X-ray polarimetry and spectroscopy of the neutron star low-mass X-ray binary GX 9+9: An in-depth study with IXPE and NuSTAR

F. Ursini; R. Farinelli; A. Gnarini; J. Poutanen; S. Bianchi; F. Capitanio; A. Di Marco; S. Fabiani; F. La Monaca; C. Malacaria; G. Matt; R. Mikušincová; M. Cocchi; P. Kaaret; J. J.E. Kajava; M. Pilia; W. Zhang; I. Agudo; L. A. Antonelli; M. Bachetti; L. Baldini; W. H. Baumgartner; R. Bellazzini; S. D. Bongiorno; R. Bonino; A. Brez; N. Bucciantini; S. Castellano; E. Cavazzuti; C. T. Chen; S. Ciprini; E. Costa; A. De Rosa; E. Del Monte; L. Di Gesu; N. Di Lalla; I. Donnarumma; V. Doroshenko; M. Dovčiak; S. R. Ehlert; T. Enoto; Y. Evangelista; R. Ferrazzoli; J. A. Garcia; S. Gunji; K. Hayashida; J. Heyl; W. Iwakiri; S. G. Jorstad; V. Karas; F. Kislat; T. Kitaguchi; J. J. Kolodziejczak; H. Krawczynski; L. Latronico; I. Liodakis; S. Maldera; A. Manfreda; F. Marin; A. Marinucci; A. P. Marscher; H. L. Marshall; F. Massaro; I. Mitsuishi; T. Mizuno; F. Muleri; M. Negro; C. Y. Ng; S. L. O'Dell; N. Omodei; C. Oppedisano; A. Papitto; G. G. Pavlov; A. L. Peirson; M. Perri; M. Pesce-Rollins; P. O. Petrucci; M. Pilia; A. Posenti; S. Puccetti; B. D. Ramsey; J. Rankin; A. Ratheesh; O. J. Roberts; R. W. Romani; C. Sgrò; P. Slane; P. Soffitta; G. Spandre; D. A. Swartz; T. Tamagawa; F. Tavecchio; R. Taverna; Y. Tawara; A. F. Tennant; N. E. Thomas; F. Tombesi; A. Trois; S. S. Tsygankov; R. Turolla; J. Vink; M. C. Weisskopf; K. Wu; F. Xie; S. Zane

doi:10.1051/0004-6361/202346541

X-ray polarimetry and spectroscopy of the neutron star low-mass X-ray binary GX 9+9: An in-depth study with IXPE and NuSTAR

F. Ursini
, R. Farinelli
, A. Gnarini
, J. Poutanen
, S. Bianchi
, F. Capitanio
, A. Di Marco
, S. Fabiani
, F. La Monaca
, C. Malacaria
, G. Matt
, R. Mikušincová
, M. Cocchi
, P. Kaaret
, J. J.E. Kajava
, M. Pilia
, W. Zhang
, I. Agudo
, L. A. Antonelli
, M. Bachetti

L. Baldini, W. H. Baumgartner, R. Bellazzini, S. D. Bongiorno, R. Bonino, A. Brez, N. Bucciantini, S. Castellano, E. Cavazzuti, C. T. Chen, S. Ciprini, E. Costa, A. De Rosa, E. Del Monte, L. Di Gesu, N. Di Lalla, I. Donnarumma, V. Doroshenko, M. Dovčiak, S. R. Ehlert, T. Enoto, Y. Evangelista, R. Ferrazzoli, J. A. Garcia, S. Gunji, K. Hayashida, J. Heyl, W. Iwakiri, S. G. Jorstad, V. Karas, F. Kislat, T. Kitaguchi, J. J. Kolodziejczak, H. Krawczynski, L. Latronico, I. Liodakis, S. Maldera, A. Manfreda, F. Marin, A. Marinucci, A. P. Marscher, H. L. Marshall, F. Massaro, I. Mitsuishi, T. Mizuno, F. Muleri, M. Negro, C. Y. Ng, S. L. O'Dell, N. Omodei, C. Oppedisano, A. Papitto, G. G. Pavlov, A. L. Peirson, M. Perri, M. Pesce-Rollins, P. O. Petrucci, M. Pilia, A. Posenti, S. Puccetti, B. D. Ramsey, J. Rankin, A. Ratheesh, O. J. Roberts, R. W. Romani, C. Sgrò, P. Slane, P. Soffitta, G. Spandre, D. A. Swartz, T. Tamagawa, F. Tavecchio, R. Taverna, Y. Tawara, A. F. Tennant, N. E. Thomas, F. Tombesi, A. Trois, S. S. Tsygankov, R. Turolla, J. Vink, M. C. Weisskopf, K. Wu, F. Xie, S. Zane

Research output: Contribution to journal › Article › peer-review

36 Scopus citations

Abstract

We report on a comprehensive analysis of simultaneous X-ray polarimetric and spectral data of the bright atoll source GX 9+9 with the Imaging X-ray Polarimetry Explorer (IXPE) and NuSTAR. The source is significantly polarized in the 4- 8 keV band, with a degree of 2.2% ± 0.5% (uncertainty at the 68% confidence level). The NuSTAR broad-band spectrum clearly shows an iron line, and is well described by a model including thermal disc emission, a Comptonized component, and reflection. From a spectro-polarimetric fit, we obtain an upper limit to the polarization degree of the disc of 4% (at the 99% confidence level), while the contribution of Comptonized and reflected radiation cannot be conclusively separated. However, the polarization is consistent with resulting from a combination of Comptonization in a boundary or spreading layer, plus reflection off the disc, which significantly contributes in any realistic scenario.

Original language	English
Article number	A20
Journal	Astronomy and Astrophysics
Volume	676
DOIs	https://doi.org/10.1051/0004-6361/202346541
State	Published - Aug 1 2023

Keywords

Accretion
Accretion disks
Polarization
Stars: neutron
X-rays: binaries
X-rays: general
X-rays: individuals: GX 9+9

Access to Document

10.1051/0004-6361/202346541

Cite this

Ursini, F., Farinelli, R., Gnarini, A., Poutanen, J., Bianchi, S., Capitanio, F., Di Marco, A., Fabiani, S., La Monaca, F., Malacaria, C., Matt, G., Mikušincová, R., Cocchi, M., Kaaret, P., Kajava, J. J. E., Pilia, M., Zhang, W., Agudo, I., Antonelli, L. A., ... Zane, S. (2023). X-ray polarimetry and spectroscopy of the neutron star low-mass X-ray binary GX 9+9: An in-depth study with IXPE and NuSTAR. Astronomy and Astrophysics, 676, Article A20. https://doi.org/10.1051/0004-6361/202346541

@article{da6456cce9304c739302237ad60ffcdf,

title = "X-ray polarimetry and spectroscopy of the neutron star low-mass X-ray binary GX 9+9: An in-depth study with IXPE and NuSTAR",

abstract = "We report on a comprehensive analysis of simultaneous X-ray polarimetric and spectral data of the bright atoll source GX 9+9 with the Imaging X-ray Polarimetry Explorer (IXPE) and NuSTAR. The source is significantly polarized in the 4- 8 keV band, with a degree of 2.2\% ± 0.5\% (uncertainty at the 68\% confidence level). The NuSTAR broad-band spectrum clearly shows an iron line, and is well described by a model including thermal disc emission, a Comptonized component, and reflection. From a spectro-polarimetric fit, we obtain an upper limit to the polarization degree of the disc of 4\% (at the 99\% confidence level), while the contribution of Comptonized and reflected radiation cannot be conclusively separated. However, the polarization is consistent with resulting from a combination of Comptonization in a boundary or spreading layer, plus reflection off the disc, which significantly contributes in any realistic scenario.",

keywords = "Accretion, Accretion disks, Polarization, Stars: neutron, X-rays: binaries, X-rays: general, X-rays: individuals: GX 9+9",

author = "F. Ursini and R. Farinelli and A. Gnarini and J. Poutanen and S. Bianchi and F. Capitanio and \{Di Marco\}, A. and S. Fabiani and \{La Monaca\}, F. and C. Malacaria and G. Matt and R. Miku{\v s}incov{\'a} and M. Cocchi and P. Kaaret and Kajava, \{J. J.E.\} and M. Pilia and W. Zhang and I. Agudo and Antonelli, \{L. A.\} and M. Bachetti and L. Baldini and Baumgartner, \{W. H.\} and R. Bellazzini and Bongiorno, \{S. D.\} and R. Bonino and A. Brez and N. Bucciantini and S. Castellano and E. Cavazzuti and Chen, \{C. T.\} and S. Ciprini and E. Costa and \{De Rosa\}, A. and \{Del Monte\}, E. and \{Di Gesu\}, L. and \{Di Lalla\}, N. and I. Donnarumma and V. Doroshenko and M. Dov{\v c}iak and Ehlert, \{S. R.\} and T. Enoto and Y. Evangelista and R. Ferrazzoli and Garcia, \{J. A.\} and S. Gunji and K. Hayashida and J. Heyl and W. Iwakiri and Jorstad, \{S. G.\} and V. Karas and F. Kislat and T. Kitaguchi and Kolodziejczak, \{J. J.\} and H. Krawczynski and L. Latronico and I. Liodakis and S. Maldera and A. Manfreda and F. Marin and A. Marinucci and Marscher, \{A. P.\} and Marshall, \{H. L.\} and F. Massaro and I. Mitsuishi and T. Mizuno and F. Muleri and M. Negro and Ng, \{C. Y.\} and O'Dell, \{S. L.\} and N. Omodei and C. Oppedisano and A. Papitto and Pavlov, \{G. G.\} and Peirson, \{A. L.\} and M. Perri and M. Pesce-Rollins and Petrucci, \{P. O.\} and M. Pilia and A. Posenti and S. Puccetti and Ramsey, \{B. D.\} and J. Rankin and A. Ratheesh and Roberts, \{O. J.\} and Romani, \{R. W.\} and C. Sgr{\`o} and P. Slane and P. Soffitta and G. Spandre and Swartz, \{D. A.\} and T. Tamagawa and F. Tavecchio and R. Taverna and Y. Tawara and Tennant, \{A. F.\} and Thomas, \{N. E.\} and F. Tombesi and A. Trois and Tsygankov, \{S. S.\} and R. Turolla and J. Vink and Weisskopf, \{M. C.\} and K. Wu and F. Xie and S. Zane",

note = "Publisher Copyright: The Authors 2023.",

year = "2023",

month = aug,

day = "1",

doi = "10.1051/0004-6361/202346541",

language = "English",

volume = "676",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

}

Ursini, F, Farinelli, R, Gnarini, A, Poutanen, J, Bianchi, S, Capitanio, F, Di Marco, A, Fabiani, S, La Monaca, F, Malacaria, C, Matt, G, Mikušincová, R, Cocchi, M, Kaaret, P, Kajava, JJE, Pilia, M, Zhang, W, Agudo, I, Antonelli, LA, Bachetti, M, Baldini, L, Baumgartner, WH, Bellazzini, R, Bongiorno, SD, Bonino, R, Brez, A, Bucciantini, N, Castellano, S, Cavazzuti, E, Chen, CT, Ciprini, S, Costa, E, De Rosa, A, Del Monte, E, Di Gesu, L, Di Lalla, N, Donnarumma, I, Doroshenko, V, Dovčiak, M, Ehlert, SR, Enoto, T, Evangelista, Y, Ferrazzoli, R, Garcia, JA, Gunji, S, Hayashida, K, Heyl, J, Iwakiri, W, Jorstad, SG, Karas, V, Kislat, F, Kitaguchi, T, Kolodziejczak, JJ, Krawczynski, H, Latronico, L, Liodakis, I, Maldera, S, Manfreda, A, Marin, F, Marinucci, A, Marscher, AP, Marshall, HL, Massaro, F, Mitsuishi, I, Mizuno, T, Muleri, F, Negro, M, Ng, CY, O'Dell, SL, Omodei, N, Oppedisano, C, Papitto, A, Pavlov, GG, Peirson, AL, Perri, M, Pesce-Rollins, M, Petrucci, PO, Pilia, M, Posenti, A, Puccetti, S, Ramsey, BD, Rankin, J, Ratheesh, A, Roberts, OJ, Romani, RW, Sgrò, C, Slane, P, Soffitta, P, Spandre, G, Swartz, DA, Tamagawa, T, Tavecchio, F, Taverna, R, Tawara, Y, Tennant, AF, Thomas, NE, Tombesi, F, Trois, A, Tsygankov, SS, Turolla, R, Vink, J, Weisskopf, MC, Wu, K, Xie, F & Zane, S 2023, 'X-ray polarimetry and spectroscopy of the neutron star low-mass X-ray binary GX 9+9: An in-depth study with IXPE and NuSTAR', Astronomy and Astrophysics, vol. 676, A20. https://doi.org/10.1051/0004-6361/202346541

TY - JOUR

T1 - X-ray polarimetry and spectroscopy of the neutron star low-mass X-ray binary GX 9+9

T2 - An in-depth study with IXPE and NuSTAR

AU - Ursini, F.

AU - Farinelli, R.

AU - Gnarini, A.

AU - Poutanen, J.

AU - Bianchi, S.

AU - Capitanio, F.

AU - Di Marco, A.

AU - Fabiani, S.

AU - La Monaca, F.

AU - Malacaria, C.

AU - Matt, G.

AU - Mikušincová, R.

AU - Cocchi, M.

AU - Kaaret, P.

AU - Kajava, J. J.E.

AU - Pilia, M.

AU - Zhang, W.

AU - Agudo, I.

AU - Antonelli, L. A.

AU - Bachetti, M.

AU - Baldini, L.

AU - Baumgartner, W. H.

AU - Bellazzini, R.

AU - Bongiorno, S. D.

AU - Bonino, R.

AU - Brez, A.

AU - Bucciantini, N.

AU - Castellano, S.

AU - Cavazzuti, E.

AU - Chen, C. T.

AU - Ciprini, S.

AU - Costa, E.

AU - De Rosa, A.

AU - Del Monte, E.

AU - Di Gesu, L.

AU - Di Lalla, N.

AU - Donnarumma, I.

AU - Doroshenko, V.

AU - Dovčiak, M.

AU - Ehlert, S. R.

AU - Enoto, T.

AU - Evangelista, Y.

AU - Ferrazzoli, R.

AU - Garcia, J. A.

AU - Gunji, S.

AU - Hayashida, K.

AU - Heyl, J.

AU - Iwakiri, W.

AU - Jorstad, S. G.

AU - Karas, V.

AU - Kislat, F.

AU - Kitaguchi, T.

AU - Kolodziejczak, J. J.

AU - Krawczynski, H.

AU - Latronico, L.

AU - Liodakis, I.

AU - Maldera, S.

AU - Manfreda, A.

AU - Marin, F.

AU - Marinucci, A.

AU - Marscher, A. P.

AU - Marshall, H. L.

AU - Massaro, F.

AU - Mitsuishi, I.

AU - Mizuno, T.

AU - Muleri, F.

AU - Negro, M.

AU - Ng, C. Y.

AU - O'Dell, S. L.

AU - Omodei, N.

AU - Oppedisano, C.

AU - Papitto, A.

AU - Pavlov, G. G.

AU - Peirson, A. L.

AU - Perri, M.

AU - Pesce-Rollins, M.

AU - Petrucci, P. O.

AU - Pilia, M.

AU - Posenti, A.

AU - Puccetti, S.

AU - Ramsey, B. D.

AU - Rankin, J.

AU - Ratheesh, A.

AU - Roberts, O. J.

AU - Romani, R. W.

AU - Sgrò, C.

AU - Slane, P.

AU - Soffitta, P.

AU - Spandre, G.

AU - Swartz, D. A.

AU - Tamagawa, T.

AU - Tavecchio, F.

AU - Taverna, R.

AU - Tawara, Y.

AU - Tennant, A. F.

AU - Thomas, N. E.

AU - Tombesi, F.

AU - Trois, A.

AU - Tsygankov, S. S.

AU - Turolla, R.

AU - Vink, J.

AU - Weisskopf, M. C.

AU - Wu, K.

AU - Xie, F.

AU - Zane, S.

PY - 2023/8/1

Y1 - 2023/8/1

N2 - We report on a comprehensive analysis of simultaneous X-ray polarimetric and spectral data of the bright atoll source GX 9+9 with the Imaging X-ray Polarimetry Explorer (IXPE) and NuSTAR. The source is significantly polarized in the 4- 8 keV band, with a degree of 2.2% ± 0.5% (uncertainty at the 68% confidence level). The NuSTAR broad-band spectrum clearly shows an iron line, and is well described by a model including thermal disc emission, a Comptonized component, and reflection. From a spectro-polarimetric fit, we obtain an upper limit to the polarization degree of the disc of 4% (at the 99% confidence level), while the contribution of Comptonized and reflected radiation cannot be conclusively separated. However, the polarization is consistent with resulting from a combination of Comptonization in a boundary or spreading layer, plus reflection off the disc, which significantly contributes in any realistic scenario.

AB - We report on a comprehensive analysis of simultaneous X-ray polarimetric and spectral data of the bright atoll source GX 9+9 with the Imaging X-ray Polarimetry Explorer (IXPE) and NuSTAR. The source is significantly polarized in the 4- 8 keV band, with a degree of 2.2% ± 0.5% (uncertainty at the 68% confidence level). The NuSTAR broad-band spectrum clearly shows an iron line, and is well described by a model including thermal disc emission, a Comptonized component, and reflection. From a spectro-polarimetric fit, we obtain an upper limit to the polarization degree of the disc of 4% (at the 99% confidence level), while the contribution of Comptonized and reflected radiation cannot be conclusively separated. However, the polarization is consistent with resulting from a combination of Comptonization in a boundary or spreading layer, plus reflection off the disc, which significantly contributes in any realistic scenario.

KW - Accretion

KW - Accretion disks

KW - Polarization

KW - Stars: neutron

KW - X-rays: binaries

KW - X-rays: general

KW - X-rays: individuals: GX 9+9

UR - https://www.scopus.com/pages/publications/85169416023

U2 - 10.1051/0004-6361/202346541

DO - 10.1051/0004-6361/202346541

M3 - Article

AN - SCOPUS:85169416023

SN - 0004-6361

VL - 676

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

M1 - A20

ER -

X-ray polarimetry and spectroscopy of the neutron star low-mass X-ray binary GX 9+9: An in-depth study with IXPE and NuSTAR

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this