Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:0704.3203)
· On-line Data
· References in the article
· Citations to the Article (26) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (8)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
The Infrared Extinction Law at Extreme Depth in a Dark Cloud Core
Authors:
Román-Zúñiga, Carlos G.; Lada, Charles J.; Muench, August; Alves, Joao F.
Affiliation:
AA(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138; , , ), AB(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138; , , ), AC(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138; , , ), AD(Centro Astrofísico Hispano Alemán, Granada, Spain; )
Publication:
The Astrophysical Journal, Volume 664, Issue 1, pp. 357-362. (ApJ Homepage)
Publication Date:
07/2007
Origin:
UCP
ApJ Keywords:
ISM: Dust, Extinction, Infrared: ISM
DOI:
10.1086/518928
Bibliographic Code:
2007ApJ...664..357R

Abstract

We combined sensitive near-infrared data obtained with ground-based imagers on the ESO NTT and VLT telescopes with space mid-infrared data acquired with the IRAC imager on the Spitzer Space Telescope to calculate the extinction law Aλ/AKs as a function of λ between 1.25 and 7.76 μm to an unprecedented depth in Barnard 59, a star-forming, dense core located in the Pipe Nebula. The ratios Aλ/AKs were calculated from the slopes of the distributions of sources in color-color diagrams λ-Ks versus H-Ks. The distributions in the color-color diagrams are fit well with single slopes to extinction levels of AKs~7 (AV~59 mag). Consequently, there appears to be no significant variation of the extinction law with depth through the B59 line of sight. However, when slopes are translated into the relative extinction coefficients Aλ/AKs, we find an extinction law that departs from the simple extrapolation of the near-infrared power-law extinction curve, and agrees more closely with a dust extinction model for a cloud with a total to selective absorption RV=5.5 and a grain size distribution favoring larger grains than those in the diffuse interstellar medium. Thus, the difference we observe could possibly be due to the effect of grain growth in denser regions. Finally, the slopes in our diagrams are somewhat less steep than those from the study of Indebetouw et al. for clouds with lower column densities, and this indicates that the extinction law between 3 and 8 μm might vary slightly as a function of environment.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints