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J/A+A/612/A85   AKARI IRC asteroid sample diameters & albedos (Ali-Lagoa+, 2018)

The AKARI IRC asteroid flux catalogue: updated diameters and albedos. Ali-Lagoa V., Mueller T.G., Usui F., Hasegawa S. <Astron. Astrophys. 612, A85 (2018)> =2018A&A...612A..85A (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Minor planets Keywords: minor planets, asteroids: general - catalogs Abstract: The AKARI IRC all-sky survey provided more than twenty thousand thermal infrared observations of over five thousand asteroids. Diameters and albedos were obtained by fitting an empirically calibrated version of the standard thermal model to these data. After the publication of the flux catalogue in October 2016, our aim here is to present the AKARI IRC all-sky survey data and discuss valuable scientific applications in the field of small body physical properties studies. As an example, we update the catalogue of asteroid diameters and albedos based on AKARI using the near-Earth asteroid thermal model (NEATM). We fit the NEATM to derive asteroid diameters and, whenever possible, infrared beaming parameters. We fit groups of observations taken for the same object at different epochs of the survey separately, so we compute more than one diameter for approximately half of the catalogue. We obtained a total of 8097 diameters and albedos for 5170 asteroids, and we fitted the beaming parameter for almost two thousand of them. When it was not possible to fit the beaming parameter, we used a straight line fit to our sample's beaming parameter-versus-phase angle plot to set the default value for each fit individually instead of using a single average value. Our diameters agree with stellar-occultation-based diameters well within the accuracy expected for the model. They also match the previous AKARI-based catalogue at phase angles lower than 50°, but we find a systematic deviation at higher phase angles, at which near-Earth and Mars-crossing asteroids were observed. The AKARI IRC All-sky survey is an essential source of information about asteroids, especially the large ones, since, it provides observations at different observation geometries, rotational coverages and aspect angles. For example, by comparing in more detail a few asteroids for which dimensions were derived from occultations, we discuss how the multiple observations per object may already provide three-dimensional information about elongated objects even based on an idealised model like the NEATM. Finally, we enumerate additional expected applications for more complex models, especially in combination with other catalogues. Description: Table 1 contains the best-fitting values of size and beaming parameter and corresponding visible geometric albedos for the full AKARI IRC sample. We fitted the near-Earth asteroid thermal model (NEATM) of Harris (1998Icar..131..291H) to the AKARI IRC thermal infrared data (Murakami et al., 2007PASJ...59S.369M, Onaka et al., 2007PASJ...59S.401O, Ishihara et al., 2010A&A...514A...1I, Cat. II/297, Usui et al., 2011PASJ...63.1117U, Cat. J/PASJ/63/1117, Takita et al., 2012PASJ...64..126T, Hasegawa et al., 2013PASJ...65...34H, Cat. J/PASJ/65/34). The NEATM implementation is described in Ali-Lagoa and Delbo' (2017A&A...603A..55A, cat. J/A+A/603/A55). Minimum relative errors of 10, 15, and 20 percent are given for size, beaming parameter and albedo in those cases where the beaming parameter could be fitted. Otherwise, a default value of the beaming parameter is assumed based on Eq. 1 in the article, and the minimum relative errors in size and albedo increase to 20 and 40 percent (see the discussions in Mainzer et al., 2011ApJ...736..100M, Ali-Lagoa et al., 2016A&A...591A..14A, Cat. J/A+A/591/A14). We also provide the asteroid absolute magnitudes and G12 slope parameters retrieved from Oszkiewicz et al. (2012), the number of observations used in each IRC band (S9W and L18W), plus the heliocentric and geocentric distances and phase angle (r, Delta, alpha) based on the ephemerides taken from the MIRIADE service (http://vo.imcce.fr/webservices/miriade/?ephemph). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 120 8097 Best-fitting values of size and infrared beaming parameter and corresponding geometric visible albedos for the AKARI IRC sample
See also: B/astorb : Orbits of Minor Planets (Bowell+ 2014) II/297 : AKARI/IRC mid-IR all-sky Survey (ISAS/JAXA, 2010) J/PASJ/63/1117 : Asteroid catalog using AKARI (AcuA). V1. (Usui+, 2011) J/PASJ/65/34 : AKARI IRC slow-scan asteroid catalog AcuA-ISS (Hasegawa+ 2013) J/A+A/591/A14 : PCF, SpecB or SDSSB asteroids parameters (Ali-Lagoa+, 2016) J/A+A/603/A55 : WISE/NEOWISE Mars-crossing asteroids (Ali-Lagoa+, 2017) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 8 A8 --- d Asteroid designation (MPC-packed format) 10- 14 F5.2 --- H Asteroid absolute magnitude (MPC) 16- 20 F5.2 --- G Slope parameter (MPC) 22- 28 F7.2 km D Equivalent diameter 30- 36 F7.2 km e_D Equivalent diameter error bar 38- 44 F7.3 --- pV Visible geometric albedo 46- 52 F7.3 --- e_pV Visible geometric albedo error bar 54- 59 F6.2 --- eta Infrared beaming parameter 61- 66 F6.2 --- e_eta Infrared beaming parameter error bar 69- 73 A5 --- Fit [True False] Fit code: "True" means eta was fitted 75- 80 I6 --- S9W Number of data fitted in the 9-micron band 82- 87 I6 --- L18W Number of data fitted in the 18-micron band 90- 96 F7.3 au r Average heliocentric distance 98-104 F7.3 au Delta Average geocentric distance 106-110 F5.2 deg alpha Average phase angle 112-120 F9.3 d MJD Modified Julian Date
Acknowledgements: Victor Ali-Lagoa, vali(at)mpe.mpg.de
(End) Patricia Vannier [CDS] 28-Dec-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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