TY - JOUR
T1 - The origin of (90) Antiope from component-resolved near-infrared spectroscopy
AU - Marchis, F.
AU - Enriquez, J. E.
AU - Emery, J. P.
AU - Berthier, J.
AU - Descamps, P.
AU - Vachier, F.
N1 - Funding Information:
FM work was supported by the National Science Foundation under award number AAG-0807468. This research has made use of NASA’s Astrophysics Data System and Mendeley™ software. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. We are grateful to Todd Bradley and Keaton Burns for providing edits and comments that improved this manuscript and for C. Chapman and an anonymous reviewer for their valuable comments which improved significantly this manuscript.
PY - 2011/5
Y1 - 2011/5
N2 - The origin of the similarly-sized binary Asteroid (90) Antiope remains an unsolved puzzle. To constrain the origin of this unique double system, we recorded individual spectra of the components using SPIFFI, a near-infrared integral field spectrograph fed by SINFONI, an adaptive optics module available on VLT-UT4. Using our previously published orbital model, we requested telescope time when the separation of the components of (90) Antiope was larger than 0.087″, to minimize the contamination between components, during the February 2009 opposition. Several multi-spectral data-cubes in J band (SNR = 40) and H. +. K band (SNR = 100) were recorded in three epochs and revealed the two components of (90) Antiope. After developing a specific photometric extraction method and running an error analysis by Monte-Carlo simulations, we successfully extracted reliable spectra of both components from 1.1 to 2.4μm taken on the night of February 21, 2009. These spectra do not display any significant absorption features due to mafic mineral, ices, or organics, and their slopes are in agreement with both components being C- or Cb-type asteroids. Their constant flux ratio indicates that both components' surface reflectances are quite similar, with a 1-sigma variation of 7%. By comparison with 2MASS J, H, K color distribution of observed Themis family members, we conclude that both bodies were most likely formed at the same time and from the same material. The similarly-sized system could indeed be the result of the breakup of a rubble-pile proto-Antiope into two equal-sized bodies, but other scenarios of formation implying a common origin should also be considered.
AB - The origin of the similarly-sized binary Asteroid (90) Antiope remains an unsolved puzzle. To constrain the origin of this unique double system, we recorded individual spectra of the components using SPIFFI, a near-infrared integral field spectrograph fed by SINFONI, an adaptive optics module available on VLT-UT4. Using our previously published orbital model, we requested telescope time when the separation of the components of (90) Antiope was larger than 0.087″, to minimize the contamination between components, during the February 2009 opposition. Several multi-spectral data-cubes in J band (SNR = 40) and H. +. K band (SNR = 100) were recorded in three epochs and revealed the two components of (90) Antiope. After developing a specific photometric extraction method and running an error analysis by Monte-Carlo simulations, we successfully extracted reliable spectra of both components from 1.1 to 2.4μm taken on the night of February 21, 2009. These spectra do not display any significant absorption features due to mafic mineral, ices, or organics, and their slopes are in agreement with both components being C- or Cb-type asteroids. Their constant flux ratio indicates that both components' surface reflectances are quite similar, with a 1-sigma variation of 7%. By comparison with 2MASS J, H, K color distribution of observed Themis family members, we conclude that both bodies were most likely formed at the same time and from the same material. The similarly-sized system could indeed be the result of the breakup of a rubble-pile proto-Antiope into two equal-sized bodies, but other scenarios of formation implying a common origin should also be considered.
KW - Adaptive optics
KW - Asteroids, Surfaces
KW - Satellites of asteroids
KW - Spectroscopy
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U2 - 10.1016/j.icarus.2011.02.011
DO - 10.1016/j.icarus.2011.02.011
M3 - Article
AN - SCOPUS:79952897664
SN - 0019-1035
VL - 213
SP - 252
EP - 264
JO - Icarus
JF - Icarus
IS - 1
ER -