Related papers: The forward and reverse shock dynamics of Cassiope…

We present spectroscopic observations of the Be/X-ray binary X Per obtained during the period 1999 - 2018. Using new and published data, we found that during "disc-rise" the expansion velocity of the circumstellar disc is 0.4 - 0.7 km/s.…

We present new models for the forward and reverse shock thermal X-ray emission from core-collapse and Type Ia supernova remnants (SNRs) which include the efficient production of cosmic rays via non-linear diffusive shock acceleration (DSA).…

We present an analysis of the XMM-Newton and Chandra X-ray data of the young Type Ia supernova remnant 0519-69.0 in the Large Magellanic Cloud. We used data from both the Chandra ACIS and XMM-Newton EPIC-MOS instruments, and high resolution…

We present high-resolution X-ray spectra from the young supernova remnant Cas A using a 70-ks observation taken by the Chandra High Energy Transmission Grating Spectrometer (HETGS). Line emission, dominated by Si and S ions, is used for…

We present a detailed analysis of jet activity in the radio galaxy 3C348 at the center of the galaxy cluster Hercules A. We use archival Chandra data to investigate the jet-driven shock front, the radio-faint X-ray cavities, the eastern…

Supernova remnants (SNRs) are believed to be the primary location of the acceleration of Galactic cosmic rays, via diffusive shock (Fermi) acceleration. Despite considerable theoretical work the precise details are still unknown, in part…

The Centaurus A radio galaxy, due to its proximity, presents itself as one of the few systems that allow the study of relativistic jet outflows at sub-parsec distances from the central supermassive black holes, with high signal to noise. We…

Supernova remnants (SNRs) have long been considered the leading candidates for the accelerators of cosmic rays within the Galaxy through the process of diffusive shock acceleration. The connection between SNRs and cosmic rays is supported…

We report deep near-infrared and optical observations of the X-ray point source in the Cassiopeia A supernova remnant, CXO J232327.9+584842. We have identified a J=21.4 +/- 0.3 mag and Ks=20.5 +/- 0.3 mag source within the 1-sigma error…

We analyze and model the infrared spectrum of the Cassiopeia A supernova remnant, with the aim of determining the masses of various elements in the unshocked ejecta. In this way we complement the survey of the X-ray emitting ejecta of Hwang…

Long-term measurements of the radio flux density of Cassiopeia A relative to Cygnus A have been carried out at 927 and 151.5 MHz. It was found the following mean secular decrease rates of the radio emission of Cassiopeia A: $(0.72\pm 0.03)%…

Aims. We study the forward shock in the oxygen-rich young supernova remnant (SNR) 1E0102.2-7219 (1E0102 in short) via optical coronal emission from [Fe XIV] and [Fe XI]: emission lines which offer an alternative method to X-rays to do so.…

Upper limits on the shock speeds in supernova remnants can be combined with post-shock temperatures to obtain upper limits on the ratio of cosmic ray to gas pressure (P_CR / P_G) behind the shocks. We constrain shock speeds from proper…

In this paper, we present the first direct measurement of the proper motion of the neutron star (NS) in the supernova remnant (SNR) G18.9-1.1 using a 15-year Chandra baseline. After correcting the observations' astrometric solutions using…

The observations of radio emission from SNR~1987A can be accounted for on the basis of diffusive shock acceleration of electrons by the supernova blast wave. However, with this interpretation the observed spectral index implies that the…

We report the results of an X-ray proper motion measurement for the NW rim of SN1006, carried out by comparing Chandra observations from 2001 and 2012. The NW limb has predominantly thermal X-ray emission, and it is the only location in…

We report here the first study of proper motions of fast filaments in the young, oxygen-rich supernova remnant G292.0+1.8, carried out using a series of [O III] 5007 A emission-line images taken over a period of more than 21 years. Images…

Hotspots observed at the edges of extended radio lobes in high-power radio galaxies and quasars mark the position of mildly-relativistic termination shock, where the jet bulk kinetic energy is converted to the internal energy of the jet…

We have measured the expansion velocities and proper motion of the ansae in NGC7009 using high dispersion echelle spectra and archive narrow band HST images. Assuming that the ansae are moving at equal and opposite velocities from the…

The supernova remnant Cassiopeia A (Cas A) is one of the few remnants in which it is possible to observe unshocked ejecta. A deep 1.64 micron image of Cas A shows a patch of diffuse emission from unshocked ejecta, as well as brighter…