Physics
Region
100%
Gas
70%
Model
68%
Spectra
63%
Active Galactic Nuclei
60%
Ionization
53%
Clouds
45%
Ratio
42%
Temperature
40%
X Ray
34%
Calculation
33%
Quasar
30%
Nebula
29%
Galaxy
27%
Orion Nebula
27%
Photoionization
27%
Hydrogen
26%
Speed
24%
Dust
23%
Ion
20%
Reverberation
19%
Variation
19%
Collision
18%
Shapes
18%
Environment
17%
Metallicity
17%
Hubble Space Telescope
16%
Core
16%
Interstellar Matter
15%
Mathematical Model
14%
Blood Plasma
14%
Line of Sight
14%
H II Regions
14%
Line Spectra
14%
Independent Variables
13%
Star Formation
13%
Ionized Gas
13%
Molecular Clouds
12%
Space Telescope
12%
Cooling Flow
12%
Spectrometer
12%
Coefficient
12%
Electron
12%
Molecular Gas
11%
Atom
11%
Parameter
11%
Black Holes
11%
Heating
10%
Width
10%
Planetary Nebula
10%
Earth and Planetary Sciences
Emissions
52%
Region
43%
Active Galactic Nuclei
25%
Model
24%
Observation
21%
Gas
20%
Orion Nebula
16%
Spectra
15%
Show
15%
Quasar
12%
Nebulae
12%
Reverberation
10%
X Ray
10%
Investigation
10%
Abundance
10%
Photoionization
9%
Hubble Space Telescope
8%
Hydrogen
7%
Calculation
7%
Variation
7%
Cartography
7%
Line of Sight
6%
Variability
6%
Analytical Method
6%
Molecular Clouds
6%
Galaxy
6%
Speed
5%
Spectrographs
5%
Metallicity
5%
Average
5%
Line Spectra
5%
Core
5%
Accretion Disk
5%