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?

TL;DR

This study identifies an infrared counterpart to an X-ray source, suggesting it is a blazar seen through the Galactic plane, based on multi-wavelength spectral analysis indicating non-thermal emission.

Contribution

The paper presents the discovery of an infrared counterpart to CXOU J174437.3-323222 and proposes it as a blazar candidate, challenging previous pulsar association hypotheses.

Findings

Infrared counterpart detected in Ks band and Spitzer images.

Spectral modeling indicates a reddened, absorbed power law over five orders of magnitude.

Data supports a non-thermal emission origin, likely a blazar.

Abstract

We present our near infrared ESO-NTT Ks band observations of the field of IGR J17448-3232 which show no extended emission consistent with the SNR but in which we identify a new counterpart, also visible in Spitzer images up to 24 {\mu}m, at the position of the X-ray point source, CXOUJ174437.3-323222. Multi-wavelength spectral modelling shows that the data are consistent with a reddened and absorbed single power law over five 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.