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