Chandra Observations of M28

Abstract

We report the results of the first Chandra X-Ray Observatory observations of the globular cluster M28 (NGC 6626). We detect 46 X-ray sources of which 12 lie within one core radius of the center. We show that the apparently extended X-ray core emission seen with the ROSAT HRI is due to the superposition of multiple discrete sources for which we determine the X-ray luminosity function down to a limit of about $6\times 10(exp 30)$ erg/s$. We measure for the first time the unconfused phase-averaged X-ray spectrum of the 3.05-ms pulsar B 1821-24. We also present spectral analyses of the 5 brightest unidentified sources.