Multiwavelength properties of γ-ray loud binary systems.
... associated to other binary systems with black holes and /or neutron stars. Recent discovery of the γ-ray flaring activity of the Crab pulsar shows that pulsars (or the inner compact parts of the pulsar wind nebulae, PWNe) should be also considered as possible variable Galactic source population. How ...
... associated to other binary systems with black holes and /or neutron stars. Recent discovery of the γ-ray flaring activity of the Crab pulsar shows that pulsars (or the inner compact parts of the pulsar wind nebulae, PWNe) should be also considered as possible variable Galactic source population. How ...
Dust-free quasars in the early Universe
... do not have counterparts at low redshift. Figure 2 illustrates the hotdust abundance for our z < 6 sample, as well as for an unbiased sample of 362 low-redshift quasars with rest-frame NIR flux measurements in the literature12,13,19–22. Here we use the ratio of the restframe NIR-to-optical (3.5 mm t ...
... do not have counterparts at low redshift. Figure 2 illustrates the hotdust abundance for our z < 6 sample, as well as for an unbiased sample of 362 low-redshift quasars with rest-frame NIR flux measurements in the literature12,13,19–22. Here we use the ratio of the restframe NIR-to-optical (3.5 mm t ...
A Determination of the Deflection of Light by the Sun`s Gravitational
... instrument was suitable for the photography of the field of stars surroundingthe sun in a total eclipse. Attention was also drawn to the i iportanceof observing the eclipse of May 29, 1919, as this affordeda specially favourableopportunity owing to the unusual numberof bright stars in the field, suc ...
... instrument was suitable for the photography of the field of stars surroundingthe sun in a total eclipse. Attention was also drawn to the i iportanceof observing the eclipse of May 29, 1919, as this affordeda specially favourableopportunity owing to the unusual numberof bright stars in the field, suc ...
DISSERTATION
... Stars play a very important role in the cosmic cycle matter. The human body is made up of 65% of oxygen, 18% of carbon, 10% of hydrogen, and the remaining quantity of heavier elements. Except for hydrogen, which was produced during the first moments after the Big Bang, all the other material is a re ...
... Stars play a very important role in the cosmic cycle matter. The human body is made up of 65% of oxygen, 18% of carbon, 10% of hydrogen, and the remaining quantity of heavier elements. Except for hydrogen, which was produced during the first moments after the Big Bang, all the other material is a re ...
The Lupus clouds - European Southern Observatory
... lies at a similar distance from the Sun and has a similar mass of molecular gas but more vigorous star forming activity (see review by Wilking et al. in this volume) occupies a position with respect to Lupus that is roughly symmetric with respect to the center of the Upper Scorpius OB group. The sce ...
... lies at a similar distance from the Sun and has a similar mass of molecular gas but more vigorous star forming activity (see review by Wilking et al. in this volume) occupies a position with respect to Lupus that is roughly symmetric with respect to the center of the Upper Scorpius OB group. The sce ...
Infrared Astronomy
... Humans at normal body temperature, radiate most strongly in the infrared, which is definitely not seen by human eyes. The scientific discovery that the heat we all feel coming from the Sun is largely a radiation beyond the visible red colour of the solar spectrum was made by William Herschel in 1800 ...
... Humans at normal body temperature, radiate most strongly in the infrared, which is definitely not seen by human eyes. The scientific discovery that the heat we all feel coming from the Sun is largely a radiation beyond the visible red colour of the solar spectrum was made by William Herschel in 1800 ...
Neutral material around the B[e] supergiant star LHA 115
... [Oi] lines. This neutral material is most plausibly located within their dense, cool circumstellar disks, which are formed from the (probably non-spherically symmetric) wind material released by the star. Neither the formation mechanism nor the resulting structure and internal kinematics of these di ...
... [Oi] lines. This neutral material is most plausibly located within their dense, cool circumstellar disks, which are formed from the (probably non-spherically symmetric) wind material released by the star. Neither the formation mechanism nor the resulting structure and internal kinematics of these di ...
L117 SHOCK-HEATED NH3 IN A MOLECULAR JET ASSOCIATED
... IRAS 2012614106 is a young star lying in the Cygnus X complex at a distance of 1.7 kpc (Wilking et al. 1989). Its luminosity of 1.3 # 10 4 L, corresponds to a zero-age mainsequence star of spectral type B0.2. Despite the high luminosity, sensitive observations with the VLA have failed to detect a ra ...
... IRAS 2012614106 is a young star lying in the Cygnus X complex at a distance of 1.7 kpc (Wilking et al. 1989). Its luminosity of 1.3 # 10 4 L, corresponds to a zero-age mainsequence star of spectral type B0.2. Despite the high luminosity, sensitive observations with the VLA have failed to detect a ra ...
X-ray Emission Line Profiles from ... Confined Wind Shock Model
... This model can simulate data that would be observed from a star with this wind structure. We now have the ability to obtain data with enough detail to allow fruitful comparison because of new instrumentation. The Chandra satellite has spectroscopic resolution capability that is better than the Einst ...
... This model can simulate data that would be observed from a star with this wind structure. We now have the ability to obtain data with enough detail to allow fruitful comparison because of new instrumentation. The Chandra satellite has spectroscopic resolution capability that is better than the Einst ...
Chapter 24
... spiral galaxies are rich in gas and dust. The 21-cm radio radiation emitted by spirals betrays the presence of interstellar gas, and obscuring dust lanes are clearly visible in many systems (see Figures 24.2b and c). Stars are forming within the spiral arms, which contain numerous emission nebulae a ...
... spiral galaxies are rich in gas and dust. The 21-cm radio radiation emitted by spirals betrays the presence of interstellar gas, and obscuring dust lanes are clearly visible in many systems (see Figures 24.2b and c). Stars are forming within the spiral arms, which contain numerous emission nebulae a ...
Dark Matter, Dark Energy, and the Fate of the Universe
... In principle, we could determine the complete distribution of mass in the Milky Way by doing the same thing with the orbits of stars at every different distance from the galactic center. In practice, interstellar dust obscures our view of disk stars more than a few thousand light-years away from us, ...
... In principle, we could determine the complete distribution of mass in the Milky Way by doing the same thing with the orbits of stars at every different distance from the galactic center. In practice, interstellar dust obscures our view of disk stars more than a few thousand light-years away from us, ...
Chapter J2
... How Old Is the Universe? • Age of the Universe Scientist use to methods to study the age of the universe. • By measuring the distance between Earth and various galaxies, scientists can predict the rate of expansion and calculate the age of the universe. • Because the universe must at least be as old ...
... How Old Is the Universe? • Age of the Universe Scientist use to methods to study the age of the universe. • By measuring the distance between Earth and various galaxies, scientists can predict the rate of expansion and calculate the age of the universe. • Because the universe must at least be as old ...
matter and dark energy Gravitational lensing: a unique probe of dark
... temporary brightening of a star due to the magnification induced by a foreground object that crosses the line of sight to the observer. In this rare post-1919 article about lensing by its discoverer, he states ‘of course there is no hope of observing this phenomenon’. The Caltech astronomer Fritz Zw ...
... temporary brightening of a star due to the magnification induced by a foreground object that crosses the line of sight to the observer. In this rare post-1919 article about lensing by its discoverer, he states ‘of course there is no hope of observing this phenomenon’. The Caltech astronomer Fritz Zw ...
Observations, Modeling and Theory of Debris Disks
... Universidad Autónoma de Madrid Main sequence stars, like the Sun, are often found to be orbited by circumstellar material that can be categorized into two groups, planets and debris. The latter is made up of asteroids and comets, as well as the dust and gas derived from them, which makes debris dis ...
... Universidad Autónoma de Madrid Main sequence stars, like the Sun, are often found to be orbited by circumstellar material that can be categorized into two groups, planets and debris. The latter is made up of asteroids and comets, as well as the dust and gas derived from them, which makes debris dis ...
Observations, Modeling and Theory of Debris Disks
... Universidad Autónoma de Madrid Main sequence stars, like the Sun, are often found to be orbited by circumstellar material that can be categorized into two groups, planets and debris. The latter is made up of asteroids and comets, as well as the dust and gas derived from them, which makes debris dis ...
... Universidad Autónoma de Madrid Main sequence stars, like the Sun, are often found to be orbited by circumstellar material that can be categorized into two groups, planets and debris. The latter is made up of asteroids and comets, as well as the dust and gas derived from them, which makes debris dis ...
High-Energy Emission from the PSR B1259
... For weak detections such as that from the PSR B125963 field, it is important to address possible systematic errors or alternate sources for the emission. A study of residuals in the 50–200 keV band from an aggregrate of many OSSE pointings indicates that the systematic errors are smaller than the st ...
... For weak detections such as that from the PSR B125963 field, it is important to address possible systematic errors or alternate sources for the emission. A study of residuals in the 50–200 keV band from an aggregrate of many OSSE pointings indicates that the systematic errors are smaller than the st ...
Chandra News The Secret X-ray Lives of Planetary Nebulae
... hard X-ray emission is typically attributed to coronal emission from a late-type, main-sequence companion (O’Dwyer et al. 2003) — and, in at least some cases, this appears to hold for PN central stars as well (see below). However, attempts to detect such a low-mass companion to the Helix central sta ...
... hard X-ray emission is typically attributed to coronal emission from a late-type, main-sequence companion (O’Dwyer et al. 2003) — and, in at least some cases, this appears to hold for PN central stars as well (see below). However, attempts to detect such a low-mass companion to the Helix central sta ...
Thermohaline mixing and the photospheric composition of low
... Denissenkov & Merryfield 2011; Stancliffe 2010). The thermohaline mixing has therefore been studied by means of numerical simulations either by considering it as an isolated process or by combining it with other mechanisms that might contribute to the turbulence of the material (e.g., rotation, inte ...
... Denissenkov & Merryfield 2011; Stancliffe 2010). The thermohaline mixing has therefore been studied by means of numerical simulations either by considering it as an isolated process or by combining it with other mechanisms that might contribute to the turbulence of the material (e.g., rotation, inte ...
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.