Discovery of 172-s Pulsations from a Be/X-Ray Binary Candidate AX J0051.6–7311 in the SMC with ASCA

[摘要] TheresultsfromthreeASCAobservationsofAXJ0051.6–7311=RXJ0051.9–7311arereported.Coherentpulsationswithabarycentricperiodof172.40±0.03swerediscoveredinthethirdobservation,withanexceptionallylongexposuretimeof∼177ks.TheX-rayspectrumwasfoundtoremainunchangedthroughtheseobservations,withaphotonindexofof∼0.9.Energy-resolvedpulseprofilesinthethirdobservationrevealthatthepulsationsaremostlyduetophotonswithanenergyabove∼2keV.ArchivaldataofROSATandEinsteinObservatoryindicatethatAXJ0051.6–7311exhibitsafluxvariationhavingafactor≳20.

[学科分类] 天文学(综合)

[关键词] "pulsars: individual (AX J00516–7311)";"stars: emission-line;Be";"stars: neutron";"X-rays: stars"