The physical mechanism behind the acceleration of the universe
remains one of the great mysteries of modern cosmology. Given the
proliferation of dark energy models on the market, an obvious
question is: How can we rule out whole classes of dark...
Infrared observations from Spitzer Space Telescope and Herschel
Space Observatory are used to study the interstellar dust in M31. A
physical dust model is used to map the dust surface density,
dust/gas ratio, starlight heating intensity, and the...
The advent of wide-field synoptic imaging has re-invigorated the
venerable field of time domain astronomy. Our framework of optical
transients no longer has a wide six-magnitude luminosity "gap"
between the brightest novae and faintest supernovae...
A classic problem posed by long gamma ray bursts (GRB) is that
the energy output requires gravitational energy release so deep
within the host star that the prompt gamma rays should, upon naive
consideration, have been obscured. It is suggested that...
