Attempting to distangle density and kinetic temperature of the star forming molecular gas in the central regions of galaxies, we have embarked on a project involving sensitive measurements of a variety of formaldehyde (H2CO) and ammonia (NH3) transitions. Preliminary results, based on observations from the Green Bank Telescope (GBT) and the Very Large Array (VLA) are summarized and an outline for the entire project is given.

We present the main results of statistical study of general properties of isolated AGN hosts and AGN hosts in pairs at z<0.05 as concerns with the environmental influence on the nuclear galaxy activity. With this aim we compiled the sample of 61 isolated AGNs selected from 2MIG Catalog and Catalog Veron+2010, and the sample of 109 AGNs in pairs selected from NED database.

We found a significant excess content of Sy 2 type galaxies in comparison with Sy 1 type galaxies in both samples (44% and 11% among isolated AGNs, 48% and 6% among AGNs in pairs, respectively). Isolated AGN hosts of all spectral types are located, in average, at the more far distances and have a more complicated structure than AGNs in pairs as well as they are mostly of late morphological types. Our statistical analysis shows that the observed nuclear activity of isolated 2MIG AGNs during last 3 billions years and more, first of all, is connected with the internal galaxy parameters (relative mass/size, dark/visible matter content, multi-wavelength properties of gas-dust medium in accretion disks, tor's structure, central black hole mass etc.).

Differential VLBI observations of pulsars in our Galaxy can derive trigonometric parallax of them. Distance to pulsars derived by the parallax are very important to estimate some mean density of ionized gas between pulsars and the earth using rotation measures of them. Some preliminary results of distribution of the ionized gas density in our galaxy by using previous VLBI results are shown. Possibility of VLBI observations of pulsars using VERA and the other VLBI antennas will be described.

Two flares occurred simultaneously in active region NOAA 9433 on 2001 April 25. The GOES X-ray fluxes show only one peak during the two flares. The negative magnetic polarities in the two flaring regions exhibited a clockwise rotation motion around the positive polarities, which can be seen from the evolution of the SOHO/MDI magnetograms. Through analyzing the potential fields extrapolated from the MDI magnetogram, we find that there is a channel strode by a group of magnetic field lines connecting the two flaring regions.

Cool neutral gas provides the raw material for all star formation in the Universe, and yet, from a survey of the hosts of high redshift radio galaxies and quasars, we find a complete dearth of atomic (Hi 21-cm) and molecular (OH, CO, HCO+ & HCN) absorption at redshifts z ≳ 3 (Curran et al. 2008). Upon a thorough analysis of the optical photometry, we find that all of our targets have ionising (λ ≤ 912 Å) ultra-violet continuum luminosities of LUV ≳ 1023 W Hz−1. We therefore attribute this deficit to the traditional optical selection of targets biasing surveys towards the most ultra-violet luminous objects, where the intense radiation excites the neutral gas to the point where it cannot engage in star formation (Curran & Whiting 2010). However, this hypothesis does not explain why there is a critical luminosity, rather than a continuum where the detections gradually become fewer and fewer as the harshness of the radiation increases. We show that by placing a quasar within a galaxy of gas there is always a finite ultra-violet luminosity above which all of the gas is ionised. This demonstrates that these galaxies are probably devoid of star-forming material rather than this being at abundances below the sensitivity limits of current radio telescopes.

Pulsar winds, containing charged particles, waves and a net (phase-averaged) magnetic field, are thought to fuel the high-energy emission from several gamma-ray binaries. They terminate where the ram pressure matches that of the surroundings - which, in binaries, is provided by the wind of the companion. Before termination, pulsed emission can be produced by inverse Compton scattering of photons from the companion by particles in the waves. After termination, both the bulk kinetic energy of the particles and the Poynting flux in the waves are dissipated into an energetic particle population embedded in the surviving phase-averaged magnetic field. Pulsed emission is no longer possible, but a substantial flux of unpulsed high-energy photons can be produced. I will present results showing that the physical conditions at the termination shock can be divided into two regimes: a high density one, where current sheets in the wind are first compressed by an MHD shock and subsequently dissipate by reconnection, and a low density one, where the wind can first convert into an electromagnetic wave in the shock precursor, which then damps and merges into the wind nebula. The shocks surrounding isolated pulsars fall into the low-density category, but those around pulsars in binary systems, may transit from one regime to the other according to binary phase. The implications of the shock-structure dichotomy for these objects will be discussed.

Recent observations reveal that a cool disk may survive in the innermost stable circular orbit (ISCO) for some black hole X-ray binaries in the low/hard state. The spectrum is characterized by a power law with a photon index Γ ~ 1.5-2.1 in the range of 2-10 keV and a weak disk component with temperature of ~ 0.2 keV. The formation of such a cool disk in the most inner region of black hole X-ray binaries at the low/hard state is investigated within the framework of disk accretion fed by condensation of hot corona. We also calculate the emergent spectra of the inner disk and corona. It's found that our model can very well explain the spectral features of GX 339-4 and Cyg X-1, in which the thin disk may exist at ISCO in the low/hard state.

Excluding those unsettled systems undergoing mergers, bright galaxies come in two flavours: with and without discs. In this work we look for photometric evidence for presence of discs and compare it with kinematic results of the ATLAS3D survey (Cappellari et al. 2011). We fit a Sérsic (1968) function to azimuthally averaged light profiles of ATLAS3D galaxies to derive single component fits and, subsequently, we fit a combination of the Sérsic function (free index n) and an exponential function (n=1) with the purpose of decomposing the light profiles into “bulge” and “disc” components (B+D model) of all non-barred sample galaxies. We compare the residuals of the B+D models with those of the single Sérsic fits and select the B+D model as preferred only when the improvement is substantial and there are no correlations within residuals. We find that the high angular momentum objects (fast rotators) are disc dominated systems with bulges of typically low n (when their light profiles can be decomposed) or are best represented with a single Sérsic function with a low Sérsic index (n<3). Single component systems with large Sérsic indices are characteristic of low angular momentum objects (slow rotators).

On 5 January 2005, SoHO/LASCO observed two CMEs associated with eruptive filaments with different initial velocities and acceleration. The second CME accelerates much faster than the previous and the resulting interaction has been revealed in in-situ spacecraft measurements by the presence of magnetic holes at the border of the two distinct magnetic clouds. At their interface region, these magnetic clouds have embedded filament plasma that shows complex magnetic structures with a distinct magnetic flux rope configuration; these have been modeled by the Grad - Shafranov reconstruction technique. The geomagnetic consequences of these structures have been associated with substorms in recovery phase of a storm and detailed analysis is presented in Sharma et al. (2013). In the present paper, we highlight the comparison of shape and extent of two filament plasma remnants in magnetic clouds as revealed by three - dimensional (3D) reconstruction and analysis from the Solar Mass Ejection Imager (SMEI) data. The results provide an overview of the two eruptive filaments on 5 January 2005 and their interplanetary propagation.

We analyze coronagraph observations of a polar jet eruption observed by SECCHI/STEREO. The brightness distribution of the jet in white-light coronagraph images is compared with a kinetic particle model. In this first application, we consider only gravity as the dominant force on the jet particles along the magnetic field. The kinetic model explains well the observed brightness evolution. The initial particle velocity distribution is fitted by Maxwellian distributions and we find deviations of the high energy tail from the Maxwellian distributions. The jets total mass is between 3.2×1014 and 1.8×1015 g. The total kinetic energy of all the particles in the jet source region amounts from 2.1×1028 to 2.4×1029 ergs.

We have used the recently-upgraded Karl G. Jansky Very Large Array (JVLA) to conduct a K-band (~24 GHz) study of 22 massive young stellar objects in 1.3 cm continuum and a comprehensive set of diagnostic lines. This survey is unique in that it samples a wide range of massive star formation signposts simultaneously for the first time. In this proceeding we present preliminary results for the 11 sources in the 2-4 kpc distance bin. We detect compact NH3 cores in all of the fields, with many showing emission up through the (6,6) transition. Maser emission in the 25 GHz CH3OH ladder is present in 7 of 11 sources. We also detect non-thermal emission in the NH3 (3,3) transition in 7 of 11 sources.

We present the results of the astrometric monitoring of βPictoris b, the closest exoplanet imaged so far, using all VLT/NaCo data we obtained so far.

We have used the recently-upgraded Karl G. Jansky Very Large Array (VLA) in A-configuration to observe the water masers in the massive protostellar cluster NGC6334I with broad bandwidth and high spectral resolution. Four groups of maser spots are found. The two groups with the broadest velocity span (40 km/s) are towards the UCHII region and the hot core SMA1. The spatial kinematics of the SMA1 masers are consistent in sense and orientation with the large-scale CO outflow and appear to trace the base of the outflow from a protostar at the dust peak of SMA1. Additional masers at the southern end of SMA1 provide evidence for a second protostar. The highest intensity maser lies about 2″ north of SMA1. Interestingly, no water masers are seen on the equally impressive hot core SMA2. Finally, we have detected maser emission toward the enigmatic source SMA4, which shows no millimeter molecular lines despite having strong, compact submillimeter continuum and may trace another protostar.

We surveyed 28 year of Solar X-ray flares and sunspot group records supplied by the National Geophysical Data Center (NGDC) to study the dependence of different class Xray flares on the magnetic structure of sunspot groups statistically. It is found that 82.5% X-class flare, 51.4% M-class flare, 26.3% C-class flare, and 10.1% B-class flare occurred in the sunspot group with βγδ structure. There are 6.6% X-class flares, 17.5% M-class flare, 39.1% C-class flare, and 60.4% B-class flare occurred out of sunspot group.

Over the past twenty-five years, the technique of Doppler tomography has produced many 2D images of the accretion structures and other gas flows in a range of systems containing compact and non-compact stars, including cataclysmic variables, polars, Algols, x-ray, and gamma-ray binaries. Recent 3D images derived from the Radio astronomical Approach (RA) have revealed prominent gas motions beyond the central plane, and display the usual characteristics found in 2D images, as well as new evidence of tilted or precessing accretion disks around the mass gainer, and magnetic loop prominences and coronal mass ejections associated with the donor star. In this work, we have compared new 3D images derived from the back projection tomography technique with those derived from the RA method. In general, back projection produces sharper and more distinctive images than the RA method, thereby permitting a more detailed study of the physical properties of the accretion sources.

Recent γ-ray observations by the Fermi Gamma-Ray Space Telescope suggest that the γ-ray millisecond pulsar (MSP) population is separated into two subclasses with respect to pair multiplicity. Here, we calculate the cosmic-ray electron/positron spectra from MSPs. Based on the assumption of equipartition in the pulsar-wind region, the typical energy of electrons/positrons ejected by an MSP with pair multiplicity of the order of unity is ~50 TeV. In this case, we find that a large peak in the 10-50 TeV energy range would be observed in the cosmic-ray electron/positron spectrum. Even if the fraction of pair-starved MSPs is 10%, a large peak would be detectable with future missions such as CALET and CTA.

We studied three interplanetary coronal mass ejections associated with solar eruptive filaments. Filament plasma remnants embedded in these structures were identified using plasma, magnetic and compositional signatures. These features when impacted the Earth's terrestrial magnetosphere - ionosphere system, resulted in geomagnetic storms. During the main phase of associated storms, along with high density plasma structures, polarity reversals in the Y-component (dawn-to-dusk) of the interplanetary electric field seem to trigger major auroral substorms with concomitant changes in the polar ionospheric electric field. Here, we examine the cases where plasma dynamics and magnetic structuring in the presence of the prompt penetration of the electric field into the equatorial ionosphere affected the space weather while highlighting the complex geomagnetic storm-substorm relationship.

We present an overview of recent findings on the kinematics, age, and metallicity of globular cluster systems in nearby giant elliptical galaxies and their implications for understanding how giant elliptical galaxies formed and evolved.

When galaxies merge the resulting conditions are some of the most extreme found anywhere in nature. Large gas flows, shocks and active black holes all can affect the ISM. Nearby merging galaxies with strong starbursts are the only places where we can conduct detailed study of star formation in conditions that mimic those under which the majority of stars in the universe formed. Here we study molecular gas tracers in 8 galaxies selected from the VIRUS-P Investigation of the eXtreme ENvironments of Starbursts (VIXENS) survey. Each galaxy has also been observed using the integral field unit spectrograph VIRUS-P, allowing us to investigate the relation between the chemical state of the gas, star formation and total gas content. Full details can be found in Heiderman et al. (2011). Here we report on new results obtained from IRAM-30m/NRO-45m 3mm line surveys towards 14 positions in these 8 merging galaxies. We detect ≈ 25 different molecular transitions towards these objects, many which have never been observed in these galaxies before. Our measurements show that the mean fraction of dense gas increases in later-stage mergers (Fig. 1, left), as does the average optical depth of the gas. Molecular diagnostic diagrams (Fig. 1, right) show that molecular regions we probe are, in general, UV photon dominated. Triggered AGN activity, and/or cosmic ray ionisation (from SNe II in the starburst) are not yet energetically important in determining the state of the gas.

To investigate the atmospheres of ultracool brown dwarfs with temperatures covering the range of transiting and directly imaged planets, we have monitored a sample of 76 L, T and Y brown dwarfs for infrared photometric variability. This survey was conducted in the J-band using both the SOFI camera on the 3.5-m NTT and the SWIRC camera on the 6.5-m MMT. Each target was observed for a period ranging from 2.0 hours to 6.0 hours, covering a significant fraction of the expected rotation period. Breakup of the iron and silicate clouds into a patchy cloud layer has been suggested as an explanation for the variability of several objects identified at the L/T transition, and a similar process with sulfide clouds may be manifest in T/Y transition objects; our data provides the first test of these patchy cloud scenarios across the entire brown dwarf spectral range.