We report results from Chandra observations of the X-ray jet of 3C 273 during the calibration phase in 2000 January. The zeroth-order images and spectra from two 40 ks exposures with the High-Energy Transmission Grating and Low-Energy Transmission Grating + Advanced CCD Imaging Spectrometer-S show a complex X-ray structure. The brightest optical

Current muon anomalous magnetic moment data have challenged the SM, and seems to open a window to new Physics. Since the difference between SM and experimental predictions is approximately $2.6sigma$. In the framework of the General Two Higgs Doublet Model (2HDM), we calculate the muon anomalous magnetic moment to get lower and upper bounds for the

We present an outline of our study of the effects of star formation on the different components of the interstellar medium in the discs of spiral galaxies, both globally and as a function of arm and interarm environment. We are in the process of obtaining images of 57 spiral galaxies at low inclinations, and analysing them to study the distribution

We report the detection of main-sequence and blue horizontal-branch stars of the Ursa Minor dwarf spheroidal galaxy beyond its tidal radius, indicating the existence of a possible tidal extension in this satellite of the Milky Way. This tidal extension could spread out well beyond the area covered in our survey (R>80'), as suggested by the presence

The distribution on the sky of clusters of galaxies shows significant association with relatively nearby, large, active galaxies. The pattern is that of clusters paired equidistant across a central galaxy with the apparent magnitudes and redshifts of their constituent galaxies being closely matched. The clusters and the galaxies in them tend to be

A new photometric system suitable for deep, precise and quick metallicity mapping in galaxies is proposed. We find a linear correlation between our metallicity index and the Mg_2 index for stellar, globular-cluster, and early-type galaxy spectra, and model spectral energy distributions of the simple stellar populations.