3xmm j181923.7$-$170616: an x-ray binary with a 408s pulsar

Abstract

We carry out a dedicated study of 3XMM J181923.7$-$170616\ with an approximate pulsation period of 400~s using the XMM-Newton and Swift observations spanning across nine years. We have refined the period of the source to 407.904(7) s (at epoch MJD 57142) and determined a period derivative limit of $\dot{P}\le 5.9\pm 5.4\times 10^{-9}s{s}^{-1}$ ($1\sigma$). The source radiates hard, persistent X-ray emission during the observation epochs, which is best described by an absorbed \powerlaw\ model ($\Gamma \sim 0.2$--0.8) plus faint Fe lines at 6.4 keV and 6.7 keV. The X-ray flux revealed a variation within a factor of 2, along with a spectral hardening as the flux increased. The pulse shape is sinusoid-like and the spectral properties of different phases do not present significant variation. The absorption N${}_H$ $\sim 1.3\times 10^{22}c{m}^{-2}$ is similar to the total Galactic hydrogen column density along the direction, indicating that it is a distant source. A search for the counterpart in optical and near-infrared surveys reveals a low mass K-type giant, while the existence of a Galactic OB supergiant is excluded. A symbiotic X-ray binary is the favored nature of 3XMM J181923.7$-$170616 and can essentially explain the low luminosity of $2.78\times 10^{34}{d}_{10}^{2}erg{s}^{-1}$, slow pulsation, hard X-ray spectrum, and possible K3~III companion. An alternative explanation of the source is a persistent Be/X-ray binary with a companion star no earlier than B3-type.

arXiv comment15 pages, 7 figures, Published in the Astrophysical Journal

References in corpus (26)

• The chemical composition of the Sun
• The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
• The VizieR database of Astronomical Catalogues
• TEMPO2, a new pulsar timing package. I: Overview
• Calibration of X-ray absorption in our Galaxy
• The McGill Magnetar Catalog
• Electrodynamics of Magnetars: Implications for the Persistent X-ray Emission and Spindown of the Soft Gamma Repeaters and Anomalous X-ray Pulsars
• Tempo2, a new pulsar timing package. II: The timing model and precision estimates
• Be/X-ray binaries
• Unifying the observational diversity of isolated neutron stars via magneto-thermal evolution models
• The XMM-Newton serendipitous survey. VII. The third XMM-Newton serendipitous source catalogue
• The VST Photometric Halpha Survey of the Southern Galactic Plane and Bulge (VPHAS+)
• Analysis of the Quiescent Low-Mass X-ray Binary Population in Galactic Globular Clusters
• 1SXPS: A deep Swift X-ray Telescope point source catalog with light curves and spectra
• Chandra observation of the fast X-ray transient IGR J17544-2619: evidence for a neutron star?
• Two Types of X-ray Spectra in Cataclysmic Variables
• A long-period, violently-variable X-ray source in a young SNR
• Probing X-ray Absorption and Optical Extinction in the Interstellar Medium Using Chandra Observations of Supernova Remnants
• The XMM-Newton/Chandra monitoring campaign of the Galactic center region: Description of the program and preliminary results
• Discovery of two new persistent Be/X-ray pulsar systems
• Magnetar outbursts: an observational review
• Low-level accretion in neutron-star X-ray binaries
• Characterization of new hard X-ray Cataclysmic Variables
• Population Synthesis for Symbiotic X-ray Binaries
• Spectral and Timing Nature of the Symbiotic X-ray Binary 4U 1954+319: The Slowest Rotating Neutron Star in an X-ray Binary System
• Sample of Cataclysmic Variables from 400d X-ray Survey

Cited by in corpus (5)

• A new radio census of neutron star X-ray binaries
• Wind-accreting Symbiotic X-ray Binaries
• Low-Mass X-ray Binaries
• The Galactic LMXB Population and the Galactic Centre Region
• Study of the X-ray Pulsar IGR J21343+4738 based on NuSTAR, Swift, and SRG data