#starmergate

[ivovynckier]

Sir Keir Starmer: "My tailor is rich."

[thewitfire]

Mystery of X7: An Elongated Object Near the Supermassive Black Hole in the Milky Way

Mystery of X7: An Elongated Object Near the Supermassive Black Hole in the Milky Way. #X7 #supermassiveblackhole #MilkyWay #astronomy #galacticcenter #KeckObservatory #SagittariusA #Gobjects #starmerger #tidalforces #space #science #research

Mystery of X7- Scientists have finally figured out the identity of an elongated object known as X7, near a supermassive black hole at the center of our galaxy. For two decades, scientists had speculated what this object might be; however, recent research suggests X7 might actually be a cloud of gas and dust created from colliding two stars. With time, X7’s shape has changed as it’s being pulled…

[arxt1]

On r-process nucleosynthesis from matter ejected in binary neutron starmergers. (arXiv:1709.09630v1 [gr-qc])

When binary systems of neutron stars merge, a very small fraction of their rest mass is ejected, either dynamically or secularly. This material is neutron-rich and its nucleosynthesis could provide the astrophysical site for the production of heavy elements in the universe, together with a kilonova signal confirming neutron-star mergers as the origin of short gamma-ray bursts. We perform full general-relativistic simulations of binary neutron-star mergers employing three different nuclear-physics EOSs, considering both equal- and unequal-mass configurations, and adopting a leakage scheme to account for neutrino radiative losses. Using a combination of techniques, we carry out an extensive and systematic study of the hydrodynamical, thermodynamical, and geometrical properties of the matter ejected dynamically, employing the WinNet nuclear-reaction network to recover the relative abundances of heavy elements produced by each configurations. Among the results obtained, three are particularly important. First, we find that both the properties of the dynamical ejecta and the nucleosynthesis yields are robust against variations of the EOS and masses, and match very well the observed chemical abundances. Second, using a conservative but robust criterion for unbound matter, we find that the amount of ejected mass is $\lesssim 10^{-3}\,M_{\odot}$, hence at least one order of magnitude smaller than what normally assumed in modelling kilonova signals. Finally, using a simplified and gray-opacity model we assess the observability of the infrared kilonova emission finding, that for all binaries the luminosity peaks around $\sim1/2$ day in the $H$-band, reaching a maximum magnitude of $-13$, and decreasing rapidly after one day. These rather low luminosities make the prospects for detecting kilonovae less promising than what assumed so far.

from gr-qc updates on arXiv.org http://ift.tt/2wWCbm6

[ivovynckier]

Undeclared gifts and a wife out of control. The "toolmaker's son" Keir Starmer has the same ethics as Jabba the Hutt a.k.a. Supreme Court Justice Clarence Thomas.