Astrophysics (Index)About

black-body radiation

(thermal emission, thermal radiation)
(continuous spectrum characteristic of the temperature of a body)

Black-body radiation (thermal emission or thermal radiation) is electromagnetic radiation within and surrounding a body that is in thermodynamic equilibrium at a constant, uniform temperature. It is a continuum emission, i.e., producing continuous spectrum, with a specific shape is dependent only on the temperature of the body (a black-body spectrum). Planck's law (Planck function) describes the spectrum:

I(ν,T) = 2hν3/c2 × 1/(ehν/(kT)-1)

The spectrum represents an ideal case, given that thermodynamic equilibrium and uniform temperature is never perfect, but all materials produce radiation associated with their temperature. The ideal case and its equation represent a useful first approximation, e.g., for stars' spectra.

Further reading:

Referenced by pages:
atmospheric temperature profile
black body (BB)
ionized carbon fine structure line ([CII])
circumstellar disk
cosmic microwave background (CMB)
cold gas
Compton scattering
continuous spectrum
continuum emission
eclipse mapping
effective temperature (Teff)
Europa Clipper
foreground subtraction
gray body
infrared (IR)
infrared excess (IRX)
Infrared Telescope Maffei (ITM)
Kelvin-Helmholtz mechanism
Mars Observer (MO)
Mars Global Surveyor (MGS)
obscured fraction-luminosity relation
OH/IR source
1.3mm observation
Planck function
power law
protoplanetary disk (PPD)
pulsar (PSR)
Rayleigh-Jeans law
radiative forcing (RF)
secondary eclipse
spectral energy distribution (SED)
star formation rate (SFR)
shock wave
submillimeter galaxy (SMG)
spectral index (α)
standard model of a flare
stellar parameter determination
stellar temperature determination
synchrotron radiation
synthetic photometry
Sunyaev-Zel'dovich effect (SZ effect)
thermodynamic equilibrium (TE)
transition region
ultraluminous infrared galaxy (ULIRG)
Very Small Array (VSA)
Wien's displacement law
X-ray burster (XRB)
X-ray source (RS)
Yarkovsky effect
Yarkovsky-O'Keefe-Radzievskii-Paddack effect (YORP)