1 Ocak 2022 Dergi makalesi Açık Erişim

Allak, S.; Akyuz, A.; Oralhan, I. Akkaya; Avdan, S.; Aksaker, N.; Vinokurov, A.; Soydugan, F.; Sonbas, E.; Dhuga, K. S.

Dublin Core

<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:creator>Allak, S.</dc:creator>
  <dc:creator>Akyuz, A.</dc:creator>
  <dc:creator>Oralhan, I. Akkaya</dc:creator>
  <dc:creator>Avdan, S.</dc:creator>
  <dc:creator>Aksaker, N.</dc:creator>
  <dc:creator>Vinokurov, A.</dc:creator>
  <dc:creator>Soydugan, F.</dc:creator>
  <dc:creator>Sonbas, E.</dc:creator>
  <dc:creator>Dhuga, K. S.</dc:creator>
  <dc:date>2022-01-01</dc:date>
  <dc:description>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.</dc:description>
  <dc:identifier>https://aperta.ulakbim.gov.trrecord/256679</dc:identifier>
  <dc:identifier>oai:aperta.ulakbim.gov.tr:256679</dc:identifier>
  <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
  <dc:rights>http://www.opendefinition.org/licenses/cc-by</dc:rights>
  <dc:source>MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 510(3) 4355-4369</dc:source>
  <dc:title>The transient ultraluminous X-ray source, ULX-4, in M51</dc:title>
  <dc:type>info:eu-repo/semantics/article</dc:type>
  <dc:type>publication-article</dc:type>
</oai_dc:dc>