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