Discovery of the infrared counterpart of CXOU J174437.3-323222 in the field of IGR J17448-3232: a blazar candidate viewed through the Galactic Centre?

We present our near-infrared ESO-NTT K_S band observations of the field of IGR J17448-3232 which show no extended emission consistent with the supernova remnant (SNR), but in which we identify a new counterpart, also visible in Spitzer images up to 24 μm, at the position of the X-ray point source, CXOU J174437.3-323222. Multiwavelength spectral modelling shows that the data are consistent with a reddened and absorbed single power law over 5 orders of magnitude in frequency. This implies non-thermal, possibly synchrotron emission that renders the previous identification of this source as a possible pulsar, and its association to the SNR, unlikely; we instead propose that the emission may be due to a blazar viewed through the plane of the Galaxy. Based on observations collected at the European Organization for Astronomical Research in the Southern hemisphere, Chile, under ESO programme 084.D-0535 (P.I. Chaty).