A) Gas and dust B) Plasma C) Liquid water D) Rock formations
A) Gamma rays B) X-rays C) Radio waves D) Visible light
A) Heat conduction B) Ionization imbalance C) Microwave heating D) Radiative torque alignment
A) Molecular clouds B) Supernova remnants C) Reflection nebulae D) H II regions
A) Hydrogen B) Carbon C) Helium D) Oxygen
A) Diamonds B) Silicates C) Gold D) Platinum
A) Carbon monoxide (CO) B) Methane (CH4) C) Carbon dioxide (CO2) D) Polycyclic aromatic hydrocarbons (PAHs)
A) Yellow B) Red C) Blue D) Green
A) H II region B) Supernova remnant C) Dark nebula D) Reflection nebula
A) 100 ions/m3 B) 1 billion (109) molecules/m3 C) 10 quadrillion (1016) molecules/m3 D) 1 trillion (1012) molecules/m3
A) Coronal gas B) Cold dense phase C) Warm ionized medium D) Photodissociation region
A) 10% B) 50% C) 1% D) 5%
A) Red giants B) OB stars C) Neutron stars D) White dwarfs
A) O(105 K) B) < 300 K C) ~ 106 K D) ~ 104 K
A) ~ 1012 molecules/m3 B) ~ 1016 molecules/m3 C) ~ 1025 molecules/m3 D) ~ 100 ions/m3
A) Cold dense phase B) Warm intercloud phase C) Photodissociation region D) Very hot gas (T ~ 106 K)
A) Pressure varies significantly across different regions. B) The phases are roughly in pressure balance over most of the Galactic disk. C) All phases have equal density. D) Thermal pressure is more important than magnetic fields.
A) René Descartes B) Edward Barnard C) William Huggins D) Francis Bacon
A) Spectral lines from CO B) Forbidden lines of O III C) Ly-α photon from hydrogen D) 21-cm line of H I
A) Primordial nucleosynthesis B) Interstellar dust C) Stellar nucleosynthesis during stellar evolution. D) Cosmic rays
A) They decrease the density of the ISM. B) They convert surrounding gas into the warm ionized phase, increasing temperature. C) They reduce the number of hydrogen atoms. D) They create cold neutral medium.
A) Synchrotron radiation B) Photon emission from de-excitation C) Inverse Compton scattering D) Bremsstrahlung radiation
A) Millimetre wavelength lines B) Dipole radiation C) Far infrared quasi-blackbody emission D) 21-cm line emission
A) CO (carbon monoxide) B) H2 (molecular hydrogen) C) O III D) N II
A) Collision with atomic nuclei B) Synchrotron radiation C) Inverse Compton scattering D) Bremsstrahlung cooling
A) It prevents star formation in spiral arms. B) It compresses all ISM into a thin disk. C) It has no effect on the ISM. D) It influences their dynamics and structure.
A) It is profoundly modified by the central supermassive black hole. B) It only contains cold gas. C) It remains unchanged from the rest of the galaxy. D) It becomes entirely in the coronal phase.
A) Millimetre wavelength lines B) Far infrared quasi-blackbody emission C) Synchrotron radiation D) 21-cm line emission
A) Synchrotron radiation B) Quasi-blackbody emission C) Bremsstrahlung radiation D) Inverse Compton scattering
A) 2040 B) 2030 C) 2025 D) 2020
A) Scattering B) Reddening C) Emission lines D) Absorption lines
A) Buckminsterfullerene (C60) or 'buckyballs'. B) Simple hydrocarbons. C) Carbon monoxide. D) Only hydrogen and helium molecules.
A) Slipher B) Mary Lea Heger C) Edward Barnard D) Victor Hess
A) Spectroscopy B) Refraction C) Telescope lens D) Photography
A) Fine structure cooling B) Inverse Compton scattering C) Synchrotron radiation D) Bremsstrahlung radiation
A) They reduce the number of photons with energy below the Lyman limit. B) They increase the density of molecular clouds. C) They cool down the ionized gas. D) They contribute to the heating of the warm neutral medium.
A) Balmer-alpha transition B) Brackett-alpha transition C) Lyman-alpha transition D) Paschen-alpha transition
A) Far infrared quasi-blackbody emission B) Synchrotron radiation C) Bremsstrahlung radiation D) Dipole radiation from spinning nanometre-sized grains
A) Gamma-ray photons B) Synchrotron radiation C) Bremsstrahlung radiation D) Infrared emission
A) 100 parsecs (300 light years) B) 30,000 parsecs C) 10,000 parsecs D) 500 parsecs
A) 500 km/s B) 200 km/s C) 50 km/s D) 1000 km/s |