Chandra, Spitzer & VLA Observations of Young Clusters Scott Wolk - CxC/CfA
... Burkett and Hartmann (2004) ...
... Burkett and Hartmann (2004) ...
poster
... Figure 3: FUV emission lines observed with FUSE in CTTS and best fit Gaussian profiles ordered by the shift in the O vi 1032 Å line. For RU Lup an additional absorption component is used. ...
... Figure 3: FUV emission lines observed with FUSE in CTTS and best fit Gaussian profiles ordered by the shift in the O vi 1032 Å line. For RU Lup an additional absorption component is used. ...
A Legacy Study of Stellar Life Cycles in the Galactic Center
... There are X-rays from a few filaments (e.g., Lu et al. 2003), but • The X-rays don’t extend the length of the radio filament. • Most equally-bright filaments show no X-rays. ...
... There are X-rays from a few filaments (e.g., Lu et al. 2003), but • The X-rays don’t extend the length of the radio filament. • Most equally-bright filaments show no X-rays. ...
The Evolution of Coronal X
... Here is what I will speak about. First, how do we infer the past properties of the solar corona? One way is to look for archaeological evidence in the form of the composition of ancient meteorites or surface composition of the lunar surface or indirect evidence from planetary atmosphere histories. H ...
... Here is what I will speak about. First, how do we infer the past properties of the solar corona? One way is to look for archaeological evidence in the form of the composition of ancient meteorites or surface composition of the lunar surface or indirect evidence from planetary atmosphere histories. H ...
MHD Simulations of Line-Driven Hot-Star Winds
... Over the course of their lifetimes, hot, luminous, massive (OB-type) stars lose large amount of mass in nearly continous outflow called a stellar wind. These winds are driven by scattering of the star’s continuum radiaton in a large ensemble of spectral lines (Castor, Abbott & Klein 1975; CAK) There ...
... Over the course of their lifetimes, hot, luminous, massive (OB-type) stars lose large amount of mass in nearly continous outflow called a stellar wind. These winds are driven by scattering of the star’s continuum radiaton in a large ensemble of spectral lines (Castor, Abbott & Klein 1975; CAK) There ...
3. Neutron Star X-ray Binaries
... possibility of a NS-HMXB evolving into a microquasar phase since this decay is longer than the lifetime of the high-mass companion star, 107 yr for ...
... possibility of a NS-HMXB evolving into a microquasar phase since this decay is longer than the lifetime of the high-mass companion star, 107 yr for ...
MHD Simulations of Line-Driven Hot-Star Winds
... Over the course of their lifetimes, hot, luminous, massive (OB-type) stars lose large amount of mass in nearly continous outflow called a stellar wind. These winds are driven by scattering of the star’s continuum radiaton in a large ensemble of spectral lines (Castor, Abbott & Klein 1975; CAK) There ...
... Over the course of their lifetimes, hot, luminous, massive (OB-type) stars lose large amount of mass in nearly continous outflow called a stellar wind. These winds are driven by scattering of the star’s continuum radiaton in a large ensemble of spectral lines (Castor, Abbott & Klein 1975; CAK) There ...
The Swansong of Stars Orbiting Massive Black Holes
... signal drastically. The eccentricity also determines how much time a star spends within the LISA band before its final plunge. We used dynamical Monte Carlo simulations to study how two-body scattering and energy dissipation by GW emission, acting together, modify the inspiral orbits. ...
... signal drastically. The eccentricity also determines how much time a star spends within the LISA band before its final plunge. We used dynamical Monte Carlo simulations to study how two-body scattering and energy dissipation by GW emission, acting together, modify the inspiral orbits. ...
X-ray Emission Line Profile Diagnostics of Hot Star Winds
... values above 0.5 or even 1 cannot be ruled out in most cases d Ori ...
... values above 0.5 or even 1 cannot be ruled out in most cases d Ori ...
aas_gdemessieres - Astronomy at Swarthmore College
... instability (Owocki, Castor, Rybicki 1988; Feldmeier 1995) is a natural mechanism for generating shocks in a radiationdriven wind. - A third, hybrid, mechanism is the magnetically confined wind shock (MCWS) model (Babel and Montmerle 1997). A star with a magnetic field and a substantial radiation-dr ...
... instability (Owocki, Castor, Rybicki 1988; Feldmeier 1995) is a natural mechanism for generating shocks in a radiationdriven wind. - A third, hybrid, mechanism is the magnetically confined wind shock (MCWS) model (Babel and Montmerle 1997). A star with a magnetic field and a substantial radiation-dr ...
Name
... 35) Put these stars in order from hottest to coldest surface temperatures: A3, B2, F7, G8, K6. Hottest Coldest surface temperature A) B2, A3, F7, G8, K6 B) G8, K6, F7, A3, B2 C) A3, B2, F7, K6, G8 D) B2, A3, F7, K6, G8 E) F7, B2, A3, G8, K6 36) The term “blackbody” refers to an idealized object th ...
... 35) Put these stars in order from hottest to coldest surface temperatures: A3, B2, F7, G8, K6. Hottest Coldest surface temperature A) B2, A3, F7, G8, K6 B) G8, K6, F7, A3, B2 C) A3, B2, F7, K6, G8 D) B2, A3, F7, K6, G8 E) F7, B2, A3, G8, K6 36) The term “blackbody” refers to an idealized object th ...
Name
... For main sequence stars, the general rule is that the lower the surface temperature, … A) the greater the size of the core B) the greater the masses of the stars. C) the less luminous are the stars. D) the greater the diameter of the star E) the shorter the lifetime on the main sequence 40) What is ...
... For main sequence stars, the general rule is that the lower the surface temperature, … A) the greater the size of the core B) the greater the masses of the stars. C) the less luminous are the stars. D) the greater the diameter of the star E) the shorter the lifetime on the main sequence 40) What is ...
Name - MIT
... For main sequence stars, the general rule is that the lower the surface temperature, … A) the greater the size of the core B) the greater the masses of the stars. C) the less luminous are the stars. D) the greater the diameter of the star E) the shorter the lifetime on the main sequence 40) What is ...
... For main sequence stars, the general rule is that the lower the surface temperature, … A) the greater the size of the core B) the greater the masses of the stars. C) the less luminous are the stars. D) the greater the diameter of the star E) the shorter the lifetime on the main sequence 40) What is ...
Name - MIT
... E) F type 37) For main sequence stars, the general rule is that the lower the surface temperature, … A) the greater the size of the core B) the greater the masses of the stars. C) the less luminous are the stars. D) the greater the diameter of the star E) the shorter the lifetime on the main sequenc ...
... E) F type 37) For main sequence stars, the general rule is that the lower the surface temperature, … A) the greater the size of the core B) the greater the masses of the stars. C) the less luminous are the stars. D) the greater the diameter of the star E) the shorter the lifetime on the main sequenc ...
The Birth of a Supernova Seen in Real Time
... velocities inferred for GRBs and XRFs. The radio emission thus points to an ordinary core-collapse supernova in which only a tiny fraction of the explosion energy is coupled to fast ejecta. Of course, the ultimate clincher in constraining the expansion speed of the ejecta is through direct measureme ...
... velocities inferred for GRBs and XRFs. The radio emission thus points to an ordinary core-collapse supernova in which only a tiny fraction of the explosion energy is coupled to fast ejecta. Of course, the ultimate clincher in constraining the expansion speed of the ejecta is through direct measureme ...
Non-thermal hard X-ray emission from stellar coronae
... Simulations of NT components in typical stellar flares NT recognized when unphysical thermal components are found (T > 300 MK) Required > 20 total counts in the 20-40 keV band Other constraints - Neupert effect - thermalization and energy loss time scales ...
... Simulations of NT components in typical stellar flares NT recognized when unphysical thermal components are found (T > 300 MK) Required > 20 total counts in the 20-40 keV band Other constraints - Neupert effect - thermalization and energy loss time scales ...
Presentation 1: Spectroscopy
... zones, magnetic fields, or the associated magnetic dynamo and corona that our sun has. Thus their discovery 20 years ago as relatively strong soft X-ray sources was a surprise. Hot stars do have strong radiation-driven winds. These winds are subject to a line-driving instability which can lead to sh ...
... zones, magnetic fields, or the associated magnetic dynamo and corona that our sun has. Thus their discovery 20 years ago as relatively strong soft X-ray sources was a surprise. Hot stars do have strong radiation-driven winds. These winds are subject to a line-driving instability which can lead to sh ...
X-Ray Binaries
... • PSR 1913+16 (with Porb ' 8 hr, Pspin = 59 ms) discovered by Taylor & Hulse (1975) • about half a dozen are now known • orbital evolution is driven by gravitational radiation → one of the best tests of general relativity ...
... • PSR 1913+16 (with Porb ' 8 hr, Pspin = 59 ms) discovered by Taylor & Hulse (1975) • about half a dozen are now known • orbital evolution is driven by gravitational radiation → one of the best tests of general relativity ...
lecture2 - X-Ray
... The satellite was launched on December 12, 1970. The program was ended in March 1973. The other name SAS-1 2-20 keV The first full sky survey. 339 sources. ...
... The satellite was launched on December 12, 1970. The program was ended in March 1973. The other name SAS-1 2-20 keV The first full sky survey. 339 sources. ...
Introduction to Accretion Phenomena in Astrophysics
... star (usually a red dwarf). • Blue stars with rapid and strong variability. • Strong UV and X-ray emission. • Peculiar emission lines • Size: roughly Earth-Moon system. • Orbital periods: 1-10 h. • Energy sources: accretion and nuclear fusion. ...
... star (usually a red dwarf). • Blue stars with rapid and strong variability. • Strong UV and X-ray emission. • Peculiar emission lines • Size: roughly Earth-Moon system. • Orbital periods: 1-10 h. • Energy sources: accretion and nuclear fusion. ...
Sections F and G
... determines how small the accretion disc can get). Thus accretion discs around dense, compact objects are hotter than those around larger, less dense objects. Accretion discs around white dwarfs lead to optical emission (novae), while those around neutron stars (or black holes) result in X-ray emissi ...
... determines how small the accretion disc can get). Thus accretion discs around dense, compact objects are hotter than those around larger, less dense objects. Accretion discs around white dwarfs lead to optical emission (novae), while those around neutron stars (or black holes) result in X-ray emissi ...
Astronomy news
... "We found a rise and fall in X-ray light every 62 days, likely caused by the orbit of the companion star around the black hole. Because the star is located in such a dust-obscured area, this makes it hard for optical and infrared telescopes to observe the star and velocity calculations." Said Simet. ...
... "We found a rise and fall in X-ray light every 62 days, likely caused by the orbit of the companion star around the black hole. Because the star is located in such a dust-obscured area, this makes it hard for optical and infrared telescopes to observe the star and velocity calculations." Said Simet. ...
205 Advances in Natural and Applied Sciences, 4(2): 205-209, 2010 ISSN 1995-0772
... neutron star or a black hole formed after collapse of an ordinary star) and a stellar companion, orbit each other at a distance small enough to enable mass transfer from the companion star to the compact object. The transferred matter spirals towards the compact object and forms an “accretion disk” ...
... neutron star or a black hole formed after collapse of an ordinary star) and a stellar companion, orbit each other at a distance small enough to enable mass transfer from the companion star to the compact object. The transferred matter spirals towards the compact object and forms an “accretion disk” ...
Using a distant X-ray source to detect small Transneptunian Objects
... Depending on the position of the Earth in its orbit over the 6 years of the observations, the angular speed of the Earth relative to the TNO is sometimes added and sometimes subtracted. What is the maximum blocking time for the signals which could be expected from a spherical TNO with a 100 m diamet ...
... Depending on the position of the Earth in its orbit over the 6 years of the observations, the angular speed of the Earth relative to the TNO is sometimes added and sometimes subtracted. What is the maximum blocking time for the signals which could be expected from a spherical TNO with a 100 m diamet ...
Lecture 16, AGN Evolution
... (From the standard theory of accretion onto black holes, a maximum efficiency of 6% for accretion onto a non-rotating BH is derived) ...
... (From the standard theory of accretion onto black holes, a maximum efficiency of 6% for accretion onto a non-rotating BH is derived) ...
X-ray astronomy
X-ray astronomy is an observational branch of astronomy which deals with the study of X-ray observation and detection from astronomical objects. X-radiation is absorbed by the Earth's atmosphere, so instruments to detect X-rays must be taken to high altitude by balloons, sounding rockets, and satellites. X-ray astronomy is the space science related to a type of space telescope that can see farther than standard light-absorption telescopes, such as the Mauna Kea Observatories, via x-ray radiation.X-ray emission is expected from astronomical objects that contain extremely hot gasses at temperatures from about a million kelvin (K) to hundreds of millions of kelvin (MK). Although X-rays have been observed emanating from the Sun since the 1940s, the discovery in 1962 of the first cosmic X-ray source was a surprise. This source is called Scorpius X-1 (Sco X-1), the first X-ray source found in the constellation Scorpius. The X-ray emission of Scorpius X-1 is 10,000 times greater than its visual emission, whereas that of the Sun is about a million times less. In addition, the energy output in X-rays is 100,000 times greater than the total emission of the Sun in all wavelengths. Based on discoveries in this new field of X-ray astronomy, starting with Scorpius X-1, Riccardo Giacconi received the Nobel Prize in Physics in 2002. It is now known that such X-ray sources as Sco X-1 are compact stars, such as neutron stars or black holes. Material falling into a black hole may emit X-rays, but the black hole itself does not. The energy source for the X-ray emission is gravity. Infalling gas and dust is heated by the strong gravitational fields of these and other celestial objects.Many thousands of X-ray sources are known. In addition, the space between galaxies in galaxy clusters is filled with a very hot, but very dilute gas at a temperature between 10 and 100 megakelvins (MK). The total amount of hot gas is five to ten times the total mass in the visible galaxies.