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Related papers: Molecular line and continuum study of the W40 clou…

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We calculate the evolution of molecular line profiles of HCO$^+$ and C$^{18}$O toward a dense core thatis forming inside a magnetized turbulent molecular cloud. Features of the profiles can be affected more significantly by coupled velocity…

Astrophysics of Galaxies · Physics 2009-07-22 Jeong-Eun Lee , Jongsoo Kim

We present the 12CO(1-0) and 13CO(2-1) line maps obtained observing with the SEST a $\sim 1\degr \times 1\degr$ region of the Vela Molecular Ridge, Cloud D. This cloud is part of an intermediate-mass star forming region that is relatively…

We present high resolution observations of CS(J=1-0), H13CO+ (J=1-0), and SiO(v=0:J=1-0) lines, together with the 49GHz and 86GHz continuum emissions, toward W49N carried out with Nobeyama Millimeter Array. We identified 11 CS, 8 H13CO+,…

Astrophysics of Galaxies · Physics 2021-12-15 Ryosuke Miyawaki , Masahiko Hayashi , Tetsuo Hasegawa

The formation mechanism of CO clouds observed with NANTEN2 and Mopra telescope toward the stellar cluster Westerlund 2 is studied by three-dimensional magnetohydrodynamic (MHD) simulations taking into account the interstellar cooling. These…

High Energy Astrophysical Phenomena · Physics 2017-02-27 Yuta Asahina , Tomohisa Kawashima , Naoko Furukawa , Rei Enokiya , Hiroaki Yamamoto , Yasuo Fukui , Ryoji Matsumoto

Chemical composition of the massive cores forming high-mass stars can put some constrains on the time scale of the massive star formation: sulphur chemistry is of specific interest due to its rapid evolution in warm gas and because the…

Solar and Stellar Astrophysics · Physics 2009-10-28 Fabrice Herpin , Matthieu Marseille , Valentine Wakelam , Sylvain Bontemps , D. C. Lis

We used the IRAM Interferometer to obtain sub-arcsecond resolution observations of the high-mass star-forming region W3(OH) and its surroundings at a frequency of 220 GHz. With the improved angular resolution, we distinguish 3 peaks in the…

Astrophysics · Physics 2009-10-31 Friedrich Wyrowski , Peter Schilke , C. Malcolm Walmsley , Karl M. Menten

Using a source selection biased towards high mass star forming regions, we used a Large Velocity Gradient (LVG) code to calculate the H2 densities and CS column densities for a sample of Midcourse Space Experiment (MSX) 8 micron infrared…

Astrophysics of Galaxies · Physics 2015-05-13 David Gibson , Rene Plume , Edwin Bergin , Sarah Ragan , Natalie Evans

Molecular clouds, which harbor the birthplaces of stars, form out of the atomic phase of the interstellar medium (ISM). We aim to characterize the atomic and molecular phases of the ISM and set their physical properties into the context of…

RCW120 is a Galactic HII region having a beautiful ring shape bright in infrared. Our new CO J=1-0 and J=3-2 observations performed with the NANTEN2, Mopra, and ASTE telescopes have revealed that two molecular clouds with a velocity…

Astrophysics of Galaxies · Physics 2015-06-11 K. Torii , K. Hasegawa , Y. Hattori , H. Sano , A. Ohama , H. Yamamoto , K. Tachihara , S. Soga , S. Shimizu , T. Okuda , N. Mizuno , T. Onishi , A. Mizuno , Y. Fukui

The W40 complex is a nearby site of recent massive star formation composed of a dense molecular cloud adjacent to an HII region that contains an embedded OB star cluster. The HII region is beginning to blister out and break free from its…

Astrophysics · Physics 2008-08-26 Steven A. Rodney , Bo Reipurth

An investigation of dust emission associated with a large sample of HII regions has been carried out. Stacked results from this sample suggest that each HII region is at or near the center of a cluster of dense cores, that extends far…

Astrophysics of Galaxies · Physics 2019-11-06 George Bobotsis , Michel Fich

The massive infrared dark cloud G0.253+0.016 projected 45pc from the Galactic centre contains ~10^5Msun of dense gas whilst being mostly devoid of observed star-formation tracers. To scrutinise the physical properties, dynamics and…

Astrophysics of Galaxies · Physics 2014-11-12 K. G. Johnston , H. Beuther , H. Linz , A. Schmiedeke , S. E. Ragan , Th. Henning

Five regions of massive star formation have been observed in various molecular lines in the frequency range $\sim 85-89$ GHz. The studied regions possess dense cores, which host young stellar objects. The physical parameters of the cores…

Astrophysics of Galaxies · Physics 2016-10-19 L. E. Pirogov , V. M. Shul'ga , I. I. Zinchenko , P. M. Zemlyanukha , O. N. Patoka , M. Thomasson

The object W33 is a giant molecular cloud that contains star forming regions at various evolutionary stages from quiescent clumps to developed H II regions. Since its star forming regions are located at the same distance and the primary…

Astrophysics of Galaxies · Physics 2014-12-03 K. Immer , R. Galván-Madrid , C. König , H. B. Liu , K. M. Menten

We present spatially-resolved properties of molecular gas and dust in a gravitationally-lensed submillimeter galaxy H-ATLAS J090311.6+003906 (SDP.81) at $z=3.042$ revealed by the Atacama Large Millimeter/submillimeter Array (ALMA). We…

Astrophysics of Galaxies · Physics 2015-08-06 Bunyo Hatsukade , Yoichi Tamura , Daisuke Iono , Yuichi Matsuda , Masao Hayashi , Masamune Oguri

We present high-resolution infrared (2--18 micron) images of the archetypal periodic dust-making Wolf-Rayet binary system WR140 (HD 193793) taken between 2001 and 2005, and multi-colour (J -- [19.5]) photometry observed between 1989 and…

We used the CSO 10.4 meter telescope to image the 350 micron and 450 micron continuum and CO J=6-5 line emission of the IRAS 20126+4104 clump. The continuum and line observations show that the clump is isolated over a 4 pc region and has a…

Astrophysics · Physics 2009-11-13 Hiroko Shinnaga , Thomas G. Phillips , Ray S. Furuya , Riccardo Cesaroni

Massive stars are formed in molecular clouds, and produce H II regions when they evolve onto the main sequence. The expansion of H II region can both suppress and promote star formation in the vicinity. M17 H II region is a giant cometary H…

Astrophysics of Galaxies · Physics 2023-06-22 Feng-Yao Zhu , Junzhi Wang , Yaoting Yan , Qing-Feng Zhu , Juan Li

We examine the triggering process of molecular cloud formation around diffuse HII regions. We calculate the time evolution of the shell as well as of the HII region in a two-phase neutral medium, solving the UV and FUV radiative transfer,…

Astrophysics · Physics 2011-02-11 Takashi Hosokawa , Shu-ichiro Inutsuka

We present a multiwavelength study of the cometary \hii region G12.21--0.10 using the VLA and OVRO. Both radio continuum (0.3, 0.7, 2 and 3.6~cm) and spectral lines of H41$\alpha$, $^{13}$CS(2$-$1) \& (1$-$0), and NH$_{\rm 3}$(2,2) \& (4,4)…