Optimal column density measurements from multiband near-infrared observations

Abstract

We consider from a general point of view the problem of determining the extinction in dense molecular clouds. We use a rigorous statistical approach to characterize the properties of the most widely used optical and infrared techniques, namely the star count and the color excess methods. We propose a new maximum-likelihood method that takes advantage of both star counts and star colors to provide an optimal estimate of the extinction. Detailed numerical simulations show that our method performs optimally under a wide range of conditions and, in particular, is significantly superior to the standard techniques for clouds with high column-densities and affected by contamination by foreground stars.

20 pages; A&A in press

References in corpus (6)

• The Universality of Turbulence in Galactic Molecular Clouds
• Mapping the interstellar dust with near-infrared observations: An optimized multi-band technique
• Supersonic turbulence in the ISM: stellar extinction determinations as probes of the structure and dynamics of dark clouds
• Extinction with 2MASS: star counts and reddening toward the North America and the Pelican Nebulae
• A synthetic view on structure and evolution of the Milky Way
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Cited by in corpus (21)

• Probing the evolution of molecular cloud structure: From quiescence to birth
• 2MASS wide field extinction maps - I. The Pipe nebula
• Herschel-Planck dust optical-depth and column-density maps: I. Method description and results for Orion
• The California Molecular Cloud
• NICEST, a near-infrared color excess method tailored for small-scale structures
• 2MASS wide field extinction maps: II. The Ophiuchus and the Lupus cloud complexe
• The Earliest Phases of Star formation observed with Herschel (EPoS): The dust temperature and density distributions of B68
• The Structure of Molecular Clouds: I - All Sky Near Infrared Extinction Maps
• The Panchromatic Hubble Andromeda Treasury VIII: A Wide-Area, High-Resolution Map of Dust Extinction in M31
• Probing the evolution of molecular cloud structure II: From chaos to confinement
• Mass reservoirs surrounding massive infrared dark clouds: A view by near-infrared dust extinction
• A large scale extinction map of the Galactic Anticenter from 2MASS
• Structure and Fragmentation of a high line-mass filament: Nessie
• A Corona Australis cloud filament seen in NIR scattered light I. Comparison with extinction of background stars
• Hunting Galaxies to (and for) Extinction
• Extinction techniques and impact on dust property determination
• Study of magnetic field geometry and extinction in Bok globule CB130
• Dust extinction map of the Galactic plane based on the VVV survey data
• Star formation in Cometary globule 1: the second generation
• Optimal extinction measurements - I. Single-object extinction inference
• Searching for dark clouds in the outer galactic plane I -- A statistical approach for identifying extended red(dened) regions in 2MASS