相关论文: HCN and C2H2 in the atmosphere of a T8.5+T9 brown …

The James Webb Space Telescope (JWST) offers exceptional spectral resolution and wavelength coverage, which are essential for studying the coldest brown dwarfs, particularly Y dwarfs. These objects are at the cold end of the sub-stellar…

Brown dwarfs are essential probes of stellar and planetary formation, yet their low luminosities pose challenges for detection at large Galactic distances. The James Webb Space Telescope (JWST), with its unprecedented near-infrared…

We present the first brown dwarf spectral binary characterized with JWST: WISE J014656.66+423410.0, the coldest blended-light brown dwarf binary straddling the T/Y transition. We obtained a moderate resolution (R$\sim$2700) G395H spectrum…

Evidence of disequilibrium chemistry due to vertical mixing in the atmospheres of many T and Y-dwarfs has been inferred due to enhanced mixing ratios of CO and reduced NH$_3$. Atmospheric models of planets and brown dwarfs typically…

JWST is opening many avenues for exploration. For cold brown dwarfs and exoplanets, JWST has opened the door to the mid-infrared wavelength region, where such objects emit significant energy. For the first time, astronomers have access to…

We present an atmospheric retrieval analysis of the Y0 brown dwarf WISE J035934.06$-$540154.6 using the low-resolution 0.96--12 $\mu$m JWST spectrum presented in \citet{Beiler_2023}. We obtain volume number mixing ratios of the major…

High-contrast, medium-resolution spectroscopy with JWST can resolve molecular and isotopic features in cool substellar atmospheres, but for close-in companions the extracted spectra can be biased by wavelength-dependent residual stellar…

Most brown dwarfs have atmospheres with temperatures cold enough to form clouds. A variety of materials likely condense, including refractory metal oxides and silicates; the precise compositions and crystal structures of predicted cloud…

The multiplicity properties of brown dwarfs are critical empirical constraints for formation theories, while multiples themselves provide unique opportunities to test evolutionary and atmospheric models and examine empirical trends. Studies…

We used HST/WFC3 observations of a sample of 26 nearby ($\le$20 pc) mid to late T dwarfs to search for cooler companions and measure the multiplicity statistics of brown dwarfs. Tightly-separated companions were searched for using a…

Brown dwarf spectra offer vital testbeds for our understanding of the chemical and physical processes that sculpt substellar atmospheres. Recently, atmospheric retrieval approaches have been applied to a number of low-resolution (R~100)…

We conducted a search for brown dwarf candidates in a James Webb Space Telescope deep field around A2744 to investigate the space density of these objects at kiloparsec distances. Our methodology employed an initial selection based on…

The launch of the James Webb Space Telescope (JWST) marks a pivotal moment for precise atmospheric characterization of Y dwarfs, the coldest brown dwarf spectral type. In this study, we leverage moderate spectral resolution observations (R…

Benchmark brown dwarfs in wide binary systems are crucial for characterizing substellar objects and calibrating atmospheric and evolutionary models. However, brown dwarf benchmarks with subsolar metallicity, very cool temperatures, or…

By combining the JWST/NIRCam JADES and CEERS extragalactic datasets, we have uncovered a sample of twenty-one T and Y brown dwarf candidates at best-fit distances between 0.1 - 4.2 kpc. These sources were selected by targeting the blue…

Stellar-substellar binary systems are quite rare, and provide interesting benchmarks. They constrain the complex physics of substellar atmospheres, because several physical parameters of the substellar secondary can be fixed from the much…

Brown dwarfs are failed stars with very low mass (13 to 75 $M_J$), and an effective temperature lower than 2500 K. Thus, they play a key role in understanding the gap in the mass function between stars and planets. However, due to their…

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…

We present observations of the T8 dwarf 2MASS 0415-0935 with JWST's NIRSpec spectrograph using the G395H grating ($\sim$ 2.87 - 5.14 $\mu$m). We perform the first atmospheric retrieval analysis at the maximum spectral resolution of NIRSpec…

Young brown dwarfs serve as analogues of giant planets and provide benchmarks for atmospheric and formation models. JWST has enabled access to near-infrared spectra of brown dwarfs with unprecedented sensitivity. We aim to constrain their…