Metal-Depleted Brown Dwarfs
arXiv:1804.03491 · doi:10.1007/978-3-319-55333-7_173
Abstract
This chapter reviews our current knowledge of metal-poor ultracool dwarfs with spectral types later than M7. The current census of M, L, and T subdwarfs is explored. The main colour trends of subdwarfs from the optical to the mid-infrared are described and their spectral features presented, which led to a preliminary and tentative spectral classification subject to important changes in the future when more of these metal-poor objects are discovered. Their multiplicity and the determination of their physical parameters (effective temperature, gravity, metallicity, and mass) are discussed. Finally, some suggestions and future guidelines are proposed to foster our knowledge on the oldest and coolest members of our Galaxy.
12 pages, 3 figures, Review chapter to appear in "Handbook of Exoplanets", eds. Deeg, H.J. & Belmonte, J.A, Springer (2018)
References in corpus (18)
- Young L Dwarfs Identified in the Field: A Preliminary Low-Gravity, Optical Spectral Sequence from L0 to L5
- A comparison of chemistry and dust cloud formation in ultracool dwarf model atmospheres
- Characterizing Young Brown Dwarfs using Low Resolution Near-IR Spectra
- Revised metallicity classes for low-mass stars: dwarfs (dM), subdwarfs (sdM), extreme subdwarfs (esdM), and ultra subdwarfs (usdM)
- Optical Spectroscopy of 2MASS Color-Selected Ultracool Subdwarfs
- The AllWISE Motion Survey, Part 2
- Primeval very low-mass stars and brown dwarfs. I. Six new L subdwarfs, classification and atmospheric properties
- Cool Subdwarf Investigations (CSI) I: New Thoughts for the Spectral Types of K and M Subdwarfs
- Discovery of the Coolest Extreme Subdwarf
- Parallax and Luminosity Measurements of an L Subdwarf
- Twenty-three new ultra-cool subdwarfs from the Sloan Digital Sky Survey
- Primeval very low-mass stars and brown dwarfs - II. The most metal-poor substellar object
- SDSS J125637-022452: a high proper motion L subdwarf
- A New Sample of Cool Subdwarfs from SDSS: Properties and Kinematics
- New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools: II. SDSS DR7 vs UKIDSS LAS DR6, SDSS DR7 vs UKIDSS LAS DR8, SDSS DR9 vs UKIDSS LAS DR10, and SDSS DR7 vs 2MASS
- Cool Subdwarf Investigations III: Dynamical Masses of Low Metallicity Subdwarfs
- A search for lithium in metal-poor L dwarfs
- Optical and Near-Infrared Spectroscopy of the L Subdwarf SDSS J125637.13-022452.4