ABSTRACT The timing argument connects the motion of a two-body system to its mass in an expanding Universe with finite age, under assumption that it has evolved on self-gravitating orbit. It is commonly applied present-day Milky Way (MW)–M31 order infer unknown from measured kinematics. We use set Local Group analogues uchuu simulation investigate over cosmic time. find median inferred remains ...

We present the results of the systematic survey of X-ray sources in the central region of M31 using the data from XMM-Newton observations performed in the years 2000-2004. The spectral properties and variability of 123 bright X-ray sources with apparent luminosities between ∼ 1036 and 5×1038 ergs s−1 were studied in detail. The spectral properties of majority of sources in our sample have been ...

DIRECT is a project to directly obtain the distances to two important galaxies in the cosmological distance ladder, M31 and M33, using detached eclipsing binaries and Cepheids. As part of our search for these variables, we have obtained photometry and positions for thousands of stellar objects within the monitored fields, covering an area of 557.8 arcmin. In this research note we present the eq...