Star Formation in the Milky Way and Nearby Galaxies

We review progress over the past decade in observations of large-scale star formation, with a focus on the interface between extragalactic and Galactic studies. Methods of measuring gas contents and star formation rates are discussed, and updated prescriptions for calculating star formation rates are provided. We review relations between star formation and gas on scales ranging from entire galaxies to individual molecular clouds.Comment: 55 pages, 15 figures, in press for Annual Reviews of Astronomy and Astrophysics; Updated with corrected equation 5, improved references, and other minor change

Ionospheric Response to Natural and Man Made Impacts

International audienceThe problem of energy transfer from the Earth’s solid mantles to the atmosphere and surrounding space is of essential importance for the fundamental geophysics and applied studies. These processes can largely govern the structure and dynamics of the phenomena developing in the near Earth space. Moreover, the consequences of such impacts as earthquakes, hurricanes, etc. upon the Earth’s electromagnetic field and ionosphere can become an extra factor in monitoring the processes involved in the upcoming large-scale seismic and meteorological catastrophes. The acoustic-gravity waves (comprising acoustic and gravity waves and hereafter referred to as AGW) are one of the most efficient ways to transport over the ionosphere the energy of the dynamic processes developing in the low atmosphere. The early experiments of the 1950’s and 60’s on Doppler sounding even showed that the ionosphere can serve as a sensitive indicator of natural and man made disturbances. The Doppler sounding of the ionosphere revealed impulse and wave disturbances excited by powerful sources of infrasound, such as: a) megaton nuclear explosions in the atmosphere, kiloton ground industrial explosions, b) earthquakes and volcano eruptions, c) thunderstorms, tornadoes and tsunamis, d) bolides and meteorites, e) rocket launches and flights of supersonicjets, f) aurora and solar eclipse