相关论文: The current population of benchmark brown dwarfs

We aim to provide a detailed characterization of near-infrared spectra for young LT brown dwarfs, including robust spectral typing, calibrating spectral indices, identifying possible binaries, and selecting suitable spectral standards. We…

Searches of large scale surveys have resulted in the discovery of over 1000 brown dwarfs in the Solar neighbourhood. In this chapter we review the progress in finding brown dwarfs in large datasets, highlighting the key science goals, and…

Context: Brown dwarfs exhibit complex atmospheric signatures, and their properties depend sensitively on effective temperature, surface gravity, and metallicity. Several physical properties of brown dwarfs in binary systems can be well…

The physics of brown dwarfs has continuously improved since the discovery of these astrophysical bodies. The first important developments were devoted to the description of their mechanical structure, with the derivation of an appropriate…

We have developed a method "photo-type" to identify and accurately classify L and T dwarfs, onto the standard system, from photometry alone. We combine SDSS, UKIDSS and WISE data and classify point sources by comparing the izYJHKW1W2…

We report on nine wide common proper motion systems containing late-type M, L, or T companions. We confirm six previously reported companions, and identify three new systems. The ages of these systems are determined using diagnostics for…

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…

A long standing and unverified prediction of binary star evolution theory is the existence of a population of white dwarfs accreting from sub-stellar donor stars. Such systems ought to be common, but the difficulty of finding them, combined…

The determination of the fundamental properties (mass, separation, age, gravity and atmospheric properties) of brown dwarf companions allows us to infer crucial informations on their formation and evolution mechanisms. Spectroscopy of…

Almost by definition brown dwarfs are objects with masses below the hydrogen burning limit, around $0.07\ M_\odot$. Below this mass, objects never reach a steady state where they can fuse hydrogen. Here we demonstrate, in contrast to this…

Star formation theories are currently divergent regarding the fundamental physical processes that dominate the substellar regime. Observations of nearby young open clusters allow the brown dwarf (BD) population to be characterised down to…

We have been using Keck laser guide star adaptive optics to monitor the orbits of ultracool binaries, providing dynamical masses at lower luminosities and temperatures than previously available and enabling strong tests of theoretical…

We present spectropolarimetric observations and modelling of 12 DQ white dwarfs. Modelling is based on the method presented in Berdyugina et al. (2005). We use the model to fit the C_2 absorption bands to get atmospheric parameters in…

Accurate parallax measurements allow us to determine physical properties of brown dwarfs, and help us to constrain evolutionary and atmospheric models, break the age-mass degeneracy and reveal unresolved binaries. We measured absolute…

The study of high contrast imaged brown dwarfs and exoplanets depends strongly on evolutionary models. To estimate the mass of a directly imaged substellar object, its extracted photometry or spectrum is used and adjusted with model spectra…

We present paper six of the NIRSPEC Brown Dwarf Spectroscopic Survey, an analysis of multi-epoch, high-resolution (R~20,000) spectra of 25 field dwarf systems (3 late-type M dwarfs, 16 L dwarfs, and 6 T dwarfs) taken with the NIRSPEC…

We present an analysis of low-resolution infrared spectra for 25 brown dwarf candidates in the NGC 1333 molecular cloud. Candidates were chosen on the basis of their association with the high column density cloud core, and near-infrared…

We present a sample of 17 newly discovered ultracool dwarf candidates later than ~M8, drawn from 231.90 arcmin2 of {\it Hubble Space Telescope} Wide Field Camera 3 infrared imaging. By comparing the observed number counts for…

We present a method for measuring the physical parameters of the coldest T-type brown dwarfs using low resolution near infrared spectra. By comparing H_2O- and H_2-sensitive spectral ratios between empirical data and theoretical atmosphere…

Since October of 1995, employing Doppler spectroscopy astronomers have discovered as many as 20 giant planets and brown dwarfs, including companions to $\tau$ Boo, 51 Peg, $\upsilon$ And, 55 Cnc, $\rho$ CrB, 70 Vir, 16 Cyg B, and 47 UMa.…