Extraordinary Gamma-Ray Burst
... and variability seen, the outward-directed beam from Swift 1644+57 must point virtually straight at Earth. Other astronomical objects have shown somewhat similar bursts of radiation at X-ray, ultraviolet, and optical wavelengths. These have led researchers to believe they too were witnessing the tid ...
... and variability seen, the outward-directed beam from Swift 1644+57 must point virtually straight at Earth. Other astronomical objects have shown somewhat similar bursts of radiation at X-ray, ultraviolet, and optical wavelengths. These have led researchers to believe they too were witnessing the tid ...
Discovery of the optical counterpart to the X
... about 8 were bright enough in Hα to call our attention. The position of each one of these potential candidates with respect to the satellites error circle was then checked. Of these relatively strong Hα emitters only one lied inside the WFC BeppoSAX satellite position uncertainty circles (Fig.1). As ...
... about 8 were bright enough in Hα to call our attention. The position of each one of these potential candidates with respect to the satellites error circle was then checked. Of these relatively strong Hα emitters only one lied inside the WFC BeppoSAX satellite position uncertainty circles (Fig.1). As ...
MHD seismology as a tool to diagnose the coronae of X
... heating of the corona of ξ-Boo. It should be noted that it is a binary K-Dwarf with the magnetized atmosphere and flaring activities. Observations of the decaying long period oscillation of a stellar megaflare by Anfinogentov et al. (2013): In the decay phase of the U-band light curve of a stellar m ...
... heating of the corona of ξ-Boo. It should be noted that it is a binary K-Dwarf with the magnetized atmosphere and flaring activities. Observations of the decaying long period oscillation of a stellar megaflare by Anfinogentov et al. (2013): In the decay phase of the U-band light curve of a stellar m ...
a report on pulsars, written for PHAS1901
... dispersion. All electromagnetic radiation moves at a constant speed through a vacuum, but is slowed proportionally to it's wavelength when it travels through a medium. the interstellar medium is often regarded as a vacuum, but in actual fact is occupied by atoms and free electrons, albeit at extreme ...
... dispersion. All electromagnetic radiation moves at a constant speed through a vacuum, but is slowed proportionally to it's wavelength when it travels through a medium. the interstellar medium is often regarded as a vacuum, but in actual fact is occupied by atoms and free electrons, albeit at extreme ...
Informational Brochure "Enlightening Science"
... rungs of this “ladder” carry genetic information. This landmark discovery exemplifies how understanding structure is key to understanding function—a principle that is also very important in other fields, such as chemistry or materials science. The determination of complex molecular structures requir ...
... rungs of this “ladder” carry genetic information. This landmark discovery exemplifies how understanding structure is key to understanding function—a principle that is also very important in other fields, such as chemistry or materials science. The determination of complex molecular structures requir ...
Millisecond Pulsars in X-Ray Binaries - CIERA
... as well as several additional examples (see Table 1). A key element proved to be the highly flexible pointing and scheduling ability of RXTE . The Galactic X-ray sky is highly variable, with some sources lying dormant for years and only intermittently becoming active in X-ray emission. The combinati ...
... as well as several additional examples (see Table 1). A key element proved to be the highly flexible pointing and scheduling ability of RXTE . The Galactic X-ray sky is highly variable, with some sources lying dormant for years and only intermittently becoming active in X-ray emission. The combinati ...
Lectures 14 & 15 powerpoint (neutron stars & black holes)
... to be moving at a high speed through space… ...
... to be moving at a high speed through space… ...
UNIFIED PICTURE OF LARGE AND SMALL SCALE: MICRO
... • Recent solar observations show various evidence of reconnection in solar flares, microflares, and nanoflares, leading to a unified model of solar flares. • Plasmoid ejections are ubiquitous in flares and flare-like events, which may play a key role to induce fast reconnection in a fractal (turbule ...
... • Recent solar observations show various evidence of reconnection in solar flares, microflares, and nanoflares, leading to a unified model of solar flares. • Plasmoid ejections are ubiquitous in flares and flare-like events, which may play a key role to induce fast reconnection in a fractal (turbule ...
Nature template - PC Word 97
... from 2005.819 to 2005.831 during the first X-ray flare implies that acceleration of subTeV-energy electrons was particularly efficient at this time. These same electrons both produce X-rays from synchrotron radiation and scatter the X-ray photons to GeV -ray energies that are boosted to the TeV ran ...
... from 2005.819 to 2005.831 during the first X-ray flare implies that acceleration of subTeV-energy electrons was particularly efficient at this time. These same electrons both produce X-rays from synchrotron radiation and scatter the X-ray photons to GeV -ray energies that are boosted to the TeV ran ...
A scenario of planet erosion by coronal radiation*
... close to a brighter source α = 10:59:26.7, δ = 40:26:04: the instrumental spatial resolution is 6 . Tentative evidence for detection of a Fe Kα emission line suggests the brighter source may be a highly obscured AGN at z ∼ 0.2 (G. Miniutti, private comm.). In the same way as for HD 209458, we calc ...
... close to a brighter source α = 10:59:26.7, δ = 40:26:04: the instrumental spatial resolution is 6 . Tentative evidence for detection of a Fe Kα emission line suggests the brighter source may be a highly obscured AGN at z ∼ 0.2 (G. Miniutti, private comm.). In the same way as for HD 209458, we calc ...
ULXs: General Properties and Variability - X
... 1 inside X-ray ionized nebula – strong HeII 4686 and [OI] 6300 – requires 3-13x1039 ergs/sec to produce observed optical emission lines 4+ in bubble-like nebulae, 200-400 pc – 2+ with probable O-star counterpart 4+ in other nebulae ...
... 1 inside X-ray ionized nebula – strong HeII 4686 and [OI] 6300 – requires 3-13x1039 ergs/sec to produce observed optical emission lines 4+ in bubble-like nebulae, 200-400 pc – 2+ with probable O-star counterpart 4+ in other nebulae ...
this PDF file - University of Leicester
... to change its body temperature of the order of 107 K in order to accomplish the ability to switch between all 3 of these scenarios. Therefore it is deemed impossible to exist in nature, or at the least very highly unlikely. ...
... to change its body temperature of the order of 107 K in order to accomplish the ability to switch between all 3 of these scenarios. Therefore it is deemed impossible to exist in nature, or at the least very highly unlikely. ...
Cygnus X-1
... a very inconsistent source for X-ray emissions. The emissions of X-rays for Cygnus X-1 flicker in hundredth of a second bursts. It is also been proven that Cygnus X-1 is smaller than the Earth. Strangely enough, Cygnus X-1 has a companion star called HDE 226868. HDE 226868 is a supergiant with a tem ...
... a very inconsistent source for X-ray emissions. The emissions of X-rays for Cygnus X-1 flicker in hundredth of a second bursts. It is also been proven that Cygnus X-1 is smaller than the Earth. Strangely enough, Cygnus X-1 has a companion star called HDE 226868. HDE 226868 is a supergiant with a tem ...
ms
... follow the Bayesian method discussed in detail in Özel et al. (2009, 2012a). For each observable, we assign an independent probability distribution function. For the touchdown flux P (FT D )dFT D , the apparent angular size P (A)dA, and the distance P (D)dD, we use Gaussian probability distribution ...
... follow the Bayesian method discussed in detail in Özel et al. (2009, 2012a). For each observable, we assign an independent probability distribution function. For the touchdown flux P (FT D )dFT D , the apparent angular size P (A)dA, and the distance P (D)dD, we use Gaussian probability distribution ...
Non-Thermal Radio Emission from Binary Systems
... Weak-lined (WTT): non-thermal radio emission from magnetically active regions ...
... Weak-lined (WTT): non-thermal radio emission from magnetically active regions ...
the chromospheres of classical cepheids. 111. a search for transition
... argued that the regions in which they originate have a minimum extent which ranges from several tenths of a stellar radius to several stellar radii in various stars. This is much larger than the solar chromosphere, but not as extended as the chromospheres of late-type giants. In Paper I we presented ...
... argued that the regions in which they originate have a minimum extent which ranges from several tenths of a stellar radius to several stellar radii in various stars. This is much larger than the solar chromosphere, but not as extended as the chromospheres of late-type giants. In Paper I we presented ...
Deexcitation NSS 2004
... Solid state detector have a better definition than “normal” gas-filled proportional counters ...
... Solid state detector have a better definition than “normal” gas-filled proportional counters ...
X-Ray Properties of Young Stars and Stellar Clusters
... Extensive multiwavelength properties of PMS stars indicate they are highly magnetically active stars (Feigelson and Montmerle, 1999). Hundreds of Orion stars, and many in other young stellar populations, have periodic photometric variations from rotationally modulated starspots covering 10–50% of th ...
... Extensive multiwavelength properties of PMS stars indicate they are highly magnetically active stars (Feigelson and Montmerle, 1999). Hundreds of Orion stars, and many in other young stellar populations, have periodic photometric variations from rotationally modulated starspots covering 10–50% of th ...
An Analysis of the Behavior of Vela X-1
... – Occurs suddenly without a transition phase (almost like a switch) – Not an eclipse but count rate drops to below detection limits, almost 0. ...
... – Occurs suddenly without a transition phase (almost like a switch) – Not an eclipse but count rate drops to below detection limits, almost 0. ...
ppt - UCL
... • soft X-ray thermal spectrum (Tbb~ 86 eV) • low column density (NH ~ 6 x1019 cm–2 ). The source is also pulsating with P ~ 8.4 s. Until a few years ago two mechanisms were proposed for dim NSs: accretion from the interstellar medium onto an old NS or cooling of a younger object. More recently, base ...
... • soft X-ray thermal spectrum (Tbb~ 86 eV) • low column density (NH ~ 6 x1019 cm–2 ). The source is also pulsating with P ~ 8.4 s. Until a few years ago two mechanisms were proposed for dim NSs: accretion from the interstellar medium onto an old NS or cooling of a younger object. More recently, base ...
Document
... soft X-ray flare from 3 galaxies which were classified as non-active from ground based spectra. ...
... soft X-ray flare from 3 galaxies which were classified as non-active from ground based spectra. ...
High Resolution Chandra Spectroscopy of Gamma Cassiopeia (B0
... presence of Fe and Si fluorescence K features indicates that photoionization also occurs in nearby cold gas. The line profiles indicate a mean velocity at rest with a r.m.s. line broadening of 500 km s−1 and little or no asymmetry. An empirical global fitting analysis of the line and continuum spect ...
... presence of Fe and Si fluorescence K features indicates that photoionization also occurs in nearby cold gas. The line profiles indicate a mean velocity at rest with a r.m.s. line broadening of 500 km s−1 and little or no asymmetry. An empirical global fitting analysis of the line and continuum spect ...
The Radio and X-ray Jet
... These researchers managed to persuade the Space Telescope Science Institute to take a really deep exposure of a random part of the sky. A really deep exposure takes a lot of Bubble time, so they were only given time to image one region of the sky. Furthermore, their data was made generally available ...
... These researchers managed to persuade the Space Telescope Science Institute to take a really deep exposure of a random part of the sky. A really deep exposure takes a lot of Bubble time, so they were only given time to image one region of the sky. Furthermore, their data was made generally available ...
Determining the Effect of Diffuse X-ray Emission on Point Source Detection
... image, and smoothing those areas to create an image representing the diffuse X-ray emission in the region. For this, the primary tool used was the Chandra Interactive Analysis of Observations (CIAO) data analysis software, designed for use on Chandra data4 . The CIAO wavelet detection routine used f ...
... image, and smoothing those areas to create an image representing the diffuse X-ray emission in the region. For this, the primary tool used was the Chandra Interactive Analysis of Observations (CIAO) data analysis software, designed for use on Chandra data4 . The CIAO wavelet detection routine used f ...
PowerPoint Presentation - Isolated Neutron Stars, solid crust
... devoted to study the faint thermal emission from neutron stars and to search for features in their spectrum. Isolated neutron stars play a key role in compact objects astrophysics: these are the only sources in which we can see directly the surface of the compact star. ...
... devoted to study the faint thermal emission from neutron stars and to search for features in their spectrum. Isolated neutron stars play a key role in compact objects astrophysics: these are the only sources in which we can see directly the surface of the compact star. ...
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.