Dust Destruction by Charging: A Possible Origin of Grey Extinction Curves of Active Galactic Nuclei

Abstract

Observed extinction curves of active galactic nuclei (AGNs) are significantly different from those observed in the Milky Way. The observations require preferential removal of small grains at the AGN environment; however, the physics for this remains unclear. In this paper, we propose that dust destruction by charging, or Coulomb explosion, may be responsible for AGN extinction curves. Harsh AGN radiation makes a dust grain highly charged through photoelectric emission, and grain fission via the Coulomb explosion occurs when the electrostatic tensile stress of a charge grain exceeds its tensile strength. We show that the Coulomb explosion can preferentially remove both small silicate and graphite grains and successfully reproduce both flat extinction curves and the absence of 2175Å~bump.

arXiv comment8 pages, 6 Figures; Accepted for publication in ApJ

References in corpus (32)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• Infrared Emission from Interstellar Dust. II. The Diffuse Interstellar Medium
• AGN Dusty Tori: I. Handling of Clumpy Media
• Photoelectric Emission from Interstellar Dust: Grain Charging and Gas Heating
• Scattering by Interstellar Dust Grains. II. X-Rays
• Dust in active nuclei. I. Evidence for "anomalous" properties
• The global dust SED: Tracing the nature and evolution of dust with DustEM
• Dust sublimation by GRBs and its implications
• A supernova origin for dust in a high-redshift quasar
• Reverberation Measurements of the Inner Radius of the Dust Torus in 17 Seyfert Galaxies
• Dust in the polar region as a major contributor to the IR emission of AGN
• The dusty torus in the Circinus galaxy: a dense disk and the torus funnel
• Dust in active nuclei. II. Powder or gravel?
• The Nuclear Reddening Curve for Active Galactic Nuclei and the Shape of the Infra-Red to X-Ray Spectral Energy Distribution
• Parsec-scale dust emission from the polar region in the type 2 nucleus of NGC 424
• X-ray Destruction of Dust Along the Line of Sight to Gamma-Ray Bursts
• Dust inflated accretion disc as the origin of the Broad Line Region in Active Galactic Nuclei
• The extinction law at high redshift and its implications
• Redefining the torus: A unifying view of AGN in the infrared and sub-mm
• Mid-infrared interferometry of 23 AGN tori: On the significance of polar-elongated emission
• Modeling Dust and Starlight in Galaxies Observed by Spitzer and Herschel: NGC 628 and NGC 6946
• An image of the dust sublimation region in the nucleus of NGC 1068
• Rotational Disruption of Dust Grains by Radiative Torques in Strong Radiation Fields
• Multi-phase Nature of a Radiation-Driven Fountain with Nuclear Starburst in a Low-mass Active Galactic Nucleus
• Photoelectric Emission from Dust Grains Exposed to Extreme Ultraviolet and X-ray Radiation
• Extinction due to amorphous carbon grains in red quasars from the SDSS
• New evidence for the dusty wind model: Polar dust and a hot core in the type-1 Seyfert ESO323-G77
• Reverberation Measurements of the Inner Radii of the Dust Tori in Quasars
• A New Method for Measuring Extragalactic Distances
• Rapid Luminosity Decline and Subsequent Reformation of the Innermost Dust Distribution in the Changing-look AGN Mrk 590
• On inferring extinction laws in z~6 quasars as signatures of supernova dust

Cited by in corpus (14)

• Little Red Dots: Rapidly Growing Black Holes Reddened by Extended Dusty Flows
• The picture of BLR in 2.5-D FRADO: Dynamics & Geometry
• Dust attenuation evolution in $z\sim 2$-$12$ JWST galaxies
• Infrared emission of $z\sim 6$ galaxies: AGN imprints
• The dust attenuation law in $z\sim 6$ quasars
• Dusty plasma in active galactic nuclei
• Detection of the 2175Å UV Bump at z>7: Evidence for Rapid Dust Evolution in a Merging Reionisation-Era Galaxy
• Radiative transfer of ionizing radiation through gas and dust: grain charging in star forming regions
• Measurement of AGN dust extinction based on the near-infrared flux variability of WISE data
• Multiple giant eruptions and X-ray emission in the recoiling AGN/LBV candidate SDSS1133
• Modelling Grain Rotational Disruption by Radiative Torques and Extinction of Active Galactic Nuclei
• On planet formation around supermassive black holes and the grain disruption barriers by radiative torques
• H1821+643: The most X-ray and infrared luminous AGN in the Swift/BAT survey in the process of rapid stellar and supermassive black hole mass assembly
• Resonant instabilities mediated by drag and electrostatic interactions in laboratory and astrophysical dusty plasmas