Related papers: Cluster Multi-spacecraft Determination of AKR Angu…
The Cluster Wideband Data instrument has been used to determine the locations of auroral kilometric radiation (AKR) using very long baseline interferometry. The technique involves cross-correlating individual AKR bursts from all six Cluster…
We report the detection of extended X-ray emission around several powerful 3CR quasars with redshifts out to 0.73. The ROSAT HRI images of the quasars have been corrected for spacecraft wobble and compared with an empirical point-spread…
We present the first measurement of the angular two-point correlation function for AKARI 90-$\mu$m point sources, detected outside of the Milky Way plane and other regions characterized by high Galactic extinction, and categorized as…
Data collected with Polrad swept frequency analyzer during almost 2.5 years of Interball-2 mission are used to investigate the directivity properties of AKR observed in the Northern Hemisphere. In contrast with the previous, mostly…
The search of a clustering signal in the arrival directions of ultra-high-energy cosmic rays (UHECRs) is a standard method to assess the level of anisotropy of the data sets under investigation. Here, we first show how to quantify the…
We present observational results of the thermal dust continuum emission and its linear polarization in one of the nearest massive star-forming sites Orion BN/KL in Orion Molecular Cloud-1. The observations were carried out with the…
The compact stellar clusters have emerged as particularly promising candidates for cosmic rays (CR) accelerators. The star clusters, recently observed in gamma-rays, are also known sources of non-thermal X-ray emission, which is due to…
The NuSTAR mission performed a long (200 ks) observation of the Arches stellar cluster in 2015. The emission from the cluster represents a mixture of bright thermal (kT~2 keV) X-rays and the extended non-thermal radiation of the molecular…
The Arches cluster is a young, densely packed massive star cluster in our Galaxy that shows a high level of star formation activity. The nature of the extended non-thermal X-ray emission around the cluster remains unclear. The observed…
Since the discovery of active galactic nuclei (AGN) and their subclasses, a unification scheme of AGN has been long sought. Orientation-based unified models predict that some of the diversity within AGN subclasses can be explained by the…
Spectro-astrometry is applied to echelle spectra of the young intermediate mass star T CrA. The aim is to better understand the origin of the [O I] and [S II] emission from T CrA and further explore the usefulness of spectro-astrometry to…
We present Chandra observations of the X-ray environment of a sample of 6 BL Lacertae objects. The improved sensitivity of the ACIS experiment allows us to separate the core X-ray emission from the contribution of diffuse emission from the…
From extensive radiative transfer calculations we find that clumpy torus models with \No \about 5--15 dusty clouds along radial equatorial rays successfully explain AGN infrared observations. The dust has standard Galactic composition, with…
Observation of clustering of ultra-high energy cosmic rays (UHECR) suggests that they are emitted by compact sources. Assuming small deflection of UHECR during the propagation, the statistical analysis of clustering allows to estimate the…
We introduce a method to constrain the characteristic angular size of the brightest cosmic-ray sources observed above 57 \times 1018 eV. By angular size of a source, we mean the effective angular extent over which cosmic-rays from that…
Gamma-ray burst (GRB) prompt emission is highly beamed, and understanding the jet geometry and beaming configuration can provide information on the poorly understood central engine and circum-burst environment. Prior to the advent of…
Cosmic rays (CRs) are protons and atomic nuclei that flow into our Solar system and reach the Earth with energies of up to ~10^21 eV. The sources of ultra-high energy cosmic rays (UHECRs) with E >~ 10^19 eV remain unknown, although there…
Whether caused by AGN jets, shocks, or mergers, the most definitive evidence for heating in cluster cores comes from X-ray spectroscopy. Unfortunately such spectra are essentially limited to studying the emission spectrum from the cluster…
Strong magnetic fields, synchrotron emission, and Compton scattering are omnipresent in compact celestial X-ray sources. Emissions in the X-ray energy band are consequently expected to be linearly polarized. X-ray polarimetry provides a…
The arrival directions of extremely high energy cosmic rays (EHECR) above $4\times10^{19}$ eV, observed by four surface array experiments in the northern hemisphere,are examined for coincidences from similar directions in the sky. The total…