![properties of the high area-to-mass ratio space debris population in](http://s1.studyres.com/store/data/016120386_1-a28b0cfc79c19d0e0095a57d0cfd175d-300x300.png)
properties of the high area-to-mass ratio space debris population in
... [2]. The DISCOS catalogue essentially contains the unclassified USSPACECOM space object catalogue. ‘Uncorrelated’ detections correspond to objects which were not found in DISCOS. The solid line indicates the system sensitivity as determined from independent calibration measurements. All magnitudes h ...
... [2]. The DISCOS catalogue essentially contains the unclassified USSPACECOM space object catalogue. ‘Uncorrelated’ detections correspond to objects which were not found in DISCOS. The solid line indicates the system sensitivity as determined from independent calibration measurements. All magnitudes h ...
Deep Sky Catalogues, the New Uranometria and Other Stories
... Correct image of the sky. The data should be free of errors and present a complete image of the real sky, within the chosen definitions (see next criterion). Clearly defined object classes and selection criteria. The „optical“ object classes should be contained: open and globular clusters, emission- ...
... Correct image of the sky. The data should be free of errors and present a complete image of the real sky, within the chosen definitions (see next criterion). Clearly defined object classes and selection criteria. The „optical“ object classes should be contained: open and globular clusters, emission- ...
The fundamental parameters of the roAp star γ Equulei
... used the synthetic spectrum for the Kurucz model that best fitted both the star’s spectrum in the visible and the star’s photometry in the infrared. (2) We performed a linear extrapolation between 506 Å and 1854 Å, considering zero flux at 506 Å, a second linear interpolation to the infrared fluxes ...
... used the synthetic spectrum for the Kurucz model that best fitted both the star’s spectrum in the visible and the star’s photometry in the infrared. (2) We performed a linear extrapolation between 506 Å and 1854 Å, considering zero flux at 506 Å, a second linear interpolation to the infrared fluxes ...
a wide-field survey for variable stars
... Tauri variable stars. The nearby dusty, yellow cloud is Hind’s Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing ...
... Tauri variable stars. The nearby dusty, yellow cloud is Hind’s Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing ...
Cold galaxies at low and high z
... Over 100 Type Ia supernova have been found at redshifts 0.5-1.5 Comparing these to nearby supernova, we find that in cosmological models with matter only, the distant supernovae are fainter than expected for their redshift (Perlmutter 2002). ‘Dark energy’ is pushing the galaxies apart. Sept 27th 200 ...
... Over 100 Type Ia supernova have been found at redshifts 0.5-1.5 Comparing these to nearby supernova, we find that in cosmological models with matter only, the distant supernovae are fainter than expected for their redshift (Perlmutter 2002). ‘Dark energy’ is pushing the galaxies apart. Sept 27th 200 ...
Z - STScI
... Zampieri et al., Nomoto et al - low luminosity SNe form black-holes No evidence so far of the branching at high luminosity Detailed comparison with models now possible ...
... Zampieri et al., Nomoto et al - low luminosity SNe form black-holes No evidence so far of the branching at high luminosity Detailed comparison with models now possible ...
The Current Status of Galaxy Formation
... account for all but the most the extreme SFRs at high z, although this may require an implausibly high SFE (Dekel et al., 2009). 2.6 Spheroidal galaxies The baryon fraction is far from its primordial value in all systems other than massive galaxy clusters. SNe cannot eject significant amounts of gas ...
... account for all but the most the extreme SFRs at high z, although this may require an implausibly high SFE (Dekel et al., 2009). 2.6 Spheroidal galaxies The baryon fraction is far from its primordial value in all systems other than massive galaxy clusters. SNe cannot eject significant amounts of gas ...
HI in Early-type Galaxies
... regular HI disk or ring. The peak surface densities are typically around 1 M¯ pc−2 , too low for large scale star formation to occur. Figure 6 shows the HI density profile of a low-luminosity elliptical and of a more luminous E4 galaxy. The difference between these profiles is quite typical for what ...
... regular HI disk or ring. The peak surface densities are typically around 1 M¯ pc−2 , too low for large scale star formation to occur. Figure 6 shows the HI density profile of a low-luminosity elliptical and of a more luminous E4 galaxy. The difference between these profiles is quite typical for what ...
Properties of simulated Milky Way-mass galaxies in loose group and
... of interest. Details of the refinement scheme are described by Teyssier (2002). ramses includes density- and metallicitydependent radiative cooling rates, using an ionisation equilibrium with an ultra-violet radiative background (Haardt & Madau 1996). Gas cells with a density ρ exceeding a star form ...
... of interest. Details of the refinement scheme are described by Teyssier (2002). ramses includes density- and metallicitydependent radiative cooling rates, using an ionisation equilibrium with an ultra-violet radiative background (Haardt & Madau 1996). Gas cells with a density ρ exceeding a star form ...
THE NEW GALAXY: Signatures of Its Formation
... billion stars, within a sphere of diameter 20 kpc (the Gaiasphere). In “The Gaiasphere and The Limits of Knowledge” below, we look forward to a time when all stars within the Gaiasphere have complete chemical abundance measurements (including all heavy metals). Even with such a vast increase in info ...
... billion stars, within a sphere of diameter 20 kpc (the Gaiasphere). In “The Gaiasphere and The Limits of Knowledge” below, we look forward to a time when all stars within the Gaiasphere have complete chemical abundance measurements (including all heavy metals). Even with such a vast increase in info ...
THE DEARTH OF UV-BRIGHT STARS IN M32
... theoretical predictions. In contrast, the rapid evolution of these stars means few of them are found in Galactic globular clusters (the traditional testing ground for stellar evolution), while distance and reddening uncertainties hamper their study in the Galactic field population. In an elliptical ...
... theoretical predictions. In contrast, the rapid evolution of these stars means few of them are found in Galactic globular clusters (the traditional testing ground for stellar evolution), while distance and reddening uncertainties hamper their study in the Galactic field population. In an elliptical ...
Feedback in low-mass galaxies in the early Universe
... early Universe. Feedback in faint, low-mass galaxies probably facilitated the escape of ionizing radiation from galaxies when the Universe was about 500 million years old, so that the hydrogen between galaxies changed from neutral to ionized—the last major phase transition in the Universe. ...
... early Universe. Feedback in faint, low-mass galaxies probably facilitated the escape of ionizing radiation from galaxies when the Universe was about 500 million years old, so that the hydrogen between galaxies changed from neutral to ionized—the last major phase transition in the Universe. ...
Galaxies - hwchemistry
... distant galaxy, astronomers rush to observe it. – Studies show that type Ia supernovae—caused by the collapse of a white dwarf—all reach about the same absolute magnitude at maximum. – By searching for Cepheids and other distance indicators in nearby galaxies where type Ia supernovae have occurred, ...
... distant galaxy, astronomers rush to observe it. – Studies show that type Ia supernovae—caused by the collapse of a white dwarf—all reach about the same absolute magnitude at maximum. – By searching for Cepheids and other distance indicators in nearby galaxies where type Ia supernovae have occurred, ...
The behaviour of dark matter associated with 4 bright cluster
... Gemini spectroscopy to obtain a redshift z = 0.204. However, our IFU spectroscopy did not confirm this. We instead found only one bright emission line at 835.5 nm, which is not associated with lines at the foreground cluster redshift and whose 2D morphology traces the lensed image. The emission line ...
... Gemini spectroscopy to obtain a redshift z = 0.204. However, our IFU spectroscopy did not confirm this. We instead found only one bright emission line at 835.5 nm, which is not associated with lines at the foreground cluster redshift and whose 2D morphology traces the lensed image. The emission line ...
HS0702+ 6043: A star showing both short-period p
... we can easily exclude a potential F- or G-type main sequence companion. Because the star is relatively faint, 2MASS photometry is only accurate enough to require that any hypothetical companion must be later than K-type. At the supposed 1 h orbit, the Roche geometry marginally allows to fit an objec ...
... we can easily exclude a potential F- or G-type main sequence companion. Because the star is relatively faint, 2MASS photometry is only accurate enough to require that any hypothetical companion must be later than K-type. At the supposed 1 h orbit, the Roche geometry marginally allows to fit an objec ...
Do We Know of Any Maunder Minimum Stars?
... Studies of the star formation history of the galaxy, searches for extrasolar planets, and studies of the Sun as a star often benefit from the ability to determine the age of sun-like stars. But, because stars change very little during their lifetime on the main sequence, determining their age is dif ...
... Studies of the star formation history of the galaxy, searches for extrasolar planets, and studies of the Sun as a star often benefit from the ability to determine the age of sun-like stars. But, because stars change very little during their lifetime on the main sequence, determining their age is dif ...
– 1 – 1. Emission Lines in Nearby Galaxies 1.1.
... To determine the ionization levels of the various elements, one needs to know the electron temperature. The strength of forbidden lines is easy to calculate since they are almost always optically thin in HII regions and the density is low, so collisional de-excitation can be ignored. This results in ...
... To determine the ionization levels of the various elements, one needs to know the electron temperature. The strength of forbidden lines is easy to calculate since they are almost always optically thin in HII regions and the density is low, so collisional de-excitation can be ignored. This results in ...
REVIEW Early star-forming galaxies and the reionization of the Universe
... is the product of the co-moving star formation rate density, rSFR (in units of M[ yr21 Mpc23, where M[ is the solar mass), the number of hydrogen-ionizing photons per second per unit star formation rate, fQ (s21 M[21 yr), and the fraction of photons that can escape a galaxy, fesc. The rate dnion/dt ...
... is the product of the co-moving star formation rate density, rSFR (in units of M[ yr21 Mpc23, where M[ is the solar mass), the number of hydrogen-ionizing photons per second per unit star formation rate, fQ (s21 M[21 yr), and the fraction of photons that can escape a galaxy, fesc. The rate dnion/dt ...
Presentation on the universe
... 5 Which best describes the Big Bang Theory? A The universe has always been the way it is today. B The universe began from a dying star C The universe was created by a singleexplosion The universe is full of explosions, or "big bangs," D that are making it expand ...
... 5 Which best describes the Big Bang Theory? A The universe has always been the way it is today. B The universe began from a dying star C The universe was created by a singleexplosion The universe is full of explosions, or "big bangs," D that are making it expand ...
Giant molecular clouds: star factories
... lead to much higher know how these clouds are whole galaxy, however, other star formation dispersed, or destroyed. The simulations do not explicitly rates gas in GMCs could all be turned model the dark matter halo and into stars, but this would lead to stars. Rather, these are assumed to much higher ...
... lead to much higher know how these clouds are whole galaxy, however, other star formation dispersed, or destroyed. The simulations do not explicitly rates gas in GMCs could all be turned model the dark matter halo and into stars, but this would lead to stars. Rather, these are assumed to much higher ...
Digital Universe Guide - American Museum of Natural History
... pressed, move the mouse toward the left. You’re moving in reverse, flying away from the Sun. Once you move away from the Sun, switch back to Orbit Mode by selecting it from the Flight Mode Menu or by typing a lowercase o, for orbit, in the Graphics Window (where the stars are displayed). This is a k ...
... pressed, move the mouse toward the left. You’re moving in reverse, flying away from the Sun. Once you move away from the Sun, switch back to Orbit Mode by selecting it from the Flight Mode Menu or by typing a lowercase o, for orbit, in the Graphics Window (where the stars are displayed). This is a k ...
ONE- AND MULTI- ZONE MODELS: Chemical properties
... velocity clouds (Mirabel, 1989) and is claimed as a natural consequence of galaxy formation from extended halos. Infall is also desiderable to prevent gas consumption in spirals in times shorter than their ages (Tinsley, 1980a). The total rate of infall of gas in our Galaxy as estimate by Mirabel (1 ...
... velocity clouds (Mirabel, 1989) and is claimed as a natural consequence of galaxy formation from extended halos. Infall is also desiderable to prevent gas consumption in spirals in times shorter than their ages (Tinsley, 1980a). The total rate of infall of gas in our Galaxy as estimate by Mirabel (1 ...
The evolution of Red Supergiants to supernova in the LMC cluster
... (green crosses). The 10µm silicate bump can be clearly seen due to dust emission (pink dashed line). The plot also shows the significant effect scattering within the dust shell (grey dotted/dashed line), contributing to a large proportion of the optical output spectrum. ...
... (green crosses). The 10µm silicate bump can be clearly seen due to dust emission (pink dashed line). The plot also shows the significant effect scattering within the dust shell (grey dotted/dashed line), contributing to a large proportion of the optical output spectrum. ...
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.