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相关论文: Deuterium fractionation as a multi-phase component…

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The formation of singly and doubly deuterated isotopomers of formaldehyde and of singly, doubly, and multiply deuterated isotopomers of methanol on interstellar grain surfaces has been studied with a semi-empirical modified rate approach…

天体物理学 · 物理学 2009-11-07 Paola Caselli , Tatiana Stantcheva , Osama Shalabiea , Valery I. Shematovich , Eric Herbst

The Galactic Center regions $-6^\circ \le l \le 6^\circ$ and $-0.8^\circ \le b \le 0.87^\circ$ are surveyed with HCN J=1$-$0 line (88.6 GHz) on a 4$'$ grid with the 14 m telescope at the Taeduk Radio Astronomy Observatory. The data…

天体物理学 · 物理学 2009-10-28 Chang Won Lee

We present an observational and theoretical study of the ionization fraction in several massive cores located in regions that are currently forming stellar clusters. Maps of the emission from the J = 1-> O transitions of C18O, DCO+, N2H+,…

天体物理学 · 物理学 2009-10-30 Edwin A. Bergin , Rene Plume , Jonathan P. Williams , Philip C. Myers

Despite low elemental abundance of atomic deuterium in interstellar medium (ISM), observational evidences suggest that several species in gas-phase and in ices could be heavily fractionated. We explore various aspects of deuterium…

星系天体物理 · 物理学 2019-02-05 Ankan Das , Liton Majumdar , Sandip K. Chakrabarti , Dipen Sahu

We present a study of star formation in the Central Molecular Zone (CMZ) of our Galaxy through the association of three star formation indicators: 6.7 GHz CH3OH masers, 22 GHz H2O masers, and enhanced 4.5 micron emission (`green') sources.…

星系天体物理 · 物理学 2015-06-17 E. T. Chambers , F. Yusef-Zadeh , J. Ott

Chemical models predict that the deuterated fraction (the column density ratio between a molecule containing D and its counterpart containing H) of N2H+, Dfrac(N2H+), is high in massive pre-protostellar cores and rapidly drops of an order…

星系天体物理 · 物理学 2015-06-18 F. Fontani , T. Sakai , K. Furuya , N. Sakai , Y. Aikawa , S. Yamamoto

Context : Despite the low cosmic abundance of deuterium (D/H ~ 1e-5), large degrees of deuterium fractionation in molecules are observed in star forming regions with enhancements that can reach 13 orders of magnitude, which current models…

天体物理学 · 物理学 2016-08-30 B. Parise , C. Ceccarelli , A. G. G. M. Tielens , A. Castets , E. Caux , B. Lefloch , S. Maret

The Central Molecular Zone (CMZ; inner $\sim{}200~\rm{}pc$) of the Milky Way is a star formation (SF) environment with very extreme physical properties. Exploration of SF in this region is important because (i) this region allows us to test…

The deuterium fractionation of gas-phase molecules in hot cores is believed to reflect the composition of interstellar ices. The deuteration of methanol is a major puzzle, however, because the isotopologue ratio [CH2DOH]/[CH3OD], which is…

太阳与恒星天体物理 · 物理学 2015-12-02 A. Faure , M. Faure , P. Theulé , E. Quirico , B. Schmitt

High levels of deuterium fractionation of $\rm N_2H^+$ (i.e., $\rm D_{frac}^{N_2H^+} \gtrsim 0.1$) are often observed in pre-stellar cores (PSCs) and detection of $\rm N_2D^+$ is a promising method to identify elusive massive PSCs. However,…

星系天体物理 · 物理学 2021-01-13 Chia-Jung Hsu , Jonathan C. Tan , Matthew D. Goodson , Paola Caselli , Bastian Körtgen , Yu Cheng

Velocity profiles of a line of H$_3^+$ at 3.7 $\mu$m produced in warm diffuse gas have been observed toward 18 stars in the Central Molecular Zone (CMZ) of the Galaxy. Their longitude-velocity diagram indicates that the gas is radially…

星系天体物理 · 物理学 2020-10-14 Takeshi Oka , T. R. Geballe

We recently reported a population of protostellar candidates in the 20 km s$^{-1}$ cloud in the Central Molecular Zone of the Milky Way, traced by H$_2$O masers in gravitationally bound dense cores. In this paper, we report…

An accurate value of the deuterium/hydrogen (D/H) ratio in the local interstellar medium (LISM) and a better understanding of the D/H variations with position in the Galactic disk can provide essential information on the primordial D/H…

天体物理学 · 物理学 2009-11-16 Jeffrey L. Linsky

Deuterium fractionation provides a key diagnostic of the physical and chemical evolution of prestellar and protostellar cores, where it is strongly linked to CO depletion in cold, dense gas. We present the first spatially resolved maps of…

星系天体物理 · 物理学 2026-02-03 Igor Petrashkevich , Anna Punanova , Paola Caselli , Jaime E. Pineda , Olli Sipila , Anton I. Vasyunin

This letter presents a Nyquist-sampled, high-resolution [CI] 3P1-3P0 map of the -0.2 deg < l < 1.2 deg x -0.1 deg < b < 0 deg region in the Central Molecular Zone (CMZ) taken with the Atacama Submillimeter Telescope Experiment (ASTE) 10 m…

星系天体物理 · 物理学 2015-06-03 Kunihiko Tanaka , Tomoharu Oka , Shinji Matsumura , Makoto Nagai , Kazuhisa Kamegai

Context: In the last years, the H2D+ and D2H+ molecules have gained great attention as probes of cold and depleted dense molecular cloud cores. These ions are at the basis of molecular deuterium fractionation, a common characteristic…

星系天体物理 · 物理学 2015-05-19 B. Parise , A. Belloche , F. Du , R. Güsten , K. M. Menten

Observations have revealed prodigious amounts of star formation in starburst galaxies as traced by dust and molecular emission, even at large redshifts. Recent work shows that for both nearby spiral galaxies and distant starbursts, the…

天体物理学 · 物理学 2009-11-13 Jingwen Wu , Neal J. Evans , Yu Gao , Philip M. Solomon , Yancy L. Shirley , Paul A. Vanden Bout

The total deuterium abundance [D/H] in the universe is set by just two processes: the creation of deuterium in Big Bang Nucleosynthesis at an abundance of [D/H]$=2.58\pm0.13\times10^{-5}$, and its destruction within stellar interiors.…

We carry out a systematic study of the density structure of gas in the Central Molecular Zone (CMZ) in the Galactic center by extracting clumps from the APEX Telescope Large Area Survey of the Galaxy survey at 870 $\mu$m. We find that the…

星系天体物理 · 物理学 2020-07-15 Guang-Xing Li , Chuan-Peng Zhang

Analyses of spectra obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite, together with spectra from the Copernicus and IMAPS instruments, reveal an unexplained very wide range in the observed deuterium/hydrogen (D/H)…