The Hubble constant H0 describes not only the expansion of local space at redshift z ~ 0, but is also a fundamental parameter determining the evolution of the universe. Recent measurements of H0 anchored on Cepheid observations have reached a precision of several percent. However, this problem is so important that confirmation from several methods is needed to better constrain H0 and, with it, dark energy and the curvature of space. A particularly direct method involves the determination of distances to local galaxies far enough to be part of the Hubble flow through water vapor (H2O) masers orbiting nuclear supermassive black holes. The goal of this article is to describe the relevance of H0 with respect to fundamental cosmological questions and to summarize recent progress of the ‘Megamaser Cosmology Project’ (MCP) related to the Hubble constant.

The 2nd Fermi-LAT pulsar catalog includes 117 γ-ray pulsars, of which roughly one third are millisecond pulsars (MSPs) while the remaining two thirds split evenly into young radio-loud and radio-quiet pulsars. Although this large population will enable future, detailed studies of emission mechanisms and the evolution of the underlying neutron star population, some nearly-universal properties are already clear and unequivocal. We discuss some of these aspects below, including the altitude of the γ-ray emission site, the shape of the γ-ray spectrum, and the implications of the latter for the radiation mechanism.

Highly collimated, bipolar fast jets are found in asymptotic giant branch (AGB) and post-AGB stars as well as in active galactic nuclei and young stellar objects. It is still unclear how to launch such jets from dying stars that were originally spherically symmetric. Exploration of the stellar jet evolution is also expected to probe its role in shaping a planetary nebula. Interestingly, some of stellar H2O maser sources — water fountains — exhibit stellar jets with spatially and kinematically high collimation in the earliest phase (<1000 years) of the jet evolution. Such water fountains have been identified in 14 sources to date. We have recently conducted interferometric (VLBA, EVN, VERA, VLA) maser and the single-dish (ASTE) CO J = 3 → 2 line observations of the water fountains. They have revealed a typical dynamical age (< 100 yr) and the detailed kinematical structures of the water fountains, possibility of the coexistence of “equatorial flows”, and their locations and kinematics in the Milky Way. Based on these results, the masses and evolutionary statuses of the host stars are also estimated.

Water vapor megamasers from the center of active galaxies provide a powerful tool to trace accretion disks at sub-parsec resolution and, through an entirely geometrical method, measure direct distances to galaxies up to 200 Mpc. The Megamaser Cosmology Project (MCP) is formed by a team of astronomers with the aim of identifying new maser systems, and mapping their emission at high angular resolution to determine their distance. Two types of observations are necessary to measure a distance: single-dish monitoring to measure the acceleration of gas in the disk, and sensitive VLBI imaging to measure the angular size of the disk, measure the rotation curve, and model radial displacement of the maser feature. The ultimate goal of the MCP is to make a precise measurement of H0 by measuring such distances to at least 10 maser galaxies in the Hubble flow. We present here the preliminary results from a new maser system, Mrk 1419. Through a model of the rotation from the systemic masers assuming a narrow ring, and combining these results with the acceleration measurement from the Green Bank Telescope, we determine a distance to Mrk 1419 of 81 ± 10 Mpc. Given that the disk shows a significant warp that may not be entirely traced by our current observations, more sensitive observations and more sophisticated disk modeling will be essential to improve our distance estimation to this galaxy.

Observational results from strong lensing and dynamical modeling indicate that the total density profiles of early-type galaxies are close to isothermal, i.e. ρtot ∝ rγ with γ ≈ −2. To understand the origin of this universal slope we study a set of simulated spheroids formed in cosmological hydrodynamical zoom-in simulations (see Oser et al. 2010 for more details). We find that the total stellar plus dark matter density profiles of all our simulations on average can be described by a power law with a slope of γ ≈ −2.1, with a tendency towards steeper slopes for more compact, lower mass ellipticals, while the total intrinsic velocity dispersion is flat for all simulations, independent of the values of γ. Our results are in good agreement with observations of Coma cluster ellipticals (Thomas et al. 2007) and results from strong lensing (Sonnenfeld et al. 2012). We find that for z ≳ 2 the majority of the stellar build-up occurs through in-situ star formation, i.e. the gas falls to the center of the galaxy and forms stars, causing the galaxy to be more compact and thus the stellar component to be more dominant. As a result, the total density slopes at z ≈ 2 are generally steeper (around γ ≈ −3). Between z = 2 and z = 0 galaxies grow mostly through dry merging, with each merging event shifting the slope more towards γ ≈ −2. We conclude from our simulations that the steepness of the slope of present day galaxies is a signature of the importance of mostly dry mergers in the formation of an elliptical, and suggest that all elliptical galaxies will with time end up in a configuration with a density slope of γ ≈ −2. For a more detailed analysis with a larger sample of simulations see Remus et al. (2013).

We systematically investigated the climate of water-rich terrestrial planets with a negative feedback mechanism of carbonate-silicate geochemical cycle against the climate under various obliquities and semi-major axes. We found that, while the permanent ice-cap mode (partially ice-covered throughout the year) and the seasonal ice-cap mode (partially ice-covered seasonally) exist stably at low obliquity conditions, the ranges of semi-major axis for these climate modes shrink and finally disappear with an increase of obliquity. When carbonate-silicate geochemical cycle is taken into account, the ranges of semi-major axis for all the climate modes expand at any obliquities, compared with the cases without carbonate-silicate geochemical cycle, indicating that the carbonate-silicate geochemical cycle strongly stabilizes the climate for the planets with any obliquities inside the habitable zone.

As part of a deep multi-year non-redundant aperture mask infrared imaging campaign observing transition disks, we present multi-epoch monitoring of the resolved emission seen within the disk gap of LkCa 15. Orbital motion of both the central source and extended lobes as presented in Kraus and Ireland (2012) is clearly detected at the level of ~4 degrees/year (deprojected), in both K and L'-bands. Based on these data as well as single-epoch H and M bands epochs, we present two models for the central source - thermal emission as a planetary accretion signature and scattering. The thermal emission model is preferred.

We give a short introduction to the subject and review advances in understanding the basic ingredients of the mean-field dynamo theory. The discussion includes the recent analytic and numerical work in developments for the mean electromotive force of the turbulent flows and magnetic field, the nonlinear effects of the magnetic helicity, the non-local generation effects in the dynamo. We give an example of the mean-field solar dynamo model that incorporates the fairly complete expressions for the mean-electromotive force, the subsurface shear layer and the conservation of the total helicity. The model is used to shed light on the issues in the solar dynamo and on the future development of this field of research.

Knowing the distance of an astrophysical object is key to understanding it. However, at present, comparisons of theory and observations are hampered by precision (or lack thereof) in distance measurements or estimates. Putting the many recent results and new developments into the broader context of the physics driving cosmic distance determination is the next logical step, which will benefit from the combined efforts of theorists, observers and modellers working on a large variety of spatial scales, and spanning a wide range of expertise. IAU Symposium 289 addressed the physics underlying methods of distance determination across the Universe, exploring the various approaches employed to define the milestones along the road. The meeting provided an exciting snapshot of the field of distance measurement, offering not only up-to-date results and a cutting-edge account of recent progress, but also full discussion of the pitfalls encountered and the uncertainties that remain. One of the meeting's main aims was to provide a roadmap for future efforts in this field, both theoretically and observationally.

We have developed a suite of forward-modeling IDL codes (FORWARD) to convert analytic models or simulation data cubes into coronal observables, allowing a direct comparison with observations. Observables such as extreme ultraviolet, soft X-ray, white light, and polarization images from the Coronal Multichannel Polarimeter (CoMP) can be reproduced. The observer's viewpoint is also incorporated in the FORWARD analysis and the codes can output the results in a variety of forms in order to easily create movies, Carrington maps, or simply observable information at a particular point in the plane of the sky. We present a newly developed front end to the FORWARD codes which utilizes IDL widgets to facilitate ease of use by the solar physics community. Our ultimate goal is to provide as useful a tool as possible for a broad range of scientific applications.

Effects of galaxy environment on its cold gas content are studied in detail using different date sets and statistics. These include measuring the clustering of galaxies as a function of their Hi mass fraction, quantifying the depletion of Hi gas content of cluster galaxies as a function of cluster-centric radius, and comparing the dependence of environmental density on galaxy star formation rate with the dependence on Hi gas mass fraction. Results from these studies are all consistent with a picture in which ram-pressure stripping may play an important role in removing atomic gas from the outer disks of low mass satellite galaxies.

An update is given on the current status of solar and stellar dynamos. At present, it is still unclear why stellar cycle frequencies increase with rotation frequency in such a way that their ratio increases with stellar activity. The small-scale dynamo is expected to operate in spite of a small value of the magnetic Prandtl number in stars. Whether or not the global magnetic activity in stars is a shallow or deeply rooted phenomenon is another open question. Progress in demonstrating the presence and importance of magnetic helicity fluxes in dynamos is briefly reviewed, and finally the role of nonlocality is emphasized in modeling stellar dynamos using the mean-field approach. On the other hand, direct numerical simulations have now come to the point where the models show solar-like equatorward migration that can be compared with observations and that need to be understood theoretically.

Lenticular (S0) galaxies are a morphological transition class between ellipticals and early-type spirals. Recent studies indicate that the formation scenario for lenticular galaxies depends on their near-IR luminosity (Barway et al. 2007;2009;2011). Low-luminosity lenticular galaxies likely formed by the stripping of gas from the disc of late-type spiral galaxies, which in turn formed their pseudo bulges through secular evolution processes, possibly involving multiple episodes of star formation. On the other hand, more luminous lenticulars likely formed at early epochs through a rapid collapse followed by rapid star formation, similar to the formation process of elliptical galaxies, and are characterized by a old coeval stellar population in the bulge. To investigate the imprint of these distinct formation scenarios on stellar populations, we combine GALEX/SDSS/2MASS photometry to construct color-color diagrams for a carefully defined sample of ~400 lenticular galaxies. We divide the sample into bright and faint groups as suggested by Barway et al. (2007). We find the (FUV-NUV) versus (NUV-K) color-color diagram shows larger scatter for faint lenticular galaxies while bright lenticular galaxies show a much tighter relation similar to that of ellipticals. Simple Stellar Population (SSP) analysis shows that ellipticals and bright lenticulars are dominated by a stellar population of age >109 years while faint lenticular galaxies are as young as 108 years, providing evidence for relatively recent star formation activity. Further, if we use the (NUV-r) < 5.4 color criterion to identify galaxies with recent (within 500 Myr) star formation, most faint lenticular galaxies fall into this category; bright lenticulars are mostly quiescent. Most faint lenticular galaxies generally have lower velocity dispersions. If we consider velocity as a virial mass indicator, majority of faint, recently star forming, lenticular galaxies have low virial masses compared to brighter lenticular galaxies. Such systematic differences in star formation history between bright and faint lenticular galaxies are consistent with the expectations from the luminosity dependent formation scenario described above.

Planets with very little amount of water on their surface, called “land planets”, have wider habitable zones than that of Earth-like “aqua planets” (Abe et al. 2011). We investigated complete evaporation of surface liquid water for land planets using 1D energy balance model (EBM). We found that complete evaporation occurs when the planetary flux at the dry edge, which is defined as the boundary between the dry zone and the wet zone, exceeds the critical radiation flux of water saturated atmosphere. We define “complete evaporation limit” as the minimum insolation for complete evaporation that a planet receives. This limit depends on latitude of the dry edge, efficiency of meridional heat transport, and atmospheric character that modify the value of the critical flux.

The effectiveness of the ESA Gaia mission in obtaining a meaninful sample of supernovae (SNe) is based on three key points: detection rates, characterization capability and an extended validation phase. Focussing on the second, we present our investigations into the use of a range of classification techniques, whereby we demonstrate the ability to discriminate between various SN subtypes, based on the Gaia data (photometry and spectrophotometry) alone. In particular, we comment on the potential ability of Gaia to rapidly estimate SN redshifts and epochs. The methods presented here indicate that ground-based follow-up observations can then be more effectively targeted to the highest-priority SNe.

Although most nuclear 22GHz (λ=1.35 cm) H2O masers are in Seyfert 2 and LINER galaxies, only a small fraction of such galaxies host water masers. We systematically study the optical properties of the galaxies with and without nuclear H2O maser emission to better understand the relationship between H2O maser emission and properties of the central supermassive black hole and improve the detection rates in future surveys. To this end, we cross-matched the galaxies from H2O maser surveys, both detections and non-detections, with the Sloan Digital Sky Survey (SDSS) low-redshift galaxy sample. We find that maser detection rates are higher at higher optical luminosity (MB), larger velocity dispersion (σ), and higher ion [O III] λ5007 luminosity, with [O III] λ5007 being the dominant factor, and that the isotropic maser luminosity is correlated with these variables. These correlations are natural if maser emission depends on the host SMBH mass and AGN activity. We also find that the detection rate is higher for galaxies with higher extinction. These results indicate that, by pre-selecting galaxies with high extinction-corrected [O III] λ5007 flux, future maser surveys can increase detections efficiencies by a factor of ~3 to ~5.

The spatial distributions of luminous and dark matter in massive early-type galaxies (ETGs) reflect the formation processes which shaped these systems. This article reviews the predictions of cosmological simulations for the dark and baryonic components of ETGs, and the observational constraints from lensing, hydrostatic X-ray gas atmospheres, and outer halo stellar dynamics.

This article comments on the results of a new, rapid, and flexible manual method to map on-disk individual coronal loops of a two-dimensional EUV image into the three-dimensional coronal loops. The method by Gary, Hu, and Lee (2013) employs cubic Bézier splines to map coronal loops using only four free parameters per loop. A set of 2D splines for coronal loops is transformed to the best 3D pseudo-magnetic field lines for a particular coronal model. The results restrict the magnetic field models derived from extrapolations of magnetograms to those admissible and inadmissible via a fitness parameter. This method uses the minimization of the misalignment angles between the magnetic field model and the best set of 3D field lines that match a set of closed coronal loops. We comment on the implication of the fitness parameter in connection with the magnetic free energy and comment on extensions of our earlier work by considering the issues of employing open coronal loops or employing partial coronal loop.

The lifetime of contact binaries is an important parameter for studying the evolution of contact binaries. By reproducing the relative frequency of occurrence for contact binaries, we found that the lifetime of contact binaries decreases with increasing mass of the primaries. The lifetime of contact binaries is about 4%–10% of the main sequence lifetime of the primaries, and is about 0.006–0.65 Gyr. This suggests that the lifetime of contact binaries strongly depends on the mass of the primaries.

High contrast imaging observations with the Hubble Space Telescope show that the nearby star Fomalhaut is surrounded by a dusty debris belt and a candidate planet, Fomalhaut b, located just inside the edge of the belt. Fomalhaut b has unexpected characteristics, such as a relatively blue spectrum, leading to the hypothesis that the detected object is a low-mass planet hosting a giant planetary dust ring or cloud seen in reflected light. Here we present new HST/STIS observations made in 2010 and 2012 that authenticate the existence of Fomalhaut b. Our MCMC analysis of four epochs of astrometry spread over eight years indicate that the orbit has a~170 AU and e~0.85. Fomalhaut b's orbit is apsidally aligned with the main belt, and periapse is located approximately ~30 AU south of the star. We also show the existence of a ~50 AU wide azimuthal dust depletion in the dust belt. These new findings provide a revised picture of Fomalhaut as a dynamically complex system, where the orbit of Fomalhaut b and the belt structure signify the presence of additional massive planets orbiting the star.