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Related papers: Chemical segregation analysed with unsupervised cl…

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We describe a model for the thermal and dynamical equilibrium of starless cores that includes the radiative transfer of the gas and dust and simple CO chemistry. The model shows that the structure and behavior of the cores is significantly…

Astrophysics · Physics 2009-11-13 Eric Keto , Paola Caselli

Recent observations of the HDO/H$_2$O ratio toward protostars in isolated and clustered environments show an apparent dichotomy, where isolated sources show higher D/H ratios than clustered counterparts. Establishing which physical and…

Astrophysics of Galaxies · Physics 2021-05-12 S. S. Jensen , J. K. Jørgensen , K. Furuya , T. Haugbølle , Y. Aikawa

The physical structure of hot molecular cores, where forming massive stars have heated up dense dust and gas, but have not yet ionized the molecules, poses a prominent challenge in the research of high-mass star formation and…

Astrophysics of Galaxies · Physics 2018-07-04 Rainer Rolffs , Peter Schilke , Qizhou Zhang , Luis Zapata

We have conducted a spectral line survey in the 3 mm and 2 mm bands toward two positions in a spiral arm of M51 (NGC 5194) with the IRAM 30 m telescope. In this survey, we have identified 13 molecular species, including CN, CCH, N2H+, HNCO,…

Astrophysics of Galaxies · Physics 2015-06-19 Yoshimasa Watanabe , Nami Sakai , Kazuo Sorai , Satoshi Yamamoto

At the low temperatures ($\sim$10 K) and high densities ($\sim$100,000 H$_2$ molecules per cc) of molecular cloud cores and protostellar envelopes, a large amount of molecular species (in particular those containing C and O) freeze-out onto…

Astrophysics of Galaxies · Physics 2019-05-22 Paola Caselli , Olli Sipilä , Jorma Harju

We present the first detailed classification of the structures of Class 0 cores in a high resolution simulation of a giant molecular cloud. The simulated cloud contains 10^4 solar masses and produces over 350 cores which allows for…

Astrophysics of Galaxies · Physics 2015-05-20 Rowan J. Smith , Simon C. O. Glover , Ian A. Bonnell , Paul C. Clark , Ralf S. Klessen

To deepen our understanding of the chemical properties of the Planck Galactic Cold Clump (PGCC) G168.72-15.48, we performed observations of nine molecular species, namely, \ce{c-C3H}, \ce{H2CO}, \ce{HC5N}, \ce{HC7N}, \ce{SO}, \ce{CCH},…

Astrophysics of Galaxies · Physics 2020-01-08 Mengyao Tang , J. X. Ge , Sheng-Li Qin , Tie Liu , Yuefang Wu , Kee-Tae Kim , Sheng-Yuan Liu , Chao Zhang , J. H. He , Bing-Gang Ju , Xinhe Fang

Using the IRAM 30m telescope, we mapped the methanol emission in the pre-stellar core L1544 and observed singly deuterated methanol (CH$_2$DOH and CH$_3$OD) towards the dust peak of L1544. Non-LTE radiative transfer modelling was performed…

Solar and Stellar Astrophysics · Physics 2014-09-17 Luca Bizzocchi , Paola Caselli , Silvia Spezzano , Elvira Leonardo

We quantify the spatial distributions of dense cores in three spatially distinct areas of the Orion B star-forming region. For L1622, NGC2068/NGC2071 and NGC2023/NGC2024 we measure the amount of spatial substructure using the…

Astrophysics of Galaxies · Physics 2018-02-14 Richard J. Parker

Unbiased understandings of molecular distributions in a disk/envelope system of a low-mass protostellar source are crucial for investigating physical and chemical evolution processes. We have observed 23 molecular lines toward the Class 0…

Astrophysics of Galaxies · Physics 2022-01-05 Yuki Okoda , Yoko Oya , Shotaro Abe , Ayano Komaki , Yoshimasa Watanabe , Satoshi Yamamoto

Experimental studies of cell motility in culture have shown that under adequate conditions these living organisms possess the ability to organize themselves into complex structures. Such structures may exhibit a synergy that greatly…

Statistical Mechanics · Physics 2021-10-27 G. Nakamura , M. Badoual , E. Fabiani , C. Deroulers

Models of prestellar cores often assume that the cores are isolated from their environment - material outside the core boundary plays no role in the subsequent evolution. This is unlikely to be the case in reality, where cores are located…

Astrophysics of Galaxies · Physics 2022-12-07 F. D. Priestley , A. P. Whitworth , E. Fogerty

We present data from the ALMA Central Molecular Zone Exploration Survey (ACES) Large Program, which provides broad spectral-line and 3 mm continuum coverage of the Central Molecular Zone (CMZ) at a spatial resolution of 0.1 pc. The survey…

Context. Low-mass star-forming cores differ from their surrounding molecular cloud in turbulence, shape, and density structure. Aims. We aim to understand how dense cores form out of the less dense cloud material by studying the connection…

Astrophysics of Galaxies · Physics 2015-05-28 A. Hacar , M. Tafalla

We upgraded the chemical network from the UMIST Database for Astrochemistry 2006 to include isotopes such as ^{13}C and ^{18}O. This includes all corresponding isotopologues, their chemical reactions and the properly scaled reaction rate…

Astrophysics of Galaxies · Physics 2017-03-15 M. Röllig , V. Ossenkopf

We use sub-arcsecond resolution ($\sim$0.4$''$) observations with NOEMA at 1.37 mm to study the dust emission and molecular gas of 18 high-mass star-forming regions. We combine the derived physical and chemical properties of individual…

We present a 3-mm and 1.3-cm spectral line survey conducted with the Mopra 22-m and Parkes 64-m radio telescopes of a sample of 40 cold dust cores, previously observed with BLAST, including both starless and proto-stellar sources. 20…

The study of multiple molecular spectral lines in gas infalling sources can provide the physical and chemical properties of these sources and help us estimate their evolutionary stages. We report line detections within the 3 mm band using…

Astrophysics of Galaxies · Physics 2025-04-09 Yang Yang , Xi Chen , ZhiBo Jiang , Zhiwei Chen , Shuling Yu , Jun Li

Molecular inventories in starless cores are powerful tools for probing the physical and chemical structures at the earliest stages of star formation. Wide-band spectral scans are invaluable for obtaining a comprehensive view of the chemical…

Gas-phase complex organic molecules have been detected toward a range of high- and low-mass star-forming regions at abundances which cannot be explained by any known gas-phase chemistry. Recent laboratory experiments show that UV…

Astrophysics of Galaxies · Physics 2015-05-18 Karin I. Oberg , Sandrine Bottinelli , Jes K. Jorgensen , Ewine F. van Dishoeck