Robust associations of massive baryonic objects
{{Short description|Proposed type of star cluster}}
In astronomy, a RAMBO or robust association of massive baryonic objects is a dark cluster made of brown dwarfs or white dwarfs.
RAMBOs were proposed by Moore and Silk in 1995. They may have an effective radius between 1 and 15 parsecs, with masses in the range {{Solar mass|10–100,000|link=y}}.Moore, B., & Silk, J. 1995, Astrophysical Journal, 442, L5-L8 (ADS entry [http://adsabs.harvard.edu/abs/1995ApJ...442L...5M])
The name is a contrived acronym referencing the character John Rambo, in the mold of similar acronyms in astrophysics such as "MACHO" and "WIMP".
Dynamics
The dynamics of these objects, if they do exist, must be quite different from that of standard star clusters. With a very narrow mass range (all brown dwarfs or white dwarfs), the evaporation rate of these RAMBOs should be very slow as predicted by the evolution of simulated mono-component cluster models.de la Fuente Marcos, R. 1995, Astronomy and Astrophysics, 301, 407-418 (ADS entry [http://adsabs.harvard.edu/abs/1995A%26A...301..407D])
Theoretically, these very long-lived objects could exist in large numbers. The presence of a clustered thick disk-like component of dark matter in the Galaxy has been suggested by Sanchez-Salcedo (1997, 1999) and Kerins (1997).Kerins, E. J. 1997, Astronomy and Astrophysics, 322, 709-718 (ADS entry [http://adsabs.harvard.edu/abs/1997A%26A...322..709K])Sánchez-Salcedo, F. J. 1997, Astrophysical Journal, 487, L61-L64 (ADS entry [http://adsabs.harvard.edu/abs/1997ApJ...487L..61S])Sánchez-Salcedo, F. J. 1999, Monthly Notices of the Royal Astronomical Society, 303, 755-772 (ADS entry [http://adsabs.harvard.edu/abs/1999MNRAS.303..755S])