McDonald Observatory Board of Visitors Public Talk

484347ce845b7236c4791348e0eed9ba?s=47 gully
February 11, 2012

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.



February 11, 2012


  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  
  2. Ma#hew  Bate  2011  

  3. Spitzer  Science  Center  

  4. Demo  

  5. Visible   Infrared   Wavelength Brightness 700   400  

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

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

  10. Michael    Gully-­‐San<ago  

  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  
  12. IGRINS  will  instantaneously  acquire  detailed   spectra  over  a  huge

     range  in  infrared  colors       K   H  
  13. Spitzer  Science  Center  

  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  
  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  
  16. None
  17. None
  18. None
  19. None

  21. None