| 翻訳と辞書 |
| Interstellar formaldehyde ： ウィキペディア英語版 |
Interstellar formaldehyde
Interstellar formaldehyde (a topic relevant to astrochemistry) was first discovered in 1969 by L. Snyder ''et al.'' using the National Radio Astronomy Observatory. Formaldehyde (H2CO) was detected by means of the 111 - 110 ground state rotational transition at 4830 MHz.〔Snyder, L. E., Buhl, D., Zuckerman, B., & Palmer, P. 1969, Phys. Rev. Lett., 22, 679〕 On 11 August 2014, astronomers released studies, using the Atacama Large Millimeter/Submillimeter Array (ALMA) for the first time, that detailed the distribution of HCN, HNC, H2CO, and dust inside the comae of comets C/2012 F6 (Lemmon) and C/2012 S1 (ISON).
==Initial discovery==
Formaldehyde was first discovered in interstellar space in 1969 by L. Snyder ''et al.'' using the National Radio Astronomy Observatory. H2CO was detected by means of the 111 - 110 ground state rotational transition at 4830 MHz.〔Snyder, L. E., Buhl, D., Zuckerman, B., & Palmer, P. 1969, ''Phys. Rev. Lett.'', 22, 679〕
Formaldehyde was the first polyatomic organic molecule detected in the interstellar medium and since its initial detection has been observed in many regions of the galaxy.〔Zuckerman, B.; Buhl, D.; Palmer, P.; Snyder, L. E. 1970, Astrophysical Journal, 160, 485〕 The isotopic ratio of ()/() was determined to be about or less than 50% in the galactic disk.〔Henkel, C.; Guesten, R.; Gardner, F. F. 1985, Astronomy and Astrophysics, 143, 148〕 Formaldehyde has been used to map out kinematic features of dark clouds located near Gould's Belt of local bright stars.〔Sandqvist, A.; Tomboulides, H.; Lindblad, P. O. 1988, Astronomy and Astrophysics, 205, 225〕 In 2007, the first H2CO 6 cm maser flare was detected.〔Araya, E. _et al_. 2007, Astrophysical Journal, 654, L95〕 It was a short duration outburst in IRAS 18566 + 0408 that produced a line profile consistent with the superposition of two Gaussian components, which leads to the belief that an event outside the maser gas triggered simultaneous flares at two different locations.〔 Although this was the first maser flare detected, H2 masers have been observed since 1974 by Downes and Wilson in NGC 7538.〔Hoffman, I. M.; Goss, W. M.; Palmer, P. 2007, Astrophysical Journal, 654, 971〕 Unlike OH, H2O, and CH3OH, only five galactic star forming regions have associated formaldehyde maser emission, which has only been observed through the 110 → 111 transition.〔
According to Araya ''et al.'', H2CO are different from other masers in that they are weaker than most other masers (such as OH, CH3OH, and H2O) and have only been detected near very young massive stellar objects.〔Araya ''et al.'' 2007, ''Astrophysical Journal'', 669, 1050〕 Unlike OH, H2O, and CH3OH, only five galactic star forming regions have associated formaldehyde maser emission, which has only been observed through the 110 → 111 transition.〔Hoffman, I. M.; Goss, W. M.; Palmer, P. 2007, ''Astrophysical Journal'', 654, 971〕 Because of the widespread interest in interstellar formaldehyde it has recently been extensively studied, yielding new extragalactic sources, including NGC 253, NGC 520, NGC 660, NGC 891, NGC 2903, NGC 3079, NGC 3628, NGC 6240, NGC 6946, IC 342, IC 860, Arp 55, Arp 220, M82, M83, IRAS 10173+0828, IRAS 15107+0724, and IRAS 17468+1320.〔J. G. Mangum ''et al.'' 2008, ''Astrophysical Journal'', 673, 832.〕
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Interstellar formaldehyde」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|