On the nature of sn stars. I. A detailed abundance study
... questioned. There is no general agreement about their origin. We aim to derive abundances for a sample of 9 stars, including sn and non-sn stars, to determine the possible relation between sn and CP stars and compare their chemical abundances. That most sn stars belong to open clusters allows us to ...
... questioned. There is no general agreement about their origin. We aim to derive abundances for a sample of 9 stars, including sn and non-sn stars, to determine the possible relation between sn and CP stars and compare their chemical abundances. That most sn stars belong to open clusters allows us to ...
The Evolution of Isotope Ratios in the Milky Way Galaxy
... the isotope ratios of elemental abundances (from C to Zn) in the solar neighbourhood, bulge, halo, and thick disk, using chemical evolution models with updated yields of Asymptotic Giant Branch (AGB) stars and core-collapse supernovae. The evolutionary history of each element is different owing to t ...
... the isotope ratios of elemental abundances (from C to Zn) in the solar neighbourhood, bulge, halo, and thick disk, using chemical evolution models with updated yields of Asymptotic Giant Branch (AGB) stars and core-collapse supernovae. The evolutionary history of each element is different owing to t ...
Annual Report 2014 - Max Planck Institute for Astrophysics
... the directorship of Ludwig Biermann. It was estab- MPA has had an internationally-recognized numerlished as an offshoot of the Max-Planck-Institut für ical astrophysics program that was long unparalPhysik, which at that time had just moved from leled by any other institution of similar size. Göttinge ...
... the directorship of Ludwig Biermann. It was estab- MPA has had an internationally-recognized numerlished as an offshoot of the Max-Planck-Institut für ical astrophysics program that was long unparalPhysik, which at that time had just moved from leled by any other institution of similar size. Göttinge ...
astro-ph/9808039 PDF
... was the calibration standard. The corrected calibration of the GAFPIC data has been confirmed by comparison to another study that also uses HK11 as the calibration source (Mayya 1994). Also, the GAFPIC images have been refined by subtracting ghost images reflected from the Fabry-Perot blocking filte ...
... was the calibration standard. The corrected calibration of the GAFPIC data has been confirmed by comparison to another study that also uses HK11 as the calibration source (Mayya 1994). Also, the GAFPIC images have been refined by subtracting ghost images reflected from the Fabry-Perot blocking filte ...
Red supergiants and the past of Cygnus OB2
... main star-forming sites have been shifting with time. The study of this older component is made difficult by the effects of stellar evolution, and in particular by the fact that its most massive components have already disappeared as supernovae. A thus far unexplored probe of the massive star format ...
... main star-forming sites have been shifting with time. The study of this older component is made difficult by the effects of stellar evolution, and in particular by the fact that its most massive components have already disappeared as supernovae. A thus far unexplored probe of the massive star format ...
Why is the Sun very dense on the inside?
... Why do the hottest spectra (types O and B) show few absorption lines? ...
... Why do the hottest spectra (types O and B) show few absorption lines? ...
The impact of protocluster environments at z = 1.6
... at almost all masses due to the assertion that the galaxies must have a high probability of lying within the control field redshift range or the protocluster. Dashed lines marking where the protocluster galaxies are 90, 75, 50 and 25 per cent complete are shown on Fig. 2. The control field galaxies ...
... at almost all masses due to the assertion that the galaxies must have a high probability of lying within the control field redshift range or the protocluster. Dashed lines marking where the protocluster galaxies are 90, 75, 50 and 25 per cent complete are shown on Fig. 2. The control field galaxies ...
THE NEW GALAXY: Signatures of Its Formation
... that this is an over-interpretation; a smooth collapse was not one of the inferences they drew from the stellar kinematics. In 1977, the ELS picture was challenged by Searle (see also Searle & Zinn 1978) who noted that Galactic globular clusters have a wide range of metal abundances essentially inde ...
... that this is an over-interpretation; a smooth collapse was not one of the inferences they drew from the stellar kinematics. In 1977, the ELS picture was challenged by Searle (see also Searle & Zinn 1978) who noted that Galactic globular clusters have a wide range of metal abundances essentially inde ...
The connection between stellar activity cycles and magnetic field
... the number of ZDI maps one is able to produce over an activity cycle will be much more sparse when compared to the number of chromospheric observations. Therefore, it is useful to study activity cycles with chromospheric data in conjunction with the ZDI technique. There are now numerous stars that h ...
... the number of ZDI maps one is able to produce over an activity cycle will be much more sparse when compared to the number of chromospheric observations. Therefore, it is useful to study activity cycles with chromospheric data in conjunction with the ZDI technique. There are now numerous stars that h ...
INFRARED DUST BUBBLES: PROBING THE DETAILED
... southern half of the bubble. The detected 24 m and 20 cm emission along the southern interior, however, implies the existence of ionizing photons. The near absence of the 8 m shell along the lower half of this bubble thus implies the absence of PAHs. This may be because the ambient ISM density in ...
... southern half of the bubble. The detected 24 m and 20 cm emission along the southern interior, however, implies the existence of ionizing photons. The near absence of the 8 m shell along the lower half of this bubble thus implies the absence of PAHs. This may be because the ambient ISM density in ...
AR2012 - Vatican Observatory
... microscopes/microprobes and mass spectrometers. These instruments allowed ever finer measurements of chemical and isotopic compositions to be made at ever higher resolution on ever tinier samples. By contrast, the measurement of the physical properties of these samples had not been pursued with the ...
... microscopes/microprobes and mass spectrometers. These instruments allowed ever finer measurements of chemical and isotopic compositions to be made at ever higher resolution on ever tinier samples. By contrast, the measurement of the physical properties of these samples had not been pursued with the ...
Hunting for Substructure in the Milky Way
... Before a galaxy forms, the area is assumed to have low metallicity and low metal abundances. Later, supernova explosions enrich the interstellar medium with elements which subsequently are present in newly forming stars. Core-collapse supernovae explode first, around 107 years after a galaxy has for ...
... Before a galaxy forms, the area is assumed to have low metallicity and low metal abundances. Later, supernova explosions enrich the interstellar medium with elements which subsequently are present in newly forming stars. Core-collapse supernovae explode first, around 107 years after a galaxy has for ...
Stellar evolution - Statistical Physics Group
... carbon burning at the centre of the star. I t is clear that it will only be a matter of time before these calculations are carried to a later stage of nuclear evolution. There are of course still some uncertainties in the basic physics of stellar interiors and these will be mentioned later. As soon ...
... carbon burning at the centre of the star. I t is clear that it will only be a matter of time before these calculations are carried to a later stage of nuclear evolution. There are of course still some uncertainties in the basic physics of stellar interiors and these will be mentioned later. As soon ...
Which planet has never been orbited or flown past by a
... Casey, T. L., & Slater, T. F. 2002, A Comparison of Group and Individually Completed Course Evaluations in Introductory Astronomy, Astronomy Education Review, 1(2), 1. http://aer.noao.edu/AERArticle.php?issue=2§ion=2&article=3. Slater, T. F., & Adams, J. P. 2002, Mathematical Reasoning over Arit ...
... Casey, T. L., & Slater, T. F. 2002, A Comparison of Group and Individually Completed Course Evaluations in Introductory Astronomy, Astronomy Education Review, 1(2), 1. http://aer.noao.edu/AERArticle.php?issue=2§ion=2&article=3. Slater, T. F., & Adams, J. P. 2002, Mathematical Reasoning over Arit ...
The Westerbork Hydrogen Accretion in LOcal GAlaxieS \(HALOGAS
... nearby galaxies. The survey data are being used to perform careful modeling of the galaxies, characterizing their gas content, morphology, and kinematics, with the primary goal of revealing the global characteristics of cold gas accretion onto spiral galaxies in the local Universe. In this paper, we ...
... nearby galaxies. The survey data are being used to perform careful modeling of the galaxies, characterizing their gas content, morphology, and kinematics, with the primary goal of revealing the global characteristics of cold gas accretion onto spiral galaxies in the local Universe. In this paper, we ...
the optical colors of giant elliptical galaxies and their metal
... the sense that the parent galaxies are redder by ∼ 0.12 – 0.20 mag at a given galactocentric distance. However, spectroscopic indices in the blue indicate that the luminosity-weighted ages and metallicities of such galaxies are equal to that of their averaged massive metal-rich GCs at a given galact ...
... the sense that the parent galaxies are redder by ∼ 0.12 – 0.20 mag at a given galactocentric distance. However, spectroscopic indices in the blue indicate that the luminosity-weighted ages and metallicities of such galaxies are equal to that of their averaged massive metal-rich GCs at a given galact ...
THE DYNAMICAL STRUCTURE AND EVOLUTION OF GIANT
... vicinity, the total interstellar pressure is about 2:8 104 K cm;3 , which balances the weight of the ISM 14]. Of this, about 0:7 104 K cm;3 is due to cosmic rays since they pervade both the ISM and a molecular cloud, they do not contribute to the support of a cloud and may be neglected. The ma ...
... vicinity, the total interstellar pressure is about 2:8 104 K cm;3 , which balances the weight of the ISM 14]. Of this, about 0:7 104 K cm;3 is due to cosmic rays since they pervade both the ISM and a molecular cloud, they do not contribute to the support of a cloud and may be neglected. The ma ...
Stars & Galaxies - newmanlib.ibri.org
... Galaxy Types • Galaxies are usually categorized by shape into three types: – Elliptical – Spiral – Irregular ...
... Galaxy Types • Galaxies are usually categorized by shape into three types: – Elliptical – Spiral – Irregular ...
Munshi_washington_0250E_12611
... mass ratio as a function of halo mass for a new sample of simulated field galaxies using fully cosmological, LCDM, high resolution SPH + N-Body simulations carried to the present time. I find there is extremely good agreement between the simulations and predictions from the statistical Halo Occupati ...
... mass ratio as a function of halo mass for a new sample of simulated field galaxies using fully cosmological, LCDM, high resolution SPH + N-Body simulations carried to the present time. I find there is extremely good agreement between the simulations and predictions from the statistical Halo Occupati ...
Is there a Supermassive Black Hole at the Center of the Milky Way?
... parsecs, the system would be dynamically unstable with less massive stars being expelled (“evaporated”) and more massive stars sinking to the center, colliding and possibly forming a black hole. The timescale for the cluster to evaporate would be fairly short, ∼ 109 years, making it unlikely that a ...
... parsecs, the system would be dynamically unstable with less massive stars being expelled (“evaporated”) and more massive stars sinking to the center, colliding and possibly forming a black hole. The timescale for the cluster to evaporate would be fairly short, ∼ 109 years, making it unlikely that a ...
Properties of Galactic B supergiants
... Sher 25 (B1.5 Iab, Moffat 1983) is associated with a ring nebula and apparent bipolar outflows (Brandner et al. 1987a). The ring nebula is reminiscent of the inner nebula associated with SN 1987A, which is presumed to have been ejected from the Sk–69◦ 202 (B3 I, Walborn et al. 1989) progenitor. Both ...
... Sher 25 (B1.5 Iab, Moffat 1983) is associated with a ring nebula and apparent bipolar outflows (Brandner et al. 1987a). The ring nebula is reminiscent of the inner nebula associated with SN 1987A, which is presumed to have been ejected from the Sk–69◦ 202 (B3 I, Walborn et al. 1989) progenitor. Both ...
X-ray emission from supernova shock waves Tanja Kramer Nymark Department of Astronomy
... visible to the naked eye, most novae could only be seen with telescopes. Almost 400 years were to pass before the next naked-eye supernova occurred, SN 1987A in the Large Magellanic Cloud. However, with a telescope even faint novae could be observed, and as the telescopes improved, ever more novae w ...
... visible to the naked eye, most novae could only be seen with telescopes. Almost 400 years were to pass before the next naked-eye supernova occurred, SN 1987A in the Large Magellanic Cloud. However, with a telescope even faint novae could be observed, and as the telescopes improved, ever more novae w ...
A History of Star Catalogues - The Albuquerque Astronomical Society
... Scientists of the time were interested in whether the heavens are indeed immutable as previously thought, or whether there were in fact motions among the “fixed” stars. This has great philosophical importance because it was believed that heaven was perfect and changeless. Another important question ...
... Scientists of the time were interested in whether the heavens are indeed immutable as previously thought, or whether there were in fact motions among the “fixed” stars. This has great philosophical importance because it was believed that heaven was perfect and changeless. Another important question ...
Distance determination for RAVE stars using stellar models
... The power spectrum is used to measure the power of density perturbations on a certain scale. The current cosmological model predicts a HarrisonZel’dovich spectrum (P (k) ∝ k, where k is the wavenumber). This power spectrum predicts more power on small scale, so there should be more dwarf galaxies th ...
... The power spectrum is used to measure the power of density perturbations on a certain scale. The current cosmological model predicts a HarrisonZel’dovich spectrum (P (k) ∝ k, where k is the wavenumber). This power spectrum predicts more power on small scale, so there should be more dwarf galaxies th ...
HWWS 2010 - Monash University
... long pulse periods ~4-6s • Latter two are both likely classes of magnetars, (possibly young) systems with extremely high magnetic fields 1014– 1015 G • Compact central objects (CCOs) about which very little is known, associated with supernova remnants Galloway, “Accreting Neutron Stars – tiny Galact ...
... long pulse periods ~4-6s • Latter two are both likely classes of magnetars, (possibly young) systems with extremely high magnetic fields 1014– 1015 G • Compact central objects (CCOs) about which very little is known, associated with supernova remnants Galloway, “Accreting Neutron Stars – tiny Galact ...
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.