Comparison of High-resolution 3-micron

Spectra of Jupiter, Saturn, and Titan

Sang Joon Kim, Chae Kyung Sim, Aeran Jung, and Mirim SohnSchool of Space Research,

Kyung Hee University

High-resolution 1.45 – 2.45 m Planetary Spectra are NOT Available!!?

• IGRIN spectral coverage: H (1.45 - 1.90 m) and K (2.00-2.45 m) bands.

• Some high-resolution (R > 20,000) H and K spectra are available for inner planets (Earth, Venus, and Mars)

• High-resolution (R > 20,000) H and K spectra for outer planets (Jupiter, Saturn, Uranus, Neptune) and Titan are not seen in literature.

• Only after 2005, high-resolution 2.8 – 3.5 m spectra of Jupiter, Saturn, and Titan become available in literature.

• We can predict that the future IGRIN investigation of the 1.45 – 2.45 m range of the outer planets and Titan will follow the pattern of the investigation and understanding of high-resolution 2.8 – 3.5 m spectra of these solar system objects.

Spectral resolving power

Below, an example of “low” resolution spectroscopy

An example of “mid” resolution spectroscopy

An example of “High” resolution spectroscopy

An example of “Super-High” resolution spectroscopy – Reserved for our children?

(Ex) High Resolution vs Mid Resolution - Jupiter

A high-resolution spectrometer is heavy and big

Then, why don’t we put a high-resolution spectrometer on a space observatory?

Infrared Spectroscopy

vs

Infrared imaging

An Image of collisions between 22 fragments of comet S-L9 and Jupiter in 1994

Different spectral shapes caused by different electron densities

Detection of H3+ ions on the auroral zone of Jupiter

Kim et al. (2000)Methane (CH4) Fluorescence

Cassini VIMS 2004 Image

NIRSPEC/KeckII slit position on Titan at the time of Keck II observations on Nov. 21, 2001 (UT)Seo, et al. (Icarus,

2009)

Titan Resolving power : 25,000Slit size : 0.43” × 12”

Best fitting model spectrum of Titan (solid line) for 2.87 – 2.92 m compared with observed spectrum (dotted line). Unidentified features are marked by arrows. All the major absorption features are reproduced using the 2 + 3 band lines of CH3D.

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Three model spectra (green, red, and blue lines) and the NIRSPEC spectrum (black line) for the 2.92 – 2.98 m range. The green line is the best fit.

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Fig.1 Gemini/NIFS Spectro-Imagery

Deconvolved observational images with E-W/N-S scan averaged in the wavelength range of 2.05-2.07, 2.09-2.11, and 2.17-2.19 microns.

Fig.1 Gemini/NIFS Spectro-Imagery

Deconvolved observational images with E-W/N-S scan averaged in the wavelength range of 2.05-2.07, 2.09-2.11, and 2.17-2.19 microns.

3-Micron Features in High-resolution Spectra of Jupiter(Kim, Sang Joon, 2009)

Observation

• Date: 18 April, 2006 ~ 22 August 2006(UT) (20 hours)

• Observatory: UKIRT (CGS4 – Echelle)

• Resolving power: 37,000

• Slit size: 0.41 arcsec X 90 arcsec

• Slit position angle : 17.5 degree CCW

• Slit position : Along the CML

(Extracted Region : NP, EZ, SP)

• Standard Star: HD130841(A3IV)

HD125337(A1V)

Keck II/NIRSPEC observations of Saturn

Conclusion

We predict that the future IGRIN investigation of the 1.45 – 2.45 m range of Jupiter, Saturn, and Titan will follow the pattern of the exciting investigation and understanding of high-resolution 2.8 – 3.5 m spectra of these solar system objects.