Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Dust masses and grain size distributions of a sample of Galactic pulsar wind nebulae

Priestley, Felix D., Barlow, M. J., De Looze, I. and Chawner, Hannah 2020. Dust masses and grain size distributions of a sample of Galactic pulsar wind nebulae. Monthly Notices of the Royal Astronomical Society 491 (4) , pp. 6020-6031. 10.1093/mnras/stz3434

[img]
Preview
PDF - Published Version
Download (902kB) | Preview

Abstract

We calculate dust spectral energy distributions (SEDs) for a range of grain sizes and compositions, using physical properties appropriate for five pulsar wind nebulae (PWNe) from which dust emission associated with the ejecta has been detected. By fitting the observed dust SED with our models, with the number of grains of different sizes as the free parameters, we are able to determine the grain size distribution and total dust mass in each PWN. We find that all five PWNe require large (⁠≥0.1μm⁠) grains to make up the majority of the dust mass, with strong evidence for the presence of micron-sized or larger grains. Only two PWNe contain non-negligible quantities of small (⁠<0.01μm⁠) grains. The size distributions are generally well-represented by broken power laws, although our uncertainties are too large to rule out alternative shapes. We find a total dust mass of 0.02−0.28M⊙ for the Crab Nebula, depending on the composition and distance from the synchrotron source, in agreement with recent estimates. For three objects in our sample, the PWN synchrotron luminosity is insufficient to power the observed dust emission, and additional collisional heating is required, either from warm, dense gas as found in the Crab Nebula, or higher temperature shocked material. For G54.1+0.3, the dust is heated by nearby OB stars rather than the PWN. Inferred dust masses vary significantly depending on the details of the assumed heating mechanism, but in all cases large mass fractions of micron-sized grains are required.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Physics and Astronomy
Publisher: Oxford University Press
ISSN: 0035-8711
Date of First Compliant Deposit: 16 January 2020
Date of Acceptance: 4 December 2019
Last Modified: 30 Jul 2020 15:58
URI: http://orca-mwe.cf.ac.uk/id/eprint/128559

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics