48,624 research outputs found
The Hawking-Page phase transitions in the extended phase space in the Gauss-Bonnet gravity
In this paper, the Hawking-Page phase transitions between the black holes and
thermal anti-de Sitter (AdS) space are studied with the Gauss-Bonnet term in
the extended phase space, in which the varying cosmological constant plays the
role of an effective thermodynamic pressure. The Gauss-Bonnet term exhibits its
effects via introducing the corrections to the black hole entropy and Gibbs
free energy. The global phase structures, especially the phase transition
temperature and the Gibbs free energy , are systematically
investigated, first for the Schwarzschild-AdS black holes and then for the
charged and rotating AdS black holes in the grand canonical ensembles, with
both analytical and numerical methods. It is found that there are terminal
points in the coexistence lines, and decreases at large electric
potentials and angular velocities and also decreases with the Gauss-Bonnet
coupling constant .Comment: 13 pages, 13 figure
A Submillimeter Burst of S255IR~SMA1 - The Rise And Fall Of Its Luminosity
Temporal photometric variations at near infrared to submillimeter wavelengths
have been found in low-mass young stellar objects. These phenomena are
generally interpreted as accretion events of star-disk systems with varying
accretion rates. There is growing evidence suggesting that similar luminosity
flaring also occurs in high-mass star/cluster-forming regions. We report in
this Letter the rise and fall of the 900 m continuum emission and the
newly found 349.1 GHz methanol maser emission in the massive star forming
region S255IR~SMA1 observed with the Submillimeter Array and the Atacama Large
Millimeter/submillimeter Array. The level of flux variation at a factor of
2 at the submillimeter band and the relatively short 2-year duration of
this burst suggest that the event is probably similar to those milder and more
frequent minor bursts seen in 3D numerical simulations.Comment: 8 pages, 4 figures, Accepted for publication in The Astrophysical
Journal Lette
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