In protoplanetary disks, the inner boundary between an MRI active and inactive region has recently been suggested to be a promising site for planet formation. A set of numerical simulations has indeed shown that vortex formation mediated by the Rossby wave instability is a natural consequence of the disk dynamics at that location. However, such models have so far considered only the case of an isothermal equation of state, while the complex thermodynamics is at the heart of how this region works. Using the Godunov code Ramses, we have performed 3D global numerical simulations of protoplanetary disks that relax the isothermal hypothesis. We find that, at the interface, the disk thermodynamics and the turbulent dynamics are intimately entwined, because of the importance of turbulent dissipation and thermal ionisation.

The relative age of galaxies at different redshifts can be used to infer the Hubble parameter and put constraints on cosmological models. We select 23,883 quiescent luminous red galaxies (LRGs) from the SDSS DR7, dividing them into four sub-samples according to their velocity dispersions. Each sub-sample was further divided into 12 redshift bins. The spectra of the LRGs in each redshift and velocity bin were co-added. Adopting the GalexEV/SteLib model, we estimate the mean ages of the LRGs from these combined spectra by the full-spectrum fitting method and find it is consistent with the well known “downsizing” formation of galaxies. Based on the age–redshift relation, we further estimate the Hubble parameter.

The luminosity function of planetary nebula populations in galaxies at distances within 10–15 Mpc exhibits a cut-off at bright magnitudes and a functional form that is observed to be invariant among different galactic morphological types. Therefore, it is used as a secondary distance indicator applicable to both early- and late-type galaxies. Recent deep surveys of planetary nebula populations in brightest cluster galaxies (BCGs) seem to indicate that their luminosity functions deviate from those observed in the nearby galaxies. We discuss the evidence for such deviations in the Virgo Cluster, and indicate which physical mechanisms may alter the evolution of a planetary nebula envelope and its central star in the halo of BCGs. We then discuss preliminary results for distances to the Virgo, Hydra i, and Coma Clusters based on the observed planetary nebulae luminosity functions.

Since November 2003, we have monitored AGB candidates in infrared wavelengths with the Kagoshima 1m telescope. We present the latest results based on the data until June 2011. For each of 400 monitored AGB stars, we estimate the periods, amplitudes, and mean apparent magnitudes in K band. Based on the two color diagram we choose 259 objects as Miras. We use the period–luminosity relation to obtain distances to them. As results we show the 3 dimensional distribution of 259 Mira variables.

We investigate to what extent the current helicity distribution observed in solar active regions is compatible with solar dynamo models. We use an advanced 2D mean-field dynamo model with dynamo action largely concentrated near the bottom of the convective zone, and dynamo saturation based on the evolution of the magnetic helicity and algebraic quenching. For comparison, we also studied a more basic 2D mean-field dynamo model with simple algebraic alpha quenching only. Using these numerical models we obtain butterfly diagrams for both the small-scale current helicity and the large-scale magnetic helicity, and compare them with the butterfly diagram for the current helicity in active regions obtained from observations. This comparison shows that the current helicity of active regions, as estimated by −A·B evaluated at the depth from which the active region arises, resembles the observational data much better than the small-scale current helicity calculated directly from the helicity evolution equation. Here B and A are respectively the dynamo generated mean magnetic field and its vector potential.

The 4m Advance Technology Solar Telescope (ATST) is under construction on Maui, HI. With its unprecedented resolution and photon collecting power ATST will be an ideal tool for studying prominences and filaments and their role in producing Coronal Mass Ejections that drive Space Weather. The ATST facility will provide a set of first light instruments that enable imaging and spectroscopy of the dynamic filament and prominence structure at 8 times the resolution of Hinode. Polarimeters allow high precision chromospheric and coronal magnetometry at visible and infrared (IR) wavelengths. This paper summarizes the capabilities of the ATST first-light instrumentation with focus on prominence and filament science.

In this article we show that massive and hot fragments forming in protostellar disks can leave characteristic signatures in spectral energy distributions (SEDs) of young stellar objects. This occurs when the fragment evaporates dust in its atmosphere, which results in a sharp drop in opacity and subsequent rise in the surface temperature of the fragment. These hot fragments can produce local maxima in the SEDs at 5–10 μm.

Dome A on the Antarctic plateau is likely one of the best observing sites on Earth (Saunders et al. 2009). We used the CSTAR telescope (Yuan et al. 2008) to obtain time-series photometry of 104 stars with i>14.5 mag during 128 days of the 2008 Antarctic winter season (Wang et al. 2011). During the 2010 season we observed 2 × 104 stars with i>15 mag for 183 days (Wang et al. 2012). We detected a total of 262 variables, a 6 × increase relative to previous surveys of the same area and depth carried out from temperate sites (Pojmanski 2004). Our observations show that high-precision, long-term photometry is possible from Antarctica and that astronomically useful data can be obtained during 80% of the winter season.

Photometric redshifts, i.e. redshifts derived by comparing an observed spectral-energy distribution (SED) to a range of empirical or theoretical SED templates, are commonly used in studies of the high-redshift Universe. Often, the next step is to use these redshifts as fixed input parameters for SED fitting to derive physical properties for each galaxy. However, this two-step approach ignores degeneracies between redshift and, e.g., stellar mass. Here I present first results using an improved approach that integrates both methods. I find that mass determinations are, on average, three times more uncertain than they seem from the common two-step approach. If not accounted for, these underestimated uncertainties can impact our ability of making meaningful comparisons between observations and simulations of galaxy evolution.

W Aql is a binary S-type AGB star showing SiO maser emission. The dust distribution around the star is asymmetric, possibly indicating gravitational interaction between the binary pair. There are indications that the gas distribution also exhibits asymmetries. To investigate the source of the circumstellar structures, we applied for and were rewarded VLBI time to map the distribution of the SiO masers around this source and to constrain the presence and distribution of a possible magnetic field. Using VERA observations we also aim at measuring an accurate parallax to determine the binary separation, however, from showing peak emission of 21 Jy in June 2010, the SiO(1-0) v=1 line at 43 GHz has now disappeared. We find no correlation with the stellar pulsational period.

In this work, two different algorithms: Linear Discriminant Analysis (LDA) and Support Vector Machines (SVMs) are combined for the classification of unresolved sources from SDSS DR8 and UKIDSS DR8. The experimental result shows that this joint approach is effective for our case.

We present the first ground-based adaptive optics images of a silhouette disk. This disk, Orion 218-354, is seen in silhouette against the bright nebular background of Orion, and was resolved using the new Magellan Adaptive Secondary AO system and its VisAO camera in Simultaneous Differential Imaging (SDI) mode. PSF subtraction of Orion 218-354 reveals a disk ~1″ (400 AU) in radius, with the degree of absorption increasing steadily towards the center of the disk. By virtue of the central star being unsaturated, these data probe inward to a much smaller radius than previous HST images. Our data present a different picture than previous observers had hypothesized, namely that the disk is likely optically thin at Hα at least as far inward as ~20AU. In addition to being among the first high-resolution AO images taken in the optical on a large telescope, these data reveal the power of SDI imaging to illuminate disk structure, and speak to a bright future for visible AO imaging. Analysis of the results described briefly here can be found in full detail in Follette et al. (2013).

In this paper, I review some of the basic properties of the pulsar population in globular clusters (GCs) and compare it with the the Galactic disk population. The neutron stars (NSs) in GCs were likely formed - and appear to continue forming - in highly symmetric supernovae (SNe), likely from accretion-induced collapse (AIC). I review the many pulsar finds and discuss some particularly well populated GCs and why they are so. I then discuss some particularly interesting objects, like millisecond pulsars (MSPs) with eccentric orbits, which were heavily perturbed by passing stars. Some of these systems, like NGC 1851A and NGC 6544B, are almost certainly the result of exchange interactions, i.e., they are witnesses to the very same processes that created the large population of MSPs in the first place. I also review briefly the problem posed by the presence of young pulsars in GCs (with a special emphasis on a sub-class of young pulsars, the super-energetic MSPs), which suggest continuing formation of NSs in low-velocity SNe. In the final section, I discuss the possibility of an analogous population in the Galaxy and highlight a particularly interesting case, PSR J1903+0327, where the primary neutron star appears to have formed with a small-velocity kick and small fractional mass loss. Systems with primary NSs formed in electron-capture SNe should constitute a distinct low-velocity Galactic population akin in many respects to the GC population. Current high-resolution surveys of the Galactic plane should be able to detect it clearly.

The magnetorotational instability (MRI) is widely believed to be the source of turbulence in accretion discs. This turbulence is responsible for the anomalous angular momentum transport in accretion discs. The turbulence will affect other aspects of the dynamics of the disc as well, and we will concentrate on two such issues: a) what kind of oscillations can be excited by the turbulence itself, and b) how the turbulence is interacting with modes that have been excited by some other agent. This is of interest in understanding the quasi-periodic oscillations (QPOs) that have been observed in the X-ray light curves of accreting neutron star and black hole binaries. We carry out local three dimensional (3D) magnetohydrodynamic simulations of a keplerian differentially rotating accretion disc, using a shearing box configuration taking in account the effects of the vertical stratification.

The total electron content (TEC) is an important parameters in the Earth's ionosphere, related to various space weather and solar activities. However, understanding of the complex ionospheric environments is still a challenge due to the lack of direct observations, particularly in the polar areas, e.g., Antarctica. Now the Global Positioning System (GPS) can be used to retrieve total electron content (TEC) from dual-frequency observations. The continuous GPS observations in Antarctica provide a good opportunity to investigate ionospheric climatology. In this paper, the long-term variations and fluctuations of TEC over Antarctica are investigated from CODE global ionospheric maps (GIM) with a resolution of 2.5°×5° every two hours since 1998. The analysis shows significant seasonal and secular variations in the GPS TEC. Furthermore, the effects of TEC fluctuations are discussed.

I review recent developments of SiO maser observations of miras, and discuss their kinematics in the Galaxy. They are deeply related to problems in other fields, such as the noncircular motion of Galactic spiral arms, streaming motions of stars in the solar neighborhood, and the interface between the interstellar and circumstellar medium revealed by Far-IR imaging of some miras, as well as the bar structure of the Galaxy. Recent automated surveys of variable stars in optical bands have increased the number of red variables enormously. Most of these stars were not observed in the radio before because of their blue colors. We have obtained radial velocities of these long-period variables with SiO masers. The longitude-velocity diagrams have revealed interesting deviations of stellar motions from the circular motion of the Galaxy, some of which show spatial motion similar to that of the Hercules group of stars. Important developments of SiO maser observations have been made for symbiotic stars, one of which showed a nova eruption with concurrent γ ray emission in 2010 (V407 Cyg). SiO masers have been monitored for this star after the nova eruption. I summarize the SiO maser observations of individual stars also.

Magnetic helicity can be transported from sub-photosphere into corona by the emergence of helical magnetic field lines and the shuffling motions of foot-points of pre-existing coronal field lines. Active region NOAA 10930 was observed by SP and NFI of SOT on board Hinode when it pass through the solar meridian. Based on these observations, we calculate magnetic helicity flow of both terms, by regarding Doppler velocity as normal velocity. The results are compared with which calculated by method proposed by Zhang et. al. (2012). Our results show that helicity injection maps calculated by both methods have similar distribution and the integration values have the same magnitude.

We present a brief summary and description of the upcoming 12CO(1-0) Magellanic Mopra Assesment (MAGMA) SMC survey data release. The MAGMA-SMC survey has sampled 100% of the known CO in the SMC (at ∼33″ resolution; 12 pc at D = 60 kpc). Having explored 522 × 103 square parsecs throughout the SMC with 69 5′ × 5′ fields, to a sensitivity of ∼150 mK, we apply the cloudprops (Rosolowsky & Leroy 2006) cloud-search algorithm optimized for low S/N data, to detect more than 30 CO clouds with virial masses between 103–104 M⊙, mean radii ∼5 pc and 0.3–0.9 km s−1 velocity width. Typical brightness temperatures are ∼1 K Tmb. All detected molecular regions are associated with at least one 24 μm compact emission source. Smoothing rarely increases the total detected CO flux, implying the CO emission is typically confined to small spatial scales. As recent dust maps of the SMC imply extended H2 mass, the apparent compact nature of the CO population indicates some departures from the canonical Galactic XCO-factor in the low-metallicity and relatively un-evolved ISM of the SMC.

DX Cha (HD 104237) is a southern, optically bright Herbig Ae star with an infrared excess, that is part of a small stellar group younger than 5 Myr. We used the APEX and ASTE submillimeter telescopes in Chile to search for continuum and gas emission around this system. Using LABOCA on APEX we detect strong continuum emission around HD104237-A and system component HD104237-E. Our ASTE spectrum detects a double-peaked 12CO(3-2) line profile towards the system, typical of a rotating disk. The new data are used as constraints with MCFOST to produce a disk model that fits the entire SED as well as the observed CO line profile.

The physical background of scaling laws of disk galaxies is reviewed. The match between analytically derived and observed scaling laws is briefly discussed. Accurate modeling of the fraction of baryons that end up populating a disk, and the conversion efficiency of those into stars, remains a challenging task for numerical simulations. The measurement of rotational velocity tends to be made with criteria of convenience rather than through rigorous definition. And yet, the Tully–Fisher and the disk size versus rotational velocity relations exhibit surprisingly small scatter. Practical recipes (and costs) to optimize the quality of template relations are considered.