Laser Guide Star Images of the Galactic Center

Caption:
The Laser Guide Star Adaptive Optics System at the W. M. Keck Observatory takes infrared images of the Galactic Center. The image above is taken in the L'-band (3.8 microns), is 10 arcseconds in size and has a resolution of 82 milliarcseconds. At 3.8 microns, the Strehl ratio was measured at 75%, double the previous performance at this wavelength. A Strehl ratio of 100% represents a perfect, fully-corrected image. At K' (2.1 microns) the Strehl ratio was measured at 35%, a modest improvement, and the resolution was 56 milliarcseconds.

Other Images:

• Laser vs Natural Guide Star L' Image (high resolution eps format available here) The LGS image has a total integration time of 8 minutes while the NGS image has 150 minutes. The plus sign marks the position of Sgr A* in both images.
  
  
• LGS vs NGS Animation L' (3.8 micron) fading animation from Natural Guide Star (NGS) to Laser Guide Star (LGS).
  
  
  
• K' (2.1 micron) and L' (3.8 micron) two-color image. Exposures were obtained at 3.8 and 2.1 micron wavelengths, assigned a color, and combined to make a false-color image.
  
  
• He I (1.43 micron) and K_continuum (2.29 micron) two-color mosaic image This image is 80" x 80" and was created from only five pointings of the telescope in each filter and consumed just 20 minutes of telescope time. The LGS-AO system allowed the artificial guide star to be positioned at the center of each pointing.
  
  

References and Credit:
UCLA Galactic Center Group
W.M. Keck Observatory Laser Team