We report the results of the spectral monitoring of the chemically peculiar (CP2) star HD 3980 in the Li I$\lambda 6708$ spectral region. High spectral resolution observations ($R=88000$) were carried out at Mount Stromlo Observatory with the 74-inch telescope and the echelle spectrograph. HD 3980 is a late type Ap SrCrEu star with strong double-wave photometric variations in the visible and in the near infrared. We estimated the effective temperature, surface gravity, mass, luminosity, and radius of this star. The monitoring of this star shows strong spectral variations, especially in the profile of Li I$\lambda 6707.8$. We studied the variations of the equivalent width and position of the Li I line as a function of the rotating phase and compared them with the magnetic field variations and light curves taken from the literature. The synchronism of the variations of the Li I line profile, light curve, and magnetic field strength can be explained in terms of the oblique magnetic rotator model. The strong variations of position and intensity of this line with the rotation phase enable us to consider this star as a new member of the intriguing group of “Li-spotted” CP stars.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Series of H$_\alpha$ spectra and slit-jaw H$_\alpha$ filtergrams of a quiescent prominence (QP) taken at Pic du Midi Observatory on 7 November 1977 are studied. The image processing of the H$_\alpha$ filtergrams reveals an internal structure of the prominence consisting of several arches. Series of high-resolution H$_\alpha$ spectra obtained with the slit located on selected parts of one of the prominence arches chosen for Doppler shift analysis. The prominence arch show cyclic displacement along the line-of-sight (L.O.S.) direction implying Alfven string-mode oscillations.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We discuss the mass assembly history both on cluster and galaxy scales and their impact on galaxy evolution.

On cluster scale, we introduce our on-going PISCES project on Subaru, which plans to target $\sim 15$ clusters at $0.4\le z\le 1.3$ using the unique wide-field ($30'$) optical camera Suprime-Cam and the spectrograph both in optical (FOCAS, $6'$) and near-infrared (FMOS, $30'$). The main objectives of this project are twofold: (1) Mapping out the large scale structures in and around the clusters on 10–14~Mpc scale to study the hierarchical growth of clusters through assembly of surrounding groups. (2) Investigating the environmental variation of galaxy properties along the structures to study the origin of the morphology-density and star formation-density relations. Some initial results are presented.

On galactic scale, we first present the stellar mass growth of cluster galaxies out to $z\sim1.5$ based on the near-infrared imaging of distant clusters and show that the mass assembly process of galaxies is largely completed by $z\sim1.5$ and is faster than the current semi-analytic models' predictions. We then focus on the faint end of the luminosity function at $z\sim1$ based on the Subaru/XMM-Newton Deep Survey imaging data. We show the deficit of red galaxies below $M^*+2$ or 10$^{10}\,{\rm M}_{\odot}$, which suggest less massive galaxies are either genuinely young or still vigorously forming stars in sharp contrast to the massive galaxies where mass is assembled and star formation is terminated long time ago.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Components of multiple systems generally originate from the same protostellar environment. Their similarities or differences in surface chemical composition therefore relates to their individual evolutionary paths (stellar evolution, rotation) and the possible influence of a close companion.

DG Leo is a spectroscopic hierarchical triple system with almost equal-mass late-A type components. Observations with high time and high spectral resolution were used to disentangle the spectrum of each component from the composite spectra. A detailed abundance analysis of the component spectra reveals that the wide companion has a nearly solar-like composition, while both components in the close binary show Am type peculiarities.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We here present our result of deep and wide-field narrow-band imaging of the region of the ‘proto-cluster’ at $z=3.1$ around the SSA22 field. We detected 283 highly confident Ly$\alpha$ emitter candidates (LAEs) and discovered that the belt-like high surface density region of these LAEs extends over $\approx 60$ Mpc in comoving scale, which is much larger than it was known previously. We then successfully detected the 35 extended Ly$\alpha$ blobs (LABs) which are larger than 16 arcsec$^2$ in isophotal area and brighter than $0.7 \times 10^{-16}$ ergs s$^{-1}$ cm$^{-2}$. The distributions of average surface brightness and morphology are widespread from relatively compact high surface brightness objects to very diffuse low surface brightness ones. For one third of these 35 LABs, simple photo-ionization by massive stars is not sufficient to explain the Ly$\alpha$ luminosities, and other mechanisms, such as gravitational heating or superwind must be considered. From their large size and strong spatial clustering, we consider that these LABs are objects closely related to the massive galaxies in their forming phase in the environment of the proto-cluster or large-scale structure.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The Geospace Double Star Project (DSP) contains two satellites operating in the near-earth equatorial and polar regions respectively. The tasks of DSP are: (i) to provide high-resolution field, particle and wave measurements in several important near-earth magnetosphere active regions which have not been covered by existing ISTP missions in the geospace, such as the near-earth plasma sheet and its boundary layer, the ring current, the radiation belts, the dayside magnetopause boundary layer, and the polar region; (ii) to investigate the trigger mechanisms of magnetic storms, magnetospheric substorms, and magnetospheric particle storms, as well as the responses of geospace storms to solar activities and interplanetary disturbances; (iii) to set up the models describing the spatial and temporal variations of the near-earth space environment. To complete the mission, there are eight instruments on board the equatorial satellite and the polar satellite, respectively. The orbit of the equatorial satellite with a perigee at 565.5km and an apogee at 78959.9km, and the inclination is 28.17 ; while the orbit of the polar satellite is proposed with a perigee at 700km and an apogee at 40000km, as well as an inclination about 90. The equatorial satellite has been launched successfully in December 2003. Now the equatorial satellite (TC-1) and instruments operate normally. Payloads have provided good quality of data of fields and particles. Already very good conjunction in the dayside magnetopause and magnetotail with Cluster, CME effects could be investigated. The first results of data analysis have already shown great interesting. The polar (TC-2) satellite has been launched successfully in July 2004. Now the satellite operates normally. The commissioning of the payload has started since the end of July 2004 and will be finished in the middle of Sep.2004. The instrument has been normally operation and downlink the data.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Relations between the geomagnetic A$_p$-index and magnetic and flare parameters of the super active regions (SARs) are analysed. The small and mean SARs having the spot areas S$\le 1000\, \mu h$ seem to differ from the SARs being large $\delta$-spots (SARs-$\delta$) not only by their parameters but also by relations between them.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present single-dish observations of a sample of 27 nearby (z<0.018) Seyfert galaxies obtained with the ATNF/Mopra radiotelescope. The total neutral gas content for the sample is derived. We find that Seyfert galaxies are gas-rich objects with a median HI mass to blue luminosity ratio $M_{HI}/L_B\sim 0.38$ M$_\odot$/$L_\odot$, which tends to increase with decreasing optical and far-infrared luminosities. We have also found a correlation among the neutral hydrogen content of Seyfert 2 galaxies and the IRAS luminosities, similar to those found for normal spiral and starburst galaxies. Our results suggest a scenario where the star formation of Seyfert galaxies is similar to that found in starbursts, and that they are dependent of the initial neutral mass content of progenitors of galaxy disks in the blue compact-HII galaxy-Seyfert sequence. Within this sequence, the far-infrared luminosity and the total hydrogen mass correlate as $L_{fir}/L_\odot\propto (M_{HI}/M_\odot)^{1.5\pm 0.4}$.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We calculated the energy distributions of A-star atmospheres (${{T}_\text{eff}=10 000}\,{\rm K},{\log g=4.0}$) for ranges of the abundances of silicon and other light chemical elements using adequate model atmospheres. We discuss the reasons for and the magnitudes of the calculated departures of the stellar energy distribution and uvby magnitudes from those of normal stars.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The active region 8210 (AR 8210) observed on May 1, 1998 is the site of numerous flares. By studying a time series (from 17:00 UT to 21:40 UT) of reconstructed coronal magnetic configurations, we give a scenario of the eruptive phenomena in AR 8210 involving the rotation of the sunspot and the complex topology in a reconnection process. We also study the time evolution of the energy and of the helicity budget. We compute the free energy in the corona, the magnetic energy rate due to transverse photospheric motions. We conclude that the photospheric motions are related to flaring activities and occur before the injections of energy into the corona. In terms of magnetic helicity, we are able to derived the relative magnetic helicity (relative to the potential field) and the helicity of the potential field configuration. The vacuum helicity (or helicity of the potential field) is constant during the time period and characterizes the complex topology. For this time period, the relative magnetic helicity does not show obvious changes related to the flaring activity.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Using data from ACE and low-altitude polar orbit satellite of NOAA, we investigate the possible sources of the enhancements of relativistic electrons in the magnetosphere. The observations from NOAA for the different geomagnetic activity periods show that substorms injections provide seed electrons for MeV electron enhancement associated with geomagnetic storms and the energetic electrons in the solar wind provide an alternative source for the relativistic electrons in the magnetosphere during the SEP events.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We analyse the rest–frame (U$-$V) colour–magnitude relation for 2 clusters at redshift 0.7 and 0.8, drawn from the ESO Distant Cluster Survey. By comparing them with the population of red galaxies in the Coma cluster, we show that the high redshift clusters exhibit a deficit of passive faint red galaxies. Our results show that the red–sequence population cannot be explained in terms of a monolithic and synchronous formation scenario. A large fraction of faint passive galaxies in clusters today has moved onto the red sequence relatively recently as a consequence of the fact that their star formation activity has come to an end at $z<0.8$.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

High velocity shocks may provide an important source of ionizing radiation in the NLR of active galaxies. Here we present preliminary results of a new grid of MAPPINGS III shock models for shock velocities up to 1000 km s−1. This grid significantly extends the parameter space covered by the previous models, and will serve as an important component in building multi-process models of the NLR.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present a method for deriving light-weighted stellar metallicities and ages from high-resolution galaxy spectra, based on the new population synthesis code of Bruzual & Charlot (2003). The method relies on the simultaneous fit of several optical spectral absorption features that are sensitive to either age or metallicity, but not to the $\alpha$-elements abundance ratio. We have constructed a library of stochastic star formation histories, which we have used to derive median-likelihood estimates of ages and metallicities for $\sim10^5$ galaxies extracted from the Sloan Digital Sky Survey Data Release One (SDSS DR1), spanning the full range in star formation activities, from dormant early type to actively star forming. Here we discuss the results for early-type galaxies. We show that the $g-r$, $M_r$ color-magnitude relation for these galaxies is driven primarily by changes in metallicity and in heavy-element abundance ratios. Changes in light-weighted age contribute mainly to the scatter about the relation. This is consistent with previous interpretations of this relation based on lower resolution models.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Recent high resolution observations by Lites et al. (2004) show details of facular granules at $0.12^{\prime\prime}$, including dark facular lanes. For an interpretation of these data a basic facular model is constructed, consisting of a magnetic flux sheet embedded in a plane parallel atmosphere. While the maximum contrast originates from the “hot wall” of the flux-sheet depression, the model explains the wide brightening limbward of the facular magnetic field as due to a radiative transfer effect caused by the reduced opacity of the rarefied flux-sheet atmosphere. This model produces a dark, narrow lane centerward of the facular granule even in the absence of granular flow as a consequence of the cool deep layers of the magnetic flux sheet. These results carry over to a self-consistent simulation of a flux concentration in dynamic interaction with convective motion, where the dark lane deepens and broadens.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We compare recent HST observations of Seyfert and quasar NLRs and find that type–2 AGNs follow a relation consistent with that expected for a distribution of gas ionized by a central source $R_{\rm NLR,2} \propto L^{0.32 \pm 0.05}$, while type–1 objects are fit with a steeper slope of 0.55±0.05. The latter is comparable to the scaling found for the BLR size with continuum luminosity (slope: 0.5–0.7). Therefore, we investigate what we can learn about the BLR size if the NLR size is only determined by the AGN luminosity. We find that NLR and BLR size are related linearly following $R_{\rm BLR} \propto R_{\rm NLR,1}^{0.88 \pm 0.1}$. This relation can be used to estimate BH masses.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Solar prominences can be viewed as pre-eruptive states of coronal mass ejections (CMEs). Eruptive prominences are the phenomena most related to CMEs observed in the lower layers of the solar atmosphere. The most probable initial magnetic configuration of a CME is a flux rope consisting of twisted field lines which fills the whole volume of the dark cavity stretched in the corona along the photospheric polarity inversion line. Cold dense prominence matter accumulates in the lower parts of helical flux tubes, which serve as magnetic traps in the gravitation field. Coronal cavity is rather inconvenient feature for observation owing to reduced emission, so prominences and filaments are the best tracers of the flux ropes in the corona long before the beginning of eruption. Thus, the problem of the CME prediction can be reduced to the analysis of the filament equilibrium and estimation of the stability store. The height of a prominence (or a filament when observed against the disk) increases with its age and the death of a filament is usually an eruption which is followed by a CME. The filament height, then, can be a measure of its age and its readiness for eruption. In inverse-polarity models the equilibrium height of a filament is related to the value of the filament electric current. The stronger the electric current, the greater the height of the filament. However, the equilibrium and stability of a filament depend not only on its current but also on the characteristics of the external magnetic field. In order to estimate the probability of eruption, we should therefore compare the observed prominence height with a value characterizing the photospheric magnetic field. This value is the critical height, which can be found in the distribution of the magnetic field vertical gradient above the polarity inversion line. We had analyzed three dozens of filaments and found that eruptive prominences were near the limit of stability a few days before eruptions. We believe that the comparison of the real heights of prominences with the calculated critical heights could be a basis for predicting filament eruptions and following CMEs.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The lines of lithium at $\lambda 6708$ and $\lambda 6103$ are analyzed in high resolution spectra of some sharp-lined and slowly rotating roAp stars. Three spectral synthesis codes, STARSP, ZEEMAN2 and SYNTHM were used. New lines of the Rare Earth Elements from the DREAM database, and lines calculated on the basis of the NIST energy levels were included. Magnetic splitting and other line broadening processes were taken into account. Enhanced abundances of lithium in the atmospheres of the stars studied are obtained for both lithium lines. High estimates of $^6{\rm Li}/^7{\rm Li}$ ratio ($0.2\div0.5$) for the studied stars can be explained by Galactic Cosmic Ray (GCR) production by spallation reactions and the preservation of the original $^6{\rm Li}$ and $^7{\rm Li}$ by the strong magnetic fields.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

This work reports our recent results of an HI line and radio continuum imaging survey of selected southern Active galaxies made with the Very Large Array and the Australian Telescope Compact Array. Radio images are presented and rotation curves for individual galaxies were obtained. The HI total mass content in Seyfert galaxies is larger than those seen in starburst galaxies. Our trends confirm that the infrared luminosity correlates well with the total neutral gas content, which supports the scenario that star formation in the bulges of Seyfert galaxies is considerably higher than in regular late-type galaxies or spirals. We also find a trend between various observational quantities which are also discussed in this work.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We have compiled all available measurements in the UV region for the group of $\lambda$ Bootis stars. These data are compared to those of F-weak stars and known spectroscopic binary systems. We also use synthetic photometric values from standard atmospheric models to comment on the proposed spectroscopic binary nature of members of the $\lambda$ Bootis group which can be found in the literature.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html