GG Tauri's Circumbinary Disk: Models for Near‐Infrared Scattered‐Light Images and¹³CO ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfo

Abstract

We describe models that reproduce the observed near-IR scattered-light images and 13CO (J \ 1 ] 0) line proÐles from the GG Tau circumbinary disk. The observed extent of the scattered-light images requires a 0.13 Ñared circumbinary disk (as determined from millimeter observations), an inner M _ cleared region of 200 AU, and scale height of 16.6 AU at the diskÏs inner edge. To reproduce the brightness distribution, we require extinction of the illuminating starlight prior to scattering within the circumbinary disk. This extinction is obtained by including the e †ects of small circumstellar disks that are coplanar with the circumbinary disk. Further, we Ðnd that the e †ects of geometry and illumination allows the observed scattered-light pattern to be reproduced with a dust grain distribution that Ðts data from other Taurus-Auriga circumstellar environments. This indicates that unless geometries and illuminations are known, great care must be taken when attempting to determine grain properties from analysis of scattered-light images. The observed 13CO line proÐles are reproduced using the same geometry adopted for the near-IR modeling. However, we Ðnd that the 13CO abundance is lower than in the di †use interstellar medium, in agreement with previous investigations indicating CO depletion in circumstellar environments.

On the origin of H$_\mathsf{2}$CO abundance enhancements in low-mass protostars

“…Two binary sources in the T Tauri stage have been imaged in great detail; GG Tau and UY Aur (e.g., Dutrey et al 1994;Duvert et al 1998). Wood et al (1999) estimate that GG Tau has cleared its inner 200 AU radius of material and that the bulk of material is located in a circumbinary ring of thickness 600 AU. IRAS 16293-2422 could possibly be a "GG Tau in the making".…”

Visions of Nature's Planet Foundry: Images of Circumstellar Disks

“…Notable recent examples of this approach include multiwavelength image modeling of the GG Tau circumbinary ring (15,49); X2-optimized model fitting to images of HH 30's edge-on disk (4); and combined image and spectral energy distribution modeling of the HR 4796 and Fomalhaut debris disks (23,8). Key results of these and other efforts can be broken down in the following way:…”

Restoration of interferometric images

“…The model is produced using observational parameters for the ring emission taken from observations of the close binary of the quadruple GG Tau system obtained in the near-infrared by Roddier et al (1996), and reproduced afterwards in modelizations by Wood et al (1999). According to the latter we assume that:…”

“…The model is directly inspired by near-infrared observations of the famous T-Tauri binary star of the quadruple system GG Tau and their consecutive data interpretation/modelization (Roddier et al 1996;Wood et al 1999). We believe that this type of object is challenging for any kind of restoration method because it combines point-like features (the core binary star) and a diffuse one (the circumbinary ring), with a high-dynamic range between them.…”