous O4f type stars in the Large Magellanic Cloud, is the exiting star of the H II region N 50 (DEM 193). Niemela & Morrell (1986) found this hot star to be a massive short period double lined spectroscopic binary. Because luminous OB stars are usually found in young stellar groups, we have searched for such an aggregate in the vicinity of Sk–67°105.

Here we report, as a result of our search, the discovery of a new OB association in the LMC. We also find that Sk–67°105 is the most luminous star of a small compact cluster inside this OB association.
HST/WFPC2 Photometry in the 30 Doradus Nebula Beyond R136
Authors: Barbá Rodolfo H. , Walborn Nolan R.
Published: July 2016

A photometric study of the 30 Doradus Nebula beyond the core is being carried out by means of HST/WFPC2 archival images, with special attention to the numerous multiple systems and compact clusterings found there.
Stellar Metallicities in the Magellanic Clouds
Authors: Smith Verne V.
Published: July 2016

The overall stellar metallicity scale as a function of age for both Magellanic Clouds reveals that they have followed a different pattern of enrichment when compared to each other as well as to the Galactic disk. In addition, an investigation into the abundances of two key elements, oxygen and europium, shows that the detailed nucleosynthesis history of these systems is unique in comparison to any Galactic population yet studied.
Overview of the Field Stellar Population of the Magellanic Clouds
Authors: Westerlund Bengt E.
Published: July 2016

The stellar populations in the LMC, the SMC, and the Bridge region are discussed and shown to be composed of a number of well separated generations. Asymmetries are seen in the distributions of the intermediate-age and youngest generations. The possibility is considered that all generations, apart from the oldest one, have been produced by bursts of star formation.
The LMC Intermediate and Old Populations
Authors: Olszewski Edward W.
Published: July 2016

This review concentrates on the oldest populations in the LMC. Specifically, the LMC has a large extent and mass, it has star clusters coeval with those in the Milky Way halo, and more work needs to be done before we are convinced that there are similarly-aged field stars in the LMC. Further, all studied fields in the Clouds are different from Milky Way halo fields. Observations with the new generation of large telescopes can clear up the uncertainties noted in this review.
The Magellanic Clouds Photometric Survey
Authors: Zaritsky Dennis , Grebel Eva K. , Harris Jason , Thompson Ian
Published: July 2016

We present a brief description of the Magellanic Clouds Photometric Survey. In particular, we discuss examples of how the new generation of densely populated CMDs provide new information than that available previously.
Kinematics of F to M Supergiants in the 30 Dor and Shapley II Regions of the Large Magellanic Cloud
Authors: Maurice E. , Martin N. , Testor G. , Lortet M. C.
Published: July 2016

Accurate radial velocities have been obtained with the CORAVEL photoelectric scanner at ESO, La Silla, for 36 F-M supergiants in the 30 Dor and Shapley II regions of the LMC (5h20m < RA(2000) < 5h50m, −70°09′ < Dec (2000) < −68°30′). On the basis of these data, we revisit the content and spatial extent of the four kinematical groups of F-M supergiants discovered in this area by Prévot et al. 1989. Each is the oldest part of a larger star forming region, recognized by young HII regions or CO clouds, and/or a surrounding Hα + [NII] superbubble. We discuss various gas tracers including the interstellar sodium and calcium lines.
Analyses of the LMC Novae
Authors: Vanlandingham Karen M. , Schwarz Greg J. , Starrfield Sumner , Hauschildt Peter H. , Shore Steven N. , Sonneborn George
Published: July 2016

In the past 10 years, 6 classical novae have been observed in the Large Magellanic Cloud (LMC). We have begun a study of these objects using ultraviolet spectra obtained by IUE and optical spectra from nova surveys. We are using the results of this study to further our understanding of novae and stellar evolution.

Our study includes analysis of both the early, optically thick spectra using model atmospheres (Hauschildt et al. 1992), and the later nebular spectra using optimization of photoionization codes (Ferland 1996; James & Roos 1993). By analysing all the LMC novae in a consistent manner, we can compare their individual results and use their combined properties to calibrate Galactic novae. In addition, our studies can be used to determine the elemental abundances of the nova ejecta, the amount of mass ejected, and the contribution of novae to the ISM abundances. To date we have analysed Nova LMC 1988#1 (Schwarz et al. 1998) and Nova LMC 1990#1 (Vanlandingham et al. 1999), and have obtained preliminary results for Nova LMC 1991. The results of this work are presented in this poster.
Deep STIS Luminosity Functions for LMC Clusters
Authors: Elson R. , Tanvir N. , Gilmore G. , Johnson R. A. , Beaulieu S.
Published: July 2016

We present deep luminosity functions derived from HST STIS data for three rich LMC clusters (NGC 1805, NGC 1868, and NGC 2209), and for one Galactic globular cluster (NGC 6553). All of the LMC cluster luminosity functions are roughly consistent with a Salpeter IMF or with the solar neighbourhood IMF from Kroupa, Tout & Gilmore (1993). They continue to rise at least to 0.7M⊙. NGC 1868 shows evidence for mass segregation which may be primordial. A comparison of deep luminsoisty functions for seven Galactic globulars shows that the luminosity functions are eroded at low masses by amounts that are strongly correlated with distance from the Galactic plane.
Spontaneous and Induced Star Formation in the LMC
Authors: Efremov Yu.N. , Elmegreen B. G.
Published: July 2016

Spontaneous and triggered star formation in the LMC is discussed with data on star clusters ages and positions. The supershell LMC4 and the stellar arcs in the same region are suggested to be triggered by GRBs, the progenitors of which might have escaped the old elliptical cluster NGC1978, close to which are a number of X-ray binaries and the SGR/SNR N49.
Outer Halo Star Clusters: Comparisons for Cloud Clusters
Authors: Hesser J. E. , Stetson P. B. , van den Bergh S. , Bolte M. , Johnson J. A. , Harris W. E. , VandenBerg D.A. , Bell R. A. , Bond H. E. , Fullton L. E. , Fahlman G. G. , Richer H. B.
Published: July 2016

Color-magnitude diagrams reaching from the giant branches to Vlim ~ 27.0, or about three magnitudes fainter than the turnoff, have been obtained in V and I with WFPC2 on HST for NGC 2419, Pal 3, Pal 4 and Eridanus, whose relative ages are discussed.
The Stellar Complexes in the Large Magellanic Cloud
Authors: Maragoudaki F. , Kontizas M. , Kontizas E. , Dapergolas A. , Morgan D. H.
Published: July 2016

A method has been developed for the detection of stellar complexes and the derivation of their fundamental properties in the LMC. We have used digitized UKST plates in order to perform star counts and produce isodensity contour maps in various colours and luminosity slices. About 50 large stellar groupings have been revealed. Their properties favour a “top-down” mechanism acting in star forming regions.
Relaxation of Star Clusters and Color Gradients
Authors: Boily Christian
Published: July 2016

Large interstellar distances imply that protostars are dynamically decoupled from gas ram pressure (see, e.g., Aarseth, Lin & Papaloizou 1988) and are effectively isolated self-gravitating objects. With this in mind we apply Newtonian gravity to collapsing cold spheroids of point masses to model the Lin-Mestel-Shu (1965) solution for dust. Incomplete violent relaxation (e.g., van Albada 1982) means that traces of the initial orbit distribution in energy remain. We show here that furthermore the degree of orbit mixing achieved correlates well with initial morphology, by collapsing two-mass component uniform spheroids of different aspect ratio. We setup a test problem to seek out a relation between orbit survival and initial morphology which we then solve numerically.