This contribution reviews two topics of current interest in the study of black hole demographics in active galaxies: Can the stellar velocity dispersions of quasar host galaxies be measured? And can we constrain the black hole mass function below 106 M$_\odot$?To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Wide-angle, moderately deep redshift surveys such as that conducted as part of the Sloan Digital Sky Survey (SDSS) allow study of the relationship between the structural elements of the large-scale distribution of galaxies – including groups, cluster, superclusters, and voids – and the dependence of galaxy formation and evolution on these enviroments. We present a progress report on mapping efforts with the SDSS and discuss recently constructed catalogs of clusters, voids, and void galaxies, and evidence for a $420h^{-1}$Mpc supercluster or “Great Wall.” Analysis of multi-band photometry and moderate-resolution spectroscopy from the SDSS reveals environmental dependence of the star formation history of galaxies that extends over more than a factor of 100 in density, from clusters all the way to the deep interiors of voids. On average, galaxies in the rarified environments of voids exhibit bluer colors, higher specific star formation rates, lower dust content, and more disk-like morphology than objects in denser regions. This trend persists in comparisons of samples in low vs. high-density regions with similar luminosity and morphology, thus this dependence is not simply an extension of the morphology-density relation. Large-scale modulation of the halo mass function and the temperature of the intergalactic medium might explain this dependence of galaxy evolution on the large-scale environment.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We review the scientific objectives and the present status cosmic shear studies. We discuss the future prospects and the role cosmic shear could play in a precision cosmology era.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

When Jeremiah Horrocks correctly predicted, and with his friend William Crabtree observed, the Venus transit of 24 November 1639, these two men became more than the first astronomers in history to witness a rare celestial phenomenon. For Horrocks's and Crabtree's achievement constituted in may ways the first major astronomical discovery to be made in Renaissance England. It is also clear from their writings, moreover, that the two men, working in the isolation of rural Lancashire and well away from London or the universities, were fully conversant with contemporary discoveries made in continental Europe by Tycho Brahe, Galileo, Kepler, Gassendi, and others. In many ways, therefore, their work begs more questions than can easily be answered, such as why the rural North-West produced not only Horrocks and Crabtree, but other contemporary astronomers such as the Lancastrians Charles Towneley, Jeremy Shakerley, and their Yorkshire friend William Gascoigne. Yet in addition to whatever regional circumstances might have been present, and how easy it might have been for an educated rural Lancastrian to be fully informed about what astronomers in Paris, Prague, or Florence were doing, what cannot be denied is the outstanding originality of their wider achievement. For Jeremiah Horrocks in particular was a physical scientist of genius. His correct determination of the elliptical shape of the lunar orbit by 1638 when he was about 20 and his wider work on planetary dynamics place him amongst the most creative researchers of the seventeenth century. Central to Horrocks's and Crabtree's achievement was Crabtree's realisation by 1636 that contemporary published astronomical tables were unreliable, and that if one wanted to do serious work in understanding the heavens, then one had to observe and measure them for oneself, and learn to draw original conclusions.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

This paper reviews recent results on the dynamics of multiple-planet extra-solar systems, including main sequence stars and the pulsar PSR B1257+12 and, comparatively, our own Solar System. Taking into account the degree of gravitational interaction of the planets, the known planetary systems may be separated into four main groups: (Ia) Planets in Mean-motion resonance (Ib) Low-eccentricity near-resonant pairs; (II) Non-resonant planets with a significant secular dynamics; and (III) Weakly interacting planet pairs. Different analytical and numerical tools can help to understand the structure of the phase space, to identify stability mechanisms and to categorize different types of motions in the cases of more significant dynamical interaction. The origin of resonant configurations is discussed in the light of the hypothesis of planetary migration.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

In recent times, there has been keen interest in understanding Sun-Earth connection events, such as solar flares, CMEs and concomitant magnetic storms. Magnetic storms are the most dramatic and perhaps important component of space weather effects on Earth. Super-intense magnetic storms (defined here as those with Dst $<$ −500 nT, where Dst stands for the disturbance storm time index that measures the strength of the magnetic storm) although relatively rare, have the largest societal and technological relevance. Such storms can cause life-threatening power outages, satellite damage, communication failures and navigational problems. However, the data for such magnetic storms is rather scarce. For example, only one super-intense magnetic storm has been recorded (Dst=−640 nT, March 13, 1989) during the space-age (since 1958), although such storms may have occurred many times in the last 160 years or so when the regular observatory network came into existence. Thus, research on historical geomagnetic storms can help to create a good data base for intense and super-intense magnetic storms. From the application of knowledge of interplanetary and solar causes of storms gained from the spaceage observations applied to the super-intense storm of September 1-2, 1859, it has been possible to deduce that an exceptionally fast (and intense) magnetic cloud was the interplanetary cause of this geomagnetic storm with a Dst −1760 nT, nearly 3 times as large as that of March 13, 1989 super-intense storm. The talk will focus on super-intense storms of September 1-2, 1859, and also discuss the results in the context of some recent intense storms.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

After briefly summarizing the outstanding achievements and new tendencies witnessed in recent years in the studies of magnetic fields of solar active regions (ARs), we focus on the current understanding on flux appearance and disappearance. On flux appearance, the moving magnetic features (MMFs) stand still as a mystery in solar physics, although the emergence of magnetic flux in the bipolar form are fairly understood. However, the possibly sympathetic flux emergence of several ARs and the appearance of active longitudes or hot spots are poorly understood. The only confirmed model of flux disappearance is the observed flux cancellation. Detailed analysis of the alignments of transverse magnetic fields and the history of magnetic flux evolution suggest that flux cancellation is more likely to be the magnetic reconnection in the lower solar atmosphere. Magnetic and current helicity provide new diagnosis in understanding flux emergence and disappearance, and constrains the energy process in solar activity.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Designating a star as of A-type is a result of spectral classification. After separating the peculiar stars from those deemed to be normal using the results of a century of stellar astrophysical wisdom, I define the physical properties of the “normal” stars. The hotter A stars have atmospheres almost in radiative equilibrium. In the A stars convective motions can be found which increase in strength as the temperature decreases.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We have embarked in an HST program to determine the masses of black holes in spiral galaxies directly by measuring the line emission arising from an extended accretion disk. For each of the galaxies in our sample we have measured the rotation curve and determined the mass distribution within the inner 5–50 pc. We have modeled the stellar mass component using the photometric data from existing HST images and using both data sets we have derived the masses of the black holes in each galaxy. These results will be very important in clarifying the role of the black hole in powering the AGN, will shed light into the effectiveness of the accretion mechanisms and finally will be important in addressing the fundamental issue of unification for Seyfert 1 and Seyfert 2 galaxies.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The Solar and Heliospheric Observatory (SOHO), a space mission of international collaboration between ESA and NASA, has been operating almost continuosly since early 1996. The Sun and the heliosphere went through both: the minimum and maxumum of solar activity in 1996 and 2000, respectively. The perfectly working set of modern solar telescopes and insitu instrumentation has been producing an unprecedented set of most valuable observational data that are almost immediately available to the public via the Internet. A wealth of new results has been published in innumerable papers. For CME research in particular, SOHO has started a new era. CME evolution can now be studied from their initiation up to the arrival of the ejecta clouds at 1 AU. For the first time, helioseismological observations reveal flow vortices underneath sunspots, i.e., activity centers that are involved in subsequebt eruptions. Combined EUV disk observations and coronagraph images allow to differentiate between CMEs pointed towards to or away from the Earth. Thus, space weather predictions have achieved a new quality. The occurrence of “EIT waves” at CME onset was discovered, the internal structure of CMEs (including “disconnection”, magnetic topology and helicity, etc.) was made visible, statitics about CME properties and their change with solar activity were refined. Spectacular CME images and animations have been attracting the public to an unexpected extent, to the benefit of solar research in general.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

In this contribution we investigate the connection between clusters of galaxies and their large-scale environment, with an emphasis on clusters which are well characterized by their X-ray emission. We show that this connection is so tight that clusters can be used as perfect tracers of the large-scale matter distribution and thus for cosmological tests. The correlation of the X-ray traced cluster mass and the optical luminosity of the galaxy content of clusters shows that the dark matter and galaxy distribution are tightly connected, but we also observe a scatter which is so far not well understood. We further explore the correlation of the galaxy population mix with the geometry of the large-scale structure features. On larger scales we also find correlations of the properties of galaxy clusters with the density of their large-scale structure environment.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

This paper sets Jeremiah Horrocks and Much Hoole in the context of Lancashire society on the eve of the English Civil War. It focuses on the complexities of what it was to be a “Puritan” in an environment where religious labels and conflicts mattered a great deal; it examines the economic circumstances of county and locality at the time, pointing out the extent to which (despite widespread and deep poverty) the county's merchants were looking outwards to London, northern Europe and beyond; and it emphasizes that even in the apparently remote and rustic location of Much Hoole it was possible for Horrocks to sustain a scientific correspondence and to keep in touch with, and make his contribution to, developments on a much wider stage.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The measurement of weak gravitational lensing is currently limited to a precision of $\sim$10% by instabilities in galaxy shape measurement techniques and uncertainties in their calibration. The potential of large, on-going and future cosmic shear surveys will only be realised with the development of more accurate image analysis methods. We present a description of several possible shear measurement methods using the linear “shapelets” decomposition. Shapelets provides a complete reconstruction of any galaxy image, including higher-order shape moments that can be used to generalise the KSB method to arbitrary order. Many independent shear estimators can then be formed for each object, using linear combinations of shapelet coefficients. These estimators can be treated separately, to improve their overall calibration; or combined in more sophisticated ways, to eliminate various instabilities and a calibration bias. We apply several methods to simulated astronomical images containing a known input shear, and demonstrate the dramatic improvement in shear recovery using shapelets. A complete IDL software package to perform image analysis and manipulation in shapelet space can be downloaded from www.astro.caltech.edu/~rjm/shapelets/.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Analyzing the long-term evolution of active regions (ARs) permits to quantify the link between their atmospheric emission (from optical to X-rays) and the magnetic field. Multi-wavelength studies provide the full story, and not just a snapshot, of the phenomena and they allow us analyze how the atmosphere changes as the field strength decreases (with the dispersion of the AR).

The evolution of the emitted flux in various wavelength ranges contains information on the heating mechanism(s) of the different atmospheric levels. I review what we can learn from such long-term (months) multi-wavelength observations, and compare the results to other solar and stellar studies.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

This paper presents recent results concerning the planet formation, planet migration, and the long term stability of planetary systems. Most stars are found in binary systems and binary companions can disrupt both planet formation and stability. We first consider the effects of outer binary companions on the late stages of terrestrial planet formation and show how planet formation depends on the binary periastron. We then consider migration mechanisms for giant planets. In this case, planet scattering produces the full range of orbital eccentricities, but is less effective in moving planets inward (decreasing their semi-major axes). Disk torques are effective at moving planets inward, but not at increasing the eccentricities. We explore a scenario in which disk torques act in concert with planet scattering to provide the full range of orbital elements observed in extrasolar planetary systems. Finally, we consider the longer term stability of Earth-like planets in binary systems; we find that nearly 50 percent of binaries allow for Earth-like planets to remain stable over the current (4.6 Gyr) age of our solar system.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The current status of NLTE model atmosphere calculations of A type stars is reviewed. During the last decade research has concentrated on solving the restricted NLTE line formation problem for trace elements assuming LTE model atmospheres. There is a general lack of calculated NLTE line blanketed model atmospheres for A type stars, despite the availability of powerful methods and computer codes that are able to solve this task. Some directions for future model atmosphere research are suggested.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The close collaboration between the two North-country astronomers Jeremiah Horrocks and William Crabtree gave them special insight into the new astronomy published by the recently-deceased Kepler, whereby Horrocks became the only person to apprehend that the Rudolphine tables were in fact predicting a Venus transit in 1639. This paper focuses especially upon William Crabtree's role and contribution. A comparison is made with an earlier, unsuccessful endeavour by these two concerning a possible transit of Mercury. Much of the record of their work was lost during the civil war. Finally, thanks to Christiaan Huygens, Horrock's manuscript was published by Johannes Hevelius in Danzig, in 1662.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

To date, more than 130 extrasolar planets around main sequence stars are revealed mainly by the Doppler radial velocity measurements. Due to the observational biases, most of the detected planets are moving in orbits close to the host stars, with some in highly eccentric orbits. Dynamical processes during the late stage of planet formation are important to account for the present orbital properties. These processes include: planet migrations and resonance trappings caused by gravitational interactions between protostellar disk and planets, dynamical scattering due to interactions between planets, etc. In this paper, we review the major effects of these dynamical processes on the orbital characteristics of the planet systems.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Helioseismic analysis of solar global oscillations allows investigation of the internal structure and dynamics of the sun. I summarize the recent observational results, putting emphasis on the bands of slower- and faster-than-average rotation migrating in latitude over the solar cycle in a manner similar to the zones of solar activity. I also review theoretical considerations so far proposed as a cause of the periodic oscillation of the rotation profile.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We have reanalyzed in a consistent way existing reverberation data for 35 AGNs for the purpose of refining the black hole masses derived from these data. We find that the precision (or random component of the error) of reverberation-based black hole mass measurements is typically around 30%, comparable to the precision attained in measurement of black hole masses in quiescent galaxies by gas or stellar dynamical methods. As discussed in this volume by Onken et al., we have established an absolute calibration for AGN reverberation-based masses by assuming that AGNs and quiescent galaxies follow an identical relationship between black hole mass and host-galaxy bulge velocity dispersion. The scatter around this relationship implies that the typical systematic uncertainties in reverberation-based black hole masses are smaller than a factor of three. We present a preliminary version of a mass–luminosity relationship that is much better defined than any previous attempt. Scatter about the mass–luminosity relationship for these AGNs appears to be real and could be correlated with either Eddington ratio or source inclination.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html