Gas fraction and star formation efficiency at z \< 1.0⋆⋆⋆⋆⋆⋆
... and the stellar mass (M∗ ). The bulk of star-forming galaxies follow the “normal” mode of star formation in the center of correlation, and define the SFR-M∗ as “main sequence”. The galaxies in the upper envelope of this main sequence have higher SFR at a given mass. These starbursts are rather rare, ...
... and the stellar mass (M∗ ). The bulk of star-forming galaxies follow the “normal” mode of star formation in the center of correlation, and define the SFR-M∗ as “main sequence”. The galaxies in the upper envelope of this main sequence have higher SFR at a given mass. These starbursts are rather rare, ...
b) Formation of Heavy Elements
... c) Hydrogen burning in high mass stars and details of the CNO cycle More massive stars have more gravitational energy, so the core of the star may get relatively hotter than in low mass stars. When the temperature is hotter, the elements move faster, and heavier elements (that also have a higher ch ...
... c) Hydrogen burning in high mass stars and details of the CNO cycle More massive stars have more gravitational energy, so the core of the star may get relatively hotter than in low mass stars. When the temperature is hotter, the elements move faster, and heavier elements (that also have a higher ch ...
Chapter 21 Notes
... is unstable and quickly decays to cobalt-56 and then to iron56. Iron-56 is the most stable nucleus, so it neither fuses nor decays. However, within the cores of the most massive stars, neutron capture can create heavier elements, all the way up to bismuth-209. The heaviest elements are made during t ...
... is unstable and quickly decays to cobalt-56 and then to iron56. Iron-56 is the most stable nucleus, so it neither fuses nor decays. However, within the cores of the most massive stars, neutron capture can create heavier elements, all the way up to bismuth-209. The heaviest elements are made during t ...
Grades 9-12 - pdf - McDonald Observatory
... 1. Collect dust samples using the cleaning pad or clear tape. 2. Carefully remove particles from the pad (scrape with the tweezers and gently shake the pad) onto the graph paper. Then sort the contents by features (size, color, shape…) on the graph paper. Clear tape can be used to hold down the samp ...
... 1. Collect dust samples using the cleaning pad or clear tape. 2. Carefully remove particles from the pad (scrape with the tweezers and gently shake the pad) onto the graph paper. Then sort the contents by features (size, color, shape…) on the graph paper. Clear tape can be used to hold down the samp ...
Carbon, nitrogen, oxygen and lithium abundances of six
... –0.15 dex indicates a slight deficiency in carbon plus nitrogen with respect to the Sun, similar to the deficiencies found in Galactic supergiants and Orion. Lithium has been detected in all the program stars, reaching (Li)=0.6 dex for two stars. Key words: stars: abundances; supergiants – galaxies ...
... –0.15 dex indicates a slight deficiency in carbon plus nitrogen with respect to the Sun, similar to the deficiencies found in Galactic supergiants and Orion. Lithium has been detected in all the program stars, reaching (Li)=0.6 dex for two stars. Key words: stars: abundances; supergiants – galaxies ...
Measuring The Parallax of Barnard's Star
... to worry about the fact that at low altitude stars of different colors are refracted differently by the atmosphere. I had taken the images using a broad-band luminance filter and so this refraction issue could be a problem especially given that the sixth image was acquired when Barnard’s star was so ...
... to worry about the fact that at low altitude stars of different colors are refracted differently by the atmosphere. I had taken the images using a broad-band luminance filter and so this refraction issue could be a problem especially given that the sixth image was acquired when Barnard’s star was so ...
Chemical Signatures in Dwarf Galaxies
... related to one another raises an interesting series of questions. Are dwarf gal axies related to protogalactic fragments, the low mass systems that formed in a L Cold Dark Matter (LCDM) Universe that later merged to build up the large spirals that we see today? Are the dwarf spheroidal and Sloan ga ...
... related to one another raises an interesting series of questions. Are dwarf gal axies related to protogalactic fragments, the low mass systems that formed in a L Cold Dark Matter (LCDM) Universe that later merged to build up the large spirals that we see today? Are the dwarf spheroidal and Sloan ga ...
Slide 1
... Redistribution of angular momentum can provide additional mass to the central star. Magnetic torque can reduce rotation of star if ionization is high (frozen-in magn. field). Process needs ionized gas that may not be available at large distances from the protoSun. Protoplanetary disks apparently do ...
... Redistribution of angular momentum can provide additional mass to the central star. Magnetic torque can reduce rotation of star if ionization is high (frozen-in magn. field). Process needs ionized gas that may not be available at large distances from the protoSun. Protoplanetary disks apparently do ...
Astr. 170B1 Due Feb. 5 Professor Rieke and TA Melissa Halford
... The plot at the right shows a magnified section of the Vega spectrum in black. You may assume that Vega is not moving. The red plot is part of the spectrum from another star very similar to Vega except for its Doppler shift. The numbers show the location of the spectral line. Use c=300,000 km/se ...
... The plot at the right shows a magnified section of the Vega spectrum in black. You may assume that Vega is not moving. The red plot is part of the spectrum from another star very similar to Vega except for its Doppler shift. The numbers show the location of the spectral line. Use c=300,000 km/se ...
The Fundamental Plane, Stellar Popula6ons
... The youngest galaxies have higher minimum metalliciBes The least metal‐rich galaxies have older minimum ages ...
... The youngest galaxies have higher minimum metalliciBes The least metal‐rich galaxies have older minimum ages ...
Energy transport in stellar interiors
... Energy transport in stellar interiors The energy that a star radiates from its surface is generally replenished from sources or reservoirs located in its hot central region. We have seen that most stars are in a long-lived state of thermal equilibrium, in which these terms exactly balance. What woul ...
... Energy transport in stellar interiors The energy that a star radiates from its surface is generally replenished from sources or reservoirs located in its hot central region. We have seen that most stars are in a long-lived state of thermal equilibrium, in which these terms exactly balance. What woul ...
AST 112 – Activity #4 The Stellar Magnitude System
... necessary. Hint: Also refer to Table 4-1 above. (a) Is star J further than, closer to, or equal to 10 pc distant? ...
... necessary. Hint: Also refer to Table 4-1 above. (a) Is star J further than, closer to, or equal to 10 pc distant? ...
The Young Stars
... have provided most of our knowledge of Young Stellar Objects (YSOs). Due to their large numbers, however, they also provide us with statistical samples and spatial distributions. Finally, we find that both accretion and outflow have not been entirely eradicated but are still ongoing in a moderate fo ...
... have provided most of our knowledge of Young Stellar Objects (YSOs). Due to their large numbers, however, they also provide us with statistical samples and spatial distributions. Finally, we find that both accretion and outflow have not been entirely eradicated but are still ongoing in a moderate fo ...
S1-4-03 - Celestial Navigation
... Begin by showing students a star trails photograph of how stars move across the night sky in the northern hemisphere. Try to draw out more in-depth reasoning for the circular pattern and the star in the middle, explaining that the picture is of star trails due to the earth's rotation. Guide the stud ...
... Begin by showing students a star trails photograph of how stars move across the night sky in the northern hemisphere. Try to draw out more in-depth reasoning for the circular pattern and the star in the middle, explaining that the picture is of star trails due to the earth's rotation. Guide the stud ...
Be stars: one ring to rule them all
... disk dissipation of active hot stars and account for the transition from the Be to the B spectroscopic phase. Methods. We use the SIMECA code to investigate two scenarios, the first one where the disk is formed by successive outbursts of the central star. A low-density region is developing above the ...
... disk dissipation of active hot stars and account for the transition from the Be to the B spectroscopic phase. Methods. We use the SIMECA code to investigate two scenarios, the first one where the disk is formed by successive outbursts of the central star. A low-density region is developing above the ...
TISHTRIYA - Earth`s second Sun
... The heliacal rising of Tishtriya in the pre-dawn sky Once in a year the heliacal rising of Tishtriya occurs when it first becomes visible above the eastern horizon for a brief moment just before sunrise, after a period of time when it had not been visible. Each day after the first heliacal rising, t ...
... The heliacal rising of Tishtriya in the pre-dawn sky Once in a year the heliacal rising of Tishtriya occurs when it first becomes visible above the eastern horizon for a brief moment just before sunrise, after a period of time when it had not been visible. Each day after the first heliacal rising, t ...
A Tour of the Radio Universe
... This mosaic image is the sharpest wide-angle view ever obtained of M82. The galaxy is remarkable for its bright blue disk, webs of shredded clouds, and fiery-looking plumes of glowing hydrogen blasting out of its central regions. Throughout the galaxy's center, young stars are being born 10 times fa ...
... This mosaic image is the sharpest wide-angle view ever obtained of M82. The galaxy is remarkable for its bright blue disk, webs of shredded clouds, and fiery-looking plumes of glowing hydrogen blasting out of its central regions. Throughout the galaxy's center, young stars are being born 10 times fa ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.