Lithium abundances for 185 main-sequence stars
... advantage of improved photometric and spectroscopic determinations of effective temperature and metallicity as well as mass and age derived from Hipparcos absolute magnitudes, offering an opportunity to investigate the behaviour of Li as a function of these parameters. An interesting result from thi ...
... advantage of improved photometric and spectroscopic determinations of effective temperature and metallicity as well as mass and age derived from Hipparcos absolute magnitudes, offering an opportunity to investigate the behaviour of Li as a function of these parameters. An interesting result from thi ...
The Solar System
... The protostellar cloud is heated by the young star forming at its center and energy released by the collapsing cloud Inside the frost line it is too hot for ices to form. Outside the frost line it is cold enough for ices to form. Fall, 2005 ...
... The protostellar cloud is heated by the young star forming at its center and energy released by the collapsing cloud Inside the frost line it is too hot for ices to form. Outside the frost line it is cold enough for ices to form. Fall, 2005 ...
n,n - Osaka University
... But the n-sphere is determined by the cross sections, which are larger for higher E ns. Thus (Raffelt) the n-sphere for higher-E n’s is at larger r, hence T lower Tn, than it is for lower E ns. Also, the low-E n’s will have T> their n-sphere at a smaller r, T< hence higher T. So both ends of the dis ...
... But the n-sphere is determined by the cross sections, which are larger for higher E ns. Thus (Raffelt) the n-sphere for higher-E n’s is at larger r, hence T lower Tn, than it is for lower E ns. Also, the low-E n’s will have T> their n-sphere at a smaller r, T< hence higher T. So both ends of the dis ...
Evolutionary properties of galaxies and mass assembly up
... Conclusions : K-band LF and mass density up to z~2 A significant evolution of the bright end of the LF is detected, with no indication of a decrease up to z ~ 2.5 At all redshifts there is a significant difference in the slopes of the early (-0.5 < < 0) and late types (-1.4 < < -1.1) The bright ...
... Conclusions : K-band LF and mass density up to z~2 A significant evolution of the bright end of the LF is detected, with no indication of a decrease up to z ~ 2.5 At all redshifts there is a significant difference in the slopes of the early (-0.5 < < 0) and late types (-1.4 < < -1.1) The bright ...
Efficiency of gas cooling and accretion at the disc-corona
... travels through the coronal gas and eventually falls back to the disc in a time-scale of ∼80–100 Myr. Fraternali & Binney (2006) built a dynamical model of fountain clouds that follow ballistic trajectories into the galactic halo and applied it to the extraplanar H I observations of two nearby galax ...
... travels through the coronal gas and eventually falls back to the disc in a time-scale of ∼80–100 Myr. Fraternali & Binney (2006) built a dynamical model of fountain clouds that follow ballistic trajectories into the galactic halo and applied it to the extraplanar H I observations of two nearby galax ...
Building` a Galaxy SED
... Mid-term exam: October 7th. NO class on September 30 + October 2 Final exam on Dec 10: No class on Nov 9 (MD gone) Class replaced with Kavli seminar on September 11th. More info to follow.... ...
... Mid-term exam: October 7th. NO class on September 30 + October 2 Final exam on Dec 10: No class on Nov 9 (MD gone) Class replaced with Kavli seminar on September 11th. More info to follow.... ...
24.1 Hubble`s Galaxy Classification
... • Objects of relatively uniform luminosities are called “standard candles”; examples include RR Lyrae stars and Type I supernovae. • The Milky Way lies within a small cluster of galaxies called the Local Group. • Other galaxy clusters may contain thousands of galaxies. ...
... • Objects of relatively uniform luminosities are called “standard candles”; examples include RR Lyrae stars and Type I supernovae. • The Milky Way lies within a small cluster of galaxies called the Local Group. • Other galaxy clusters may contain thousands of galaxies. ...
1 REDSHIFT OR TIRED LIGHT. In the Universe, energy quanta are
... Even more quickly than in the Earth's atmosphere, because on a route of a few millimeters, "redshift" is realized when a light ray goes through a simple pane of glass. The density of quantum gas of glass causes that quanta of UV radiation reduce their power, "cool down" to the violet color, by which ...
... Even more quickly than in the Earth's atmosphere, because on a route of a few millimeters, "redshift" is realized when a light ray goes through a simple pane of glass. The density of quantum gas of glass causes that quanta of UV radiation reduce their power, "cool down" to the violet color, by which ...
ASTR 104 - Wagner Homework 1
... differences between these two types of galaxies? 5. I have told you that quasars are extremely luminous. Explain the evidence that we have that this is correct. 6. We said that the Milky Way galaxy contained more mass than we could see. Why do we think that the same is true of clusters of galaxies? ...
... differences between these two types of galaxies? 5. I have told you that quasars are extremely luminous. Explain the evidence that we have that this is correct. 6. We said that the Milky Way galaxy contained more mass than we could see. Why do we think that the same is true of clusters of galaxies? ...
Chapter 15 Stars, Galaxies, and Universe
... •Spiral – bulge in middle, arms spiral outward •Spiral arms contain new stars, gas, dust •New stars formed in spiral arms •Elliptical – round or oval shape, billions of stars, little gas or dust, therefore old stars •Irregular – smaller than other galaxies •Young stars, lots of gas and dust •Located ...
... •Spiral – bulge in middle, arms spiral outward •Spiral arms contain new stars, gas, dust •New stars formed in spiral arms •Elliptical – round or oval shape, billions of stars, little gas or dust, therefore old stars •Irregular – smaller than other galaxies •Young stars, lots of gas and dust •Located ...
A massive hypergiant star as the progenitor of the supernova SN
... ‘super outbursts’ may involve the ejection of massive, many-solar-mass shells4,28, along with very luminous optical displays, during which the luminosity of the star may increase by an order of magnitude or more. These events (sometimes called supernova impostors26) can therefore be confused with ge ...
... ‘super outbursts’ may involve the ejection of massive, many-solar-mass shells4,28, along with very luminous optical displays, during which the luminosity of the star may increase by an order of magnitude or more. These events (sometimes called supernova impostors26) can therefore be confused with ge ...
How To Find Newborn Black Holes Kazumi Kashiyama (UCB)
... of Model V36 will form a disk. The edge of the helium cores of the two models is apparent in the sharp inflection in the angular momentum at 8.3 M⊙ and 15.0 M⊙ . Mass loss was included in the calculation, but due to the low metallicity, only 0.05 M⊙ and 0.15 M⊙ was lost in V24 and V36, respectively. ...
... of Model V36 will form a disk. The edge of the helium cores of the two models is apparent in the sharp inflection in the angular momentum at 8.3 M⊙ and 15.0 M⊙ . Mass loss was included in the calculation, but due to the low metallicity, only 0.05 M⊙ and 0.15 M⊙ was lost in V24 and V36, respectively. ...
Link
... 1994). The Sun appears to be well inside this expanding ring. The nearest OB associations, such as Sco-Cen (d ≈ 150 pc), Per OB2 (d ≈ 300 pc), Orion OB1 (d ≈ 400), and Lac OB1b (d ≈ 500 pc), and the B and A stars that trace the so-called ‘Gould’s Belt’ of nearby young and intermediate age stars are ...
... 1994). The Sun appears to be well inside this expanding ring. The nearest OB associations, such as Sco-Cen (d ≈ 150 pc), Per OB2 (d ≈ 300 pc), Orion OB1 (d ≈ 400), and Lac OB1b (d ≈ 500 pc), and the B and A stars that trace the so-called ‘Gould’s Belt’ of nearby young and intermediate age stars are ...
PPT
... •Rather than occurring individually in space, galaxies are grouped in clusters ranging in size from a few dozens to thousands of galaxies. •The Coma Cluster, shown at right, is 300 million light years from the Milky Way and contains more than 1,000 (and possibly as many as 10,000) galaxies. •The Mil ...
... •Rather than occurring individually in space, galaxies are grouped in clusters ranging in size from a few dozens to thousands of galaxies. •The Coma Cluster, shown at right, is 300 million light years from the Milky Way and contains more than 1,000 (and possibly as many as 10,000) galaxies. •The Mil ...
Astronomy 114 - Department of Astronomy
... Spectra of stars reveal temperature (1/2) Overall, stars have blackbody (thermal) spectra Relative strength of absorption lines is a sensitive probe of temperature ...
... Spectra of stars reveal temperature (1/2) Overall, stars have blackbody (thermal) spectra Relative strength of absorption lines is a sensitive probe of temperature ...
Meilland
... Disk of Be stars (Delaa+ 2011, Meilland+ 2011, Smith+ 2012, Stee+2012) Disk and/or Wind of YSO (Peraut+ 2010, Benisty+ 2013) Interacting binary (Bonneau+ 2011) Wind of supergiants (Chesneau+ 2010) Peculiar stars (Mourard+ 2012) ...
... Disk of Be stars (Delaa+ 2011, Meilland+ 2011, Smith+ 2012, Stee+2012) Disk and/or Wind of YSO (Peraut+ 2010, Benisty+ 2013) Interacting binary (Bonneau+ 2011) Wind of supergiants (Chesneau+ 2010) Peculiar stars (Mourard+ 2012) ...
Spectra of Afterglows
... & non-relativistic phase. A useful model for accounting afterglows should thus be able to describe the overall processes from ultrarelativistic and highly radiative phase to nonrelativistic and adiabatic phase. Especially, it should lead to the well known Sedov limit: β∝ R-3/2, as the expansion gett ...
... & non-relativistic phase. A useful model for accounting afterglows should thus be able to describe the overall processes from ultrarelativistic and highly radiative phase to nonrelativistic and adiabatic phase. Especially, it should lead to the well known Sedov limit: β∝ R-3/2, as the expansion gett ...
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.