SIMBAD references

J. Rodriguez, Commissariat a l'Energie Atomique (CEA), Service d'Astrophysique (SA), Saclay; J. A. Tomsick, University of California, San Diego (UCSD); L. Foschini, Instituto di Astrofisica Spaziale e Fisica Cosmica, Consiglio Nazionale delle Ricerche, Bologna; R. Walter, Integral Science Data Center, Versoix; A. Goldwurm, CEA/SA, report that an XMM-Newton target-of-opportunity observation on Mar. 4.85 UT shows a bright source at R.A. = 16h32m01s.9, Decl. = -47o52'29" (equinox 2000.0; uncertainty about 4"), with both EPIC cameras (pn and MOS) during an effective exposure of about 4500 s. The source location is consistent with that for IGR J16320-4752 and AX J1631.9-4752 reported from earlier INTEGRAL, ASCA, and Beppo-SAX observations (IAUC 8076, 8077; Sugizaki et al. 2001, Ap.J. Suppl. 134, 77). A fit to an EPIC-pn spectrum with an absorbed power law gives a photon index of 1.6 (+0.2, -0.1) and a hydrogen column density of 21.3 (+3.7, -1.4) x 10**22 cm**-2 (1-sigma uncertainties). The EPIC-pn source count rate varies between about 0.1 and 0.6 count/s during the observation. The difference in the power-law index, compared to that obtained with ASCA and Beppo-SAX, may suggest that the source undergoes spectral transitions similar to those of x-ray binaries. Longer x-ray observations and multiwavelength follow-ups are strongly encouraged.