Massive quiescent galaxies at cosmic noon Robert Feldmann UC Berkeley
... The left-hand panel demonstrates that the SFR at fixed halo mass has been monotonically decreasing since very early • ratedep redshifts. This of decrease is different for different halo masses. At moderate to high redshifts (z > 2), larger halo masses generically have larger average SFRs. However, a ...
... The left-hand panel demonstrates that the SFR at fixed halo mass has been monotonically decreasing since very early • ratedep redshifts. This of decrease is different for different halo masses. At moderate to high redshifts (z > 2), larger halo masses generically have larger average SFRs. However, a ...
Star-Planet Interactions
... and circularized on a timescale of the order of a few tens of Myr thanks to tidal dissipation inside the planet itself. Considering a simple model for the probability of such a tidal encounter, Lanza & Shkolnik (2014) can account for the observed distribution of the orbital periods of the planets in ...
... and circularized on a timescale of the order of a few tens of Myr thanks to tidal dissipation inside the planet itself. Considering a simple model for the probability of such a tidal encounter, Lanza & Shkolnik (2014) can account for the observed distribution of the orbital periods of the planets in ...
The Nature of the Stars
... come in a range of beautiful colors: Blue stars have high surface temperatures, while the surface temperatures of red and yellow stars are relatively low. How have we learned these things? How can we know the nature of the stars, objects so distant that their light takes years or centuries to reach ...
... come in a range of beautiful colors: Blue stars have high surface temperatures, while the surface temperatures of red and yellow stars are relatively low. How have we learned these things? How can we know the nature of the stars, objects so distant that their light takes years or centuries to reach ...
THE ABSOLUTE MAGNITUDE OF RR LYRAE - Cosmos
... stars with larger relative errors have brighter luminosities, i.e., have smaller parallaxes, appears clearly when the true parallax is small, compared with error of parallax. Similarly the distant stars have too faint luminosities, i.e., have too large parallaxes, mainly because the true parallax is ...
... stars with larger relative errors have brighter luminosities, i.e., have smaller parallaxes, appears clearly when the true parallax is small, compared with error of parallax. Similarly the distant stars have too faint luminosities, i.e., have too large parallaxes, mainly because the true parallax is ...
Stardust--Snapshots of Stars
... A group of researchers from Washington University in St. Louis, Missouri and the Carnegie Institution of Washington collaborated with CAMECA to develop and implement an exciting new automated analysis technique on the NanoSIMS that expands on automated methods developed in the early 2000s to study p ...
... A group of researchers from Washington University in St. Louis, Missouri and the Carnegie Institution of Washington collaborated with CAMECA to develop and implement an exciting new automated analysis technique on the NanoSIMS that expands on automated methods developed in the early 2000s to study p ...
The Blue Stragglers in M67 and Single
... 3.1. Fitting the Observed SEDs for Brightest Members For all the luminous high membership probability stragglers, among which 24 are classiÐed as blue stragglers (more luminous and bluer than the main-sequence turno† point) as listed in Table 1, we have 11 Ðlters covering 3890È9190 A that well deÐn ...
... 3.1. Fitting the Observed SEDs for Brightest Members For all the luminous high membership probability stragglers, among which 24 are classiÐed as blue stragglers (more luminous and bluer than the main-sequence turno† point) as listed in Table 1, we have 11 Ðlters covering 3890È9190 A that well deÐn ...
Duplicity and masses
... Duplicity is a key question in astrophysics, and there is no doubt that the Milky Way would look entirely different if stars were single. Binaries provide direct measurements of stellar or galactic quantities and several astronomical phenomena occur only in binary systems. The binary rate, the distr ...
... Duplicity is a key question in astrophysics, and there is no doubt that the Milky Way would look entirely different if stars were single. Binaries provide direct measurements of stellar or galactic quantities and several astronomical phenomena occur only in binary systems. The binary rate, the distr ...
Words: The Power Within - Endeavor Charter School
... Sol + stit (stop, stay) Literal definition – sun stop Dictionary definition – (n) either of the two times in the year when the sun reaches its highest or lowest point in the sky at noon, marked by the longest or shortest day The summer solstice occurs around June 21 and the winter solstice a ...
... Sol + stit (stop, stay) Literal definition – sun stop Dictionary definition – (n) either of the two times in the year when the sun reaches its highest or lowest point in the sky at noon, marked by the longest or shortest day The summer solstice occurs around June 21 and the winter solstice a ...
PPT
... At lower temperatures, white dwarfs are expected to crystallize and phase separation of the main constituents of the core of a typical white dwarf, 12C and 16O, is expected to occur. This sequence of events is expected to introduce significant delays in the cooling times, but has not been proven ...
... At lower temperatures, white dwarfs are expected to crystallize and phase separation of the main constituents of the core of a typical white dwarf, 12C and 16O, is expected to occur. This sequence of events is expected to introduce significant delays in the cooling times, but has not been proven ...
Chapter 6 in the LSST Science Book
... have begun bound to one another, and both may be on their first approach to the Milky Way, not already bound to it. Attempts to model the motion of the Clouds together with a formation model for the Magellanic Stream in light of the new data (e.g., Besla et al. 2009) are very much works in progress. ...
... have begun bound to one another, and both may be on their first approach to the Milky Way, not already bound to it. Attempts to model the motion of the Clouds together with a formation model for the Magellanic Stream in light of the new data (e.g., Besla et al. 2009) are very much works in progress. ...
Heavy Element Abundances in Late-B and Early
... The determination of abundances for the very heavy elements, for both normal and peculiar stars within the spectral type range mid-B to mid-A is vital to two independent fields of study: the nature of CP stars and galactic chemical evolution. Several classes of CP stars coexist within this spectral ...
... The determination of abundances for the very heavy elements, for both normal and peculiar stars within the spectral type range mid-B to mid-A is vital to two independent fields of study: the nature of CP stars and galactic chemical evolution. Several classes of CP stars coexist within this spectral ...
O stars with weak winds: the Galactic case - Max-Planck
... the broader the profile, the lower the precision of the fit of the line. The typical error on Teff is usually of ± 2000 K but can be reduced when many optical He lines are available. Note that the errors we give are 2σ errors (we have Teff − error < Teff < Teff + error). We also checked that our fin ...
... the broader the profile, the lower the precision of the fit of the line. The typical error on Teff is usually of ± 2000 K but can be reduced when many optical He lines are available. Note that the errors we give are 2σ errors (we have Teff − error < Teff < Teff + error). We also checked that our fin ...
Spectroscopy – Lecture 1
... the spectral distribution of the emergent radiation by treating each wavelength separately using its own proper values of j and k.“ ...
... the spectral distribution of the emergent radiation by treating each wavelength separately using its own proper values of j and k.“ ...
Elliptical galaxies
... The effective radius Re is strongly correlated with the absolute magnitude MB ...
... The effective radius Re is strongly correlated with the absolute magnitude MB ...
The Pluto “Smackdown” and The “New” Solar System
... Differences in organic chemistry important as a function of stellar ...
... Differences in organic chemistry important as a function of stellar ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.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.