The subject of this paper is stochastic acceleration by plasma turbulence, a process akin to
the original model proposed by Fermi. We review the relative merits of different acceleration …

No, within a broad class of scenarios. Gravitational-wave (GW) astronomy will open a new
window on compact objects such as neutron stars and black holes (BHs). It is often stated …

We present the first fully simultaneous fits to the near-infrared (NIR) and X-ray spectral slope
(and its evolution) during a very bright flare from Sgr A*, the supermassive black hole at the …

Energetic flares are observed in the Galactic supermassive black hole Sagittarius A* from
radio to X-ray wavelengths. On a few occasions, simultaneous flares have been detected in …

This paper reports measurements of Sgr A* made with NACO in L'band (3.80 μm), Ks band
(2.12 μm), and H band (1.66 μm), and with VISIR in N band (11.88 μm) at the ESO VLT, as …

In 2006 February, shortly after its launch, Swift began monitoring the center of the Milky Way
with the on board X-Ray Telescope using short 1-ks exposures performed every 1–4 days …

We have carried out Very Large Array (VLA) continuum observations to study the variability
of Sgr A* at 43 GHz (λ= 7 mm) and 22 GHz (λ= 13 mm). A low level of flare activity has been …

Although Sgr A* is known to be variable in radio, millimeter, near-IR, and X-rays, the
correlation of the variability across its spectrum has not been fully studied. Here we describe …

Context. Our Galaxy hosts at its dynamical center Sgr A*, the closest supermassive black
hole. Surprisingly, its luminosity is several orders of magnitude lower than the Eddington …

We report the first time series of broadband infrared color measurements of Sgr A*, the
variable emission source associated with the supermassive black hole at the Galactic …