A Self-consistent Model for Brown Dwarf Populations
نویسندگان
چکیده
Abstract We present a self-consistent model of the Milky Way to reproduce observed distributions (spectral type, absolute J -band magnitude, effective temperature) and total velocity dispersion brown dwarfs. For our model, we adopt parametric forms for star formation history initial-mass function, published evolutionary models, theoretical age–velocity relations. Using standard Markov Chain Monte Carlo methods, derive power-law index function α = −0.71 ± 0.11, which is an improvement over previous studies. consider gamma-function form history, though find that this complex only slightly favored declining exponential. variance linearly increases with age has initial value σ 0 = 9.0 − + 11 km s −1 best reproduces dispersions. Given similarities main-sequence stars, suggests dwarfs likely via similar processes, but recognize sizable uncertainties on σ 0 preclude firm conclusions. To further refine these conclusions, suggest wide-field infrared imaging or low-resolution spectroscopic surveys, such as Nancy Grace Roman Space Telescope Euclid, could provide large samples robust spectral types probe thickness thin disk. In way, number counts population demographics same physical processes kinematic measurements, however may larger be subject different selection biases.
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2022
ISSN: ['2041-8213', '2041-8205']
DOI: https://doi.org/10.3847/1538-4357/ac6de5