A new, clean catalogue of extragalactic non-nuclear X-ray sources in nearby galaxies
A new, clean catalogue of extragalactic non-nuclear X-ray sources in nearby galaxies
 
  We have created a new, clean catalogue of extragalactic non-nuclear X-ray sources by correlating the 3XMM-DR4 data release of the XMM-Newton Serendipitous Source Catalogue with the Third Reference Catalogue of Bright Galaxies and the Catalogue of Neighbouring Galaxies, using an improved version of the method presented in Walton et al. Our catalogue contains 1314 sources, of which 384 are candidate ultraluminous X-ray sources (ULXs). The resulting catalogue improves upon previous catalogues in its handling of spurious detections by taking into account XMM-Newton quality flags. We estimate the contamination of ULXs by background sources to be 24 per cent. We define a 'complete' subsample as those ULXs in galaxies for which the sensitivity limit is below 10 39 erg s -1 and use it to examine the hardness ratio properties between ULX and non-ULX sources, and ULXs in different classes of host galaxy. We find that ULXs have a similar hardness ratio distribution to lower luminosity sources, consistent with previous studies. We also find that ULXs in spiral and elliptical host galaxies have similar distributions to each other independent of host galaxy morphology, however, our results do support previous indications that the population of ULXs is more luminous in star-forming host galaxies than in non-star-forming galaxies. Our catalogue contains further interesting subpopulations for future study, including Eddington Threshold sources and highly variable ULXs. We also examine the highest luminosity (L X > 5 × 10 40 erg s -1) ULXs in our catalogue in search of intermediate-mass black hole candidates, and find nine new possible candidates.
black hole physics, catalogues, X-rays: binaries, X-rays: general
  
  
  5554-5573
  
    
      Earnshaw, H. P.
      
        5fd81de0-79fa-4e5a-9297-5812a8f6787e
      
     
  
    
      Roberts, T. P.
      
        c4f83289-5e07-43c8-9c3e-2a4b46c73c05
      
     
  
    
      Middleton, M. J.
      
        f91b89d9-fd2e-42ec-aa99-1249f08a52ad
      
     
  
    
      Walton, D. J.
      
        3cf6ea78-7dd5-4765-8c09-ba2af76f11e7
      
     
  
    
      Mateos, S.
      
        6e94d6d1-3e8f-4392-bafa-bc8c3ced3da7
      
     
  
  
   
  
  
    
    
  
    
    
  
    
      11 March 2019
    
    
  
  
    
      Earnshaw, H. P.
      
        5fd81de0-79fa-4e5a-9297-5812a8f6787e
      
     
  
    
      Roberts, T. P.
      
        c4f83289-5e07-43c8-9c3e-2a4b46c73c05
      
     
  
    
      Middleton, M. J.
      
        f91b89d9-fd2e-42ec-aa99-1249f08a52ad
      
     
  
    
      Walton, D. J.
      
        3cf6ea78-7dd5-4765-8c09-ba2af76f11e7
      
     
  
    
      Mateos, S.
      
        6e94d6d1-3e8f-4392-bafa-bc8c3ced3da7
      
     
  
       
    
 
  
    
      
  
  
  
  
  
  
    Earnshaw, H. P., Roberts, T. P., Middleton, M. J., Walton, D. J. and Mateos, S.
  
  
  
  
   
    (2019)
  
  
    
    A new, clean catalogue of extragalactic non-nuclear X-ray sources in nearby galaxies.
  
  
  
  
    Monthly Notices of the Royal Astronomical Society, 483 (4), .
  
   (doi:10.1093/mnras/sty3403). 
  
  
   
  
  
  
  
  
   
  
    
    
      
        
          Abstract
          We have created a new, clean catalogue of extragalactic non-nuclear X-ray sources by correlating the 3XMM-DR4 data release of the XMM-Newton Serendipitous Source Catalogue with the Third Reference Catalogue of Bright Galaxies and the Catalogue of Neighbouring Galaxies, using an improved version of the method presented in Walton et al. Our catalogue contains 1314 sources, of which 384 are candidate ultraluminous X-ray sources (ULXs). The resulting catalogue improves upon previous catalogues in its handling of spurious detections by taking into account XMM-Newton quality flags. We estimate the contamination of ULXs by background sources to be 24 per cent. We define a 'complete' subsample as those ULXs in galaxies for which the sensitivity limit is below 10 39 erg s -1 and use it to examine the hardness ratio properties between ULX and non-ULX sources, and ULXs in different classes of host galaxy. We find that ULXs have a similar hardness ratio distribution to lower luminosity sources, consistent with previous studies. We also find that ULXs in spiral and elliptical host galaxies have similar distributions to each other independent of host galaxy morphology, however, our results do support previous indications that the population of ULXs is more luminous in star-forming host galaxies than in non-star-forming galaxies. Our catalogue contains further interesting subpopulations for future study, including Eddington Threshold sources and highly variable ULXs. We also examine the highest luminosity (L X > 5 × 10 40 erg s -1) ULXs in our catalogue in search of intermediate-mass black hole candidates, and find nine new possible candidates.
         
      
      
        
          
            
  
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 sty3403
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      Accepted/In Press date: 10 December 2018
 
    
      e-pub ahead of print date: 22 December 2018
 
    
      Published date: 11 March 2019
 
    
  
  
    
  
    
     
        Additional Information:
        This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2018 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
      
    
  
    
  
    
  
    
  
    
     
        Keywords:
        black hole physics, catalogues, X-rays: binaries, X-rays: general
      
    
  
    
  
    
  
  
  
    
  
  
        Identifiers
        Local EPrints ID: 429019
        URI: http://eprints.soton.ac.uk/id/eprint/429019
        
          
        
        
        
          ISSN: 1365-2966
        
        
          PURE UUID: ffae5cbe-4f56-43f4-8d3b-dad61f75f4e5
        
  
    
        
          
        
    
        
          
        
    
        
          
            
          
        
    
        
          
        
    
        
          
        
    
  
  Catalogue record
  Date deposited: 19 Mar 2019 17:30
  Last modified: 09 Apr 2025 18:27
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      Contributors
      
          
          Author:
          
            
            
              H. P. Earnshaw
            
          
        
      
          
          Author:
          
            
            
              T. P. Roberts
            
          
        
      
        
      
          
          Author:
          
            
            
              D. J. Walton
            
          
        
      
          
          Author:
          
            
            
              S. Mateos
            
          
        
      
      
      
    
  
   
  
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