The abundance of brown dwarfs
The amount of mass contained in low-mass objects is investigated anew. Instead of using a mass-luminosity relation to convert a luminosity function to a mass function, I predict the mass-luminosity relation from assumed mass functions and the luminosity functions of Jahreiss and Wielen (1997) and Go...
| Main Author: | |
|---|---|
| Format: | Journal article |
| Published: |
1998
|
| _version_ | 1797101522347098112 |
|---|---|
| author | Binney, J |
| author_facet | Binney, J |
| author_sort | Binney, J |
| collection | OXFORD |
| description | The amount of mass contained in low-mass objects is investigated anew. Instead of using a mass-luminosity relation to convert a luminosity function to a mass function, I predict the mass-luminosity relation from assumed mass functions and the luminosity functions of Jahreiss and Wielen (1997) and Gould et al (1997). Comparison of the resulting mass-luminosity relations with data from binary stars constrains the permissible mass functions. If the mass function is assumed to be a power law, the best fitting slope lies either side of the critical slope, -2, below which the mass in low-mass objects is divergent, depending on the luminosity function adopted. If these power-law mass functions are truncated at 0.001Msun, the contribution to the local density of stars lies between 0.016 and 0.039 Msun pc^-3, in conformity with the density measured dynamically from Hipparcos stars. If the mass function is generalized from a power law to a low-order polynomial in log(M), the mass in stars with M<0.1Msun is either negligible or strongly divergent, depending on the order of the polynomial adopted. |
| first_indexed | 2024-03-07T05:53:06Z |
| format | Journal article |
| id | oxford-uuid:e993793c-c4c2-48f7-8a0d-498ea415e0a6 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T05:53:06Z |
| publishDate | 1998 |
| record_format | dspace |
| spelling | oxford-uuid:e993793c-c4c2-48f7-8a0d-498ea415e0a62022-03-27T10:55:18ZThe abundance of brown dwarfsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:e993793c-c4c2-48f7-8a0d-498ea415e0a6Symplectic Elements at Oxford1998Binney, JThe amount of mass contained in low-mass objects is investigated anew. Instead of using a mass-luminosity relation to convert a luminosity function to a mass function, I predict the mass-luminosity relation from assumed mass functions and the luminosity functions of Jahreiss and Wielen (1997) and Gould et al (1997). Comparison of the resulting mass-luminosity relations with data from binary stars constrains the permissible mass functions. If the mass function is assumed to be a power law, the best fitting slope lies either side of the critical slope, -2, below which the mass in low-mass objects is divergent, depending on the luminosity function adopted. If these power-law mass functions are truncated at 0.001Msun, the contribution to the local density of stars lies between 0.016 and 0.039 Msun pc^-3, in conformity with the density measured dynamically from Hipparcos stars. If the mass function is generalized from a power law to a low-order polynomial in log(M), the mass in stars with M<0.1Msun is either negligible or strongly divergent, depending on the order of the polynomial adopted. |
| spellingShingle | Binney, J The abundance of brown dwarfs |
| title | The abundance of brown dwarfs |
| title_full | The abundance of brown dwarfs |
| title_fullStr | The abundance of brown dwarfs |
| title_full_unstemmed | The abundance of brown dwarfs |
| title_short | The abundance of brown dwarfs |
| title_sort | abundance of brown dwarfs |
| work_keys_str_mv | AT binneyj theabundanceofbrowndwarfs AT binneyj abundanceofbrowndwarfs |