X-ray spectro-polarimetric characterization of GX 340+0 in the horizontal branch: a highly inclined source?

Abstract

We report the first detection of X-ray polarization in the horizontal branch for GX 340+0 as obtained by Imaging X-ray Polarimetry Explorer (IXPE). A polarization degree of 4.3%$\pm$0.3% is obtained. This value is in agreement with the previous polarization measurements of Z-sources in the horizontal branch. Spectro-polarimetric analysis, performed using a broad-band spectral model obtained by NICER and NuSTAR quasi-simultaneous observations, allowed us to constrain the polarization for the soft and hard spectral components typical to these sources. The polarization angle for the two components differs by $\sim 40°$. This result could be explained by a misalignment of the NS rotations axis with respect to the accretion disk axis. We provide a comparison of the results with polarization expected in different models. Theoretical expectations for the polarization of the disk and the Comptonization components favor an orbital inclination for GX 340+0 higher than 60°, as expected for Cyg-like sources, in contrast with results we report for the reflection component using broad-band spectrum.

arXiv commentA&A 691, A253 (2024)

References in corpus (47)

• On the Absorption of X-rays in the Interstellar Medium
• The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission
• The MAXI Mission on the ISS: Science and Instruments for Monitoring All Sky X-Ray Images
• Jets in neutron star X-ray binaries: a comparison with black holes
• Stingray: A Modern Python Library For Spectral Timing
• ixpeobssim: a Simulation and Analysis Framework for the Imaging X-ray Polarimetry Explorer
• Analyzing the Data from X-ray Polarimeters with Stokes Parameters
• Boundary layer, accretion disk and X-ray variability in luminous LMXBs
• Accretion Disk Boundary Layers Around Neutron Stars: X-ray Production in Low-Mass X-ray Binaries
• Relativistic Lines and Reflection from the Inner Accretion Disks Around Neutron Stars
• Relativistic iron emission lines in neutron star low-mass X-ray binaries as probes of neutron star radii
• Sco X-1: The Evolution and Nature of the Twin Compact Radio Lobes
• The radio luminosity of persistent X-ray binaries
• Design, Construction, and Test of the Gas Pixel Detectors for the IXPE Mission
• Handling Background in IXPE polarimetric data
• Spectra of the spreading layers on the neutron star surface and constraints on the neutron star equation of state
• A weighted analysis to improve the X-ray polarization sensitivity of IXPE
• Boundary layer emission and Z-track in the color-color diagram of luminous LMXBs
• Sco X-1: Energy Transfer from the Core to the Radio Lobes
• Detection of Reflection Features in the Neutron Star Low-Mass X-ray Binary Serpens X-1 with NICER
• Relativistic X-ray Reflection Models for Accreting Neutron Stars
• Polarized X-rays from windy accretion in Cygnus X-1
• GX 17+2: X-ray spectral and timing behaviour of a bursting Z source
• Discovery of kilohertz quasi-periodic oscillations in the Z source GX 340+0
• Spectral Investigations of the nature of the Sco X-1 like sources
• Accretion geometry of the neutron star low mass X-ray binary Cyg X-2 from X-ray polarization measurements
• Disk reflection signatures in the spectrum of the bright Z-source GX 340+0
• Polarization of X-ray emission from the Sgr B2 cloud
• Discovery of strongly variable X-ray polarization in the neutron star low-mass X-ray binary transient XTE J1701$-$462
• Radius Constraints from Reflection Modeling of Cygnus X-2 with NuSTAR and NICER
• 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
• On the spreading layer emission in luminous accreting neutron stars
• Highly Significant Detection of X-Ray Polarization from the Brightest Accreting Neutron Star Sco X-1
• Analytical techniques for polarimetric imaging of accretion flows in Schwarzschild metric
• First detection of X-ray polarization from the accreting neutron star 4U 1820-303
• X-ray polarisation properties of thermal-radiative disc winds in binary systems
• Stability of the photon indices in Z-source GX 340+0 for spectral states
• X-Ray Polarized View on the Accretion Geometry in the X-Ray Binary Circinus X-1
• A connection between accretion states and the formation of ultra-relativistic outflows in a neutron star X-ray binary
• An Ultra-Fast X-ray Disk Wind in the Neutron Star Binary GX 340+0
• Radio and X-ray observations of jet ejection in Cygnus X-2
• Discovery of a strong rotation of the X-ray polarization angle in the galactic burster GX 13+1
• On the illumination of neutron star accretion discs
• New polarimetric study of the galactic X-ray burster GX 13+1
• On the disc reflection spectroscopy of NS LMXB Serpens~X-1: analysis of a recent NuSTAR observation
• General Relativity effects and line emission
• Evidence of hard power-law spectral cutoff and disc reflection features from the X-ray transient XTE J1739-285

Cited by in corpus (6)

• Polarized radiation from the spreading layer of the weakly magnetized neutron stars
• X-ray Dips and Polarization Angle Swings in GX 13+1
• X-ray polarization of Z-type neutron star low-mass X-ray binaries -- I. Model-independent, time-resolved X-ray polarimetry
• X-ray spectropolarimetric characterization of the Z-source GX 340+0 in the normal branch
• IXPE view of the Sco-like source GX 349+2 in the normal branch
• X-ray polarization of Z-type neutron star low-mass X-ray binaries -- II. Spectropolarimetric analysis