We review the available near- and mid-infrared photometry for white dwarfsobtained from the Two Micron All-Sky Survey (2MASS) and by the Spitzer SpaceTelescope. Both data sets have recently been used to seek white dwarfs withinfrared excesses due to the presence of unresolved companions or circumstellardisks, and also to derive the atmospheric parameters of cool white dwarfs. Wefirst attempt to evaluate the reliability of the 2MASS photometry by comparingit with an independent set of published JHK CIT magnitudes for 160 cool whitedwarf stars, and also by comparing the data with the predictions of detailedmodel atmosphere calculations. The possibility of using 2MASS to identifyunresolved M dwarf companions or circumstellar disks is then discussed. We alsorevisit the analysis of 46 binary candidates from Wachter et al. using thesynthetic flux method and confirm the large near-infrared excesses in mostobjects. We perform a similar analysis by fitting Spitzer 4.5 and 8 micronphotometric observations of white dwarfs with our grid of model atmospheres,and demonstrate the reliability of both the Spitzer data and the theoreticalcalculations up to 8 micron. Finally, we search for massive disks resultingfrom the merger of two white dwarfs in a 2MASS sample composed of 57 massivedegenerates, and show that massive disks are uncommon in such stars.
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