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The Fourth VLBA Calibrator Survey - VCS4: This paper presents the fourth extension to the Very Long Baseline Array (VLBA) Calibrator Survey, containing 258 new sources not previously observed with very long baseline interferometry (VLBI). This survey, based on three 24 hour VLBA observing sessions, fills remaining area...
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Compact Galaxies at Intermediate Redshifts Quench Faster than Normal-sized Galaxies: Massive quiescent compact galaxies have been discovered at high redshifts, associated with rapid compaction and cessation of star formation (SF). In this work we set out to quantify the time-scales in which SF is quenched in compact ...
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QU Carinae: a SNeIa progenitor?: Optical spectra obtained in 2006-07 of the nova-like cataclysmic variable QU Car are studied for radial velocities, line profiles, and line identifications. We are not able to confirm the reported 10.9 hr orbital period from 1982,partly because our sampling is not ideal for this purpose...
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Star Formation Signatures in the Condensation Downstream of HH 80N: HH80N is one of the Herbig-Haro objects that have associated quiescent dense clumps. We report CO and CS BIMA observations that reveal star formation within the HH80N dense clump. The CO emission reveals clearly a bipolar molecular outflow centered on ...
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On the (non-)enhancement of the Lyman α equivalent width by a multiphase interstellar medium: It has been suggested that radiative transfer effects may explain the unusually high equivalent widths (EWs) of the Lya line, observed occasionally from starburst galaxies, especially at high redshifts. If the dust is locked...
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NICER Discovery of Millisecond X-ray Pulsations and an Ultracompact Orbit in IGR J17494-3030: We report the detection of 376.05 Hz (2.66 ms) coherent X-ray pulsations in NICER observations of a transient outburst of the low-mass X-ray binary IGR J17494-3030 in 2020 October/November. The system is an accreting millise...
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Multi-Scale CLEAN: A comparison of its performance against classical CLEAN in galaxies using THINGS: A practical evaluation of the Multi-Scale CLEAN algorithm is presented. The data used in the comparisons are taken from The HI Nearby Galaxy Survey (THINGS). The implementation of Multi-Scale CLEAN in the CASA softwar...
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Why do only some Radio Galaxies acquire giant Sizes?: We study the morphology of the radio emission of giant radio galaxies (GRGs), a rare type of active galaxies, in order to find new clues for the reasons of their large size. Using radio images from two sky surveys at 1.4 GHz we quantified their radio morphology by m...
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Photometric and spectroscopic variability of 53 Per: A new investigation of the variability of the SPB-type star 53 Per is presented. The analysis of the BRITE photometry allowed us to determine eight independent frequencies and the combination one. Five of these frequencies and the combination one were not known befor...
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The full spectral radiative properties of Proxima Centauri: The discovery of Proxima b, a terrestrial temperate planet, presents the opportunity of studying a potentially habitable world in optimal conditions. A key aspect to model its habitability is to understand the radiation environment of the planet in the full sp...
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Empirical models for Dark Matter Halos. I. Nonparametric Construction of Density Profiles and Comparison with Parametric Models: We use techniques from nonparametric function estimation theory to extract the density profiles, and their derivatives, from a set of N-body dark matter halos. We consider halos generated f...
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Evidence for a New Class of Extreme UV Sources: Most of the sources detected in the extreme ultraviolet (EUV; 100 Ang to 600 Ang) by the Rosat WFC and EUVE all-sky surveys have been identified with active late-type stars and hot white dwarfs that are near enough to escape absorption by interstellar gas. However, about ...
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SPI data analysis: the CESR/Toulouse approach: In order to allow for an efficient and flexible scientific analysis of data from the SPI imaging spectrometer aboard INTEGRAL, I developed a set of analysis executables that are publicly available through the internet. The software is fully compatible with the ISDC data fo...
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The radial gradient of the near-surface shear layer of the Sun: Helioseismology has provided unprecedented information about the internal rotation of the Sun. One of the important achievements was the discovery of two radial shear layers: one near the bottom of the convection zone (the tachocline) and one near the surf...
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High Energy Observations of XRF 030723: Evidence for an Off-axis Gamma-Ray Burst?: We report High Energy Transient Explorer 2 (HETE-2) Wide Field X-ray Monitor/French Gamma Telescope observations of XRF030723 along with observations of the XRF afterglow made using the 6.5m Magellan Clay telescope and the Chandra X-ra...
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Gas Giant Simulations of Eddy-Driven Jets Accompanied by Deep Meridional Circulation: Jupiter's atmosphere comprises several dynamical regimes: the equatorial eastward flows and surrounding retrograde jets; the midlatitudes, with the eddy-driven, alternating jet-streams and meridional circulation cells; and the jet-f...
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An Empirical Correlation of $T_{\rm max}$ - $M_{\rm WD}$ of Dwarf Novae and The Average White Dwarf Mass in Cataclysmic Variables in the Galactic Bulge: The mean white dwarf (WD) mass in the Galactic bulge cataclysmic variables (CVs) was measured by applying the the shock temperature-WD mass correlation of magnetic...
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The Galactic Sky seen by H.E.S.S: The H.E.S.S. experiment is an array of four imaging Cherenkov telescopes located in the Khomas Highlands of Namibia. It has been operating in its full configuration since December 2003 and detects very-high-energy (VHE) gamma rays ranging from 100 GeV to 50 TeV. Since 2004, the continu...
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Toward a direct measurement of the cosmic acceleration: roadmap and forecast on FAST: HI absorption systems are great targets for direct measurement of the Sandage-Loeb (SL) effect throughout a wide range of redshift for ground-based radio telescopes. We demonstrate the significance of improving the accuracy of SL ef...
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Clumpy Streams from Clumpy Halos: Detecting Missing Satellites with Cold Stellar Structures: Dynamically cold stellar streams are ideal probes of the gravitational field of the Milky Way. This paper re-examines the question of how such streams might be used to test for the presence of "missing satellites" -the many t...
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Geysers in the Lagoon: new Herbig-Haro objects in M8: Aims: We search for direct evidence of ongoing star formation by accretion in the Lagoon Nebula (M8), using optical wide-field narrow-band imaging obtained at La Silla Observatory. Methods: We examine [SII] and Halpha images for line-emission features that could b...
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Resolving the Disc-Halo Degeneracy II: NGC 6946: The mass-to-light ratio (M/L) is a key parameter in decomposing galactic rotation curves into contributions from the baryonic components and the dark halo of a galaxy. One direct observational method to determine the disc M/L is by calculating the surface mass density of...
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Global Simulations of Magnetorotational Instability in The Collapsed Core of A Massive Star: We performed the first numerical simulations of magnetorotational instability from a sub-magnetar-class seed magnetic field in core collapse supernovae. As a result of axisymmetric ideal MHD simulations, we found that the mag...
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Effect of an external mass distribution on the magnetized accretion disk: In this paper, we constructed the magnetized thick disk model analytically around the static black hole in the presence of an external distribution of matter up to the quadrupole moment. This space-time is a solution to Einstein's field equation ...
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The cold circumgalactic environment of MAMMOTH-I: dynamically cold gas in the core of an Enormous Ly-alpha Nebula: The MAMMOTH-I Nebula at redshift 2.3 is one of the largest known Ly-alpha nebulae in the Universe, spanning ~440 kpc. Enormous Ly-alpha nebulae like MAMMOTH-I typically trace the densest and most active ...
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A Dynamic Galaxy: Stellar Age Patterns Across the Disk of M101: Using deep, narrowband imaging of the nearby spiral galaxy M101, we present stellar age information across the full extent of the disk of M101. Our narrowband filters measure age-sensitive absorption features such as the Balmer lines and the slope of the c...
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Fluid Dynamics of Stellar Jets in Real Time: Third Epoch HST Images of HH 1, HH 34, and HH 47: We present new, third-epoch HST H-alpha and [S II] images of three HH jets (HH 1 and 2, HH 34, and HH 47) and compare these images with those from the previous epochs. The high-spatial resolution, coupled with a time-series...
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X-ray emission from black-hole binaries: The properties of X-ray emission from accreting black holes are reviewed. The contemporary observational picture and current status of theoretical understanding of accretion and formation of X-ray radiation in the vicinity of the compact object are equally in the focus of this c...
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K-band spectroscopy of pre-cataclysmic variables: We have taken K-band spectroscopy of a sample of 13 pre-CVs in order to examine them for anomalous chemical abundances. In particular, we study the strength of the 12CO and 13CO absorption bands that have been found diminished and enhanced, respectively, in similar stud...
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Structure and Evolution of Internally Heated Hot Jupiters: Hot Jupiters receive strong stellar irradiation, producing equilibrium temperatures of $1000 - 2500 \ \mathrm{Kelvin}$. Incoming irradiation directly heats just their thin outer layer, down to pressures of $\sim 0.1 \ \mathrm{bars}$. In standard irradiated evol...
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NG7538 IRS1 N: modeling a circumstellar maser disk: We present an edge-on Keplerian disk model to explain the main component of the 12.2 and 6.7 GHz methanol maser emission detected toward NGC7538-IRS1 N. The brightness distribution and spectrum of the line of bright masers are successfully modeled with high amplificat...
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Evidence for dark matter interactions in cosmological precision data?: We study a two-parameter extension of the cosmological standard model $\Lambda$CDM in which cold dark matter interacts with a new form of dark radiation. The two parameters correspond to the energy density in the dark radiation fluid $\Delta N_\math...
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Planetary Nebulae towards the Galactic bulge. I. [OIII] fluxes: We present [OIII]{\lambda}5007 fluxes and angular diameters for 435 Planetary Nebulae (PN) in the central 10' x 10' region towards the Galactic bulge. Our sample is taken from the new discoveries of the MASH PN surveys as well as previously known PN. This ...
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The effect of photometric redshift uncertainties on galaxy clustering and baryonic acoustic oscillations: In the upcoming era of high-precision galaxy surveys, it becomes necessary to understand the impact of redshift uncertainties on cosmological observables. In this paper we explore the effect of sub-percent photom...
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All Quiet in Globular Clusters: Cataclysmic Variables (CVs) should be present in large numbers in Globular Clusters (GCs). Numerous low-luminosity X-ray sources identified over the past few years as candidate CVs in GCs support this notion. Yet, very few "cataclysms," the characteristic feature of this class of objects...
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Universal protoplanetary disk size under complete non-ideal magnetohydrodynamics: The interplay between ion-neutral friction, Hall effect, and the Ohmic dissipation: The role of non-ideal magnetohydrodynamics has been proven critical during the formation of the protoplanetary disk, particularly in regulating its si...
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A Novel Estimator for the Equation of State of the IGM by Ly$α$ Forest Tomography: We present a novel procedure to estimate the Equation of State of the intergalactic medium in the quasi-linear regime of structure formation based on Ly$\alpha$ forest tomography and apply it to 21 high quality quasar spectra from the ...
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C$^+$ detection of warm dark gas in diffuse clouds: We present the first results of the Herschel open time key program, Galactic Observations of Terahertz C$^+$ (GOT C+) survey of the [CII] fine-structure line at 1.9 THz (158 microns) using the HIFI instrument on Herschel. We detected 146 interstellar clouds along sixt...
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Dynamical neutrino masses in the generalized Chaplygin gas scenario with mass varying CDM: Neutrinos coupled to an underlying scalar field in the scenario for unification of mass varying dark matter and cosmon-{\em like} dark energy is examined. In the presence of a tiny component of mass varying neutrinos, the condi...
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VERITAS follow-up observation of the blazar TXS 0506+056: The gamma-ray blazar TXS 0506+056 was found with an enhanced gamma-ray emission state in spatial and temporal coincidence with the IceCube high energy neutrino event IC170922A. This is the most significant association by far between a high-energy neutrino event ...
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The molecular cloud S242: physical environment and star formation activities: We present a multi-wavelength study to probe the star formation (SF) processes on a larger scale (~1.05 deg x 0.56 deg) around the S242 site. The S242 molecular cloud is depicted in a velocity range from -3.25 to 4.55 km/s and has spatially...
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Cosmology with the shear-peak statistics: Weak-lensing searches for galaxy clusters are plagued by low completeness and purity, severely limiting their usefulness for constraining cosmological parameters with the cluster mass function. A significant fraction of `false positives' are due to projection of large-scale str...
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Optimising Spectroscopic and Photometric Galaxy Surveys: Efficient Target Selection and Survey Strategy: The next generation of spectroscopic surveys will have a wealth of photometric data available for use in target selection. Selecting the best targets is likely to be one of the most important hurdles in making the...
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A Frequency Comb calibrated Solar Atlas: The solar spectrum is a primary reference for the study of physical processes in stars and their variation during activity cycles. In Nov 2010 an experiment with a prototype of a Laser Frequency Comb (LFC) calibration system was performed with the HARPS spectrograph of the 3.6m ...
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Numerical Analysis of Relativistic Boltzmann-kinetic Equations to Solve Relativistic Shock Layer Problems: The relativistic shock layer problem was numerically analyzed by using two relativistic Boltzmann-kinetic equations. One is Marle model, and the other is Anderson-Witting model. As with Marle model, the temperat...
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A comparison between Fast Multipole Algorithm and Tree-Code to evaluate gravitational forces in 3-D: We present tests of comparison between our versions of the Fast Multipole Algorithm (FMA) and ``classic'' tree-code to evaluate gravitational forces in particle systems. We have optimized the Greengard's original vers...
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A new insight into neutrino energy loss by electron capture of iron group nuclei in magnetars surface: Based on the relativistic mean-field effective interactions theory, and Lai dong model \citep{b37, b38, b39}, we discuss the influences of superstrong magnetic fields (SMFs) on electron Fermi energy, nuclear blindin...
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Ultraviolet Imaging Telescope (UVIT) observation of the Galactic Globular Cluster NGC 7492: We present detailed photometric observations of the Galactic globular cluster NGC 7492 using the data obtained with two far-ultraviolet (FUV: 1300 - 1800 \AA) and three near-ultraviolet (NUV: 2000 - 3000 \AA) filters of Ultrav...
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High resolution CMB power spectrum from the complete ACBAR data set: In this paper, we present results from the complete set of cosmic microwave background (CMB) radiation temperature anisotropy observations made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR) operating at 150 GHz. We include new data fro...
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Optical Observations of the Type Ic Supernova 2007gr in NGC 1058 and Implications for the Properties of its Progenitor: We present extensive optical observations of the normal Type Ic supernova (SN) 2007gr, spanning from about one week before maximum light to more than one year thereafter. The optical light and color...
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New X-ray Clusters in the EMSS I: Modifications to the XLF: The complete ensemble of Einstein Imaging Proportional Counter (IPC) X-ray images has been re-processed and re-analyzed using a multi-aperture source detection algorithm. A catalog of 772 new source candidates detected within the central regions of the 1435 IP...
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Near-IR observations of UCHII regions: We present adaptive-optics (AO) assisted J, H and K/K' images of 8 UCHII regions taken with the ALFA and ADONIS AO systems at Calar Alto and La Silla observatories. The images show details of the stellar population and the near-IR morphology of UCHIIs with unprecedented resolution...
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CMB anisotropy power spectrum statistics: Much attention has been given to the problem of estimating cosmological parameters from the $C_l$ measured by future experiments. Many of the approaches which are being used either invoke poorly controlled approximations or are computationally expensive. We derive exact results...
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WALLABY Pilot Survey: HI in the host galaxy of a Fast Radio Burst: We report on the commensal ASKAP detection of a fast radio burst (FRB), FRB20211127I, and the detection of neutral hydrogen (HI) emission in the FRB host galaxy, WALLABYJ131913-185018 (hereafter W13-18). This collaboration between the CRAFT and WALLABY ...
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A comprehensive comparison of cosmological models from latest observational data: We investigate in detail some popular cosmological models in light of the latest observational data, including the Union2.1 supernovae compilation, the baryon acoustic oscillation measurements from the WiggleZ Dark Energy Survey, the co...
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Search for Continuous Gravitational Waves from Scorpius X-1 in LIGO O2 Data: We present the results of a search in LIGO O2 public data for continuous gravitational waves from the neutron star in the low-mass X-ray binary Scorpius X-1. We search for signals with $\approx$ constant frequency in the range 40-180 Hz. Tha...
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Magneto-Rotational Transport in the Early Sun: Angular momentum transport must have occurred in the Sun's radiative zone to explain its current solid body rotation. We survey the stability of the early Sun's radiative zone with respect to diffusive rotational instabilities, for a variety of plausible past configuration...
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The Very Small Array: The Very Small Array (VSA) is a fourteen-element interferometer designed to study the cosmic microwave background on angular scales of 2.4 to 0.2 degrees (angular multipoles l = 150 to 1800). It operates at frequencies between 26 and 36 GHz, with a bandwidth of 1.5 GHz, and is situated at the Teid...
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Optical and near-infrared photometric monitoring of the transient X-ray binary A0538-66 with REM: The transient Be/X-ray binary A0538-66 shows peculiar X-ray and optical variability. Despite numerous studies, the intrinsic properties underlying its anomalous behaviour remain poorly understood. Since 2014 September we...
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A Radio Observatory on the Lunar Surface for Solar studies (ROLSS): By volume, more than 99% of the solar system has not been imaged at radio frequencies. Almost all of this space (the solar wind) can be traversed by fast electrons producing radio emissions at frequencies lower than the terrestrial ionospheric cutoff, ...
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CAOS spectroscopy of Am stars Kepler targets: The {\it Kepler} space mission and its {\it K2} extension provide photometric time series data with unprecedented accuracy. These data challenge our current understanding of the metallic-lined A stars (Am stars) for what concerns the onset of pulsations in their atmospheres...
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Multi-wavelength spectral modelling of the candidate neutrino blazar PKS 0735+178: The BL Lac object PKS 0735+178 was in its historic $\gamma$-ray brightness state during December 2021. This period also coincides with the detection of a neutrino event IC211208A, which was localized close to the vicinity of PKS 0735+1...
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What can BeppoSAX tell us about short GRBs: An update from the Subsecond GRB Project: We present some statistical considerations on the BeppoSAX hunt for subsecond GRBs at the Scientific Operation Center. Archive analysis of a BATSE/SAX sub-sample of bursts indicates that the GRB Monitor is sensitive to short (< 2 se...
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The aromatic infrared bands as seen by ISO-SWS: probing the PAH model: We discuss the Aromatic Infrared Band (AIB) profiles observed by ISO-SWS towards a number of bright interstellar regions where dense molecular gas is illuminated by stellar radiation. Our sample spans a broad range of excitation conditions (exciting...
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Application of Deep Learning Methods for Distinguishing Gamma-Ray Bursts from Fermi/GBM TTE Data: To investigate GRBs in depth, it is crucial to develop an effective method for identifying GRBs accurately. Current criteria, e.g., onboard blind search, ground blind search, and target search, are limited by manually se...
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Development of a cosmic ray oriented trigger for the fluorescence telescope on EUSO-SPB2: The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2), in preparation, aims to make the first observations of Ultra-High Energy Cosmic Rays (UHECRs) from near space using optical techniques. EUSO-SPB2 ...
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Shock Waves and Cosmic Ray Acceleration in the Outskirts of Galaxy Clusters: The outskirts of galaxy clusters are continuously disturbed by mergers and gas infall along filaments, which in turn induce turbulent flow motions and shock waves. We examine the properties of shocks that form within $r_{200}$ in sample gala...
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The Role of a Massive Central Singularity in Galactic Mergers on the Survival of the Core Fundamental Plane: In order for the core Fundamental Plane (cFP) to endure, small ellipticals must not survive mergers with giant ellipticals, despite the fact the small secondary galaxy can be as much as a million times more de...
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Hot One-Temperature Accretion Flows Around Black Holes: We describe hot, optically-thin solutions for one-temperature accretion disks around black holes. We include cooling by synchrotron, bremsstrahlung, and Comptonization. Our solutions are thermally and viscously stable, with gas temperatures on the order of $T \sim...
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Multi-messenger astronomy with Centaurus A: We calculated for the nearest active galactic nucleus (AGN), Centaurus A (Cen A), the flux of high energy cosmic rays and of accompanying secondary photons and neutrinos expected from hadronic interactions in the source. We used as two basic models for the generation of ultra...
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Binning is Sinning: Redemption for Hubble Diagram using Photometrically Classified Type Ia Supernovae: Bayesian Estimation Applied to Multiple Species (BEAMS) is implemented in the BEAMS with Bias Corrections (BBC) framework to produce a redshift-binned Hubble diagram (HD) for Type Ia supernovae (SNe Ia). BBC correct...
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Gaia view of primitive inner-belt asteroid families: Searching for the origins of asteroids Bennu and Ryugu: Near-Earth asteroids Ryugu and Bennu, were visited, characterised, and sampled by the Hayabusa2 and OSIRIS-REx missions: remote sensing data and sample return analysis showed that both asteroids have primitive...
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A Comparison of Weak Lensing Measurements From Ground- and Space-Based Facilities: We assess the relative merits of weak lensing surveys, using overlapping imaging data from the ground-based Subaru telescope and the Hubble Space Telescope (HST). Our tests complement similar studies undertaken with simulated data. Fro...
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Black hole spin and size of the X-ray emitting region(s) in the Seyfert 1.5 galaxy ESO 362-G18: We report results from multi-epoch X-ray observations of the Seyfert 1.5 galaxy ESO 362-G18 performed between November 2005 and June 2010. ESO 362-G18 generally exhibits the typical X-ray spectrum of type 1 Active Galactic...
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Multiplicity among solar-type stars IV. The CORAVEL radial velocities and the spectroscopic orbits of nearby K dwarfs: Context. The statistical properties of binary stars are clues for understanding their formation process. A radial velocity survey was carried on amongst nearby G-type stars and the results were publi...
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Characterizing the Conditional Galaxy Property Distribution using Gaussian Mixture Models: Line-intensity mapping (LIM) is a promising technique to constrain the global distribution of galaxy properties. To combine LIM experiments probing different tracers with traditional galaxy surveys and fully exploit the scienti...
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Observational Consequences of the Recently Proposed Super-Earth Orbiting GJ436: Ribas and collaborators have recently proposed that an additional, ~5 M_earth planet orbits the transiting planet host star GJ436. Long-term dynamical interactions between the two planets leading to eccentricity excitation might provide a...
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Indirect dark matter searches in Gamma- and Cosmic Rays: Dark matter candidates such as weakly-interacting massive particles are predicted to annihilate or decay into Standard Model particles leaving behind distinctive signatures in gamma rays, neutrinos, positrons, antiprotons, or even anti-nuclei. Indirect dark matte...
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A Comparative Study of Convolutional Neural Networks for the Detection of Strong Gravitational Lensing: As we enter the era of large-scale imaging surveys with the up-coming telescopes such as LSST and SKA, it is envisaged that the number of known strong gravitational lensing systems will increase dramatically. Howev...
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Density, Velocity, and Magnetic Field Structure in Turbulent Molecular Cloud Models: We use 3D numerical MHD simulations to follow the evolution of cold, turbulent, gaseous systems with parameters representing GMC conditions. We study three cloud simulations with varying mean magnetic fields, but identical initial ve...
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Generating realistic synthetic meteoroid orbits: Context. Generating a synthetic dataset of meteoroid orbits is a crucial step in analysing the probabilities of random grouping of meteoroid orbits in automated meteor shower surveys. Recent works have shown the importance of choosing a low similarity threshold value of ...
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The Properties of Long-Period Variables in the Large Magellanic Cloud from MACHO: We present a new analysis of the long-period variables in the Large Magellanic Cloud (LMC) from the MACHO Variable Star Catalog. Three-quarters of our sample of evolved, variable stars have periodic light curves. We characterize the sta...
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Light pollution is skyrocketing: Artificial light at night is a pollutant that is rising fast, as demonstrated by Kyba et al. (1) work by analyzing ten of thousands observations by citizen scientists in the last 12 years. The study found that the dimmest stars are vanishing, progressively hidden by a 10 percent yearly ...
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Precessing Warped Be Disk Triggering the Giant Outbursts in 2009 and 2011 in A 0535+262/V725 Tau: We carried out optical high-dispersion spectroscopic monitoring of the Be disk in a Be/X-ray binary A 0535+262/V725 Tau from 2009 to 2012, covering two giant outbursts and several normal outbursts. This monitoring was pe...
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Turbulence in the Molecular Interstellar Medium: The observational record of turbulence within the molecular gas phase of the interstellar medium is summarized. We briefly review the analysis methods used to recover the velocity structure function from spectroscopic imaging and the application of these tools on sets of...
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Cosmology with cosmic web environments II. Redshift-space auto and cross power spectra: Degeneracies among parameters of the cosmological model are known to drastically limit the information contained in the matter distribution. In the first paper of this series, we shown that the cosmic web environments; namely the ...
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Interstellar Deuterium, Nitrogen, and Oxygen Abundances Toward GD 246, WD 2331$-$475, HZ 21, and Lan 23: Results from the FUSE Mission: The interstellar abundances of D I, N I, and O I in the local ISM are studied us ing high-resolution spectra of four hot white dwarfs. The spectra of GD 246, WD 2331$-$475, HZ 21, an...
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A Chi-Squared Analysis of the Measurements of Two Cosmological Parameters Over Time: The aim of this analysis was to determine whether or not the given error bars truly represented the dispersion of values in a historical compilation of two cosmological parameters: the amplitude of mass fluctuations ($\sigma_8$) and ...
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The accretion of galaxies into groups and clusters: We use the galaxy stellar mass and halo merger tree information from the semi-analytic model galaxy catalogue of Font et al. (2009) to examine the accretion of galaxies into a large sample of groups and clusters, covering a wide range in halo mass (10E12.9 to 10E15.3 ...
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A Multiwavelength Investigation of Unidentified EGRET Sources: Statistical studies indicate that the 271 point sources of high-energy gamma rays belong to two groups: a Galactic population and an isotropic extragalactic population. Many unidentified extragalactic sources are certainly blazars, and it is the intention o...
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Starless Cores: Dense low mass cores in nearby clouds like Taurus and Auriga are some of the simplest sites currently forming stars like our Sun. Because of their simplicity and proximity, dense cores offer the clearest view of the different phases of star formation, in particular the conditions prior to the onset of g...
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Magnetic Accretion and Photopolarimetric Variability in Classical T Tauri Stars: We employ a Monte Carlo radiation transfer code to investigate the multi- wavelength photopolarimetric variability arising from a spotted T Tauri star surrounded by a dusty circumstellar disk. Our aim is to assess the ability of the magn...
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The data acquisition system for the ANTARES neutrino telescope: The ANTARES neutrino telescope is being constructed in the Mediterranean Sea. It consists of a large three-dimensional array of photo-multiplier tubes. The data acquisition system of the detector takes care of the digitisation of the photo-multiplier tube ...
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Disk Evolution and Bar Triggering Driven by Interactions with Dark Matter Substructure: We study formation and evolution of bar-disk systems in fully self-consistent cosmological simulations of galaxy formation in the LCDM WMAP3 Universe. In a representative model we find that the first generation of bars form in res...
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Did the 2000 November 8 solar flare accelerate protons to >=40 GeV?: It has been reported that a 5.7sigma directional muon excess coincident with the 2000 July 14 solar flare was registered by the L3 precision muon spectrometer [Ruiguang Wang, Astroparticle Phys., 31(2009) 149]. Using a same analysis method and similar...
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The 2dF-SDSS LRG and QSO survey: evolution of the clustering of luminous red galaxies since z = 0.6: We present an analysis of the small-to-intermediate scale clustering of samples of Luminous Red Galaxies (LRGs) from the Sloan Digital Sky Survey and the 2dF-SDSS LRG and QSO (2SLAQ) survey carefully matched to have t...
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Abundance stratification in Type Ia supernovae - V. SN 1986G bridging the gap between normal and subluminous SNe Ia: A detailed spectroscopic analysis of SN 1986G has been performed. SN 1986G `bridges the gap' between normal and sub luminous type Ia supernova (SNe Ia). The abundance tomography technique is used to de...
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Rayleigh scattering: blue sky thinking for future CMB observations: Rayleigh scattering from neutral hydrogen during and shortly after recombination causes the CMB anisotropies to be significantly frequency dependent at high frequencies. This may be detectable with Planck, and would be a strong signal in any future spa...
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Echelle Spectroscopy of a GRB Afterglow at z=3.969: A New Probe of the Interstellar and Intergalactic Media in the Young Universe: We present an echelle spectrum of the Swift GRB 050730, obtained four hours after the burst using the MIKE spectrograph on the Magellan Clay Telescope when the afterglow was at R=17.7. Th...
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The Penn State - Toruń Centre for Astronomy Planet Search stars. III. The evolved stars sample: We present basic atmospheric parameters ($T_{eff}$, $log g$, $v_{t}$ and [Fe/H]), rotation velocities and absolute radial velocities as well as luminosities, masses, ages and radii for 402 stars (including 11 single-lined ...
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