We measure the oxygen metallicity of the ionized gas along the major axis of seven dwarf star-forming galaxies. Two of them, SDSSJ1647+21 and SDSSJ2238+14, show sime0.5 dex metallicity decrements in inner regions with enhanced star formation activity. This behavior is similar to the metallicity drop observed in a number of local tadpole galaxies by

A selection of amino acids, namely arginine, proline and tyrosine previously irradiated to 3.2 mega-Gray in the solid state and analyzed by differential scanning calorimetry (DSC) and optical rotatory dispersion (ORD) were analyzed in the present work by mass spectrometry with the purpose to identify the radiolysis products and validate the results

The paper describes the operations of ESA's Optical Ground Station (OGS) during the Lunar Laser Communications Demonstration (LLCD) experiment, performed in October and November 2013 with NASA's Lunar Atmospheric and Dust Environmental Explorer (LADEE) spacecraft. First the transmitter and receiver designs at the OGS telescope are described, which

In relation to the gas giants that have been observed, Jupiter is located relatively far from its star. Observing Jupiter as an exoplanet can provide information about what to expect when getting data from similar gas giants around other stars. Even though Jupiter's transmission spectrum can be difficult to observe when looking from the Earth, it

We present nuclear spectral energy distributions (SEDs) from 1 to 18 μm of a small sample of nearby, nearly face-on and undisturbed Seyfert galaxies without prominent nuclear dust lanes. These nuclear SEDs probe the central ˜35 pc of the galaxies, on average, and include photometric and spectroscopic infrared (IR) data. We use these SEDs, the

With archival and new Hubble Space Telescope observations, we have refined the space-velocity measurements of the stars in the central region of the remnant of Tycho's supernova (SN) 1572, one of the historical Galactic Type Ia supernova remnants (SNRs). We derived a proper motion for Tycho-G of (μαcos δ; μδ)J2000.0 = (-2.63; -3.98) ± (0.06; 0.04)