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.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Brown dwarf populations in open clusters

We present the results of multiple simulations of open clusters, modelling the dynamics of a population of brown dwarf members. We consider the effects of a large range of primordial binary populations, including the possibilities of having brown dwarf members contained within a binary system. We also examine the effects of various cluster diameters and masses. Our examination of a population o...

متن کامل

A Foreground Field Brown Dwarf ?

We examine recent claims that the T-type brown dwarf S Ori 053810.1-203626 (S Ori 70) is a spectroscopically verified low mass (3 −1 MJup) member of the 1–8 Myr σ Orionis cluster. Comparative arguments by Mart́in & Zapatero Osorio asserting that S Ori 70 exhibits low surface gravity spectral features indicative of youth and low mass are invalidated by the fact that their comparison object was no...

متن کامل

Exploring Brown Dwarf Disks

We discuss the spectral energy distribution of three very low mass objects in Chamaeleon I for which ground-based spectroscopy and photometry as well as ISO measurements in the mid-infrared are available (Comerón et al. 2000; Persi et al. 2000). One of these stars (Cha Hα1) is a bona-fide brown dwarf, with mass 0.04–0.05 M⊙. We show that the observed emission is very well described by models of...

متن کامل

Brown Dwarf Disks With

We present ALMA continuum and spectral line data at 0.89 mm and 3.2 mm for three disks surrounding young brown dwarfs and very low mass stars in the Taurus star forming region. Dust thermal emission is detected and spatially resolved for all the three disks, while CO(J = 3 − 2) emission is seen in two disks. We analyze the continuum visibilities and constrain the disks physical structure in dus...

متن کامل

Exploring Brown Dwarf

We discuss the spectral energy distribution of three very low mass objects in Chamaeleon I for which ground-based spectroscopy and photometry as well as ISO measurements in the mid-infrared are available (Comerr on et al. 2000; Persi et al. 2000). One of these stars (Cha H1) is a bona-de brown dwarf, with mass 0.04{0.05 M. We show that the observed emission is very well described by models of c...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: The Astrophysical Journal

سال: 2022

ISSN: ['2041-8213', '2041-8205']

DOI: https://doi.org/10.3847/1538-4357/ac6de5