Anticorrelation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323
Anticorrelation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323
 
  We report the evidence for the anticorrelation between pulsed fraction (PF) and luminosity of the X-ray pulsar SXP 1323, found for the first time in a luminosity range 1035-1037 erg s-1 from observations spanning 15 yr. The phenomenon of a decrease in X-ray PF when the source flux increases has been observed in our pipeline analysis of other X-ray pulsars in the Small Magellanic Cloud. It is expected that the luminosity under a certain value decreases as the PF decreases due to the propeller effect. Above the propeller region, an anticorrelation between the PF and the flux might occur either as a result of an increase in the unpulsed component of the total emission or a decrease of the pulsed component. Additional modes of accretion may also be possible, such as spherical accretion and a change in emission geometry. At higher mass accretion rates, the accretion disc could also extend closer to the neutron star surface, where a reduced inner radius leads to hotter inner disc emission. These modes of plasma accretion may affect the change in the beam configuration to fan-beam dominant emission.
Pulsars: individual: SXP 1323, X-rays: binaries
  
  
  L1-L6
  
    
      Yang, Jun
      
        47673b30-c7b5-4342-a34f-9f506c1804a3
      
     
  
    
      Zezas, Andreas
      
        b09e794a-5973-4f3d-bdb1-6a709e560df8
      
     
  
    
      Coe, Malcolm J.
      
        04dfb23b-1456-46a3-9242-5cee983471d5
      
     
  
    
      Drake, Jeremy J.
      
        8c6fab1e-a517-4a97-ad90-904e79cda61a
      
     
  
    
      Hong, Jae Sub
      
        12e1ec71-e93d-4c74-b7cd-cb27848cf094
      
     
  
    
      Laycock, Silas G.T.
      
        d4e5bb78-7038-4e42-aaf5-9fdc20f60037
      
     
  
    
      Wik, Daniel R.
      
        f4f10fac-a438-44be-8cdf-ebe76ce0c7be
      
     
  
  
   
  
  
    
    
  
    
    
  
    
      September 2018
    
    
  
  
    
      Yang, Jun
      
        47673b30-c7b5-4342-a34f-9f506c1804a3
      
     
  
    
      Zezas, Andreas
      
        b09e794a-5973-4f3d-bdb1-6a709e560df8
      
     
  
    
      Coe, Malcolm J.
      
        04dfb23b-1456-46a3-9242-5cee983471d5
      
     
  
    
      Drake, Jeremy J.
      
        8c6fab1e-a517-4a97-ad90-904e79cda61a
      
     
  
    
      Hong, Jae Sub
      
        12e1ec71-e93d-4c74-b7cd-cb27848cf094
      
     
  
    
      Laycock, Silas G.T.
      
        d4e5bb78-7038-4e42-aaf5-9fdc20f60037
      
     
  
    
      Wik, Daniel R.
      
        f4f10fac-a438-44be-8cdf-ebe76ce0c7be
      
     
  
       
    
 
  
    
      
  
  
  
  
  
  
    Yang, Jun, Zezas, Andreas, Coe, Malcolm J., Drake, Jeremy J., Hong, Jae Sub, Laycock, Silas G.T. and Wik, Daniel R.
  
  
  
  
   
    (2018)
  
  
    
    Anticorrelation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323.
  
  
  
  
    Monthly Notices of the Royal Astronomical Society: Letters, 479 (1), .
  
   (doi:10.1093/mnrasl/sly085). 
  
  
   
  
  
  
  
  
   
  
    
    
      
        
          Abstract
          We report the evidence for the anticorrelation between pulsed fraction (PF) and luminosity of the X-ray pulsar SXP 1323, found for the first time in a luminosity range 1035-1037 erg s-1 from observations spanning 15 yr. The phenomenon of a decrease in X-ray PF when the source flux increases has been observed in our pipeline analysis of other X-ray pulsars in the Small Magellanic Cloud. It is expected that the luminosity under a certain value decreases as the PF decreases due to the propeller effect. Above the propeller region, an anticorrelation between the PF and the flux might occur either as a result of an increase in the unpulsed component of the total emission or a decrease of the pulsed component. Additional modes of accretion may also be possible, such as spherical accretion and a change in emission geometry. At higher mass accretion rates, the accretion disc could also extend closer to the neutron star surface, where a reduced inner radius leads to hotter inner disc emission. These modes of plasma accretion may affect the change in the beam configuration to fan-beam dominant emission.
         
      
      
        
          
            
  
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 Anticorrelation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323
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 sly085
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  More information
  
    
      Accepted/In Press date: 8 May 2018
 
    
      e-pub ahead of print date: 14 May 2018
 
    
      Published date: September 2018
 
    
  
  
    
  
    
  
    
  
    
  
    
  
    
     
        Keywords:
        Pulsars: individual: SXP 1323, X-rays: binaries
      
    
  
    
  
    
  
  
  
    
  
  
        Identifiers
        Local EPrints ID: 425638
        URI: http://eprints.soton.ac.uk/id/eprint/425638
        
          
        
        
        
          ISSN: 1745-3925
        
        
          PURE UUID: c7f4b787-ed8a-4798-8ec5-6ff36632454e
        
  
    
        
          
        
    
        
          
        
    
        
          
            
              
            
          
        
    
        
          
        
    
        
          
        
    
        
          
        
    
        
          
        
    
  
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  Date deposited: 30 Oct 2018 17:30
  Last modified: 16 Mar 2024 02:35
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      Contributors
      
          
          Author:
          
            
            
              Jun Yang
            
          
        
      
          
          Author:
          
            
            
              Andreas Zezas
            
          
        
      
        
      
          
          Author:
          
            
            
              Jeremy J. Drake
            
          
        
      
          
          Author:
          
            
            
              Jae Sub Hong
            
          
        
      
          
          Author:
          
            
            
              Silas G.T. Laycock
            
          
        
      
          
          Author:
          
            
            
              Daniel R. Wik
            
          
        
      
      
      
    
  
   
  
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