2001AJ....122...21M

We present observations of the Rapid Burster (RB, also known as MXB 1730-335) using the Chandra High Energy Transmission Grating Spectrometer. The average interval between type II (accretion) bursts was about 40 s. There was one type I (thermonuclear flash) burst and about 20 minibursts that are probably type II bursts whose peak flux is 10%-40% of the average peak flux of the other type II bursts. The time-averaged spectra of the type II bursts are well fitted by a blackbody with a temperature of kT=1.6 keV, a radius of 8.9 km for a distance of 8.6 kpc, and an interstellar column density of 1.7x10²² cm^–2. No narrow emission or absorption lines were clearly detected. The 3 σ upper limits to the equivalent widths of any features are less than 10 eV in the 1.1-7.0 keV band and as small as 1.5 eV near 1.7 keV. We suggest that Comptonization destroys absorption features such as the resonance line of Fe XXVI.