English
Related papers

Related papers: Relative velocities between $^{13}$CO structures w…

200 papers

We study the properties of all major HVC complexes from a sample compiled 1991 by Wakker & van Woerden (WvW). We use the Leiden/Argentine/Bonn all sky 21-cm line survey and decompose the profiles into Gaussian components. We find a well…

Astrophysics · Physics 2009-11-11 Peter M. W. Kalberla , Urmas Haud

Using the PMO-13.7m millimeter telescope at Delingha in China, we have conducted a large-scale simultaneous survey of $^{12}$CO, $^{13}$CO, and C$^{18}$O J=1-0 emission toward the Rosette molecular cloud (RMC) region with a sky coverage of…

Astrophysics of Galaxies · Physics 2018-10-10 Chong Li , Hongchi Wang , Miaomiao Zhang , Yuehui Ma , Min Fang , Ji Yang

We compute structure functions and Fourier spectra of 2D centroid velocity (CV) maps in order to study the gas dynamics of typical molecular clouds (MCs) in numerical simulations. We account for a simplified treatment of time-dependent…

Solar and Stellar Astrophysics · Physics 2015-06-23 Erik Bertram , Lukas Konstandin , Rahul Shetty , Simon C. O. Glover , Ralf S. Klessen

Structures in molecular ISM are observed to follow a power-law relation between the velocity dispersion and spatial size, known as Larson's first relation, which is often attributed to the turbulent nature of molecular ISM and imprints the…

Astrophysics of Galaxies · Physics 2024-10-22 Haoran Feng , Zhiwei Chen , Zhibo Jiang , Yuehui Ma , Yang Yang , Shuling Yu , Dongqing Ge , Wei Zhou , Fujun Du , Chen Wang , Shiyu Zhang , Yang Su , Ji Yang

The condensation of diffuse gas into molecular clouds occurs at a rate driven largely by turbulent dissipation. This process still has to be caught in action and characterized. A mosaic of 13 fields was observed in the CO(1-0) line with the…

Astrophysics of Galaxies · Physics 2015-05-14 E. Falgarone , J. Pety , P. Hily-Blant

Using spectral-line observations of HNCO, N2H+, and HNC, we investigate the kinematics of dense gas in the central ~250 pc of the Galaxy. We present SCOUSE (Semi-automated multi-COmponent Universal Spectral-line fitting Engine), a line…

Kinematic distances to 750 molecular clouds identified in the 13CO J=1-0 Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey (BU-FCRAO GRS) are derived assuming the Clemens rotation curve of the Galaxy. The…

Astrophysics of Galaxies · Physics 2009-07-22 Julia Roman-Duval , James M. Jackson , Mark Heyer , Alexis Johnson , Jill Rathborne , Ronak Shah , Robert Simon

We measure the velocity dispersion, $\sigma$, and surface density, $\Sigma$, of the molecular gas in nearby galaxies from CO spectral line cubes with spatial resolution $45$-$120$ pc, matched to the size of individual giant molecular…

The kinematics of molecular gas are crucial for setting the stage for star formation. One key question related to the kinematic properties of gas is how they depend on the spatial scale. We aim to describe the CO spectra, velocity…

Astrophysics of Galaxies · Physics 2022-11-16 Andri Spilker , Jouni Kainulainen , Jan Orkisz

We report the detection of extremely broad emission toward two molecular clumps in the Galactic central molecular zone. We have mapped the Sagittarius C complex ($-0^\circ.61 < l < -0^\circ.27$, $-0^\circ.29 < b < 0^\circ.04$) in the HCN…

Astrophysics of Galaxies · Physics 2015-06-18 Kunihiko Tanaka , Tomoharu Oka , Shinji Matsumura , Makoto Nagai , Kazuhisa Kamegai

Numerical simulations have explored the possibility to form molecular clouds through either a quasi-static, self-gravitating mechanism or the collision of gas streams or lower-density clouds. They also quantitatively predict the…

We observed a 10x20 pc region of the molecular cloud M17 in the 12CO and 13CO J=3-2 and J=2-1 transitions to determine their global behavior and to assess the reliability of using ratios of CO line intensities integrated over an entire…

Astrophysics · Physics 2009-10-31 C. D. Wilson , J. E. Howe , M. L. Balogh

New-generation spectroscopic surveys of the Milky Way plane have been revealing the structure of the interstellar medium, allowing the simultaneous study of dense structures from single star-forming objects or systems to entire spiral arms.…

Studies of the Milky Way's disk-halo interface have historically identified inflowing and outflowing gas incompatible with disk rotation on the basis of radial velocity, leading to the well-known categories of intermediate-velocity clouds…

The probability density functions (pdfs) of molecular line centroid velocity fluctuations and fluctuation differences at different spatial lags are estimated for several nearby molecular clouds with active internal star formation. The data…

Astrophysics · Physics 2009-10-31 M. S. Miesch , J. M. Scalo , J. Bally

We investigate how the spectral properties of atomic (HI) and molecular (H$_2$) gas, traced by CO(2-1), are related in M33 on $80$ pc scales. We find the HI and CO(2-1) velocity at peak intensity to be highly correlated, consistent with…

We compare the structure of synthetic dust polarization with synthetic molecular line emission from radiative transfer calculations using a 3-dimensional, turbulent collapsing-cloud magnetohydrodynamics simulation. The histogram of relative…

Astrophysics of Galaxies · Physics 2023-03-29 Renato Mazzei , Zhi-Yun Li , Che-Yu Chen , Laura Fissel , Mike Chen , James Park

We report a new search for 12CO(1-0) emission in high-velocity clouds (HVCs) performed with the IRAM 30 m telescope. This search was motivated by the recent detection of cold dust emission in the HVCs of Complex C. Despite a spatial…

Astrophysics · Physics 2009-11-13 M. Dessauges-Zavadsky , F. Combes , D. Pfenniger

We present the survey of $^{12}$CO/$^{13}$CO/C$^{18}$O (J=1-0) toward the California Molecular Cloud (CMC) within the region of 161.75$^{\circ} \leqslant l \leqslant$ 167.75$^{\circ}$,-9.5$^{\circ} \leqslant b \leqslant $-7.5$^{\circ}$,…

Astrophysics of Galaxies · Physics 2021-11-03 Weihua Guo , Xuepeng Chen , Jiancheng Feng , Li Sun , Chen Wang , Yang Su , Yan Sun , Yiping Ao , Shaobo Zhang , Xin Zhou , Lixia Yuan , Ji Yang

We study the physical properties and 3D distribution of molecular clouds (MCs) toward the Cygnus region using the MWISP CO survey and Gaia DR3 data. Based on Gaussian decomposition and clustering for $\rm ^{13}CO$ lines, over 70% of the…