The Relationship between the Optical Depth of the 9.7 μm Silicate Absorption Feature and Infrared Differential Extinction in Dense Clouds

Citations Over TimeTop 10% of 2007 papers

Abstract

We have examined the relationship between the optical depth of the 9.7 mm silicate absorption feature ( ) t 9.7 and the near-infrared color excess, , in the Serpens, Taurus, IC 5146, Chameleon I, Barnard 59, and E(J K ) s Barnard 68 dense clouds/cores. Our data set, based largely on Spitzer IRS spectra, spans E(J K ) p 0.3-10 s mag (corresponding to visual extinction between about 2 and 60 mag). All lines of sight show the 9.7 mm silicate feature. Unlike in the diffuse ISM where a tight linear correlation between the 9.7 mm silicate feature optical depth and the extinction ( ) is observed, we find that the silicate feature in dense clouds does not show a A V monotonic increase with extinction. Thus, in dense clouds, is not a good measure of total dust column density. t 9.7 With few exceptions, the measured values fall well below the diffuse ISM correlation line for t E(J K ) 1 9.7 s mag ( mag). Grain growth via coagulation is a likely cause of this effect.

Related Papers

• → Low osmium solubility in silicate at high pressures and temperatures(2009)34 cited
• → Silicate anions formed in tetramethylammonium silicate methanolic solutions as studied by 29Si nuclear magnetic resonance(1989)45 cited
• → A possible explanation of immiscibility in silicate melts(1960)3 cited
• Recent Advances in the Synthesis and Properties of Polymer-Layered Silicate Nanocomposite(2001)
• → Measuring Optical Extinction Towards Young Stellar Objects Using Diffuse Interstellar Bands(2022)