1Anicia Arredondo,1Humberto Campins,2Noemi Pinilla-Alonso,3,4Juliade León,5,3Vania Lorenzi,5,6DavidMorat
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2020.114028]
1Physics Department, University of Central Florida, P.O. Box 162385, Orlando, FL 32816, USA
2Florida Space Institute, University of Central Florida, Orlando, FL 32816, USA
3Instituto de Astrofísica de Canarias, C/Vía Láctea s/n, 38205, La Laguna, Tenerife, Spain
4Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain
5Fundación Galileo Galilei – INAF, La Palma (TF), Spain
6Observatório Nacional, Coordenação de Astronomia e Astrofísica, Rio de Janeiro 20921-400, Brazil
There are eight primitive asteroid families in the inner main belt. The PRIMitive Asteroid Spectroscopic Survey (PRIMASS) has characterized all eight families using visible spectroscopy, and two of the families at near infrared wavelengths. This work is part of our survey at near infrared wavelengths and adds a third family, Chaldaea, to it. We see a compositional trend with inclination in the lower inclination families, however, the higher inclination families show more complexity. So far, primitive inner belt families appear spectrally similar (but not identical) in the near infrared despite their diversity at visible wavelengths.
We observed 15 objects in the Chaldaea primitive inner belt family using the NASA InfraRed Telescope Facility (IRTF) and the Telescopio Nazionale Galileo (TNG) between January 2017 and February 2020. Our survey shows that the Chaldaea family is spectrally homogeneous in the NIR, similar to what was seen in the other primitive inner belt families in the near infrared. The Chaldaea family spectra have overwhelmingly concave shapes and have red slopes (average slope 0.85 ± 0.42%/1000 Å in the region between 0.95 and 2.3 μm). We compare these new spectra with spectra from the Klio family and find that they are similar at these wavelengths, which is consistent with these two families having originated from the same parent body.