E. A. Trofimova, I. I. Zinchenko, P. M. Zemlyanukha, M. Thomasson
{"title":"单氘化氨 NH2D 线高质量恒星形成区调查","authors":"E. A. Trofimova, I. I. Zinchenko, P. M. Zemlyanukha, M. Thomasson","doi":"10.1134/S1063772924700719","DOIUrl":null,"url":null,"abstract":"<p>The present survey represents a continuation of our study of high mass star forming regions in the lines of deuterated molecules, the first results of which were published in [1]. This paper present the results of observations of 50 objects in the line of ortho modification of singly deuterated ammonia NH<sub>2</sub>D <span>\\(1_{{11}}^{s}{-} 1_{{01}}^{a}\\)</span> at a frequency of 85.9 GHz, carried out using the 20-m radio telescope of the Onsala Space Observatory (Sweden). This line is detected in 29 sources. The analysis of obtained data, as well as the fact that the gas density in the investigated sources, according to independent estimates, is significantly lower than the critical density for this NH<sub>2</sub>D transition, indicate non-LTE excitation of NH<sub>2</sub>D. Based on non-LTE modeling, estimates of the relative content of the NH<sub>2</sub>D molecule and the degree of deuterium enrichment were obtain, and the dependencies of these parameters on temperature and velocity dispersion were analyzed with and without taking into account detection limits assuming the same gas density in all sources. An anti-correlation between the NH<sub>2</sub>D relative abundances and the kinetic temperature is revealed in a temperature range of 15–50 K. At the same time, a significant decrease in the ratio of the NH<sub>2</sub>D/NH<sub>3</sub> abundances with increasing temperature, predicted by the available chemical models, is not observed under the adopted assumptions. An anti-correlation was also revealed between the relative content of the main isotopologue of ammonia NH<span>\\(_{3}\\)</span> and the velocity dispersion, while no statistically significant correlation with the kinetic temperature of sources in the same temperature range was found.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 8","pages":"771 - 789"},"PeriodicalIF":1.1000,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A Survey of High-Mass Star Forming Regions in the Line of Singly Deuterated Ammonia NH2D\",\"authors\":\"E. A. Trofimova, I. I. Zinchenko, P. M. Zemlyanukha, M. Thomasson\",\"doi\":\"10.1134/S1063772924700719\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The present survey represents a continuation of our study of high mass star forming regions in the lines of deuterated molecules, the first results of which were published in [1]. This paper present the results of observations of 50 objects in the line of ortho modification of singly deuterated ammonia NH<sub>2</sub>D <span>\\\\(1_{{11}}^{s}{-} 1_{{01}}^{a}\\\\)</span> at a frequency of 85.9 GHz, carried out using the 20-m radio telescope of the Onsala Space Observatory (Sweden). This line is detected in 29 sources. The analysis of obtained data, as well as the fact that the gas density in the investigated sources, according to independent estimates, is significantly lower than the critical density for this NH<sub>2</sub>D transition, indicate non-LTE excitation of NH<sub>2</sub>D. Based on non-LTE modeling, estimates of the relative content of the NH<sub>2</sub>D molecule and the degree of deuterium enrichment were obtain, and the dependencies of these parameters on temperature and velocity dispersion were analyzed with and without taking into account detection limits assuming the same gas density in all sources. An anti-correlation between the NH<sub>2</sub>D relative abundances and the kinetic temperature is revealed in a temperature range of 15–50 K. At the same time, a significant decrease in the ratio of the NH<sub>2</sub>D/NH<sub>3</sub> abundances with increasing temperature, predicted by the available chemical models, is not observed under the adopted assumptions. An anti-correlation was also revealed between the relative content of the main isotopologue of ammonia NH<span>\\\\(_{3}\\\\)</span> and the velocity dispersion, while no statistically significant correlation with the kinetic temperature of sources in the same temperature range was found.</p>\",\"PeriodicalId\":55440,\"journal\":{\"name\":\"Astronomy Reports\",\"volume\":\"68 8\",\"pages\":\"771 - 789\"},\"PeriodicalIF\":1.1000,\"publicationDate\":\"2024-10-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Astronomy Reports\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://link.springer.com/article/10.1134/S1063772924700719\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Astronomy Reports","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1134/S1063772924700719","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
A Survey of High-Mass Star Forming Regions in the Line of Singly Deuterated Ammonia NH2D
The present survey represents a continuation of our study of high mass star forming regions in the lines of deuterated molecules, the first results of which were published in [1]. This paper present the results of observations of 50 objects in the line of ortho modification of singly deuterated ammonia NH2D \(1_{{11}}^{s}{-} 1_{{01}}^{a}\) at a frequency of 85.9 GHz, carried out using the 20-m radio telescope of the Onsala Space Observatory (Sweden). This line is detected in 29 sources. The analysis of obtained data, as well as the fact that the gas density in the investigated sources, according to independent estimates, is significantly lower than the critical density for this NH2D transition, indicate non-LTE excitation of NH2D. Based on non-LTE modeling, estimates of the relative content of the NH2D molecule and the degree of deuterium enrichment were obtain, and the dependencies of these parameters on temperature and velocity dispersion were analyzed with and without taking into account detection limits assuming the same gas density in all sources. An anti-correlation between the NH2D relative abundances and the kinetic temperature is revealed in a temperature range of 15–50 K. At the same time, a significant decrease in the ratio of the NH2D/NH3 abundances with increasing temperature, predicted by the available chemical models, is not observed under the adopted assumptions. An anti-correlation was also revealed between the relative content of the main isotopologue of ammonia NH\(_{3}\) and the velocity dispersion, while no statistically significant correlation with the kinetic temperature of sources in the same temperature range was found.
期刊介绍:
Astronomy Reports is an international peer reviewed journal that publishes original papers on astronomical topics, including theoretical and observational astrophysics, physics of the Sun, planetary astrophysics, radio astronomy, stellar astronomy, celestial mechanics, and astronomy methods and instrumentation.