McDonald Observatory Board of Visitors Public Talk

As at graduate student at UT Austin, I have been developing an innovative technology for infrared astronomy. The technology is called a Silicon immersion grating and has the power to revolutionize studies of stars in their formation. This talk introduces the technology, how it works, and why it's so useful in astronomy. The technlogy has enabled an entirely new instrument, IGRINS, at McDonald observatory. I conclude with how IGRINS and its successor GMTNIRS will be able to probe protoplanetary disks, and directly measure the atmospheres of exoplanets.

Transcript

1. New Technologies Shed Light on
   Newborn Stars and Planets!
   Michael  Gully-­‐San/ago  
   Graduate  Student  
   The  University  of  Texas  at  Aus/n  
   Department  of  Astronomy  
   

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2. Ma#hew  Bate  2011  
   

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3. Spitzer  Science  Center  
   

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4. Demo  
   

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5. Visible  
   Infrared  
   Wavelength
   Brightness
   700   400  
   900  
   

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6. The  interac/on  of  this  ultra-­‐rela/vis/c,  well-­‐
   collimated  jet  with  the  previously  ejected  
   common-­‐envelope  material  can  explain  both  the  
   X-­‐ray  and  UVOIR  emission  components.  
   Es/ma/ng  that  the  in-­‐spiral  takes  5 orbits  or  1.5 
   yr  and  material  is  ejected  at  escape  velocity,  the  
   outer  ejecta  are  at  a  distance  of  a  few  /mes  1014 
   cm  at  the  /me  of  the  merger,  consistent  with  the  
   radius  of  the  UVOIR  black  body.  We  assume  that  
   the  ejecta  form  a  broad  torus  with  a  narrow,  
   low-­‐density  funnel  along  the  rota/on  axis  of  the  
   system  that  permits  the  passage  of  the  γ-­‐
   radia/on  generated  in  the  jet.  Most  of  the  jet  
   hits  the  inner  boundary  of  the  common-­‐
   envelope  ejecta  and  only  a  small  frac/on  of  it  
   propagates  through  the  funnel.  The  X-­‐ray  
   emission  is  produced  by  shocks  created  by  the  
   interac/on  of  the  jet  with  the  inner  boundary  of  
   the  common-­‐envelope  shell.  
   The  interac/on  of  this  ultra-­‐rela/vis/c,  well-­‐collimated  jet  with  the  previously  ejected  common-­‐envelope  material  can  explain  both  the  X-­‐ray  and  UVOIR  emission  components.  Es/ma/ng  that  the  in-­‐spiral  takes  5 orbits  or  1.5 yr  and  material  is  ejected  at  escape  velocity,  the  outer  ejecta  are  at  a  distance  of  a  few  /mes  1014 cm  at  the  /me  of  the  merger,  consistent  with  the  radius  of  the  UVOIR  black  body.  We  assume  that  the  ejecta  form  a  broad  torus  with  a  narrow,  low-­‐density  funnel  along  the  rota/on  axis  of  the  system  that  permits  the  passage  of  the  γ-­‐radia/on  generated  in  the  jet.  Most  of  the  jet  hits  the  inner  boundary  of  the  common-­‐envelope  ejecta  and  only  a  small  frac/on  of  it  propagates  through  the  funnel.  The  X-­‐ray  emission  is  produced  by  shocks  created  by  the  interac/on  of  the  jet  with  the  inner  boundary  of  the  common-­‐envelope  shell.  
   

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7. High  resolu/on  visible  spectrum  of  the  star  Arcturus.  
   NOAO/AURA/NSF  
   

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8. High  resolu/on  infrared  spectroscopy  for  
   astronomy  has  been  limited  by  two  technologies:  
   Detectors   Diffrac/on  gra/ngs:  
   Familiar  Analogues:  
   Digital  cameras  (without  the  lens)  
   CDs  and  DVDs  (the  underside)  
   

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9. Silicon  immersion  gra/ngs  made  at  UT  Aus/n  summer  2011  
   

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10. Michael    Gully-­‐San

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11. IGRINS:  
    Immersion  GRa/ng  Infrared  Spectrograph  
    •  Collabora/on  with  UT  Aus/n/McDonald  Observatory  and  partner  Korean  
    Ins/tutes  
    •  Integra/on  and  tes/ng  star/ng  this  summer/fall  
    •  Des/ned  for  the  107”  Harlan  J.  Smith  Telescope  by  next  winter  
    

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12. IGRINS  will  instantaneously  acquire  detailed  
    spectra  over  a  huge  range  in  infrared  colors      
    K  
    H  
    

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13. Spitzer  Science  Center  
    

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14. Figure  7  from  Warm  H2O  and  OH  Disk  Emission  in  V1331  Cyg  
    Greg  W.  Doppmann  et  al.  2011  ApJ  738  112  doi:10.1088/0004-­‐637X/738/1/112  
    Detailed  spectra  help  to  put  together  a  story  
    of  the  forma/on  of  stars  and  planets.  
    Here  we  see  evidence  for  water  in  the  disk  
    surrounding  a  new  star.  
    Spitzer  Science  Center  
    

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15. GMTNIRS:  
    Giant  Magellan  Telescope  Near-­‐
    Infrared  Spectrograph  
    •  Proposed  first  light  
    instrument  for  the  GMT  
    •  Very  high  resolu/on  
    •  Ability  to  detect  and  analyze  
    planet  atmospheres  
    J  
    H  
    K  
    L  
    M
    R  
    B  
    G  
    

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20. BONUS  MATERIAL  
    

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