AKARI Near Infrared Asteroid Spectral Catalog Ver.1 ================================================================================ AKARI/IRC Near-Infrared Asteroid Spectroscopic Survey: AcuA-spec Usui, F., Hasegawa, S., Ootsubo, T., and Onaka, T. =2019PASJ...71....1U ================================================================================ ADC_Keywords: Solar system ; Minor planets ; Spectra, infrared Mission_Name: AKARI Keywords: space vehicles - minor planets, asteroids: general - infrared: planetary systems - techniques: spectroscopic Description: This catalog contains near-infrared (2.5-5.0 micron) low-resolution (R ~ 100) spectra of main-belt asteroids obtained with the Infrared Camera (IRC; Onaka et al. 2007, Ohyama et al. 2007) onboard the infrared astronomical satellite AKARI (Murakami et al. 2007) in the warm mission period of AKARI (called Phase 3). 147 pointed observations for 66 asteroids with a diameter of 40 km or larger were performed in the grism mode of 2.5-5 micron band. By subtracting thermal emission of asteroids themselves and dividing with the solar spectrum, the reflectance spectra of asteroids are retrieved. It should be noted that (a) the signal of 4 Vesta was saturated in the 3-micron band thoroughly and (b) the thermal emission of 4015 Wilson-Harrington was dominated in the 3-micron band due to its high temperature. Thus the reflectance spectra of these two objects could not be extracted. In total, the reflectance spectra of 64 asteroids are summarized in this catalog which comprises 22 C-complex, 17 S-complex, 22 X-complex, and 3 D-complex asteroids. There still remain the wavy patterns likely due to the contamination of neighboring stars or insufficient data reduction. These unreliable wavelengths are flagged in the spectral data. Data users must be careful about these flagged spectra. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file target.txt . 147 Target list flux/*.txt . 147 Individual spectra of flux desity (1) reflectance/*.txt . 64 Individual spectra of relative reflectance (2) -------------------------------------------------------------------------------- Note (1): The name of spectrum of flux density is represented by a combination of asteroid number (Number), name (Name), and Observational ID (ObsID) with extension as "Number_Name_ObsID.txt" stored in "flux/". Note (2): The name of spectrum of relative reflectance is represented by a combination of asteroid number (Number) and name (Name) with extension as "Number_Name.txt" stored in "reflectance/". Byte-by-byte Description of file: target.txt -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- Number Asteroid's number 6- 22 A17 --- Name Asteroid's name 24- 34 A11 --- ObsID Observational ID 36- 54 A19 --- Datetime Observation datetime (UT) 56- 63 F8.4 deg RA Right ascension (J2000) 65- 72 F8.4 deg Dec Declination (J2000) -------------------------------------------------------------------------------- Byte-by-byte Description of file: flux/*.txt -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 5 F5.3 micron Lambda Wavelength in micron 7- 13 F7.2 mJy Flux Observed flux density 15- 20 F6.2 mJy e_Flux Uncertainty in Flux 22- 22 I1 --- sflag Saturation flag (3) 24- 24 I1 --- csflag Stellar contamination flag (4) -------------------------------------------------------------------------------- Note (3): Saturation flag for bright objects. 0 = not saturated 1 = saturated Note (4): Stellar contamination flag by neighboring stars 0 = not contaminated 1 = contaminated by neighboring star(s) Byte-by-byte Description of file: reflectance/*.txt -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 5 F5.3 micron Lambda Wavelength in micron 7- 12 F6.3 --- Refl Relative Reflectance (5) 14- 18 F5.3 --- e_Refl Uncertainty in Relative Reflectance 20- 20 I1 --- eflag Error flag (6) 22- 22 I1 --- sflag Saturation flag (3) 24- 24 I1 --- ctflag Thermal contamination flag (7) 26- 26 I1 --- csflag Stellar contamination flag (4) -------------------------------------------------------------------------------- Note (5): Normalized at 2.6 micron. Note (6): Error flag for uncertainty of the spectra > 0.1. 0 = good 1 = large uncertainty in relative reflectance Note (7): Thermal contamination flag (wavelength > lambda_trunc) 0 = not severely contaminated 1 = severely contaminated by thermal emission -------------------------------------------------------------------------------- History: * 30-Nov-2018: Documentation prepared by Fumihiko Usui * 13-Feb-2019: Reference updated (Usui et al. 2019) Author's address: Fumihiko Usui, usui(at)cps-jp.org ================================================================================ (End) Fumihiko Usui [Kobe University] 13-Feb-2019