WASP-39bの大気中の光化学的に生成されたSO2
Shang-Min Tsai1,2, Elspeth K H Lee3, Diana Powell4
1Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, UK. shangmit@ucr.edu.
Nature
|April 26, 2023
まとめ
天文学 者 たち は,外惑星 の 中 で 二酸化硫黄 (SO2) を 検出 し た
科学分野:
- 惑星科学
- 外惑星の大気
- 天体化学
背景:
- 光化学は惑星の大気組成に不可欠です
- 決定的な光化学的物質は 以前は 惑星外の大気中に発見されませんでした
- JWSTは,WASP-39bの大気中の二酸化硫黄 (SO2) に起因するスペクトルの特徴を検出しました.
研究 の 目的:
- WASP-39b系外惑星における二酸化硫黄 (SO2) の起源を調査する.
- 光化学モデルを用いてSO2の存在と分布を確認する.
- 外惑星の大気特性のトレーサとしてSO2を評価する.
主な方法:
- NIRSpec PRISMとG395HによるJWSTの観測を活用した.
- SO2の分布をシミュレートするために一連の光化学モデルを使用した.
- 4.05ミクロメートルのスペクトルの吸収を分析した.
主要な成果:
- 光化学モデルはSO2の観測された4.05ミクロムのスペクトル特性をうまく説明しました.
- SO2は硫化水素 (H2S) 破壊による硫黄の酸化によって生成される.
- SO2の特徴は,WASP-39bが太陽の10倍の金属性を示しています.
結論:
- WASP-39bのSO2の検出は,系外惑星の大気中の光化学の役割を確認しています.
- SO2は系外惑星の大気金属性の 価値あるトレーサとして機能します
- 紫外線や熱赤外線でのさらなる観測により,SO2の詳細が明らかになる可能性があります.
関連する概念動画
The Sulfur Cycle
45.3K
Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the atmosphere as sulfur dioxide (SO2), sulfur is released by decaying organisms, weathered rocks, geothermal vents, volcanos, and burning fossil fuels. It is deposited into the ecosystem, cycled through the biotic community, and either released back into the atmosphere as gas or deposited in marine sediment for long-term storage and eventual...
45.3K
Photosystem II
71.6K
The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
71.6K
Anoxygenic Photosynthesis
58
Anoxygenic photosynthesis is a phototrophic process that captures light energy to drive carbon fixation without producing molecular oxygen. Unlike oxygenic photosynthesis, which utilizes water as an electron donor and releases oxygen, anoxygenic phototrophs use alternative electron donors such as hydrogen sulfide (H₂S), elemental sulfur (S⁰), or thiosulfate (S₂O₃²⁻). This process is carried out by diverse groups of bacteria, including purple bacteria, green...
58
The Calvin Benson Cycle
4.7K
Ribulose 1,5- bisphosphate carboxylase/oxygenase (RuBisCo) is a critical enzyme that catalyzes carbon dioxide assimilation during photosynthesis. However, it is an inefficient enzyme, having an extremely slow catalytic rate. A typical enzyme can process about a thousand molecules per second; however, RuBisCo fixes only around three-carbon dioxides per second. Photosynthetic cells compensate for this slow rate by synthesizing very high amounts of RuBisCo, making it the most abundant single...
4.7K
Oxygenic Photosynthesis
52
Oxygenic photosynthesis is a fundamental process in which light energy is harnessed to drive the oxidation of water, leading to the production of molecular oxygen (O₂), adenosine triphosphate (ATP), and nicotinamide adenine dinucleotide phosphate (NADPH). This process is essential for sustaining aerobic life on Earth and is primarily carried out by cyanobacteria, algae, and plants. The core of oxygenic photosynthesis lies in the thylakoid membranes, where chlorophyll pigments facilitate...
52
Sulfur Assimilation
46
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to...
46


