Danie
Mao-Chang Liang
l Current Status
1. Associate Research Fellow of
Research Center for Environmental Changes,
128 Sec. 2, Academia Rd., Nankang
Pasadena, Taipei 115, Taiwan
Tel: 886-2-2653-9885ext852
Fax: 886-2-2783-3584
E-mail: mcl@rcec.sinica.edu.tw
l Personal Information
1. Born on July 20, 1976 (
2. B.S. in Physics in 1998 (1994-1998) at National Tsing Hua University
3. M.S. in Physics in 2000 (1998-2000) at National Tsing Hua University
Institution: Institute of Astronomy and Astrophysics (ASIAA), Academia Sinica
Thesis: Multi-Wavelength Studies of Interacting Galaxies
Advisors: Fred K. Y. Lo and Hsiang-Kuang Chang
4. Ph.D. in Planetary Science (Astronomy minor) in 2005 (2002-2005) at California Institute of Technology
Thesis: Chemical and Dynamical Processes in the Atmospheres of Solar and Extrasolar Planets and their Satellites
Advisors: Yuk L. Yung and Geoffrey A. Blake
l Professional
Experience
1. Research
Assistant, Academia Sinica,
2. Research Assistant, California Institute of Technology, Division of Geology and Planetary Sciences, (2002-2005)
3. Teaching Assistant, California Institute of Technology, Division of Geology and Planetary Sciences, (2003-2005)
4. Staff, Division of Geological and Planetary Sciences, California Institute of Technology, (2006-2006)
5. Visiting Scholar (Staff), Division of Geological and Planetary Sciences, California Institute of Technology, (2006-2007)
6. Assistant Research Fellow, Research Center for Environmental Changes, Academia Sinica, (2006-2008)
7. Assistant Professor (joint appointment), Graduate Institute of Astronomy, National Central University, (2008-)
8. Associate Research Fellow, Research Center for Environmental Changes, Academia Sinica, (2008-)
l Abstracts of Current Research of Interest
1. Extrasolar Planets
Observations of life signatures and chemical compositions on solar and extrasolar planets require a specific window.
To date a total of 133 extrasolar planets around main sequence stars have been discovered, and most have masses
and radii close to that of Jupiter. Our understanding of these objects is poor. How they are formed and how they
evolve are still unknown, because we do not know what they are composed of. Also, these planets may provide a
new laboratory for understanding and solving of an old problem in dynamicshydrodynamic escape. The tentative
detections of H, C, and O in the atmosphere of the "hot Jupiter" HD 209458b suggest that the atmosphere is currently
experiencing hydrodynamic loss (Vidal-Madjar et al. 2003; 2004). We have performed initial calculations for HD 209458b,
which has an orbital distance of 0.05 AU (Liang et al. 2003; 2004), whence we obtained two results: (1) An extremely
high abundance of atomic hydrogen in the upper atmosphere of HD 209458b (whose mixing ratio can be as high as unity,
see Liang et al. 2003), and (2) The insignificance of hydrocarbon aerosols in the same object (Liang et al. 2004). The
former result provides a theoretical basis for the source of hydrodynamic escape. The latter results tell us that we will
be able to detect atmospheric constituents up to the Rayleigh scattering limit and/or the top of the clouds of high temperature
condensates.
2. The Origin of Life
Many organic molecules have been identified in comets, meteorites, and the interstellar medium. The most complex
of these are likely formed and synthesized on grain surfaces, avoiding direct exposure to the interstellar UV field
(see the review by Ehrenfreund & Charnley 2000). The findings of organic compounds in space greatly broaden our
perspective and revive an old proposal that the first life on Earth may have been delivered from space. The recent
discovery of extremophiles ("superbugs," which can survive in extreme conditions, e.g., extreme heat, extreme cold,
extreme pressure, darkness, and toxic-waste waters) expands our view of life and suggests that simple life, if not so
complex as animals and human beings, is ubiquitous (e.g., Davies 1999 and Ward & Brownlee 2000). Thus, it is
important to study and investigate possible habitats of life on terrestrial and extra-terrestrial planets and their satellites.
From the discoveries of organic compounds in space and bacteria in extreme conditions on the Earth, we learned that
(1) Dust grain surface chemistry is the key to synthesizing complex molecules, and (2) Life as we know it requires liquid
water.
l Selected Publications
1. Liang, Mao-Chang; Parkinson, Christopher D.; Lee, Anthony Y.-T.; Yung, Yuk L.; Seager, Sara, Source of Atomic Hydrogen in the Atmosphere of HD 209458b, ApJ Lett., 596, 247, 2003.
2. Liang, Mao-Chang, Blake, Geoffrey A., and Yung, Yuk L., A Semi-Analytic Model for Photo-Induced Isotopic Fractionation in Simple Molecules, J. Geophys. Res., 109(D10), D10308, 2004.
3. Mao-Chang Liang, Geoffrey A. Blake, Brenton R. Lewis, and Yuk L. Yung, Oxygen Isotope Composition of Carbon Dioxide in the Middle Atmosphere, 2005, submitted
l Research
Experience
1. Carbon-Oxygen
Fusion Experiments using 9SDH-2 Accelerator,
2. X-ray
Observation of Neutron Star,
3. Luminous
Infrared Galaxies (BIMA, VLA, UKIRT), Academia Sinica,
4. Photolysis Induced Isotopic fractionation of Nitrous Oxide (N2O), California Institute of Technology, Division of Geology and Planetary Sciences, (2001-)
5. VLA 7-mm Observation
of Circumstellar Disk around Vega-type Stars,
Academia Sinica,
6. GBT Survey of Extra-Galactic
Water Megamasers of Dusty Early-Type Radio-loud Galaxies,
Academia Sinica,
7. VLBA Observation
of Galactic center Sgr A*,
Academia Sinica,
8. Photochemical Calculation in Planetary Atmospheres (extrasolar planet HD 209458b, Earth, Jupiter) and the Atmospheres of Their Satellites (Callisto), California Institute of Technology, Division of Geology and Planetary Sciences, (2002-)
9. Dynamics in
Gas Giants (Jupiter and HD 209458b),
10. Calculation
on Isotopic Composition of Ozone (O3), Carbon Dioxide (CO2),
Sulfur Dioxide (SO2), and Hydrogen Cyanide (HCN), California
Institute of Technology, Division of Geology and Planetary Sciences, (2004-)
l Research of Interest
1. Luminous Infrared Galaxies
2. Extra-Galactic Magamasers
3. Structural Variation of Sgr A*
4. Atmospheric Science: Chemistry and Dynamics
5. Formation (Isotpic Composition in Chondrites) and Evolution (Hydrodynamic Escape) of Solar Systems
6. The Origin of Life
7. Cosmology, Black Hole Physics
8. Dusty Plasma
Last updated:
Feb-22-2007