The Stellar Population Synthesis Technique Charlie Conroy Princeton
... A Parametric Dust Model Lets construct a flexible dust model: • Two dust components: 1. dust around young stars with optical depth τ1 i.e. stars embedded in molecular cloud 2. dust around old stars with optical depth τ2 i.e. cirrus dust a) old dust can be clumpy, with gaussian PDF characterized by ...
... A Parametric Dust Model Lets construct a flexible dust model: • Two dust components: 1. dust around young stars with optical depth τ1 i.e. stars embedded in molecular cloud 2. dust around old stars with optical depth τ2 i.e. cirrus dust a) old dust can be clumpy, with gaussian PDF characterized by ...
Numerical Star-Formation Studies-
... In all of the nearby galaxies where high resolution observations are possible the molecular gas is largely organized into giant clouds (the so called giant molecular clouds or GMCs) of mass ≈ 104 − 107 M with average densities ∼ 100 H2 molecules per cm3 , separated by a more diffuse intercloud medi ...
... In all of the nearby galaxies where high resolution observations are possible the molecular gas is largely organized into giant clouds (the so called giant molecular clouds or GMCs) of mass ≈ 104 − 107 M with average densities ∼ 100 H2 molecules per cm3 , separated by a more diffuse intercloud medi ...
Lithium abundances along the red giant branch: FLAMES
... bump, which is expected from isochrones at 13.m 8 J0 14.m 1. Furthermore, we discarded all targets that had fewer than two quality flags “A” in the 2MASS JHK photometry and targets that had another source within 3 that was not fainter by at least 2.m 0 in the J-band than the target itself. Thi ...
... bump, which is expected from isochrones at 13.m 8 J0 14.m 1. Furthermore, we discarded all targets that had fewer than two quality flags “A” in the 2MASS JHK photometry and targets that had another source within 3 that was not fainter by at least 2.m 0 in the J-band than the target itself. Thi ...
The Significance of Mega Stars
... fish. Here the word “conjunction” means a conjunction in longitude, both at 10½° Aquarius. Even though the Sun and Deneb were 60° apart in terms of latitude, there was still a conjunction in longitude, with the Sun crossing the Deneb meridian at the time of the miracle. Just as there are meridians— ...
... fish. Here the word “conjunction” means a conjunction in longitude, both at 10½° Aquarius. Even though the Sun and Deneb were 60° apart in terms of latitude, there was still a conjunction in longitude, with the Sun crossing the Deneb meridian at the time of the miracle. Just as there are meridians— ...
An Overview of the Gaia
... • There is secular evolution as well. • Galaxies evolved chemically, under the right conditions, since each generation of stars progressively enriches the gas. ...
... • There is secular evolution as well. • Galaxies evolved chemically, under the right conditions, since each generation of stars progressively enriches the gas. ...
black hole
... The core of helium ash cannot generate nuclear energy. Nevertheless, it can grow hotter—because it contracts and converts gravitational energy into thermal energy. The rising temperature heats the unprocessed hydrogen just outside the core—hydrogen that was never previously hot enough to fuse. ...
... The core of helium ash cannot generate nuclear energy. Nevertheless, it can grow hotter—because it contracts and converts gravitational energy into thermal energy. The rising temperature heats the unprocessed hydrogen just outside the core—hydrogen that was never previously hot enough to fuse. ...
1 solar and stellar abundances of the elements
... cluster containing brilliant blue stars we can be reasonably sure that we are dealing with a fairly young population. Many such dusters are known, e.g. the Pleiades and the double cluster in Perseus. In a few clusters we appear to be observing the actual formation of stars from the interstellar medi ...
... cluster containing brilliant blue stars we can be reasonably sure that we are dealing with a fairly young population. Many such dusters are known, e.g. the Pleiades and the double cluster in Perseus. In a few clusters we appear to be observing the actual formation of stars from the interstellar medi ...
Magnitudes lesson plan
... magnitude six, and the other visible stars were arbitrarily placed between magnitudes one and six according to their apparent brightness. Apparent Magnitude refers to the apparent brightness of one star relative to another as seen with the unaided eye. Keep in mind this refers to the apparent bright ...
... magnitude six, and the other visible stars were arbitrarily placed between magnitudes one and six according to their apparent brightness. Apparent Magnitude refers to the apparent brightness of one star relative to another as seen with the unaided eye. Keep in mind this refers to the apparent bright ...
A comparison of the s- and r-process element evolution in local
... Aims. We study the nucleosynthesis of several neutron capture elements (barium, europium, lanthanum, and yttrium) in local group dwarf spheroidal (dSph) galaxies and in the Milky Way by comparing the predictions of detailed chemical evolution models with the observed data. We analyse the differences ...
... Aims. We study the nucleosynthesis of several neutron capture elements (barium, europium, lanthanum, and yttrium) in local group dwarf spheroidal (dSph) galaxies and in the Milky Way by comparing the predictions of detailed chemical evolution models with the observed data. We analyse the differences ...
Folie 1
... Young stars are fainter than expected Young stars accrete not enough material T-Tauri accretion rates are 10-7MSUN/yr or lower.... it would take 10 million years to assemble the Sun ...
... Young stars are fainter than expected Young stars accrete not enough material T-Tauri accretion rates are 10-7MSUN/yr or lower.... it would take 10 million years to assemble the Sun ...
Teacher`s Guide - Cornell Science Inquiry Partnerships
... understand what they mean, is one of the most important activities in science, especially at its most fundamental level. In the 1920s and 1930s, for example, Edwin Hubble and others discovered that there is a relationship between the distance of faraway galaxies and the speed at which the galaxies m ...
... understand what they mean, is one of the most important activities in science, especially at its most fundamental level. In the 1920s and 1930s, for example, Edwin Hubble and others discovered that there is a relationship between the distance of faraway galaxies and the speed at which the galaxies m ...
William Herschel`s Wonderful Decade, 1781-1790
... who was wasting much of his time teaching the aristocracy to fiddle. It was also evident to Banks, a skilled wheeler-dealer, how to bring about the conversion of Herschel into a full-time astronomer. Galileo had long ago exploited the unwritten rules of patronage and had named the moons of Jupiter i ...
... who was wasting much of his time teaching the aristocracy to fiddle. It was also evident to Banks, a skilled wheeler-dealer, how to bring about the conversion of Herschel into a full-time astronomer. Galileo had long ago exploited the unwritten rules of patronage and had named the moons of Jupiter i ...
IAC_L2_thindisk
... Diversion to radial migration (Sellwood & Binney 2002) Stars in disk galaxies can migrate in radius under the torque of a passing transient spiral wave. Stars moving at similar angular velocity to the spiral are flipped from one near-circular orbit to another: inwards or outwards. The spiral wave m ...
... Diversion to radial migration (Sellwood & Binney 2002) Stars in disk galaxies can migrate in radius under the torque of a passing transient spiral wave. Stars moving at similar angular velocity to the spiral are flipped from one near-circular orbit to another: inwards or outwards. The spiral wave m ...
3.2 Black body Radiation
... space astronomy - is an extremely important part of modern astronomy which has fantastically enriched our view of the universe over the past few decades. However, space astronomy is very expensive and difficult to carry out. ...
... space astronomy - is an extremely important part of modern astronomy which has fantastically enriched our view of the universe over the past few decades. However, space astronomy is very expensive and difficult to carry out. ...
Stellar populations
... Main points • Also known as open star clusters • About 400 known; ~18000 may exist in Galaxy • Gal. latitude b ≤ 5º in most cases, very few >10º • Open clusters are mainly young Popn I objects • Typically they contain a few hundred stars • The stars are coeval (of same age), at essentially same dist ...
... Main points • Also known as open star clusters • About 400 known; ~18000 may exist in Galaxy • Gal. latitude b ≤ 5º in most cases, very few >10º • Open clusters are mainly young Popn I objects • Typically they contain a few hundred stars • The stars are coeval (of same age), at essentially same dist ...
FY1995 Q1 Oct-Dec NO.. - National Optical Astronomy Observatory
... elements compared to hydrogen is constant from star to star. This suggests that the cluster formation was rapid, occurring in less than the characteristic time for heavy metal enrichment by Type II supernovae. (In fact, the energetics of these supernovae may have been responsible for clearing the ga ...
... elements compared to hydrogen is constant from star to star. This suggests that the cluster formation was rapid, occurring in less than the characteristic time for heavy metal enrichment by Type II supernovae. (In fact, the energetics of these supernovae may have been responsible for clearing the ga ...
The Origin and Evolution of Dust in Galaxies
... Star formation rate (SFR) > Gas injection rate from SNe and AGB LMC star formation depends on the large reservoir of existing ISM gas The LMC is getting gas poorer. The SFR is likely to be declining with time. Chemical evolution of the LMC ISM is very slow process (~1 Gyrs) – ISM gas : 8x108 Msun (H ...
... Star formation rate (SFR) > Gas injection rate from SNe and AGB LMC star formation depends on the large reservoir of existing ISM gas The LMC is getting gas poorer. The SFR is likely to be declining with time. Chemical evolution of the LMC ISM is very slow process (~1 Gyrs) – ISM gas : 8x108 Msun (H ...
Summary of Talks at Growing Black Holes 2004 in Garching
... z objects -> implication : rapid chemical enrichment near the quasar itself (although not necessarily in the galaxy farther out). NV emission implies multiple generations of star formation. Fe II emission might be from metal-free Pop III stars. BH mass estimates. Work of Vestergaard and Dietrich/H ...
... z objects -> implication : rapid chemical enrichment near the quasar itself (although not necessarily in the galaxy farther out). NV emission implies multiple generations of star formation. Fe II emission might be from metal-free Pop III stars. BH mass estimates. Work of Vestergaard and Dietrich/H ...
Chapter 1 - Pearson Education
... as galaxies and clusters of galaxies occupy regions where gravity has won out against the overall expansion That is, while the universe as a whole continues to expand, individual galaxies and their contents do not expand. Most galaxies, including our own Milky Way, probably formed within a few billi ...
... as galaxies and clusters of galaxies occupy regions where gravity has won out against the overall expansion That is, while the universe as a whole continues to expand, individual galaxies and their contents do not expand. Most galaxies, including our own Milky Way, probably formed within a few billi ...
Chapter 17 Star Stuff Agenda How does a star`s mass affect nuclear
... • Fusion progresses no further in a low-mass star because the core temperature never grows hot enough for fusion of heavier elements (some He fuses to C to make oxygen) • Degeneracy pressure supports the white dwarf against gravity ...
... • Fusion progresses no further in a low-mass star because the core temperature never grows hot enough for fusion of heavier elements (some He fuses to C to make oxygen) • Degeneracy pressure supports the white dwarf against gravity ...
Homologous Stellar Models and Polytropes Main Sequence Stars
... stars for which the CNO-Cycle is the most important source of energy have very large values of L(r)/(4 π r2) in the core. The resulting high temperature gradient ensures efficient convective energy transport in the core. • Because of the extreme sensitivity of CNO burning to temperature, nuclear rea ...
... stars for which the CNO-Cycle is the most important source of energy have very large values of L(r)/(4 π r2) in the core. The resulting high temperature gradient ensures efficient convective energy transport in the core. • Because of the extreme sensitivity of CNO burning to temperature, nuclear rea ...
CENTRAL TEXAS COLLEGE
... Each part of the course is not self-contained. You may expect that basic concepts presented at the beginning of the course will be built upon day by day, added to, expanded upon, etc., so that with time you will have both specific and overall understandings. It is important to link together each pie ...
... Each part of the course is not self-contained. You may expect that basic concepts presented at the beginning of the course will be built upon day by day, added to, expanded upon, etc., so that with time you will have both specific and overall understandings. It is important to link together each pie ...
H II region
An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.