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Rotation Measures for Globular Cluster Pulsars at a Unique Probe of the Galactic Magnetic Field

Anna Ho
October 12, 2017

Rotation Measures for Globular Cluster Pulsars at a Unique Probe of the Galactic Magnetic Field

as presented at galaxy coffee at the MPIA on 9 October 2014

Anna Ho

October 12, 2017
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  1. Rota%on  Measures  for  Globular  Cluster  Pulsars  as  a   Unique

     Probe  of  the  Galac%c  Magne%c  Field   Anna  Ho   Fulbright  Scholar,  MPIA   Galaxy  Coffee,  9  October  2014  
  2. Rota%on  Measures  for  Globular  Cluster  Pulsars  as  a   Unique

     Probe  of  the  Galac%c  Magne%c  Field   1.  Measuring  <B>  using  RotaHon  Measures  
  3. Rota%on  Measures  for  Globular  Cluster  Pulsars  as  a   Unique

     Probe  of  the  Galac%c  Magne%c  Field   1.  Measuring  <B>  using  RotaHon  Measures   2.  Why  pulsars  in  globular  clusters?    
  4. Rota%on  Measures  for  Globular  Cluster  Pulsars  as  a   Unique

     Probe  of  the  Galac%c  Magne%c  Field   1.  Measuring  <B>  using  RotaHon  Measures   2.  Why  pulsars  in  globular  clusters?     3.  CalculaHng  pulsar  rotaHon  measures  
  5. Rota%on  Measures  for  Globular  Cluster  Pulsars  as  a   Unique

     Probe  of  the  Galac%c  Magne%c  Field   1.  Measuring  <B>  using  RotaHon  Measures   2.  Why  pulsars  in  globular  clusters?     3.  CalculaHng  pulsar  rotaHon  measures   4.  Results:  mapping  <B>  
  6. Faraday  rota%on:     •  λ-­‐dependent  rotaHon      

          Dispersion:   •  λ-­‐dependent  Hme  delay             Probing  <B>  with  Rota%on  Measures  
  7. Why  Pulsars  in   Globular  Clusters?   Why  Pulsars?  

      •  Strong  linear  polarizaHon   •  No  intrinsic  Faraday  rotaHon  (Noutsos  2012)     Why  GC  Pulsars?   •   Dense  populaHons  -­‐>  probe  small-­‐scale  structure   Terzan  5:  35  MSPs   •  D=5.9  kpc,  l  =  3.8º,  b  =  1.7º     •  0.01-­‐4  pc  separaHon   •  Precise  DMs  (Ransom  2007)  
  8. Calcula%ng   RM   •  3  years  of  Green  Bank

     Telescope  observaHons  at  L-­‐band   (1.5  GHz)  and  S-­‐band  (2  GHz)  totaling  >  5  days  per  pulsar   •  Least  squares  fit  for  RM:     Ter5C,  single  phase  bin   RM0:  175,  dRM:  1.51  +/-­‐  0.06   New  RM:  176.51  +/-­‐  0.06   X2  =  1.48