A) Plasma B) Rock formations C) Gas and dust D) Liquid water
A) Gamma rays B) Visible light C) X-rays D) Radio waves
A) Heat conduction B) Radiative torque alignment C) Ionization imbalance D) Microwave heating
A) H II regions B) Molecular clouds C) Supernova remnants D) Reflection nebulae
A) Helium B) Hydrogen C) Carbon D) Oxygen
A) Platinum B) Silicates C) Diamonds D) Gold
A) Polycyclic aromatic hydrocarbons (PAHs) B) Carbon dioxide (CO2) C) Carbon monoxide (CO) D) Methane (CH4)
A) Blue B) Red C) Yellow D) Green
A) Reflection nebula B) Supernova remnant C) H II region D) Dark nebula
A) 100 ions/m3 B) 1 trillion (1012) molecules/m3 C) 1 billion (109) molecules/m3 D) 10 quadrillion (1016) molecules/m3
A) Photodissociation region B) Warm ionized medium C) Cold dense phase D) Coronal gas
A) 50% B) 1% C) 5% D) 10%
A) Neutron stars B) White dwarfs C) Red giants D) OB stars
A) O(105 K) B) < 300 K C) ~ 106 K D) ~ 104 K
A) ~ 1025 molecules/m3 B) ~ 1016 molecules/m3 C) ~ 100 ions/m3 D) ~ 1012 molecules/m3
A) Very hot gas (T ~ 106 K) B) Cold dense phase C) Photodissociation region D) Warm intercloud phase
A) The phases are roughly in pressure balance over most of the Galactic disk. B) Pressure varies significantly across different regions. C) All phases have equal density. D) Thermal pressure is more important than magnetic fields.
A) Francis Bacon B) René Descartes C) Edward Barnard D) William Huggins
A) Ly-α photon from hydrogen B) 21-cm line of H I C) Forbidden lines of O III D) Spectral lines from CO
A) Primordial nucleosynthesis B) Interstellar dust C) Cosmic rays D) Stellar nucleosynthesis during stellar evolution.
A) They decrease the density of the ISM. B) They create cold neutral medium. C) They convert surrounding gas into the warm ionized phase, increasing temperature. D) They reduce the number of hydrogen atoms.
A) Photon emission from de-excitation B) Bremsstrahlung radiation C) Synchrotron radiation D) Inverse Compton scattering
A) Far infrared quasi-blackbody emission B) Millimetre wavelength lines C) Dipole radiation D) 21-cm line emission
A) H2 (molecular hydrogen) B) CO (carbon monoxide) C) N II D) O III
A) Synchrotron radiation B) Bremsstrahlung cooling C) Inverse Compton scattering D) Collision with atomic nuclei
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 only contains cold gas. B) It remains unchanged from the rest of the galaxy. C) It is profoundly modified by the central supermassive black hole. D) It becomes entirely in the coronal phase.
A) Synchrotron radiation B) 21-cm line emission C) Far infrared quasi-blackbody emission D) Millimetre wavelength lines
A) Synchrotron radiation B) Quasi-blackbody emission C) Inverse Compton scattering D) Bremsstrahlung radiation
A) 2020 B) 2030 C) 2040 D) 2025
A) Emission lines B) Reddening C) Scattering D) Absorption lines
A) Only hydrogen and helium molecules. B) Carbon monoxide. C) Buckminsterfullerene (C60) or 'buckyballs'. D) Simple hydrocarbons.
A) Victor Hess B) Slipher C) Edward Barnard D) Mary Lea Heger
A) Refraction B) Telescope lens C) Spectroscopy D) Photography
A) Inverse Compton scattering B) Bremsstrahlung radiation C) Synchrotron radiation D) Fine structure cooling
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) Balmer-alpha transition B) Lyman-alpha transition C) Brackett-alpha transition D) Paschen-alpha transition
A) Dipole radiation from spinning nanometre-sized grains B) Far infrared quasi-blackbody emission C) Synchrotron radiation D) Bremsstrahlung radiation
A) Infrared emission B) Gamma-ray photons C) Bremsstrahlung radiation D) Synchrotron radiation
A) 100 parsecs (300 light years) B) 30,000 parsecs C) 10,000 parsecs D) 500 parsecs
A) 500 km/s B) 1000 km/s C) 200 km/s D) 50 km/s |