astro-ph coffee suggested papers for Thu, Jan 26, 2012 at 03:00:00 PM
astro-ph coffee will be held at the date and time above in the PAB 3rd-floor reading room. Some suggested papers of interest are listed below.
11 Jan 2012
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Most Sun-like stars in the Galaxy reside in gravitationally bound pairs of stars (binaries). Although long anticipated, the existence of a /`circumbinary planet/' orbiting such a pair of normal stars was not definitively established until the discovery of the planet transiting (that is, passing in front of) Kepler-16. Questions remained, however, about the prevalence of circumbinary planets and their range of orbital and physical properties. Here we report two additional transiting circumbinary ...
Democratic societies are built around the principle of free and fair
elections, that each citizen's vote should count equal. National elections can
be regarded as large-scale social experiments, where people are grouped into
usually large numbers of electoral districts and vote according to their
preferences. The large number of samples implies certain statistical
consequences for the polling results which can be used to identify election
irregularities. Using a suitable data collapse, we find ...
The first stars in the universe are thought to be massive, forming in dark
matter halos with masses around 10^6 solar masses. Recent simulations suggest
that these metal-free (Population III) stars may form in binary or multiple
systems. Because of their high stellar masses and small host halos, their
feedback ionizes the surrounding 3 kpc of intergalactic medium and drives the
majority of the gas from the potential well. The next generation of stars then
must form in this gas-poor environment,...
Hennebelle & Chabrier 2008 (HC08) attempted to derive the stellar IMF as a
consequence of turbulent density fluctuations, using an argument similar to
Press & Schechter 1974 for Gaussian random fields. Like that example, however,
this solution does not resolve the 'cloud in cloud' problem; it also does not
extend to large scales that dominate the velocity/density fluctuations. In
principle, these can change the results at the order-of-magnitude level. Here,
we use the results from Hopki...
The nearby A4-type star Fomalhaut hosts a debris belt in the form of an
eccentric ring, which is thought to be caused by dynamical influence from a
giant planet companion. In 2008, a detection of a point-source inside the inner
edge of the ring was reported and was interpreted as a direct image of the
planet, named Fomalhaut b. The detection was made at ~600--800 nm, but no
corresponding signatures were found in the near-infrared range, where the bulk
emission of such a planet should be expecte...
This article presents a review on the observations and theoretical modeling
of the evaporation of extrasolar planets. The observations and the resulting
constraints on the upper atmosphere (thermosphere and exosphere) of the
"hot-Jupiters". are described. The early observations of the first discovered
transiting extrasolar planet, HD209458b, allowed the discovery that this planet
has an extended atmosphere of escaping hydrogen. Subsequent observations showed
the presence of oxygen and carbon at...
With a uniform VLT SINFONI data set of nine targets, we have developed an
empirical grid of J,H,K spectra of the atmospheres of objects estimated to have
very low substellar masses of \sim5-20 MJup and young ages of \sim1-50 Myr.
Most of the targets are companions, objects which are especially valuable for
comparison with atmosphere and evolutionary models, as they present rare cases
in which the age is accurately known from the primary. Based on the sample
youth, all objects are expected to ha...
astroph.py v0.91ijc based on the original astroph.py. Updated 2012/01/26 12:00:41