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?

P. A. Curran (1) , S. Chaty (1) , J. A. Zurita Heras (2) , J. A. Tomsick , T. J. Maccarone

1 AIM (UMR7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
2 APC (UMR_7164) - AstroParticule et Cosmologie

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).

Keywords: radiation mechanisms: non-thermal; infrared: general; X-rays: individual: CXOU J174437.3-323222; X-rays: individual: IGR J17448-3232

Domains: Sciences of the Universe [physics]; Astrophysics [astro-ph]

P. A. Curran, S. Chaty, J. A. Zurita Heras, J. A. Tomsick, T. J. Maccarone. 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?. Monthly Notices of the Royal Astronomical Society: Letters, 2011, 417, pp.L26-L30. ⟨10.1111/j.1745-3933.2011.01113.x⟩. ⟨insu-03622599⟩