The incidence of mid-infrared excesses in G and K giants

Abstract

Using photometric data from the 2MASS and GLIMPSE catalogues, I investigate the incidence of mid-infrared excesses (~10 microns) of G and K stars of luminosity class III. In order to obtain a large sample size, stars are selected using a near-IR colour-magnitude diagram. Sources which are candidates for showing mid-IR excess are carefully examined and modelled to determined whether they are likely to be G/K giants. It is found that mid-IR excesses are present at a level of (1.8 +/- 0.4) x 10^-3. While the origin of these excesses remains uncertain, it is plausible that they arise from debris discs around these stars. I note that the measured incidence is consistent with a scenario in which dust lifetimes in debris discs are determined by Poynting-Robertson drag rather than by collisions.

arXiv commentAccepted for publication in MNRAS. 13 pages, 5 figures, 2 tables (1 landscape table)

References in corpus (14)

• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• Infrared Emission from Interstellar Dust. II. The Diffuse Interstellar Medium
• GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
• The Wavelength Dependence of Interstellar Extinction from 1.25 to 8.0 microns Using GLIMPSE Data
• Modelling the Galactic Interstellar Extinction Distribution in Three Dimensions
• Old stellar Galactic disc in near-plane regions according to 2MASS: scales, cut-off, flare and warp
• The Insignificance of P-R Drag in Detectable Extrasolar Planetesimal Belts
• A Dusty Disk Around GD 362, a White Dwarf With a Uniquely High Photospheric Metal Abundance
• A Debris Disk around the Central Star of the Helix Nebula?
• Tycho 2 stars with infrared excess in the MSX Point Source Catalogue
• Polycyclic Aromatic Hydrocarbons Orbiting HD 233517, an Evolved Oxygen-Rich Red Giant
• The Frequency of Mid-Infrared Excess Sources in Galactic Surveys

Cited by in corpus (5)

• GRACES observations of young [alpha/Fe]-rich stars
• Li-rich RGB stars in the Galactic Bulge
• A Substantial Dust Disk Surrounding an Actively Accreting First-Ascent Giant Star
• Multi-wavelength Radio Continuum Emission Studies of Dust-free Red Giants
• FGK 22 $\mu$m Excess Stars in LAMOST DR2 Stellar Catalog