Exposure-corrected image of the field around J1109 (labelled in white) extracted from Chandra ACIS-I data over the 0.3–8 keV energy band. The image was smoothed with a Gaussian filter with a kernel radius of 3 pixels (one ACIS pixel corresponds to 0.492 arcsec), and a logarithmic scale was adopted for better visualization. North is up, east to the right. The green ellipse has semi-major and semi-minor axes of 5.5 and 4.3 arcmin, respectively, at a position angle of 39.2° (measured from north towards east), and represents the error region (at 95% c.l.) for the position of the gamma-ray source FL8Y J1109.8−6500 obtained using 8 years of Fermi/LAT data. The magenta circle represents the error region for the position of the hard X-ray source IGR J11098−6457, obtained using 2995 ks of INTEGRAL IBIS data between 2002 and 2010 (see the 8 yr INTEGRAL IBIS soft gamma-ray survey catalogue by Bird et al. 2016 for more details). The yellow circle represents the error region for the position of the hard X-ray source 4PBC J1109.3−6501, obtained using 32.8 Ms of Swift BAT data between 2004 December and 2013 March (see the 100-month Palermo Swift BAT catalogue by Cusumano et al. 2014 for more details). The colour code on the right indicates the S/N at the different positions in the image.