Asteroid shapes and thermal properties from combined optical and mid-infrared photometry inversion

Kód výsledku v IS VaVaI

RIV/00216208:11320/17:10361079 - isvavai.cz

Výsledek na webu

https://arxiv.org/abs/1706.01232

DOI - Digital Object Identifier

10.1051/0004-6361/201730868

Jazyk výsledku

angličtina

Název v původním jazyce

Asteroid shapes and thermal properties from combined optical and mid-infrared photometry inversion

Popis výsledku v původním jazyce

Optical lightcurves can be used for the shape and spin reconstruction of asteroids. Due to unknown albedo, these models are scale-free. When thermal infrared data are available, they can be used for scaling the shape models and for deriving thermophysical properties of the surface by applying a thermophysical model. We introduce a new method of simultaneous inversion of optical and thermal infrared data that allows the size of an asteroid to be derived along with its shape and spin state. The method optimizes all relevant parameters (shape and its size, spin state, light-scattering properties, thermal inertia, surface roughness) by gradient-based optimization. The thermal emission is computed by solving the 1-D heat diffusion equation. Calibrated optical photometry and thermal fluxes at different wavelengths are needed as input data. We demonstrate the reliability and test the accuracy of the method on selected targets with different amount and quality of data. Our results in general agree with those obtained by independent methods. Combining optical and thermal data into one inversion method opens a new possibility for processing photometry from large optical sky surveys with the data from WISE. It also provides more realistic estimates of errors of thermophysical parameters.

Název v anglickém jazyce

Asteroid shapes and thermal properties from combined optical and mid-infrared photometry inversion

Popis výsledku anglicky

Optical lightcurves can be used for the shape and spin reconstruction of asteroids. Due to unknown albedo, these models are scale-free. When thermal infrared data are available, they can be used for scaling the shape models and for deriving thermophysical properties of the surface by applying a thermophysical model. We introduce a new method of simultaneous inversion of optical and thermal infrared data that allows the size of an asteroid to be derived along with its shape and spin state. The method optimizes all relevant parameters (shape and its size, spin state, light-scattering properties, thermal inertia, surface roughness) by gradient-based optimization. The thermal emission is computed by solving the 1-D heat diffusion equation. Calibrated optical photometry and thermal fluxes at different wavelengths are needed as input data. We demonstrate the reliability and test the accuracy of the method on selected targets with different amount and quality of data. Our results in general agree with those obtained by independent methods. Combining optical and thermal data into one inversion method opens a new possibility for processing photometry from large optical sky surveys with the data from WISE. It also provides more realistic estimates of errors of thermophysical parameters.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

GA15-04816S: Celkový obraz hlavního pásu planetek - fyzikální vlastnosti planetek odvozené inverzí optické a infračervené fotometrie

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Astronomy & Astrophysics [online]

ISSN

1432-0746

e-ISSN

—

Svazek periodika

604

Číslo periodika v rámci svazku

07

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

8

Strana od-do

—

Kód UT WoS článku

000408480100117

EID výsledku v databázi Scopus

2-s2.0-85026524430