INTEGRAL discovery of a new hard X-ray transient: IGR J17177-3656

A. Frankowski; C. Ferrigo; E. Bozzo; T. J.-L. Courvoiser; A. Tramacere; J. Chenevez; S. Brandt; J. Rodriguez; I. Caballero; S. Zhang; V. Beckmann; M. Kuehnel; L. Barragan; I. Kreykenbohm; A. Paizis; M. Fiocchi; F. Capitanio; L. Natalucci; M. Del Santo; K. Watanabe; G. Puehlhofer; P. Jonker; L. Kuiper; K. Pottschmidt; S. P. Drave; A. Malizia; V. Sguera; R.  Landi; S. Migliari; P. R. den Hartog

INTEGRAL discovery of a new hard X-ray transient: IGR J17177-3656

A. Frankowski, C. Ferrigo^*, E. Bozzo, T. J.-L. Courvoiser, A. Tramacere, J. Chenevez, S. Brandt, J. Rodriguez, I. Caballero, S. Zhang, V. Beckmann, M. Kuehnel, L. Barragan, I. Kreykenbohm, A. Paizis, M. Fiocchi, F. Capitanio, L. Natalucci, M. Del Santo, K. WatanabeG. Puehlhofer, P. Jonker, L. Kuiper, K. Pottschmidt, S. P. Drave, A. Malizia, V. Sguera, R. Landi , S. Migliari, P. R. den Hartog

^*Corresponding author for this work

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

Abstract

We report on the discovery of a new transient source, IGR J17177-3656, detected during the INTEGRAL observation performed from 2011-03-15 09:23 to 2011-03-15 22:42 UT. The source was detected by IBIS/ISGRI at a significance level of 13 and 9 standard deviations, in the 20-40 keV and 40-80 keV energy bands, respectively. The corresponding fluxes were 20+/-1 and 22+/-2 mCrab (exposure time is 24 ks). The source is also marginally detected by combining the two JEM-X units in the 10-20 keV band with a flux of 8+/-3 mCrab (total exposure 12.5 ks). It is not detected in the 3-10 keV band with a 3 sigma upper limit of 5 mCrab. The best determined source position from the IBIS/ISGRI data is at: RA = 259.414 (17:17:39) Dec = -36.938 (-36:56:17) (J2000) with a 90% confinement radius of 2.2 arcmin. The best position determined from the JEM-X monitor is RA=259.443 (17:17:46), Dec=-36.945 (-36:56:42) (J2000) with a 90% confinement radius of 1.5 arcmin, fully consistent with the ISGRI position. The IBIS/ISGRI spectrum (20-150 keV) can be well described by a power-law with photon index 1.8+/-0.3 (chi2/dof=0.5 for 8 dof). The estimated 20-100 keV flux is 3.7e-10 erg/s/cm2. We could not detect any significant variability during the observation. A subsequent INTEGRAL observation from the Galactic bulge monitoring program was performed on 2011-03-16 from 12:33 to 14:51 UT (exposure of 5.4 ks): the source flux in the 20-40 keV (40-80 keV) band was 23+/-4 mCrab (30+/-6 mCrab), suggesting an increasing luminosity trend. Previous INTEGRAL observations of the region were performed between 2011-03-13 03:21 and 2011-03-13 16:39. We derived a 5 sigma upper limit on the source flux in the 20-40 keV band of 7 mCrab, exploiting an IBIS/ISGRI effective exposure time of 8 ks. A Swift/XRT pointed observation in the region of the source was performed between 2011-01-27 08:21 and 2011-01-27 08:30 (exposure time is 548 s), no source was detected in the FOV with a 3 sigma upper limit of 1.5e-12 erg/s/cm2 in the 1-10 keV band (0.05 mCrab), assuming a power-law spectrum with photon index 1.8 and Galactic absorption (NH = 1.2e22 cm-2). We encourage multiwavelength observations to investigate the nature of the system, which has the typical characteristics of either an X-ray transient in an initial hard state or a transient highly absorbed source.

Original language	English
Publication date	16 Mar 2011
Publication status	Published - 16 Mar 2011

Series	The Astronomer's telegram
Number	ATel #3223

Keywords

Transient
Gamma Ray
X-ray

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Frankowski, A., Ferrigo, C., Bozzo, E., Courvoiser, T. J.-L., Tramacere, A., Chenevez, J., Brandt, S., Rodriguez, J., Caballero, I., Zhang, S., Beckmann, V., Kuehnel, M., Barragan, L., Kreykenbohm, I., Paizis, A., Fiocchi, M., Capitanio, F., Natalucci, L., Del Santo, M., ... den Hartog, P. R. (2011, Mar 16). INTEGRAL discovery of a new hard X-ray transient: IGR J17177-3656. The Astronomer's telegram No. ATel #3223 http://www.astronomerstelegram.org/?read=3223

@misc{56256f9934f74b0a9fed50b44f586d6c,

title = "INTEGRAL discovery of a new hard X-ray transient: IGR J17177-3656",

abstract = "We report on the discovery of a new transient source, IGR J17177-3656, detected during the INTEGRAL observation performed from 2011-03-15 09:23 to 2011-03-15 22:42 UT. The source was detected by IBIS/ISGRI at a significance level of 13 and 9 standard deviations, in the 20-40 keV and 40-80 keV energy bands, respectively. The corresponding fluxes were 20+/-1 and 22+/-2 mCrab (exposure time is 24 ks). The source is also marginally detected by combining the two JEM-X units in the 10-20 keV band with a flux of 8+/-3 mCrab (total exposure 12.5 ks). It is not detected in the 3-10 keV band with a 3 sigma upper limit of 5 mCrab. The best determined source position from the IBIS/ISGRI data is at: RA = 259.414 (17:17:39) Dec = -36.938 (-36:56:17) (J2000) with a 90% confinement radius of 2.2 arcmin. The best position determined from the JEM-X monitor is RA=259.443 (17:17:46), Dec=-36.945 (-36:56:42) (J2000) with a 90% confinement radius of 1.5 arcmin, fully consistent with the ISGRI position. The IBIS/ISGRI spectrum (20-150 keV) can be well described by a power-law with photon index 1.8+/-0.3 (chi2/dof=0.5 for 8 dof). The estimated 20-100 keV flux is 3.7e-10 erg/s/cm2. We could not detect any significant variability during the observation. A subsequent INTEGRAL observation from the Galactic bulge monitoring program was performed on 2011-03-16 from 12:33 to 14:51 UT (exposure of 5.4 ks): the source flux in the 20-40 keV (40-80 keV) band was 23+/-4 mCrab (30+/-6 mCrab), suggesting an increasing luminosity trend. Previous INTEGRAL observations of the region were performed between 2011-03-13 03:21 and 2011-03-13 16:39. We derived a 5 sigma upper limit on the source flux in the 20-40 keV band of 7 mCrab, exploiting an IBIS/ISGRI effective exposure time of 8 ks. A Swift/XRT pointed observation in the region of the source was performed between 2011-01-27 08:21 and 2011-01-27 08:30 (exposure time is 548 s), no source was detected in the FOV with a 3 sigma upper limit of 1.5e-12 erg/s/cm2 in the 1-10 keV band (0.05 mCrab), assuming a power-law spectrum with photon index 1.8 and Galactic absorption (NH = 1.2e22 cm-2). We encourage multiwavelength observations to investigate the nature of the system, which has the typical characteristics of either an X-ray transient in an initial hard state or a transient highly absorbed source.",

keywords = "Transient, Gamma Ray, X-ray",

author = "A. Frankowski and C. Ferrigo and E. Bozzo and Courvoiser, {T. J.-L.} and A. Tramacere and J. Chenevez and S. Brandt and J. Rodriguez and I. Caballero and S. Zhang and V. Beckmann and M. Kuehnel and L. Barragan and I. Kreykenbohm and A. Paizis and M. Fiocchi and F. Capitanio and L. Natalucci and {Del Santo}, M. and K. Watanabe and G. Puehlhofer and P. Jonker and L. Kuiper and K. Pottschmidt and Drave, {S. P.} and A. Malizia and V. Sguera and R. Landi and S. Migliari and {den Hartog}, {P. R.}",

year = "2011",

month = mar,

day = "16",

language = "English",

series = "The Astronomer's telegram",

publisher = "R. Rutledge",

number = "ATel #3223",

type = "Other",

}

Frankowski, A, Ferrigo, C, Bozzo, E, Courvoiser, TJ-L, Tramacere, A, Chenevez, J , Brandt, S, Rodriguez, J, Caballero, I, Zhang, S, Beckmann, V, Kuehnel, M, Barragan, L, Kreykenbohm, I, Paizis, A, Fiocchi, M, Capitanio, F, Natalucci, L, Del Santo, M, Watanabe, K, Puehlhofer, G, Jonker, P, Kuiper, L, Pottschmidt, K, Drave, SP, Malizia, A, Sguera, V, Landi , R, Migliari, S & den Hartog, PR 2011, INTEGRAL discovery of a new hard X-ray transient: IGR J17177-3656.. <http://www.astronomerstelegram.org/?read=3223>

TY - ICOMM

T1 - INTEGRAL discovery of a new hard X-ray transient: IGR J17177-3656

AU - Frankowski, A.

AU - Ferrigo, C.

AU - Bozzo, E.

AU - Courvoiser, T. J.-L.

AU - Tramacere, A.

AU - Chenevez, J.

AU - Brandt, S.

AU - Rodriguez, J.

AU - Caballero, I.

AU - Zhang, S.

AU - Beckmann, V.

AU - Kuehnel, M.

AU - Barragan, L.

AU - Kreykenbohm, I.

AU - Paizis, A.

AU - Fiocchi, M.

AU - Capitanio, F.

AU - Natalucci, L.

AU - Del Santo, M.

AU - Watanabe, K.

AU - Puehlhofer, G.

AU - Jonker, P.

AU - Kuiper, L.

AU - Pottschmidt, K.

AU - Drave, S. P.

AU - Malizia, A.

AU - Sguera, V.

AU - Landi , R.

AU - Migliari, S.

AU - den Hartog, P. R.

PY - 2011/3/16

Y1 - 2011/3/16

N2 - We report on the discovery of a new transient source, IGR J17177-3656, detected during the INTEGRAL observation performed from 2011-03-15 09:23 to 2011-03-15 22:42 UT. The source was detected by IBIS/ISGRI at a significance level of 13 and 9 standard deviations, in the 20-40 keV and 40-80 keV energy bands, respectively. The corresponding fluxes were 20+/-1 and 22+/-2 mCrab (exposure time is 24 ks). The source is also marginally detected by combining the two JEM-X units in the 10-20 keV band with a flux of 8+/-3 mCrab (total exposure 12.5 ks). It is not detected in the 3-10 keV band with a 3 sigma upper limit of 5 mCrab. The best determined source position from the IBIS/ISGRI data is at: RA = 259.414 (17:17:39) Dec = -36.938 (-36:56:17) (J2000) with a 90% confinement radius of 2.2 arcmin. The best position determined from the JEM-X monitor is RA=259.443 (17:17:46), Dec=-36.945 (-36:56:42) (J2000) with a 90% confinement radius of 1.5 arcmin, fully consistent with the ISGRI position. The IBIS/ISGRI spectrum (20-150 keV) can be well described by a power-law with photon index 1.8+/-0.3 (chi2/dof=0.5 for 8 dof). The estimated 20-100 keV flux is 3.7e-10 erg/s/cm2. We could not detect any significant variability during the observation. A subsequent INTEGRAL observation from the Galactic bulge monitoring program was performed on 2011-03-16 from 12:33 to 14:51 UT (exposure of 5.4 ks): the source flux in the 20-40 keV (40-80 keV) band was 23+/-4 mCrab (30+/-6 mCrab), suggesting an increasing luminosity trend. Previous INTEGRAL observations of the region were performed between 2011-03-13 03:21 and 2011-03-13 16:39. We derived a 5 sigma upper limit on the source flux in the 20-40 keV band of 7 mCrab, exploiting an IBIS/ISGRI effective exposure time of 8 ks. A Swift/XRT pointed observation in the region of the source was performed between 2011-01-27 08:21 and 2011-01-27 08:30 (exposure time is 548 s), no source was detected in the FOV with a 3 sigma upper limit of 1.5e-12 erg/s/cm2 in the 1-10 keV band (0.05 mCrab), assuming a power-law spectrum with photon index 1.8 and Galactic absorption (NH = 1.2e22 cm-2). We encourage multiwavelength observations to investigate the nature of the system, which has the typical characteristics of either an X-ray transient in an initial hard state or a transient highly absorbed source.

AB - We report on the discovery of a new transient source, IGR J17177-3656, detected during the INTEGRAL observation performed from 2011-03-15 09:23 to 2011-03-15 22:42 UT. The source was detected by IBIS/ISGRI at a significance level of 13 and 9 standard deviations, in the 20-40 keV and 40-80 keV energy bands, respectively. The corresponding fluxes were 20+/-1 and 22+/-2 mCrab (exposure time is 24 ks). The source is also marginally detected by combining the two JEM-X units in the 10-20 keV band with a flux of 8+/-3 mCrab (total exposure 12.5 ks). It is not detected in the 3-10 keV band with a 3 sigma upper limit of 5 mCrab. The best determined source position from the IBIS/ISGRI data is at: RA = 259.414 (17:17:39) Dec = -36.938 (-36:56:17) (J2000) with a 90% confinement radius of 2.2 arcmin. The best position determined from the JEM-X monitor is RA=259.443 (17:17:46), Dec=-36.945 (-36:56:42) (J2000) with a 90% confinement radius of 1.5 arcmin, fully consistent with the ISGRI position. The IBIS/ISGRI spectrum (20-150 keV) can be well described by a power-law with photon index 1.8+/-0.3 (chi2/dof=0.5 for 8 dof). The estimated 20-100 keV flux is 3.7e-10 erg/s/cm2. We could not detect any significant variability during the observation. A subsequent INTEGRAL observation from the Galactic bulge monitoring program was performed on 2011-03-16 from 12:33 to 14:51 UT (exposure of 5.4 ks): the source flux in the 20-40 keV (40-80 keV) band was 23+/-4 mCrab (30+/-6 mCrab), suggesting an increasing luminosity trend. Previous INTEGRAL observations of the region were performed between 2011-03-13 03:21 and 2011-03-13 16:39. We derived a 5 sigma upper limit on the source flux in the 20-40 keV band of 7 mCrab, exploiting an IBIS/ISGRI effective exposure time of 8 ks. A Swift/XRT pointed observation in the region of the source was performed between 2011-01-27 08:21 and 2011-01-27 08:30 (exposure time is 548 s), no source was detected in the FOV with a 3 sigma upper limit of 1.5e-12 erg/s/cm2 in the 1-10 keV band (0.05 mCrab), assuming a power-law spectrum with photon index 1.8 and Galactic absorption (NH = 1.2e22 cm-2). We encourage multiwavelength observations to investigate the nature of the system, which has the typical characteristics of either an X-ray transient in an initial hard state or a transient highly absorbed source.

KW - Transient

KW - Gamma Ray

KW - X-ray

M3 - Net publication - Internet publication

T3 - The Astronomer's telegram

ER -

INTEGRAL discovery of a new hard X-ray transient: IGR J17177-3656

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