In X-rays, the Galactic Centre (GC) Region appears as a complex of diffuse thermal and non-thermal X-ray emission intermixed with a population of luminous discrete sources. Here we present some new findings from the XMM-Newton GC survey, focusing particularly on Sgr A, Sgr A East, the Radio Arc region, and a newly discovered X-ray non-thermal filament.

A recent health care policy article describes the sustained growth rate (SGR) as a mythical sword of Damocles hanging over the physicians (1). The SGR formula is an approach to restrain the growth of Medicare spending on physician services. It threatens to impose a 24.4% decrease in the Medicare physician fee schedule on April 1, 2014, if not fixed. The Bipartisan Budget Act of 2013 (2), which ...

Context. The black hole at the Galactic Center, Sgr A*, is the prototype of a galactic nucleus at a very low level of activity. Its radio through submm-wave emission is known to come from a region close to the event horizon, however, the source of the emission is still under debate. A successful theory explaining the emission is based on a relativistic jet model scaled down from powerful quasar...

We report on the rapid X-ray variability of the variable star and X-ray transient GM Sgr (SAX J1819.3–2525; XTE J1819–254) as observed on 15 Sept. 1999 by the proportional counter array (PCA) on board the Rossi X-ray Timing Explorer (RXTE). During the first ∼900 seconds of the first RXTE/PCA observation, GM Sgr showed very strong Xray fluctuations by a factor of 4 on time scales of seconds to a...

Context. The Sagittarius (Sgr) dwarf spheroidal galaxy is currently being disrupted under the strain of the Milky Way. A reliable reconstruction of Sgr star formation history can only be obtained by combining core and stream information. Aims. We present radial velocities for 67 stars belonging to the Sgr Stream. For 12 stars in the sample we also present iron (Fe) and α-element (Mg, Ca) abunda...

It was suggested that some of the short-duration Gamma-Ray Bursts (GRB) are giant flares of Soft Gammaray Repeaters (SGR) in nearby galaxies. To test this hypothesis, I have constructed a sample of 47 short GRBs, detected by the Inter-Planetary Network (IPN), for which the position is constrained by at least one annulus on the celestial sphere. For each burst, I have checked whether its IPN 3-σ...

Doubling time (DT) is widely used for quantification of tumor growth rate. DT is usually determined from two volume estimations with measurement time intervals comparable with or shorter than DT. Clinical data show that the frequency distribution of DT in patients is positively skewed, with some very long DT values compared with the average DT. Growth rate can also be quantified using specific ...

The galactic center compact radio source Sgr A was discovered on 13 and 15 February 1974 by Bruce Balick and Robert L. Brown using the Green Bank 35 km radio link interferometer (Balick & Brown 1974). We discuss other observations of this source in the years 1965-1985. Early VLBI observations are described. The name Sgr A was first used by Robert L. Brown (1982) and has become the accepted name...