The outflow was detected by the millimeter-wavelength signature of a molecule called hydroxyl (OH), which appeared as an absorption line
: essentially, the shadow of an OH fingerprint in the galaxy's bright infrared light.
The goal is to click on a dip caused by a known absorption line
. That's why it's important to use a prominent A-type star for calibration.
By modulating DFB laser's driving current and working temperature, the center wavelength can be tuned across the absorption line
of a target gas.
In the field of optical spectroscopy, a two-parameter assessment of the characteristics of the absorption line
is provided by the peak position ([E.sub.Peak]) and the full width at half maximum (FWHM).
In the IR spectrum of suspension dispersed for 2 hours the intensity absorption line
corresponds to the absorption line
in the spectrum of carboxymethyl cellulose (i.e.
Another feature is a strong absorption line
of Mg II at 4482 [Angstrom] (Figure 3).
Chandra grating spectromers, combined with earlier XMM-Newton and Chandra observations, gave a 4[sigma] detection of the OVII K[alpha] absorption line
in the spectrum of a background blazer (a bright nonthermal source thought to be powered by accretion onto a supermassive black hole) at redshift z = 0.165 behind the SculpterWall, a large superstructure of galaxies at z = 0.03 .
The quantities [[PHI].sub.0] and [PHI] are the incident and the transmitted radiant powers; [S.sub.T] is the molecular transition line strength of the probed absorption line
at gas temperature T which is matched to the actually present isotopic abundance by means of [r.sub.iso], which is the ratio of the abundance in the sample compared to the value for which the line strength is reported.
Radiation absorption analysis for a given substance can be done for a single absorption line
(dispersive methods) or for wide spectrum (non-dispersive methods) , .
Spectroscopic observations map the Mrk 509 warm absorber, study the mini-broad absorption line
quasar PG 1126-041, determine the source of reddening in low ionization BAL quasars, and probe quasar winds using narrow intrinsic absorption lines
A circularly polarized laser light transmitted through a glass cell containing a vapor of alkali atoms (e.g., Cs) resonates when its frequency equals the first absorption line
of the alkali atoms, thus creating a spin alignment that precesses with a frequency proportional to the modulus of an externally applied magnetic field, [B.sub.0] (Larmor frequency, [w.sub.L] = [gamma][absolute value of [B.sub.0]]).
But the aim is to create a system with a small cell containing acetylene gas and send the beam from the laser through it: if the laser is not on the right frequency, the light "dips" as it goes through the absorption line
and comes back.