English
Related papers

Related papers: Multi log-normal density structure in Cygnus-X mol…

200 papers

Using infrared to (sub)millimeter data from Spitzer, Herschel, the James Clerk Maxwell Telescope, and the IRAM 30-m telescope, we conducted an unbiased survey of the massive dense cores (MDCs) in the Cygnus X molecular cloud complex, aimed…

Astrophysics of Galaxies · Physics 2019-02-27 Yue Cao , Keping Qiu , Qizhou Zhang , Yuwei Wang , Bo Hu , Junhao Liu

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…

We have measured the probability distribution function (PDF) of cosmic matter density field from a suite of N-body simulations. We propose the generalized normal distribution of version 2 (Nv2) as an alternative fitting formula to the…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Jihye Shin , Juhan Kim , Christophe Pichon , Donghui Jeong , Changbom Park

The structure of molecular clouds (MCs) holds important clues on the physical processes that lead to their formation and subsequent evolution. While it is well established that turbulence imprints a self-similar structure to the clouds,…

Despite the simplicity of theoretical models of supersonically turbulent, isothermal media, their predictions successfully match the observed gas structure and star formation activity within low-pressure (P/k < 10^5 K cm^-3) molecular…

We have modified the iterative procedure introduced by Lin et al. (2016), to systematically combine the submm images taken from ground based (e.g., CSO, JCMT, APEX) and space (e.g., Herschel, Planck) telescopes. We applied the updated…

This study presents a catalog of 8107 molecular clouds that covers the entire Galactic plane and includes 98% of the $^{12}$CO emission observed within $b\pm5^\circ$. The catalog was produced using a hierarchical cluster identification…

Astrophysics of Galaxies · Physics 2017-01-11 Marc-Antoine Miville-Deschênes , Norman Murray , Eve J. Lee

We have obtained deep HI observations in the direction of 22 continuum sources without previously detected cold neutral medium (CNM). 18 CNM clouds were detected with the typical HI column density of $3\times10^{18}$ cm$^{-2}$. Our…

Astrophysics · Physics 2007-05-23 Snezana Stanimirovic , Carl Heiles , Nissim Kanekar

We have performed a multi-species hydrodynamical simulation of the formation and evolution of Lyman alpha clouds in a flat CDM dominated universe with an external flux of ionizing radiation. We solve the fully coupled non-equilibrium rate…

Astrophysics · Physics 2009-10-28 Yu Zhang , Peter Anninos , Michael L. Norman

In this work we use models of molecular clouds (MC), and non-LTE radiative transfer calculations, to obtain a theoretical calibration of the relation between LTE 13CO column density and true column density in MCs. The cloud models consist…

Astrophysics · Physics 2008-02-03 Paolo Padoan , Mika Juvela , John Bally , AAke Nordlund

We compare velocity structure in the Polaris Flare molecular cloud at scales ranging from 0.015 pc to 20 pc to simulations of supersonic hydrodynamic and MHD turbulence computed with the ZEUS MHD code. We use several different statistical…

Astrophysics · Physics 2007-05-23 Volker Ossenkopf , Mordecai-Mark Mac Low

We present a first principle approach to obtain analytical predictions for spherically-averaged cosmic densities in the mildly non-linear regime that go well beyond what is usually achieved by standard perturbation theory. A large deviation…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-25 Cora Uhlemann , Sandrine Codis , Christophe Pichon , Francis Bernardeau , Paulo Reimberg

Sub-millimetre dust emission is often used to derive the column density N of dense interstellar clouds. The observations consist of data at several wavelengths but of variable resolution. We examine two procedures that been proposed for the…

Astrophysics of Galaxies · Physics 2015-06-15 M. Juvela , J. Malinen , T. Lunttila

Recent surveys of the Galactic plane in the dust continuum and CO emission lines reveal that large ($\gtrsim 50$~pc) and massive ($\gtrsim 10^5$~$M_\odot$) filaments, know as giant molecular filaments (GMFs), may be linked to galactic…

The probability distribution functions (PDFs) of the average densities of the diffuse ionized gas (DIG) and the diffuse atomic gas are close to lognormal, especially when lines of sight at |b|<5 degree and |b|>5 degree are considered…

Astrophysics of Galaxies · Physics 2015-05-27 Elly M. Berkhuijsen , Andrew Fletcher

We present results of the classification of cloud structures toward the Orion A Giant Molecular Cloud based on wide-field $^{12}$CO ($J$ = 1--0), $^{13}$CO ($J$ = 1-0), and C$^{18}$O ($J$ = 1-0) observations using the Nobeyama 45 m radio…

We use a suite of high resolution molecular cloud simulations carried out with the moving mesh code Arepo to explore the nature of star-forming filaments. The simulated filaments are identified and categorised from column density maps in…

Astrophysics of Galaxies · Physics 2015-06-22 Rowan J. Smith , Simon C. O. Glover , Ralf. S. Klessen

Probability density functions (PDF) of statistical distributions of cluster sizes N, where N is the number of particles in the cluster, often seem to have less freedom than expected from considering the number of degrees of freedom at the…

Data Analysis, Statistics and Probability · Physics 2011-03-08 Sascha Vongehr , Shaochun Tang , Xiangkang Meng

We study the effect of density fluctuations induced by turbulence on the HI/H$_2$ structure in photodissociation regions (PDRs) both analytically and numerically. We perform magnetohydrodynamic numerical simulations for both subsonic and…

Astrophysics of Galaxies · Physics 2017-07-26 Shmuel Bialy , Blakesley Burkhart , Amiel Sternberg

In this paper we discuss the physical conditions of clumpy nature in the IC 348 molecular cloud. We combine new observations of fully sampled maps in [C I] at 492 GHz and 12CO 4--3, taken with the KOSMA 3 m telescope at about 1' resolution,…

Astrophysics · Physics 2009-11-13 K. Sun , V. Ossenkopf , C. Kramer , B. Mookerjea , M. Röllig , M. Cubick , J. Stutzki