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Related papers: Centroid Velocity Statistics of Molecular Clouds

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A robust prediction of $\Lambda{\rm CDM}$ cosmology is the halo circular velocity function (CVF), a dynamical cousin of the halo mass function. The correspondence between theoretical and observed CVFs is uncertain, however: cluster galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Louis E. Abramson , Rik J. Williams , Andrew J. Benson , Juna A. Kollmeier , John S. Mulchaey

We present the results of a high angular resolution, multi-transition analysis of the molecular gas in M82. The analysis is based on the two lowest transitions of 12CO and the ground transition of the rare isotopes 13CO and C18O measured…

Astrophysics · Physics 2009-10-31 A. Weiss , N. Neininger , S. Huettemeister , U. Klein

In the advent of large scale surveys, individually modelling strong-gravitational lenses and their counterpart time-delays in order to precisely measure $H_0$ will become computationally expensive, and highly complex. A complimentary…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-25 David Harvey

We present a new approach for quantifying the abundance of galaxy clusters and constraining cosmological parameters using dynamical measurements. In the standard method, galaxy line-of-sight (LOS) velocities, $v$, or velocity dispersions…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 M. Ntampaka , H. Trac , J. Cisewski , L. C. Price

Context. Molecular Clouds (MCs) are the place where stars are formed and their feedback starts to take place, regulating the evolution of galaxies. Therefore, MCs represent the critical scale at which to study how ultra-violet (UV) photons…

Astrophysics of Galaxies · Physics 2025-03-12 Fabio Di Mascia , Andrea Pallottini , Laura Sommovigo , Davide Decataldo

We present CO(2-1) and $^{13}$CO(2-1) maps of the Cygnus-X molecular cloud complex using the 10m Heinrich Hertz Submillimeter Telescope (SMT). The maps cover the southern portion of the complex which is strongly impacted by the feedback…

Astrophysics of Galaxies · Physics 2023-12-22 Jonah C. Baade , Shuo Kong , John H. Bieging , Thomas Folkers

We present theoretically-established values of the CO-to-H2 and C-to-H2 conversion factors that may be used to estimate the gas masses of external galaxies. We consider four distinct galaxy types, represented by M51, NGC 6946, M82 and SMC…

Astrophysics · Physics 2009-06-23 T. A. Bell , S. Viti , D. A. Williams

Atmospheric carbon dioxide concentrations are being closely monitored by remote sensing experiments which rely on knowing line intensities with an uncertainty of 0.5% or better. We report a theoretical study providing rotation-vibration…

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…

We study the anisotropy of centroid and integrated intensity maps with synthetic observations. We perform post-process radiative transfer including the optically thick regime that was not covered in Hern\'andez-Padilla et al. (2020). We…

Astrophysics of Galaxies · Physics 2024-06-25 D. Hernández-Padilla , A. Esquivel , A. Lazarian , P. F. Velázquez , J. Cho

Observed chemical species in the Venusian mesosphere show local-time variabilities. SO2 at the cloud top exhibits two local maxima over local time, H2O at the cloud top is uniformly distributed, and CO in the upper atmosphere shows a…

Earth and Planetary Astrophysics · Physics 2021-12-15 Wencheng D. Shao , Xi Zhang , João Mendonça , Thérèse Encrenaz

Molecular clouds (MCs) in galaxies are complex places with many phases. It is, therefore, essential to study the physics and kinematics of the MCs using multiple emission lines. We probe the physics of the molecular gas and dust in the…

Astrophysics of Galaxies · Physics 2022-03-25 Selçuk Topal

Some theories of dense molecular cloud formation involve dynamical environments driven by converging atomic flows or collisions between preexisting molecular clouds. The determination of the dynamics and physical conditions of the gas in…

Solar and Stellar Astrophysics · Physics 2015-06-18 I. Jimenez-Serra , P. Caselli , F. Fontani , J. C. Tan , J. D. Henshaw , J. Kainulainen , A. K. Hernandez

The Central Molecular Zone (CMZ) is the way station at the heart of our Milky Way Galaxy, connecting gas flowing in from Galactic scales with the central nucleus. Key open questions remain about its 3-D structure, star formation properties,…

Aims: Our aims are threefold: a) To compare the $uv$ and mm-wave results; b) to interpret 13CO and 12CO abundances in terms of the physical processes which separately and jointly determine them; c) to interpret observed J=1-0 rotational…

Astrophysics · Physics 2009-11-13 H. S. Liszt

We present results from high-resolution three-dimensional simulations of turbulent interstellar gas that self-consistently follow its coupled thermal, chemical and dynamical evolution, with a particular focus on the formation and…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. C. O. Glover , C. Federrath , M. -M. Mac Low , R. S. Klessen

Spectra of the cellular photospheric flows are determined from full-disk Doppler velocity observations acquired by the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory (SDO) spacecraft. Three different…

Solar and Stellar Astrophysics · Physics 2015-10-01 David H. Hathaway , Thibaud Teil , Aimee A. Norton , Irina Kitiashvili

The C$^{+}$ ion is an important coolant of interstellar gas, and so the [CII] fine structure line is frequently observed in the interstellar medium. However, the physical and chemical properties of the [CII]-emitting gas are still unclear.…

We have mapped 27 massive star-forming regions associated with water masers using three dense gas tracers: HC3N 10-9, HNC 1-0 and C2H 1-0. The FWHM sizes of HNC clumps and C2H clumps are about 1.5 and 1.6 times higher than those of HC3N,…

Solar and Stellar Astrophysics · Physics 2015-03-19 Juan Li , Junzhi Wang , Qiusheng Gu , Zhi-yu Zhang , Xingwu Zheng

Throughout the passage within the Galactic halo, high-velocity clouds (HVCs) sweep up ambient magnetic fields and form stretched and draped configurations of magnetic fields around them. Many earlier numerical studies adopt spherically…

Astrophysics of Galaxies · Physics 2023-05-03 Seoyoung Lyla Jung , Asger Grønnow , Naomi McClure-Griffiths