Mercury’s Sodium Exospherefrom Maui

AEOS & Tohoku ObservatoryJune 2006

AEOS Telescope +Image-Slicer/ Spectrograph

Data Reduction and Results for June 8, 2006

IMAGE SLICER DETAIL

FIRST ROW SECOND ROW THIRD ROW FORTH ROW

ARROWS POINT TO FIRST COLUMN

COLUMN #1, ROW #1

COLUMN #1, ROW #1

2.4 mm

2.8 mm

• 3.7-meter telescope with adaptive optics

• Scale: 0.5 arc-seconds per fiber

• 1-minute exposures

• Twilight not significant

• Calibrated with standard stars

• June 8: 10 data cubes

• June 9: 8 data cubes

AEOS + Image-Slicer Spectrograph:Observing parameters

Mercury

Flat Field

SodiumLamp

AEOS + Image-Slicer Spectrograph: Raw Data

• Spectrally un-warp the images

• Choose wavelength (row)

• Fiber brightness = sum of 5 pixels

AEOS + Image-Slicer Spectrograph:Image Reconstruction Method

Mercury

Flat Field

AEOS + Image-Slicer Spectrograph:Remove Spectral Curvature

AEOS + Image-Slicer Spectrograph:

Locate Each Fiber at Each Wavelength

AEOSReconstructed Images

Mercury reconstructed

Flat field reconstructed

Final Image (continuum)

Each raw image yields a data cube of 1024 images

• Ganymede spectrum =

solar spectrum without Na emission

• (Ganymede spectrum) x (Merc. Image) =

artificial data cube of Mercury w/o Na

• Subtract artificial data cube from real data cube to yield Na emission

AEOS + Image-Slicer Spectrograph:Subtraction of surface-reflected solar spec.

-

=

Mercury at D1+D2 Merc. x Gany. at D1+D2

Na Exosphere

AEOS June 8, 2006(VR=10.0 km/s away)

Tohoku Observatory +Image-Slicer/ Spectrograph

Data Reduction and Results for June 15, 2006

• 16-inch Meade• Same image-slicer/spectrograph• 3 arc-seconds per fiber• 2-minute exposures• Dates:

– June 14: 5 data cubes– June 15: 5 data cubes– June 17: 9 data cubes– June 18: 8 data cubes

Tohoku Observatory, Maui+ Image-Slicer/Spectrograph:

Observing parameters

Tohoku U. @ Maui June 15, 2006(VR=8.6 km/s away)