Herschel-Planck dust optical-depth and column-density maps. I. Method description and results for Orion

Author(s)

Marco Lombardi, Hervé Bouy, Joao Alves, Charles J. Lada

Abstract

We present high-resolution, high dynamic range column-density and color-temperature maps of the Orion complex using a combination of Planck dust-emission maps, Herschel dust-emission maps, and 2MASS NIR dust-extinction maps. The column-density maps combine the robustness of the 2MASS NIR extinction maps with the resolution and coverage of the Herschel and Planck dustemission maps and constitute the highest dynamic range column-density maps ever constructed for the entire Orion complex, covering 0:01 mag < A

_K < 30 mag, or 2 × 10

²⁰ cm

^-2 < N < 5 × 10

²³ cm

^-2 . We determined the ratio of the 2:2 μm extinction coefficient to the 850 μm opacity and found that the values obtained for both Orion A and B are significantly lower than the predictions of standard dust models, but agree with newer models that incorporate icy silicate-graphite conglomerates for the grain population. We show that the cloud projected probability distribution function, over a large range of column densities, can be well fitted by a simple power law. Moreover, we considered the local Schmidt-law for star formation, and confirm earlier results, showing that the protostar surface density Σ*follows a simple law Σ*∝ Σ

^β

_gas , with β 2.

Organisation(s)

Department of Astrophysics

External organisation(s)

Spanish National Research Council (CSIC), Universitá degli Studi di Milano, Harvard-Smithsonian Center for Astrophysics

Journal

Astronomy & Astrophysics

Volume

566

No. of pages

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/201323293

Publication date

06-2014

Peer reviewed

Yes

Austrian Fields of Science 2012

103003 Astronomy, 103004 Astrophysics

Keywords

ASJC Scopus subject areas

Astronomy and Astrophysics, Space and Planetary Science

Portal url

https://ucrisportal.univie.ac.at/en/publications/herschelplanck-dust-opticaldepth-and-columndensity-maps-i-method-description-and-results-for-orion(afd551ae-ca00-46ac-ab13-faa2837c1715).html