Carbon, nitrogen, oxygen and lithium abundances of six
... models for 5 M stars in the range of temperatures 3600 < Teff < 4750, in steps of 200/250 K, gravities –0.5 < log g < 3.5 in steps of 0.5 dex, metallicities –0.6 < [Fe/H] < +0.6 in steps of 0.3 dex, and microturbulent velocity vt = 2 km s−1 . A code for interpolation in this grid was used to obtain ...
... models for 5 M stars in the range of temperatures 3600 < Teff < 4750, in steps of 200/250 K, gravities –0.5 < log g < 3.5 in steps of 0.5 dex, metallicities –0.6 < [Fe/H] < +0.6 in steps of 0.3 dex, and microturbulent velocity vt = 2 km s−1 . A code for interpolation in this grid was used to obtain ...
1. INTRODUCTION 2. MASS AND LIGHT
... 2. The argument of ° 2 fails because the intervening structures happen to be contained within 5¡ of the LMC center (although they must extend over at least the inner D3¡ to account for the observed events). This possibility could only apply to a self-gravitating structure and not to an intrinsically ...
... 2. The argument of ° 2 fails because the intervening structures happen to be contained within 5¡ of the LMC center (although they must extend over at least the inner D3¡ to account for the observed events). This possibility could only apply to a self-gravitating structure and not to an intrinsically ...
Extragalactic Astronomical Masers I
... Properties of astronomical masers are 1) isotropic luminosity of masers is about six orders of magnitude larger than that of stellar masers, while the emitting region is only about one astronomical unit (≈1.5×1013 cm), very compact (Thus, the maser emitting region is called a maser spot.), 2) line-w ...
... Properties of astronomical masers are 1) isotropic luminosity of masers is about six orders of magnitude larger than that of stellar masers, while the emitting region is only about one astronomical unit (≈1.5×1013 cm), very compact (Thus, the maser emitting region is called a maser spot.), 2) line-w ...
STEREO observations of long period variables
... In order to extract the sample, the first step was to select those stars showing the largest difference in the weighted mean magnitude observed by the two satellites. We anticipated that the majority of these would be due to systematic effects, mostly relating to flat-fielding near the edges of the ...
... In order to extract the sample, the first step was to select those stars showing the largest difference in the weighted mean magnitude observed by the two satellites. We anticipated that the majority of these would be due to systematic effects, mostly relating to flat-fielding near the edges of the ...
Searching for the Secrets of Massive Star Birth
... galactic interstellar medium (ISM). The first stars to form in the universe were massive. They were responsible for cosmic re-ionization and its initial chemical enrichment. Massive stars continue to power the “galactic ecology”, the cyclic conversion of the ISM into stars, the enrichment of the ISM ...
... galactic interstellar medium (ISM). The first stars to form in the universe were massive. They were responsible for cosmic re-ionization and its initial chemical enrichment. Massive stars continue to power the “galactic ecology”, the cyclic conversion of the ISM into stars, the enrichment of the ISM ...
Suppose you tried to determine where we are in the galaxy by
... a) True, the Sun's motion in the galaxy shows that we are near the edge of the Milky Way disk and therefore exterior to most of the mass of the galaxy. b) True, the Milky Way's rotation curve stops increasing well before the orbit of the Sun, indicating that the majority of the Milky Way's mass li ...
... a) True, the Sun's motion in the galaxy shows that we are near the edge of the Milky Way disk and therefore exterior to most of the mass of the galaxy. b) True, the Milky Way's rotation curve stops increasing well before the orbit of the Sun, indicating that the majority of the Milky Way's mass li ...
Evolution of the barium abundance in the early Galaxy from a NLTE
... extremely metal-poor stars (EMP stars): 6 turnoff stars and 35 giants. Methods. The NLTE profiles of the three unblended Ba ii lines (4554 Å, 5853 Å, 6496 Å) have been computed. The computations were made with a modified version of the MULTI code, applied to an atomic model of the Ba atom with 31 lev ...
... extremely metal-poor stars (EMP stars): 6 turnoff stars and 35 giants. Methods. The NLTE profiles of the three unblended Ba ii lines (4554 Å, 5853 Å, 6496 Å) have been computed. The computations were made with a modified version of the MULTI code, applied to an atomic model of the Ba atom with 31 lev ...
THE KEPLER CLUSTER STUDY: STELLAR ROTATION IN NGC 6811
... NASA’s Kepler mission offers a special opportunity to overcome this difficulty. Kepler provides nearly uninterrupted photometric measurements of unprecedented duration (years), cadence (minutes), and precision (ppm). As part of the Kepler mission, The Kepler Cluster Study (Meibom & Kepler Team 2010) ...
... NASA’s Kepler mission offers a special opportunity to overcome this difficulty. Kepler provides nearly uninterrupted photometric measurements of unprecedented duration (years), cadence (minutes), and precision (ppm). As part of the Kepler mission, The Kepler Cluster Study (Meibom & Kepler Team 2010) ...
Long-term monitoring of the short period SU UMa
... 4.1. superhump period change Her simply lies in the majority of SU UMa-type dwarf Historically, the superhump period had been known to novae. decrease during the course of the superoutburst before In order to examine whether V844 Her shows other the tidal instability was discovered (Haefner et al. 1 ...
... 4.1. superhump period change Her simply lies in the majority of SU UMa-type dwarf Historically, the superhump period had been known to novae. decrease during the course of the superoutburst before In order to examine whether V844 Her shows other the tidal instability was discovered (Haefner et al. 1 ...
Instrument Proposal Document
... that have been successfully demonstrated in the laboratory environment but have yet to be deployed in any astronomical instrument. The iBTF (imaging Bragg Tunable Filter) concept utilizes a Volume Phase Holographic (or Bragg Diffraction) Grating (VPHG) in double-pass configuration while the new Fabr ...
... that have been successfully demonstrated in the laboratory environment but have yet to be deployed in any astronomical instrument. The iBTF (imaging Bragg Tunable Filter) concept utilizes a Volume Phase Holographic (or Bragg Diffraction) Grating (VPHG) in double-pass configuration while the new Fabr ...
The extended structure of the dwarf irregular galaxies Sextans A and
... previously traced with surface photometry, out to ∼ 4 kpc from their centres along their major axes. Older stars are found to have more extended distribution than younger populations. We obtain the first estimate of the mean metallicity for the old stars in Sex B, from the colour distribution of the ...
... previously traced with surface photometry, out to ∼ 4 kpc from their centres along their major axes. Older stars are found to have more extended distribution than younger populations. We obtain the first estimate of the mean metallicity for the old stars in Sex B, from the colour distribution of the ...
SPY — The ESO Supernovae Type Ia Progenitor Survey
... components can be determined (Fig. 8). For our example HE14140848 we derived a period of P=12h25m44s and semi-amplitudes K1 = 127 km/s and K2 = 96 km/s. The ratio of velocity amplitudes is directly related to the mass ratio of both components: M2 / M1 = K1 / K2 = ...
... components can be determined (Fig. 8). For our example HE14140848 we derived a period of P=12h25m44s and semi-amplitudes K1 = 127 km/s and K2 = 96 km/s. The ratio of velocity amplitudes is directly related to the mass ratio of both components: M2 / M1 = K1 / K2 = ...
Protostellar/PMS Mass Infall Luminosity Problem
... mass, as in the Herschel Orion Protostar Survey (HOPS, Manoj et al. 2013; Fisher et al. 2013; Stutz et al. 2013) ...
... mass, as in the Herschel Orion Protostar Survey (HOPS, Manoj et al. 2013; Fisher et al. 2013; Stutz et al. 2013) ...
Test 3 Review Clicker Questions
... a) cannot explain how the Sun is stable. b) detect only one-third the number of neutrinos expected by theory. c) cannot detect neutrinos easily. d) are unable to explain how neutrinos ...
... a) cannot explain how the Sun is stable. b) detect only one-third the number of neutrinos expected by theory. c) cannot detect neutrinos easily. d) are unable to explain how neutrinos ...
Star Formation in the Milky Way - HubbleSOURCE
... “dark cloud cores” are seen with deep, sensitive infrared exposures that can peer through the clouds, and at radio wavelengths where the cloud material emits Tracy Beck - HSB ...
... “dark cloud cores” are seen with deep, sensitive infrared exposures that can peer through the clouds, and at radio wavelengths where the cloud material emits Tracy Beck - HSB ...
black hole masses and host galaxy evolution of radio
... fit overall spectral features, including many absorption lines, over a wide range of wavelengths. Our high signal-to-noise ratio (S/N) spectra give very accurate redshifts with typical errors of less than 0.0001. Values for some redshifts given in the literature turned out to be wrong or inaccurate, ...
... fit overall spectral features, including many absorption lines, over a wide range of wavelengths. Our high signal-to-noise ratio (S/N) spectra give very accurate redshifts with typical errors of less than 0.0001. Values for some redshifts given in the literature turned out to be wrong or inaccurate, ...
Transport of angular momentum in massive stars
... has a big effect on the change of the rotational surface velocity of the stars, hence these stars also were not used. The reason to stop at 20 M is the low number of stars above this mass, making statistical analysis difficult. Also stars that clearly left the main sequence where not used. This was ...
... has a big effect on the change of the rotational surface velocity of the stars, hence these stars also were not used. The reason to stop at 20 M is the low number of stars above this mass, making statistical analysis difficult. Also stars that clearly left the main sequence where not used. This was ...
Stars & Galaxies - newmanlib.ibri.org
... Different Kinds of Stars • Even a brief glance at the stars shows us that they differ in brightness. • As one looks at the stars more carefully, it becomes apparent that they are not all the ...
... Different Kinds of Stars • Even a brief glance at the stars shows us that they differ in brightness. • As one looks at the stars more carefully, it becomes apparent that they are not all the ...
Corrugations in the Disk of the Edge
... the midplane at larger radii. However, at small and intermediate projected radii, regular undulations are clearly visible across the disk of the galaxy. Furthermore, it can be seen that a portion of the galaxy near x = 0 is displaced from the kinematically-defined center-of-mass. One possible explan ...
... the midplane at larger radii. However, at small and intermediate projected radii, regular undulations are clearly visible across the disk of the galaxy. Furthermore, it can be seen that a portion of the galaxy near x = 0 is displaced from the kinematically-defined center-of-mass. One possible explan ...
3. Cosmology and the Origin and Evolution of Galaxies
... (SEDs) of mm galaxies at rest-frame mid-IR to radio wavelengths can provide photometric-redshifts with sufficient accuracy7. There has also been some success in the measurement of optical and IR spectroscopic redshifts for a fraction of the bright mm galaxies (S850µm > 5 mJy) with reliable radio coun ...
... (SEDs) of mm galaxies at rest-frame mid-IR to radio wavelengths can provide photometric-redshifts with sufficient accuracy7. There has also been some success in the measurement of optical and IR spectroscopic redshifts for a fraction of the bright mm galaxies (S850µm > 5 mJy) with reliable radio coun ...
Gas Mass Fractions and the Evolution of Spiral Galaxies
... of Υ∗ with the many underlying variables. The most important aspect of equation (3) is the normalization to dynamical constraints which give the most reliable estimate of the mass contained in stars. Without this, it is always possible to contrive models in which the stars contain all or none of the ...
... of Υ∗ with the many underlying variables. The most important aspect of equation (3) is the normalization to dynamical constraints which give the most reliable estimate of the mass contained in stars. Without this, it is always possible to contrive models in which the stars contain all or none of the ...
Article PDF - IOPscience
... 0.3. It is the late types that are inferred to be gas rich, on the basis of the H I alone. If we are missing enormous amounts of molecular gas in late types, it will only make yet more gas-rich galaxies, which are already inferred to be very gas rich. Hence, our qualitative results are very robust, ...
... 0.3. It is the late types that are inferred to be gas rich, on the basis of the H I alone. If we are missing enormous amounts of molecular gas in late types, it will only make yet more gas-rich galaxies, which are already inferred to be very gas rich. Hence, our qualitative results are very robust, ...
Dark matter distribution and indirect detection in dwarf spheroidal
... The gamma or neutrino flux in given by: ...
... The gamma or neutrino flux in given by: ...
Cosmic distance ladder
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are ""close enough"" (within about a thousand parsecs) to Earth. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.The ladder analogy arises because no one technique can measure distances at all ranges encountered in astronomy. Instead, one method can be used to measure nearby distances, a second can be used to measure nearby to intermediate distances, and so on. Each rung of the ladder provides information that can be used to determine the distances at the next higher rung.