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A new hard X-ray transient discovered by INTEGRAL: IGR J17494-3030

ATel #3984; R. Boissay (ISDC, Univ. of Geneva, Switzerland), J. Chenevez (DTU Space, Denmark); E. Bozzo, C. Ferrigno (ISDC, U. of Geneva, Switzerland); V. Grinberg, J. Wilms (Dr. Karl Remeis Obs. and ECAP, Germany); I. Caballero (CEA Saclay, France); M. Cadolle-Bel (ESA/ESAC, Spain); M. Del Santo, M. Fiocchi (INAF/IAPS, Roma, Italy); L. Kuiper (SRON, NL); A. Paizis, L. Sidoli (INAF/IASF-Milano, Italy); G. Puehlhofer (IAA-Tuebingen, Germany); V. Sguera (INAF/IASF Bologna); K. Watanabe (Florida Gulf Coast Univ., USA); J. Enright, E. Graham, K. Jacob, D. Rusk (Dublin City University)
on 20 Mar 2012; 16:12 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Carlo Ferrigno (Carlo.Ferrigno@unige.ch)

Subjects: X-ray, Gamma Ray, Binary, Black Hole, Neutron Star, Transient

Referred to by ATel #: 3985, 3986, 3989, 4006, 4886

INTEGRAL discovered a new hard X-ray transient, IGR J17494-3030, during the Galactic center observations performed from 2012-03-17 07:20 to 2012-03-19 21:17 UTC (PI J. Wilms).

The source is detected in the IBIS/ISGRI mosaic at a significance level of 9 σ (on-source time 200 ks) in the 20-40 keV energy band and 6 σ in the 40-80 keV one. The corresponding fluxes are 5.9±0.6 mCrab and 6±1 mCrab (4.5±0.5 × 10-11 and 1.2±0.2 × 10-11 erg/s/cm2, uncertainties are at 68% c.l.).

The source is also detected by JEM-X at a significance level of 6 σ in the 3-10 keV energy band and 3 σ in the 10-25 keV energy band. The corresponding fluxes are 4.1±0.7 mCrab (7±1 × 10-11 erg/s/cm2) and 5.2±1.7 mCrab (4.7±1.5 × 10-11 erg/s/cm2), respectively (effective exposure time 72 ks). The best source position determined with the two JEM-X instruments is
RA= 267.35 (17h 49m 24s)
DEC= -30.50 (-30d 30' 00")
(J2000) with an associated pointing uncertainty of 1.3 arcmin (the Galactic coordinates are l= 358.23 b=-2.025).

The IBIS/ISGRI spectrum can be described (χ2red/d.o.f.=0.6/4) by a power-law (Γ=1.7 ± 1.0, uncertainty at 90% c.l.). The 20-60 keV flux estimated from the spectral fit is 7.6 × 10-11 erg/s/cm2.

Multi-wavelength follow-up observations are encouraged to unveil the nature of this transient.