DOC - IVOA
... groups of like stars without making explicit searches by star name one at a time or by cross correlation of established catalogs. This is a common request to archive centers holding spectroscopic datasets. NASA’s International Ultraviolet Explororer (IUE) satellite project, with the Far Ultraviolet ...
... groups of like stars without making explicit searches by star name one at a time or by cross correlation of established catalogs. This is a common request to archive centers holding spectroscopic datasets. NASA’s International Ultraviolet Explororer (IUE) satellite project, with the Far Ultraviolet ...
The KMOS Redshift One Spectroscopic Survey
... at progressively high redshifts, in that galaxies with the same rotation velocity in the distant Universe have lower stellar masses (e.g. Swinbank et al. 2006). This suggests either higher gas fractions as measured directly by Tacconi et al. (2010) or increased dark matter fractions or perhaps even ...
... at progressively high redshifts, in that galaxies with the same rotation velocity in the distant Universe have lower stellar masses (e.g. Swinbank et al. 2006). This suggests either higher gas fractions as measured directly by Tacconi et al. (2010) or increased dark matter fractions or perhaps even ...
Unraveling the Helix Nebula: Its Structure and Knots
... lack of ions with high emissivity give the nebula a superficial appearance of having a central cavity (O1998). This single disk model must now be superseded by a more complex ...
... lack of ions with high emissivity give the nebula a superficial appearance of having a central cavity (O1998). This single disk model must now be superseded by a more complex ...
Confirmation of Hostless Type Ia Supernovae Using Hubble Space
... above results are based on αd = −1.0, which is true for field galaxies (Blanton et al. 2003), but αd may be higher in rich galaxy clusters (e.g., Milne et al. 2007). Adopting αd = −1.5 as an upper limit, the MENeaCS survey estimated that . 2% of the stellar mass in dwarf cluster galaxies below dete ...
... above results are based on αd = −1.0, which is true for field galaxies (Blanton et al. 2003), but αd may be higher in rich galaxy clusters (e.g., Milne et al. 2007). Adopting αd = −1.5 as an upper limit, the MENeaCS survey estimated that . 2% of the stellar mass in dwarf cluster galaxies below dete ...
Master Thesis - Sterrenkunde RU Nijmegen
... Stars are usually born in groups from large clouds, which contract when gravity overcomes the internal pressure. The most important parameter of a star is its mass at birth, which determines the stars further evolution. Stars with a mass of 0.08M or more, fuse hydrogen to helium in their core. Star ...
... Stars are usually born in groups from large clouds, which contract when gravity overcomes the internal pressure. The most important parameter of a star is its mass at birth, which determines the stars further evolution. Stars with a mass of 0.08M or more, fuse hydrogen to helium in their core. Star ...
Improving Galactic Center Astrometry by Reducing the Effects of
... We present significantly improved proper motion measurements of the Milky Way’s central stellar cluster. These improvements are made possible by refining our astrometric reference frame with a new geometric optical distortion model for the W. M. Keck II 10 m telescope’s Adaptive Optics camera (NIRC2 ...
... We present significantly improved proper motion measurements of the Milky Way’s central stellar cluster. These improvements are made possible by refining our astrometric reference frame with a new geometric optical distortion model for the W. M. Keck II 10 m telescope’s Adaptive Optics camera (NIRC2 ...
The Density Profiles of Massive, Relaxed Galaxy Clusters - HAL-Insu
... 2010a). Measuring the shape of the radial density profile to test whether the NFW form (or the result of numerical simulations generally) is valid over the full range of scales – for any mass and concentration – is more challenging, but possibly more profound. The tools mentioned so far cannot test ...
... 2010a). Measuring the shape of the radial density profile to test whether the NFW form (or the result of numerical simulations generally) is valid over the full range of scales – for any mass and concentration – is more challenging, but possibly more profound. The tools mentioned so far cannot test ...
Astronomy Astrophysics The accretion environment in Vela X-1 during a flaring period using
... orbiting its companion with a period of 8.964 days. The distance at periastron is only 0.6 stellar radii (a ∼ 53 R ; van Kerkwijk et al. 1995) from the stellar surface, well within the acceleration zone of the stellar wind. Despite the status of the Vela X-1 system as an archetypal wind accretor, t ...
... orbiting its companion with a period of 8.964 days. The distance at periastron is only 0.6 stellar radii (a ∼ 53 R ; van Kerkwijk et al. 1995) from the stellar surface, well within the acceleration zone of the stellar wind. Despite the status of the Vela X-1 system as an archetypal wind accretor, t ...
Far-ultraviolet and far-infrared bivariate luminosity function of galaxies:
... Far-ultraviolet (FUV) and far-infrared (FIR) luminosity functions (LFs) of galaxies show a strong evolution from z = 0 to z = 1, but the FIR LF evolves much stronger than the FUV one. The FUV is dominantly radiated from newly-formed short-lived OB stars, while the FIR is emitted by dust grains heate ...
... Far-ultraviolet (FUV) and far-infrared (FIR) luminosity functions (LFs) of galaxies show a strong evolution from z = 0 to z = 1, but the FIR LF evolves much stronger than the FUV one. The FUV is dominantly radiated from newly-formed short-lived OB stars, while the FIR is emitted by dust grains heate ...
ppt - ciera
... BSS have been detected for the first time by Sandage (1953) according to their position in the CMD, BSS should be more massive than ...
... BSS have been detected for the first time by Sandage (1953) according to their position in the CMD, BSS should be more massive than ...
Optical hydrogen absorption consistent with a thin bow shock
... where Fi is a single observation and Fout is the master post-transit spectrum. In order to obtain the final transmission spectra all observations must be normalized and aligned in wavelength space. Changes in spectral resolution due to temperature or instrument flexure are minimal and do not affect ...
... where Fi is a single observation and Fout is the master post-transit spectrum. In order to obtain the final transmission spectra all observations must be normalized and aligned in wavelength space. Changes in spectral resolution due to temperature or instrument flexure are minimal and do not affect ...
Evolutionary and pulsational properties of white dwarf stars
... lives passively, getting rid of their outer layers and forming white dwarfs. For this reason, the present population of white dwarfs contains valuable information about the evolution of individual stars from birth to death and about the star formation rate throughout the history of our Galaxy. These ...
... lives passively, getting rid of their outer layers and forming white dwarfs. For this reason, the present population of white dwarfs contains valuable information about the evolution of individual stars from birth to death and about the star formation rate throughout the history of our Galaxy. These ...
Radio pulsars
... than doubled the number of known pulsars • New population of high-B pulsars and new SNR associations • Globular clusters contain many millisecond pulsars • Precision timing of binary millisecond pulsars measures many properties of binary stars and tests general relativity. • Discovery of highly rela ...
... than doubled the number of known pulsars • New population of high-B pulsars and new SNR associations • Globular clusters contain many millisecond pulsars • Precision timing of binary millisecond pulsars measures many properties of binary stars and tests general relativity. • Discovery of highly rela ...
Full THESIS in PDF - Leiden Observatory
... Molecular Cloud, and it is a vast reservoir of cold molecular gas and interstellar dust. Although the Orion Nebula is the only molecular cloud visible to the naked eye, similar clouds are numerously scattered throughout the Milky Way and some of them are close enough to Earth, so that they can be st ...
... Molecular Cloud, and it is a vast reservoir of cold molecular gas and interstellar dust. Although the Orion Nebula is the only molecular cloud visible to the naked eye, similar clouds are numerously scattered throughout the Milky Way and some of them are close enough to Earth, so that they can be st ...
OBSERVATIONS OF DISINTEGRATING, EVAPORATING AND HOT
... Hot exoplanets with semi-major axes smaller than 0.05 AU can go considerable alteration from the high energy radiation of their host stars radiation from driving winds to altering the thermal profiles to disintegrating nearby planets. A variety of exoplanets are studied in this high irradiation envi ...
... Hot exoplanets with semi-major axes smaller than 0.05 AU can go considerable alteration from the high energy radiation of their host stars radiation from driving winds to altering the thermal profiles to disintegrating nearby planets. A variety of exoplanets are studied in this high irradiation envi ...
The evolution of massive stars and their spectra
... the evolution of the spectra of massive stars throughout their entire evolution, since the modern atmospheric/wind models have never been coupled to stellar evolutionary models. Here we bridge this gap by performing, for the first time, coupled calculations of stellar evolution with the Geneva code ...
... the evolution of the spectra of massive stars throughout their entire evolution, since the modern atmospheric/wind models have never been coupled to stellar evolutionary models. Here we bridge this gap by performing, for the first time, coupled calculations of stellar evolution with the Geneva code ...
GRAVITATIONAL SETTLING OF 22Ne AND WHITE DWARF
... of post–asymptotic giant branch stars of low and intermediate masses that reach the hot white dwarf stage with hydrogen-rich surface layers. The basic inner structure expected in a typical white dwarf consists of a degenerate core mostly composed of a mixture of carbon and oxygen (the ashes of core ...
... of post–asymptotic giant branch stars of low and intermediate masses that reach the hot white dwarf stage with hydrogen-rich surface layers. The basic inner structure expected in a typical white dwarf consists of a degenerate core mostly composed of a mixture of carbon and oxygen (the ashes of core ...
from z=0 to z=1
... significantly higher SFR, higher attenuation, higher stellar mass, and higher correlation length than LBGs. 7. At intermediate redshifts of z~0.6, UV selected galaxies show moderate evolution in stellar mass in the sense that for a given luminosity, galaxies at z=0.6 have stellar mass ~2 times less ...
... significantly higher SFR, higher attenuation, higher stellar mass, and higher correlation length than LBGs. 7. At intermediate redshifts of z~0.6, UV selected galaxies show moderate evolution in stellar mass in the sense that for a given luminosity, galaxies at z=0.6 have stellar mass ~2 times less ...
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.