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Probing the MSP prenatal stage: the optical identification of the X-ray burster EXO 1745-248 in Terzan 5

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 نشر من قبل Barbara Lanzoni
 تاريخ النشر 2015
  مجال البحث فيزياء
والبحث باللغة English
 تأليف F.R. Ferraro




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We report on the optical identification of the neutron star burster EXO 1745-248 in Terzan 5. The identification was performed by exploiting HST/ACS images acquired in Directors Discretionary Time shortly after (approximately 1 month) the Swift detection of the X-ray burst. The comparison between these images and previous archival data revealed the presence of a star that currently brightened by ~3 magnitudes, consistent with expectations during an X-ray outburst. The centroid of this object well agrees with the position, in the archival images, of a star located in the Turn-Off/Sub Giant Branch region of Terzan 5. This supports the scenario that the companion should has recently filled its Roche Lobe. Such a system represents the pre-natal stage of a millisecond pulsar, an evolutionary phase during which heavy mass accretion on the compact object occurs, thus producing X-ray outbursts and re-accelerating the neutron star.



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