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