Soft X-ray emission lines in the X-ray binary Swift J1858.6-0814 observed with XMM-Newton Reflection Grating Spectrometer: disc atmosphere or wind?

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Buisson D. J. K., Altamirano D., Trigo M. D., Mendez M., Armas Padilla M., Segura N. C., ...Daha Fazla

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, cilt.498, sa.1, ss.68-76, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 498 Sayı: 1
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1093/mnras/staa2258
  • Dergi Adı: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Applied Science & Technology Source, Communication Abstracts, INSPEC, Metadex, zbMATH, DIALNET, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.68-76
  • Atatürk Üniversitesi Adresli: Evet

Özet

We find soft X-ray emission lines from the X-ray binary Swift J1858.6-0814 in data from XMM-Newton Reflection Grating Spectrometer (RGS): NVII, OVII, and OVIII, as well as notable residuals short of a detection at Ne IX and other higher ionization transitions. These could be associated with the disc atmosphere, as in accretion disc corona sources, or with a wind, as has been detected in Swift J1858.6-0814 in emission lines at optical wavelengths. Indeed, the NVII line is redshifted, consistent with being the emitting component of a P-Cygni profile. We find that the emitting plasma has an ionization parameter log (xi) = 1.35 +/- 0.2 and a density n > 1.5 x 10(11) cm(-3). From this, we infer that the emitting plasma must be within 10(13) cm of the ionizing source, similar to 5 x 10(7) r(g) for a 1.4 M-circle dot neutron star, and from the line width that it is at least 10(4) r(g) away [2 x 10(9)(M/1.4M(circle dot)) cm]. We compare this with known classes of emission-line regions in other X-ray binaries and active galactic nuclei.