INVESTIGATING THE NATURE OF IGR J17454–2919 USING X-RAY AND NEAR-INFRARED OBSERVATIONS

Abstract

IGR J17454−2919 is a hard X-ray transient discovered by INTEGRAL on 2014 September 27. We report on our 20 ks Chandra observation of the source, performed about five weeks after the discovery, as well as on INTEGRAL and Swift long-term monitoring observations. X-ray broad-band spectra of the source are compatible with an absorbed power law, Γ ~ 1.6–1.8, N[subscript H] ~ (10–12) X 10[superscript 22] cm[superscript -2], with no trace of a cut-off in the data up to about 100 keV, and with an average absorbed 0.5–100 keV flux of about (7.1–9.7) X 10[superscript -10] erg cm[superscript -2] s[superscript -1]. With Chandra, we determine the most accurate X-ray position of IGR J17454−2919, α[subscript J2000] = 17[superscript h]45[superscript m]27[s over .]69, δ[subscript J2000] = −29°19' 53[" over .]8 (90% uncertainty of 0[" over .]6), consistent with the NIR source 2MASS J17452768–2919534. We also include NIR investigations from our observations of the source field on 2014 October 6 with GROND. With the multi-wavelength information at hand, we discuss the possible nature of IGR J17454−2919.