Investigating the nature of IGR J17454-2919 using X-ray and Near-Infrared observations

TL;DR

This study characterizes IGR J17454-2919 using X-ray and near-infrared data, revealing its spectral properties, precise position, and potential nature, contributing to understanding its classification as a transient X-ray source.

Contribution

First detailed multi-wavelength analysis of IGR J17454-2919, providing accurate localization and spectral characterization to infer its nature.

Findings

X-ray spectra fit absorbed power-law with no high-energy cutoff.

Precise X-ray position matches NIR source 2MASS J17452768-2919534.

Flux measurements indicate a persistent high-energy emission.

Abstract

IGR J17454-2919 is a hard X-ray transient discovered by INTEGRAL on 2014 September 27. We report on our 20ks Chandra observation of the source, performed about five weeks after the discovery, as well as on INTEGRAL and Swift monitoring long-term observations. X-ray broad-band spectra of the source are compatible with an absorbed power-law, $\Gamma\sim$1.6-1.8, ${\rm N_H}\sim$(10-12)$\times 10^{22}\,{\rm cm}^{-2}$, with no trace of a cut-off in the data up to about 100keV, and with an average absorbed 0.5-100keV flux of about (7.1-9.7)${\times 10^{-10}~erg~cm^{-2}~s^{-1}}$. With Chandra, we determine the most accurate X-ray position of IGR J17454-2919, $\alpha_{J2000}$=17$^{h}$ 45$^{m}$ 27$^{s}$.69, $\delta_{J2000}$= $-$29$^{\circ}$ 19$^{\prime}$ 53$^{\prime \prime}$.8 (90% uncertainty of 0$^{\prime\prime}$.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.