相关论文: Statistical study of auroral omega bands

Studying the environments of 0.4<z<1.2 UV-selected galaxies, as examples of extreme star-forming galaxies (with star formation rates in the range of 3-30 M_sol/yr), we explore the relationship between high rates of star-formation, host halo…

We present the initial results of an observational study into the variation of the dominant length-scale of quiet solar emission: supergranulation. This length-scale reflects the radiative energy in the plasma of the upper solar…

A 2.1-year periodic oscillation of the gamma-ray flux from the blazar PG 1553+113 has previously been tentatively identified in almost 7 year of data from the Fermi Large Area Telescope. After 15 years of Fermi sky-survey observations,…

We present low frequency observations at $315$ and $745$ MHz from the upgraded Giant Metrewave Radio Telescope (uGMRT) of the edge-on, nearby galaxy NGC $4631$. We compare the observed surface brightness profiles along the minor axis of the…

Blazars are powerful, variable emitters from radio to gamma-ray wavelengths. Even though the general picture of synchrotron emission at low energies and inverse Compton at the high energy end is well established, many important aspects of…

Our aim is to study the large-scale structure of different types of AGN using the medium-deep XMM-LSS survey. We measure the two-point angular correlation function of ~ 5700 and 2500 X-ray point-like sources over the ~ 11 sq. deg. XMM-LSS…

This is the first paper of a series exploring the multi-frequency properties of a sample of eleven nearby low excitation radio galaxies (LERGs) in the southern sky. We are conducting an extensive study of different galaxy components (stars,…

We compare the zonal flow pattern in subsurface layers of the Sun with the distribution of surface magnetic features like sunspots and polar faculae. We demonstrate that in the activity belt, the butterfly pattern of sunspots coincides with…

Upflows and downflows at active region (AR) boundaries have been frequently observed with spectroscopic observations at extreme ultraviolet (EUV) passbands. In this paper, we report the coexistence of upflows and downflows at the AR…

Solar active regions show a wide variety of oscillatory phenomena. The presence of the magnetic field leads to the appearance of several wave modes, whose behavior is determined by the sunspot thermal and magnetic structure. We aim to study…

Aims. We report the results of a novel determination of the solar oxygen abundance using spatially resolved observations and inversions. We seek to derive the photospheric solar oxygen abundance with a method that is robust against…

Cheung identified a sample of 100 candidate X-shaped radio galaxies using the NRAO FIRST survey; these are small-axial-ratio extended radio sources with off-axis emission. Here we present radio images of 52 of these sources that have been…

A large sample of known and likely gamma-ray blazars has been monitored twice per week since late 2007 at 15 GHz with the Owens Valley Radio Observatory (OVRO) 40-meter Telescope. The sample contains about 1700 sources, including the…

Helioseismic observations have detected small temporal variations of the rotation rate below the solar surface corresponding to the so-called `torsional oscillations' known from Doppler measurements of the surface. These appear as bands of…

We present auroral evidence for multiple and, most probably, small scale reconnection in the near Earth magnetospheric plasma sheet current layer during auroral activity. Hall currents as the source of upward and downward field-aligned…

Ground-based optical astronomical observations supported by or in the vicinity of laser guide-star systems can be contaminated by Raman-scattered laser photons. Anticipating, alleviating, and correcting for the impact of this self-inflicted…

Quasi-periodic propagating intensity disturbances have been observed in large coronal loops in EUV images over a decade, and are widely accepted to be slow magnetosonic waves. However, spectroscopic observations from Hinode/EIS revealed…

Since late 2007, we have been monitoring a large sample of known and likely gamma-ray-loud blazars at 15 GHz twice per week with the Owens Valley Radio Observatory (OVRO) 40 m Telescope. Our initial sample included the 1158 sources above…

The MeerKAT Large Area Synoptic Survey (MeerKLASS) collaboration has acquired multiple passes of L-band (856-1712 MHz) scanning observations over a 268 deg$^2$ sky region. This scanning enables efficient, large-area sky surveys by…

The distribution of Ge-O-Ge and Si-O-Si bond angles alpha in amorphous germania and silica is re-determined on the basis of diffraction experiments. The bond angle alpha joining adjacent tetrahedra is the central parameter of any continuous…