Debiasing The Neowise Cryogenic Mission Comet Populations

Keywords

comets; general infrared; planetary systems Oort Cloud surveys

Abstract

We use NEOWISE data from the four-band and three-band cryogenic phases of the Wide-field Infrared Survey Explorer mission to constrain size distributions of the comet populations and debias measurements of the short- and long-period comet (LPC) populations. We find that the fit to the debiased LPC population yields a cumulative size-frequency distribution (SFD) power-law slope (β) of -1.0 0.1, while the debiased Jupiter-family comet (JFC) SFD has a steeper slope with β = -2.3 0.2. The JFCs in our debiased sample yielded a mean nucleus size of 1.3 km in diameter, while the LPCs' mean size is roughly twice as large, 2.1 km, yielding mean size ratios () that differ by a factor of 1.6. Over the course of the 8 months of the survey, our results indicate that the number of LPCs passing within 1.5 au are a factor of several higher than previous estimates, while JFCs are within the previous range of estimates of a few thousand down to sizes near 1.3 km in diameter. Finally, we also observe evidence for structure in the orbital distribution of LPCs, with an overdensity of comets clustered near 110 inclination and perihelion near 2.9 au that is not attributable to observational bias.

Publication Date

8-1-2017

Publication Title

Astronomical Journal

Volume

154

Issue

2

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.3847/1538-3881/aa72df

Socpus ID

85026916242 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85026916242

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