相关论文: Modeling mass functions of clumps formed during th…

Aims: We derive the probability density functions (PDFs) of column density for a complete sample of prominent molecular cloud complexes closer than 200 pc. Methods: We derive near-infrared dust extinction maps for 23 molecular cloud…

The isothermal gravitational collapse and fragmentation of a region within a molecular cloud and the subsequent formation of a protostellar cluster is investigated numerically. The clump mass spectrum which forms during the fragmentation…

Molecular clouds (MCs) are highly structured and ``turbulent''. Colliding gas streams of atomic hydrogen have been suggested as a possible source of MCs, imprinting the filamentary structure as a consequence of dynamical and thermal…

Giant molecular clouds (GMCs) are well-studied in the local Universe, however, exactly how their properties vary during galaxy evolution is poorly understood due to challenging resolution requirements, both observational and computational.…

We have extensively mapped a sample of dense molecular clouds (L1512, TMC-1C, L1262, Per 7, L1389, L1251E) in lines of HC3N, CH3OH, SO and C^{18}O. We demonstrate that a high degree of chemical differentiation is present in all of the…

All stars are born in molecular clouds, and most in giant molecular clouds (GMCs), which thus set the star formation activity of galaxies. We first review their observed properties, including measures of mass surface density, Sigma, and…

Astronomers have constructed models of globular clusters for over 100 years. These models mainly fall into two categories: (i) static models, such as King's model and its variants, and (ii) evolutionary models. Most attention has been given…

In a recent paper, Elmegreen (2000) has made a cogent case, from an observational point of view, that the lifetimes of molecular clouds are comparable to their dynamical timescales. If so, this has important implications for the mechanisms…

(Abridged) The Census of High- and Medium-mass Protostars (CHaMP) is the first large-scale (280 degree<l<300 degree, -4 degree<b<2 degree), unbiased, sub-parsec resolution survey of Galactic molecular clumps and their embedded stars. Barnes…

In the Milky Way there are thousands of stellar clusters each harboring from a hundred to a million stars. Although clusters are common, the initial conditions of cluster formation are still not well understood. To determine the processes…

Observations show that molecular gas in spiral galaxies is organized into a network of interconnected systems through the gravitational coupling of multi-scale hub-filament structures. Building on this picture, we model molecular gas in the…

A physical model and two-dimensional numerical method for computing the evolution and spectra of protostellar clouds are described. The physical model is based on a system of magneto-gasdynamical equations, including ohmic and ambipolar…

The formation of stars is inextricably linked to the structure of their parental molecular clouds. Here we take a number of nearby giant molecular clouds (GMCs) and analyse their column density and mass distributions. This investigation is…

We present an analysis of the integrated properties of the stellar populations in the Universidad Complutense de Madrid Survey of Halpha-selected galaxies. In this paper, the first of a series, we describe in detail the techniques developed…

Stars form within molecular clouds but our understanding of this fundamental process remains hampered by the complexity of the physics that drives their evolution. We review our observational and theoretical knowledge of molecular clouds…

Mixture models combine multiple components into a single probability density function. They are a natural statistical model for many situations in astronomy, such as surveys containing multiple types of objects, cluster analysis in various…

We analyse extinction maps of nearby Giant Molecular Clouds to forge a link between driving processes of turbulence and modes of star formation. Our investigation focuses on cloud structure in the column density range above the self…

Context. Stars form in dense, dusty clumps of molecular clouds, but little is known about their origin, their evolution and their detailed physical properties. In particular, the relationship between the mass distribution of these clumps…

The formation and evolution of cold diffuse clouds (CDCs), the parent objects of dense molecular clouds, affects both the star formation process and that of larger-scale galactic evolution. We have begun a pilot study of one CDC's dust…

It is widely recognized that cold dark matter models predict abundant dark matter substructure in halos of all sizes. Galaxy-galaxy lensing provides a unique opportunity to directly measure the presence and the mass of such substructures in…