光子作用與光譜分析實驗室

發佈於 分類: pps

歡迎對低溫光物理與光化學與光譜量測技術有興趣的大學部專題生與碩士班及博士班研究生加入光子作用與光譜分析實驗室。 光子作用與光譜分析實驗室,主要是利用超高真空系統搭配氦氣循環式低溫系統模擬太空之低溫、低壓環境 (壓力 <1×10-10 torr, 溫度 ~ 10 K),並以氣體低溫固化技術控制實驗中所模擬的彗星、小行星等表面冰晶組成成分與厚度。以微波氫氣放電管所產生之真空紫外光源與國家同步輻射研究中心之同步輻射光源(極紫外光與X-ray)探討光子在低溫冰晶表面上之光物理與光化學作用。2019年初,我們新增設了電子槍提供模擬星際環境中100-1500 eV的電子來源,探討電子與冰晶作用及X-ray照射冰晶所產生的二次電子與歐傑電子作用間的差異性。 由於目前一般量產的紅外光譜儀的時間解析能力不足,因而在冰晶分子的光衍化過程與光脫附過程中,生命時間極為短暫的自由基、中間產物與分子激發態震動能階躍遷等是無法被觀測到的。近期,我們將與交通大學電物系羅志偉教授合作,使用羅志偉教授所發展的飛秒級時間解析超寬頻紅外光譜量測技術,進行星際複雜有機分子生成與脫附機制的時間解析研究。 我們與Dr. Ciaravella、Prof. Cecchi-Pestellini (INAF – Osservatorio Astronomico di Parlamento, Italy)及Dr. Muñoz Caro (Molecular Astrophysics Laboratory, Centre of Astrobiology, Spain)針對星際複雜有機分子生成與脫附機制,進行了X-ray、真空紫外光子與電子照射冰晶的國際合作研究。因此,實驗室的專題生與碩博士研究生會有至義大利巴勒摩與西班牙馬德利進行移地研究的機會。 歡迎對我們研究議題有興趣的專題生與碩博士研究生,前來參觀 Photoprocessing & Spectroscopy Lab (科學四館 R408) 聯絡方式: 03-4227151 ext 65304 / asperchen@phy.ncu.edu.tw

X‐ray versus Ultraviolet Irradiation of Astrophysical Ice Analogs Leading to Formation of Complex Organic Molecules

發佈於 分類: pps2019

In astrochemistry, complex organic molecules (COMs) are defined as species with at least one C atom and six or more atoms in total. More than 70 COMs were detected toward various interstellar and circumstellar regions. With the exception of methanol, CH3OH, these COMs were only detected in the gas phase. But their sole existence challenges the scheme of gas-phase reactions and […]

Synthesis of Complex Organic Molecules in Soft X-ray Irradiated Ices

發佈於 分類: pps2019

We study the chemical evolution of H2O:CO:NH3 ice mixtures irradiated with soft X-rays, in the range 250−1250 eV. We identify many nitrogen-bearing molecules such as e.g., OCN−, NH+4 , HNCO, CH3CN, HCONH2, and NH2COCONH2. Several infrared features are compatible with glycine or its isomers. During the irradiation, we detected through mass spectroscopy many species desorbing […]

Accretion and photodesorption of CO ice as a function of the incident angle of deposition

發佈於 分類: pps2019

Non-thermal desorption processes of molecules present in inter- and circum-stellar ice mantles on dust grains, in particular ultraviolet (UV) photon-induced desorption, have gained impor- tance in recent years. These processes may account for the observed gas phase abundances of certain molecules like CO toward cold interstellar clouds. Ice mantle growth results from gas molecules impinging […]