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We investigate interaction effects on the dynamics and morphology of the galaxy pairs AM,2058-381 and AM,1228-260. This work is based on $r$ images and long-slit spectra obtained with the Gemini Multi-Object Spectrograph at the Gemini South Telescope. The luminosity ratio between the main (AM,2058A) and secondary (AM,2058B) components of the first pair is a factor of $sim$ 5, while for the other pair, the main (AM,1228A) component is 20 times more luminous than the secondary (AM,1228B). The four galaxies have pseudo-bulges, with a Sersic index $n<2$. Their observed radial velocities profiles (RVPs) present several irregularities. The receding side of the RVP of AM,2058A is displaced with respect to the velocity field model, while there is a strong evidence that AM,2058B is a tumbling body, rotating along its major axis. The RVPs for AM,1228A indicate a misalignment between the kinematic and photometric major axes. The RVP for AM,1228B is quite perturbed, very likely due to the interaction with AM,1228A. NFW halo parameters for AM,2058A are similar to those of the Milky Way and M,31. The halo mass of AM,1228A is roughly 10% that of AM,2058A. The mass-to-light (M/L) of AM,2058 agrees with the mean value derived for late-type spirals, while the low M/L for AM,1228A may be due to the intense star formation ongoing in this galaxy.
We present optical and X-ray observations of two tidally distorted, extremely low-mass white dwarfs (WDs) with massive companions. There is no evidence of neutron stars in our Chandra and XMM observations of these objects. SDSS J075141.18$-$014120.9
{it Kepler} satellite photometry and phase-resolved spectroscopy of the ultracompact AM CVn type binary SDSS J190817.07+394036.4 are presented. The average spectra reveal a variety of weak metal lines of different species, including silicon, sulphur
The nominal Kepler mission provided very high-precision photometric data. Using these data, interesting phenomena such as spots, and ``hump and spike features were observed in the light curves of some normal A and metallic lined A stars (Am stars). H
We present Chandra and Swift X-ray observations of four extremely low-mass (ELM) white dwarfs with massive companions. We place stringent limits on X-ray emission from all four systems, indicating that neutron star companions are extremely unlikely a
We present the results of a two and a half year optical photometric monitoring programme covering 16 AM CVn binaries using the Liverpool Telescope on La Palma. We detected outbursts in seven systems, one of which (SDSS J0129) was seen in outburst for