LABORATORY STUDY OF THE IR SPECTRA OF METHANE ICES IN THE POLAR ENVIRONMENT
Секция: ЗВЕЗДЫ И МЕЖЗВЕЗДНАЯ СРЕДА
Авторы:
1.
Ural Federal University
2.
Ural Federal University
3.
Ural Federal University
4.
Ural Federal University
5.
Ural Federal University
Тип:
Статья конференции
Опубликовано:
27.12.2024
Классификаторы:
ВАК 1 Естественные науки
УДК 52 Астрономия. Геодезия
УДК 53 Физика
УДК 520 Инструменты, приборы и методы астрономических наблюдений, измерений и анализа
УДК 521 Теоретическая астрономия. Небесная механика. Фундаментальная астрономия. Теория динамической и позиционной астрономии
УДК 523 Солнечная система
УДК 524 Звезды и звездные системы. Вселенная Солнце и Солнечная система
УДК 52-1 Метод изучения
УДК 52-6 Излучение и связанные с ним процессы
ГРНТИ 41.00 АСТРОНОМИЯ
ГРНТИ 29.35 Радиофизика. Физические основы электроники
ГРНТИ 29.31 Оптика
ГРНТИ 29.33 Лазерная физика
ГРНТИ 29.27 Физика плазмы
ГРНТИ 29.05 Физика элементарных частиц. Теория полей. Физика высоких энергий
ОКСО 03.06.01 Физика и астрономия
ОКСО 03.05.01 Астрономия
ОКСО 03.04.03 Радиофизика
ББК 2 ЕСТЕСТВЕННЫЕ НАУКИ
ББК 223 Физика
ТБК 614 Астрономия
ТБК 6135 Оптика
BISAC SCI004000 Astronomy
BISAC SCI005000 Physics / Astrophysics
УДК 52 Астрономия. Геодезия
УДК 53 Физика
УДК 520 Инструменты, приборы и методы астрономических наблюдений, измерений и анализа
УДК 521 Теоретическая астрономия. Небесная механика. Фундаментальная астрономия. Теория динамической и позиционной астрономии
УДК 523 Солнечная система
УДК 524 Звезды и звездные системы. Вселенная Солнце и Солнечная система
УДК 52-1 Метод изучения
УДК 52-6 Излучение и связанные с ним процессы
ГРНТИ 41.00 АСТРОНОМИЯ
ГРНТИ 29.35 Радиофизика. Физические основы электроники
ГРНТИ 29.31 Оптика
ГРНТИ 29.33 Лазерная физика
ГРНТИ 29.27 Физика плазмы
ГРНТИ 29.05 Физика элементарных частиц. Теория полей. Физика высоких энергий
ОКСО 03.06.01 Физика и астрономия
ОКСО 03.05.01 Астрономия
ОКСО 03.04.03 Радиофизика
ББК 2 ЕСТЕСТВЕННЫЕ НАУКИ
ББК 223 Физика
ТБК 614 Астрономия
ТБК 6135 Оптика
BISAC SCI004000 Astronomy
BISAC SCI005000 Physics / Astrophysics
Язык материала:
английский
Ключевые слова:
ISM: molecules, clouds, lines and bands; infrared: ISM; methods: laboratory: solid state; astrochemistry
Финансирование:
This research work is funded by the Russian Ministry of Science and Higher Education via the State Assignment Contract FEUZ-2020-0038
Аннотация (русский):
We grew the pure methane ice and mixed binary ices of methane with polar molecules: water, carbon dioxide, methanol and ammonia under ultrahigh vacuum cryogenic conditions similar to those in cold prestellar clouds. The composition of ices was chosen to reflect current astrochemical notions. The following interstellar ice analogues were obtained: H$_2$O : CH$_4$ = 10 : 1, CO$_2$ : CH$_4$ = 5 : 1, CH$_3$OH : CH$_4$ = 2 : 1, NH$_3$ : CH$_4$ = 1 : 1, that are new to the literature and infrared spectra ice analogues databases. We report the significance of deposition temperature for the internal structure of ices, which gets revealed on infrared spectra during the warm up for ices deposited at 6.7 K and 10 K. We link the observed differences to solid methane being in amorphous phase ($T < 9.3$ K) and low-temperature crystalline (9.3 K$ < T < 20$ K) phases. We also note that the direct comparison between laboratory and observational spectra is possible since the deformation mode line shape doesn't depend on the grain size or shape near 7.7 $\mu$m, only on the temperature and molecular environment. Solid methane is a fairly abundant molecule in prestellar objects. With the James Webb Space Telescope (JWST) launch the quality of spectra has risen significantly and we hope that this work will be an asset to assigning the methane component in star-forming regions.
We grew the pure methane ice and mixed binary ices of methane with polar molecules: water, carbon dioxide, methanol and ammonia under ultrahigh vacuum cryogenic conditions similar to those in cold prestellar clouds. The composition of ices was chosen to reflect current astrochemical notions. The following interstellar ice analogues were obtained: H$_2$O : CH$_4$ = 10 : 1, CO$_2$ : CH$_4$ = 5 : 1, CH$_3$OH : CH$_4$ = 2 : 1, NH$_3$ : CH$_4$ = 1 : 1, that are new to the literature and infrared spectra ice analogues databases. We report the significance of deposition temperature for the internal structure of ices, which gets revealed on infrared spectra during the warm up for ices deposited at 6.7 K and 10 K. We link the observed differences to solid methane being in amorphous phase ($T < 9.3$ K) and low-temperature crystalline (9.3 K$ < T < 20$ K) phases. We also note that the direct comparison between laboratory and observational spectra is possible since the deformation mode line shape doesn't depend on the grain size or shape near 7.7 $\mu$m, only on the temperature and molecular environment. Solid methane is a fairly abundant molecule in prestellar objects. With the James Webb Space Telescope (JWST) launch the quality of spectra has risen significantly and we hope that this work will be an asset to assigning the methane component in star-forming regions.
Ключевые слова:
ISM: molecules, clouds, lines and bands; infrared: ISM; methods: laboratory: solid state; astrochemistry
ISM: molecules, clouds, lines and bands; infrared: ISM; methods: laboratory: solid state; astrochemistry
1. Boogert A.C.A., Gerakines P.A., Whittet D.C.B., 2015, Annual Review of Astronomy and Astrophysics, 53, p. 541
2. Gerakines P.A. and Hudson R.L., 2015, The Astrophysical Journal Letters, 805, 2, id. L20
3. McClure M.K., Rocha W.R.M., Pontoppidan K.M., et al., 2023, Nature Astronomy, 7, p. 431
