On the Origin of Metals in Some Hot White Dwarf Photospheres

TL;DR

This study investigates the presence of dust and gas disks around hot white dwarfs to understand the origin of atmospheric metals, but finds no conclusive evidence of accretion from disrupted planetary material.

Contribution

It provides observational constraints on the existence of circumstellar disks around hot white dwarfs and discusses the implications for metal pollution origins.

Findings

No evidence of dust or gas disks detected

White dwarf atmospheres are polluted with heavy elements

Accretion from disrupted minor planets not conclusively observed

Abstract

We have searched for evidence for dust and gas disks at a sample of hot DA white dwarfs 20 000K < Teff < 50 000K, without success. Although their atmospheres are polluted with heavy elements, we cannot yet convincingly and conclusively show that any of these objects is accreting metals from surrounding material derived from disrupted minor planets in an old solar system.