A new hard X-ray transient discovered by INTEGRAL: IGR J18179-1621

M. Tuerler; J. Chenevez; E. Bozzo; C. Ferrigno; A. Tramacere; I. Caballero; J. Rodriguez; M. Cadelle-Bel; C. Sanchez-Fernandez; M. Del Santo; M. Fiocchi; A. Tarana; P. R. den Hartog; I. Kreykenbohm; M. Kuehnel; A. Paizis; G. Puehlhofer; K. Watanabe; G. Weidenspointer; S. Zhang

A new hard X-ray transient discovered by INTEGRAL: IGR J18179-1621

M. Tuerler
, J. Chenevez
, E. Bozzo
, C. Ferrigno^*
, A. Tramacere
, I. Caballero
, J. Rodriguez
, M. Cadelle-Bel
, C. Sanchez-Fernandez
, M. Del Santo
, M. Fiocchi
, A. Tarana
, P. R. den Hartog
, I. Kreykenbohm
, M. Kuehnel
, A. Paizis
, G. Puehlhofer
, K. Watanabe
, G. Weidenspointer
, S. Zhang

^*Corresponding author for this work

Commissariat à l’énergie atomique et aux énergies alternatives
European Space Astronomy Centre
National Institute for Astrophysics
Stanford University
Erlangen Centre for Astroparticle Physics
Eberhard-Karls-Universität Tübingen
Florida Gulf Coast University
MPE
IHEP
University of Geneva

Research output: Other contribution › Net publication - Internet publication › Research

Abstract

INTEGRAL discovered a new hard X-ray transient, IGR J18179-1621, during the inner Galactic disk observations performed on 2012-02-29 from 02:20 to 15:41 UTC.

The source was detected in the IBIS/ISGRI mosaic at a significance level of 16 σ (effective exposure time 30 ks) in the 20-40 keV energy band. The corresponding flux was 16±1 mCrab (1.2±0.1 × 10-10 erg/s/cm2) (uncertainties are 68% c.l.).

The source was also detected by JEM-X at a significance level of 8 σ in the 3-10 keV energy band and 10 σ in the 10-25 keV energy band. The corresponding fluxes were 17.7±2.2 mCrab (3.0±0.4 × 10-10 erg/s/cm2) and 36.4±3.6 mCrab (4.4±0.4 × 10-10 erg/s/cm2), respectively (effective exposure time 11.9 ks). The best source position determined with the two JEM-X instruments is
RA=274.467 (18h17m52s);
DEC=-16.357 (-16d21'25")
(J2000) with an associated uncertainty of 1.5 arcmin.

The combined JEM-X and IBIS/ISGRI spectrum can be well described (χ2red/d.o.f.=0.4/12) by a cut-off power-law (Γ=-0.5 ± 0.5, Ecutoff=4.9-0.9+1.5 keV) plus a broad Gaussian absorption line (Ecentroid=20.8-1.8+1.4 keV, σ=3.0-1.3+1.8 keV, τ=10-4+5, model uncertainties at 90% c.l.). The 3-50 keV flux estimated from the spectral fit is 1.0 × 10-9 erg/s/cm2. If the absorption line is interpreted as due to cyclotron scattering, this new source would be a high mass X-ray binary pulsar with a magnetic field in the emitting region of ~1.7 × 1012 Gauss. However, the non-detection of a higher harmonic might indicate that a model with two emission components could also be used (see also the case of X-Per, Doroshenko et al., 2012, arXiv:1202.6271).

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

Original language	English
Publication date	1 Mar 2012
Publication status	Published - 1 Mar 2012

Series	The Astronomer's telegram
Number	ATel #3947

Keywords

X-ray
Black hole
Neutron star
Transient
Gamma ray
Binary

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Tuerler, M., Chenevez, J., Bozzo, E., Ferrigno, C., Tramacere, A., Caballero, I., Rodriguez, J., Cadelle-Bel, M., Sanchez-Fernandez, C., Del Santo, M., Fiocchi, M., Tarana, A., den Hartog, P. R., Kreykenbohm, I., Kuehnel, M., Paizis, A., Puehlhofer, G., Watanabe, K., Weidenspointer, G., & Zhang, S. (2012, Mar 1). A new hard X-ray transient discovered by INTEGRAL: IGR J18179-1621. The Astronomer's telegram No. ATel #3947 http://www.astronomerstelegram.org/?read=3947

@misc{62ce2eaed51245f1b2238e901ee0e423,

title = "A new hard X-ray transient discovered by INTEGRAL: IGR J18179-1621",

abstract = "INTEGRAL discovered a new hard X-ray transient, IGR J18179-1621, during the inner Galactic disk observations performed on 2012-02-29 from 02:20 to 15:41 UTC. The source was detected in the IBIS/ISGRI mosaic at a significance level of 16 σ (effective exposure time 30 ks) in the 20-40 keV energy band. The corresponding flux was 16±1 mCrab (1.2±0.1 × 10-10 erg/s/cm2) (uncertainties are 68\% c.l.). The source was also detected by JEM-X at a significance level of 8 σ in the 3-10 keV energy band and 10 σ in the 10-25 keV energy band. The corresponding fluxes were 17.7±2.2 mCrab (3.0±0.4 × 10-10 erg/s/cm2) and 36.4±3.6 mCrab (4.4±0.4 × 10-10 erg/s/cm2), respectively (effective exposure time 11.9 ks). The best source position determined with the two JEM-X instruments is RA=274.467 (18h17m52s); DEC=-16.357 (-16d21'25{"}) (J2000) with an associated uncertainty of 1.5 arcmin. The combined JEM-X and IBIS/ISGRI spectrum can be well described (χ2red/d.o.f.=0.4/12) by a cut-off power-law (Γ=-0.5 ± 0.5, Ecutoff=4.9-0.9+1.5 keV) plus a broad Gaussian absorption line (Ecentroid=20.8-1.8+1.4 keV, σ=3.0-1.3+1.8 keV, τ=10-4+5, model uncertainties at 90\% c.l.). The 3-50 keV flux estimated from the spectral fit is 1.0 × 10-9 erg/s/cm2. If the absorption line is interpreted as due to cyclotron scattering, this new source would be a high mass X-ray binary pulsar with a magnetic field in the emitting region of \textasciitilde{}1.7 × 1012 Gauss. However, the non-detection of a higher harmonic might indicate that a model with two emission components could also be used (see also the case of X-Per, Doroshenko et al., 2012, arXiv:1202.6271). Multiwavelength follow-up observations are encouraged to unveil the nature of this transient. ",

keywords = "X-ray, Black hole, Neutron star, Transient, Gamma ray, Binary",

author = "M. Tuerler and J. Chenevez and E. Bozzo and C. Ferrigno and A. Tramacere and I. Caballero and J. Rodriguez and M. Cadelle-Bel and C. Sanchez-Fernandez and \{Del Santo\}, M. and M. Fiocchi and A. Tarana and \{den Hartog\}, \{P. R.\} and I. Kreykenbohm and M. Kuehnel and A. Paizis and G. Puehlhofer and K. Watanabe and G. Weidenspointer and S. Zhang",

year = "2012",

month = mar,

day = "1",

language = "English",

series = "The Astronomer's telegram",

publisher = "R. Rutledge",

number = "ATel \#3947",

type = "Other",

}

Tuerler, M, Chenevez, J, Bozzo, E, Ferrigno, C, Tramacere, A, Caballero, I, Rodriguez, J, Cadelle-Bel, M, Sanchez-Fernandez, C, Del Santo, M, Fiocchi, M, Tarana, A, den Hartog, PR, Kreykenbohm, I, Kuehnel, M, Paizis, A, Puehlhofer, G, Watanabe, K, Weidenspointer, G & Zhang, S 2012, A new hard X-ray transient discovered by INTEGRAL: IGR J18179-1621. <http://www.astronomerstelegram.org/?read=3947>

TY - ICOMM

T1 - A new hard X-ray transient discovered by INTEGRAL: IGR J18179-1621

AU - Tuerler, M.

AU - Chenevez, J.

AU - Bozzo, E.

AU - Ferrigno, C.

AU - Tramacere, A.

AU - Caballero, I.

AU - Rodriguez, J.

AU - Cadelle-Bel, M.

AU - Sanchez-Fernandez, C.

AU - Del Santo, M.

AU - Fiocchi, M.

AU - Tarana, A.

AU - den Hartog, P. R.

AU - Kreykenbohm, I.

AU - Kuehnel, M.

AU - Paizis, A.

AU - Puehlhofer, G.

AU - Watanabe, K.

AU - Weidenspointer, G.

AU - Zhang, S.

PY - 2012/3/1

Y1 - 2012/3/1

N2 - INTEGRAL discovered a new hard X-ray transient, IGR J18179-1621, during the inner Galactic disk observations performed on 2012-02-29 from 02:20 to 15:41 UTC. The source was detected in the IBIS/ISGRI mosaic at a significance level of 16 σ (effective exposure time 30 ks) in the 20-40 keV energy band. The corresponding flux was 16±1 mCrab (1.2±0.1 × 10-10 erg/s/cm2) (uncertainties are 68% c.l.). The source was also detected by JEM-X at a significance level of 8 σ in the 3-10 keV energy band and 10 σ in the 10-25 keV energy band. The corresponding fluxes were 17.7±2.2 mCrab (3.0±0.4 × 10-10 erg/s/cm2) and 36.4±3.6 mCrab (4.4±0.4 × 10-10 erg/s/cm2), respectively (effective exposure time 11.9 ks). The best source position determined with the two JEM-X instruments is RA=274.467 (18h17m52s); DEC=-16.357 (-16d21'25") (J2000) with an associated uncertainty of 1.5 arcmin. The combined JEM-X and IBIS/ISGRI spectrum can be well described (χ2red/d.o.f.=0.4/12) by a cut-off power-law (Γ=-0.5 ± 0.5, Ecutoff=4.9-0.9+1.5 keV) plus a broad Gaussian absorption line (Ecentroid=20.8-1.8+1.4 keV, σ=3.0-1.3+1.8 keV, τ=10-4+5, model uncertainties at 90% c.l.). The 3-50 keV flux estimated from the spectral fit is 1.0 × 10-9 erg/s/cm2. If the absorption line is interpreted as due to cyclotron scattering, this new source would be a high mass X-ray binary pulsar with a magnetic field in the emitting region of ~1.7 × 1012 Gauss. However, the non-detection of a higher harmonic might indicate that a model with two emission components could also be used (see also the case of X-Per, Doroshenko et al., 2012, arXiv:1202.6271). Multiwavelength follow-up observations are encouraged to unveil the nature of this transient.

AB - INTEGRAL discovered a new hard X-ray transient, IGR J18179-1621, during the inner Galactic disk observations performed on 2012-02-29 from 02:20 to 15:41 UTC. The source was detected in the IBIS/ISGRI mosaic at a significance level of 16 σ (effective exposure time 30 ks) in the 20-40 keV energy band. The corresponding flux was 16±1 mCrab (1.2±0.1 × 10-10 erg/s/cm2) (uncertainties are 68% c.l.). The source was also detected by JEM-X at a significance level of 8 σ in the 3-10 keV energy band and 10 σ in the 10-25 keV energy band. The corresponding fluxes were 17.7±2.2 mCrab (3.0±0.4 × 10-10 erg/s/cm2) and 36.4±3.6 mCrab (4.4±0.4 × 10-10 erg/s/cm2), respectively (effective exposure time 11.9 ks). The best source position determined with the two JEM-X instruments is RA=274.467 (18h17m52s); DEC=-16.357 (-16d21'25") (J2000) with an associated uncertainty of 1.5 arcmin. The combined JEM-X and IBIS/ISGRI spectrum can be well described (χ2red/d.o.f.=0.4/12) by a cut-off power-law (Γ=-0.5 ± 0.5, Ecutoff=4.9-0.9+1.5 keV) plus a broad Gaussian absorption line (Ecentroid=20.8-1.8+1.4 keV, σ=3.0-1.3+1.8 keV, τ=10-4+5, model uncertainties at 90% c.l.). The 3-50 keV flux estimated from the spectral fit is 1.0 × 10-9 erg/s/cm2. If the absorption line is interpreted as due to cyclotron scattering, this new source would be a high mass X-ray binary pulsar with a magnetic field in the emitting region of ~1.7 × 1012 Gauss. However, the non-detection of a higher harmonic might indicate that a model with two emission components could also be used (see also the case of X-Per, Doroshenko et al., 2012, arXiv:1202.6271). Multiwavelength follow-up observations are encouraged to unveil the nature of this transient.

KW - X-ray

KW - Black hole

KW - Neutron star

KW - Transient

KW - Gamma ray

KW - Binary

M3 - Net publication - Internet publication

T3 - The Astronomer's telegram

ER -

A new hard X-ray transient discovered by INTEGRAL: IGR J18179-1621

Abstract

Keywords

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