The transient ultraluminous X-ray source, ULX-4, in M51


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Allak S., AKYÜZ A., AKKAYA ORALHAN İ., Avdan S., AKSAKER N., Vinokurov A., ...Daha Fazla

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, cilt.510, sa.3, ss.4355-4369, 2022 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 510 Sayı: 3
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1093/mnras/stab3693
  • 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.4355-4369
  • Anahtar Kelimeler: galaxies: individual: M51, X-rays: binaries, X-rays: general, QUASI-PERIODIC OSCILLATIONS, NGC 5408 X-1, BLACK-HOLE, OPTICAL COUNTERPARTS, ORBITAL PERIOD, TIME LAGS, MASS, STAR, DISCOVERY, PULSAR
  • Çukurova Üniversitesi Adresli: Evet

Özet

We present the results of a temporal and spectral analysis of the transient source ULX-4 in the galaxy M51. The data used were drawn from Chandra, XMM-Newton, and Swift-XRT archives, spanning the years 2000-2019.. The X-ray flux of the source is seen to vary by two orders of magnitudes within a month but a short-term variability was not observed over the time intervals of 100-2000 s in the 0.3-10 keV energy band. We find some evidence for the existence of bi-modality feature in the flux distribution of ULX-4. We identified two optical sources as possible counterparts within an error radius of 0.'' 18 at 95 per cent confidence level for ULX-4 based on the archival Hubble Space Telescope (HST)/ACS and HST/WFC3 data. Blackbody fits of the spectral energy distributions (SEDs) indicate the spectral type to be B-type stars. One of these counterparts exhibits a low-amplitude optical periodicity of 264 +/- 37 d in the F606W filter; if we assume this apparent periodicity is associated with the orbital motion of the donor, then it is more likely that the donor is a red supergiant satisfying the long periodicity and accretion via Roche lobe overflow. Consequently, the SED would then have to be interpreted as a superposition of emissions from a cold donor and a hot flow component, most likely from an accretion disc. If, on the other hand, the periodicity is superorbital in nature i.e. due to possible interactions of the compact object with a circumstellar disc, the donor could then be a Be/X star hosting a neutron star.