The immediate neighborhood of Sgr A^* shows a modest amount of activity when examined closely, but displays nothing that would herald the presence of a supermassive black hole, except for a localized X-ray source. Sgr A^* is not coincident with the plasma structures that constitute Sgr A West, although it lies at the end of a string of tiny, thermally emitting blobs which may have resulted from gas dynamics in the presence of a black hole (sources ϵ, ζ, and η in Yusef  Zadeh et al 1990). Wardle and Yusef-Zadeh (1992) and Melia et al (1996) have suggested that these blobs were formed when the collective winds from the emission-line stars closest to Sgr A^* (the stars constituting the IRS16 complex), which are all displaced to the East of it, pass by the black hole and are gravitationally concentrated downstream into the observed blobs. The fact that these are a series of blobs rather than a continuous stream can presumably be attributed in this scenario to a thermal instability in the compressed flow. Kinematical studies of the plasma blobs, including both proper motions and radial velocities, will ultimately enable this hypothesis to be tested. In any case, understanding these winds is extremely important because this is likely to be the source of matter accreted onto the black hole.

The region immediately around Sgr A^* in projection also shows up as faint, extended, mid-infrared emission (Stolovy et al 1996; Morris et al 2001 and in preparation), although it cannot be associated directly with the black hole because such emission can be found over much of the region, probably as a result of thermal emission from warm dust in the Sgr A West complex. In fact, this lumpy, extended mid-infrared emission will make it difficult to measure the flux of Sgr A^* at these crucial wavelengths above the synchrotron cut-off.

X-ray emission from Sgr A^* has recently been measured with the CXO by Baganoff et al (2002). The steady-state source is relatively dim, with a 0.5-10 keV luminosity of 4 × 10³³ erg s⁻¹, and appears to be extended by about 1 arcsec, or ∼0.04 pc. This persistent flux (constant over at least a few years) may be attributable to emission from the outermost parts of the accretion flow. During an observation with the CXO in 2000, Sgr A^* underwent a few-hour flare, increasing its X-ray flux by a factor of about 50 relative to the quiescent value (Baganoff et al 2001). The short timescale (∼20 min) of the substructure of this flare dictates that it must have come from a region less than about 20 Schwarzschild radii in size. The X-rays can therefore allow us to probe the environment of the black hole all the way in to near the event horizon. The theoretical interpretation of the flare emission is discussed by Markoff et al (2001). Ongoing simultaneous observations at a variety of wavelengths should really help constrain models for the events or instabilities which produced the X-rays.