Summary: Rhee et al. 2007

Characterization of Dusty Debris Disks: The IRAS and HIPPARCOS Catalog

Purpose: cross-correlate Hipparcos stars with IRAS

Introduction

• definition of a debris disk: excess flux (w.r.t. the model stellar photosphere) betweeen 25-100 um
• >10 Myrs old --> the dust is second generation
• recall LHB ~ within 600 Myr
• IRAS and SPITZER searches
• as of 2007, several hundred IR-excess stars
• estimate dust mass from submm flux and/or tau
• tau=Lir/Lbol
• predict mass from tau and radius
• THE PROBLEM: most IR excess stars are isolated field stars with poorly determined ages. If we want to choose stars with IR excesses in stellar groups, we are getting a limited sampling of ages. 

Search and Selection Technique

• distance limited to 120 pc
• 60 um IRAS sources
• SED fitting using chi^2 minimization
• stellar photosphere from Hauschildt et al. 1999
• requires fluxes at B, V, J, H, and Ks 
• convert Tycho B and V from table 2 in Bessell (200)
• (or from simbad)
• JHKs came from 1MASS
• convert mags to flux densities (janskies) using Cox 2000
• use a chi^2 fitting with stellar radius and effective temperature as free parameters
• "convolve the filter function with the model spectra" = ???