幻灯片 1
... does not make sense in a classical model with electrons orbiting around a nucleus, but can be explained by atomic wavefunctions|an electron with a high principal quantum number (and little angular momentum) has a nite probability of being found at small radial distances. The study of X-rays has deve ...
... does not make sense in a classical model with electrons orbiting around a nucleus, but can be explained by atomic wavefunctions|an electron with a high principal quantum number (and little angular momentum) has a nite probability of being found at small radial distances. The study of X-rays has deve ...
multiwavelength observations of the gamma-ray
... Blazars (BL Lac objects and gamma-ray loud flat spectrum radio quasars (FSRQs)) are the most extreme type of active galactic nuclei (AGNs). They were historically defined through extreme flux variability throughout the electromagnetic spectrum, and sometimes strong and variable linear polarization a ...
... Blazars (BL Lac objects and gamma-ray loud flat spectrum radio quasars (FSRQs)) are the most extreme type of active galactic nuclei (AGNs). They were historically defined through extreme flux variability throughout the electromagnetic spectrum, and sometimes strong and variable linear polarization a ...
6 Big Bang Nucleosynthesis - Course Pages of Physics Department
... occurs at a higher temperature T4 ∼ 0.3 MeV. But we noted earlier that only deuterium stays close to its equilibrium abundance once it gets large. Helium begins to form only when there is sufficient deuterium available, in practice slightly above Td . Helium forms then rapidly. The available number ...
... occurs at a higher temperature T4 ∼ 0.3 MeV. But we noted earlier that only deuterium stays close to its equilibrium abundance once it gets large. Helium begins to form only when there is sufficient deuterium available, in practice slightly above Td . Helium forms then rapidly. The available number ...
Spacecraft Navigation Using X-Ray Pulsars
... large antennas (on the order of 25 m in diameter or larger) to detect sources, which would be impractical for most spacecraft. Also, neighboring celestial objects including the sun, moon, Jupiter, and close stars, as well as distance objects such as radio galaxies, quasars, and the galactic diffuse ...
... large antennas (on the order of 25 m in diameter or larger) to detect sources, which would be impractical for most spacecraft. Also, neighboring celestial objects including the sun, moon, Jupiter, and close stars, as well as distance objects such as radio galaxies, quasars, and the galactic diffuse ...
Silicon single photon imaging detectors
... EMCCDs, but chose another conventional CCDs [7]. These devices can be operated with a more sophisticated digitizing circuit on the output, so that the discrete jumps in the output charge can be recognized as corresponding to different numbers of absorbed photons. One compromise to this approach is t ...
... EMCCDs, but chose another conventional CCDs [7]. These devices can be operated with a more sophisticated digitizing circuit on the output, so that the discrete jumps in the output charge can be recognized as corresponding to different numbers of absorbed photons. One compromise to this approach is t ...
Chandra News March 2005 Published by the Chandra X-ray Center (CXC)
... a scan of the Galactic plane with a rocket-borne detector. In 1979, the first Einstein observation of this region showed that this source was the Carina Nebula, over 1 degree in extent - a bright (by present standards) diffuse source sprinkled with dozens of point-like O stars. Although η Carinae it ...
... a scan of the Galactic plane with a rocket-borne detector. In 1979, the first Einstein observation of this region showed that this source was the Carina Nebula, over 1 degree in extent - a bright (by present standards) diffuse source sprinkled with dozens of point-like O stars. Although η Carinae it ...
ON THE POLAR CAPS OF THE THREE MUSKETEERS1
... function of phase, as the stars’ rotation brings into view different emitting regions. The hot spots, which have very different apparent dimensions (in spite of the similarity of the three neutron stars polar cap radii) are responsible for the bulk of the phase variation. The amplitude of the observ ...
... function of phase, as the stars’ rotation brings into view different emitting regions. The hot spots, which have very different apparent dimensions (in spite of the similarity of the three neutron stars polar cap radii) are responsible for the bulk of the phase variation. The amplitude of the observ ...
Candidate detector assessment for the CASTOR
... magnitudes above this point the data from the EMCCD would be processed in analog mode, at which point the gain dispersion reduces the effective signal to noise ratio, compared to a typical CCD. When the energy of the UV photons exceeds twice the bandgap energy in silicon, there is a chance that mult ...
... magnitudes above this point the data from the EMCCD would be processed in analog mode, at which point the gain dispersion reduces the effective signal to noise ratio, compared to a typical CCD. When the energy of the UV photons exceeds twice the bandgap energy in silicon, there is a chance that mult ...
HRC Update Ralph Kraft and Junfeng Wang
... Mike Juda and the CXC Calibration team with the support of the HRC instrument team) to evaluate the effect of a progressive increase of the high voltage on both the top and bottom MCPs and determine how much of the lost QE in the wing plates could be recovered by a small increase to the HV. This pla ...
... Mike Juda and the CXC Calibration team with the support of the HRC instrument team) to evaluate the effect of a progressive increase of the high voltage on both the top and bottom MCPs and determine how much of the lost QE in the wing plates could be recovered by a small increase to the HV. This pla ...
How Stars Work (Part II)
... energy an electron gains if it moves 1 cm through a 1 volt field 14 electron volts to remove an electron from a hydrogen atom Energy equivalent of one atomic mass unit (mass of proton & neutron) is 931.4 MeV An electron has a mass which is roughly 1/1870 that of the proton If an electron and a posit ...
... energy an electron gains if it moves 1 cm through a 1 volt field 14 electron volts to remove an electron from a hydrogen atom Energy equivalent of one atomic mass unit (mass of proton & neutron) is 931.4 MeV An electron has a mass which is roughly 1/1870 that of the proton If an electron and a posit ...
Ong page 1 of VHE astro
... HE g from inverse Compton or proton cascade in jets? Six g sources from EGRET. Want to see pulsed VHE g signal. e.g. Crab nebula powered by central pulsar determine mechanism and nebular magnetic field g from in shock wave, maybe also p0 decay? bursts of gamma rays lasting 10 msec to 1000 sec, some ...
... HE g from inverse Compton or proton cascade in jets? Six g sources from EGRET. Want to see pulsed VHE g signal. e.g. Crab nebula powered by central pulsar determine mechanism and nebular magnetic field g from in shock wave, maybe also p0 decay? bursts of gamma rays lasting 10 msec to 1000 sec, some ...
Coevolution of SMBHs and host galaxies at high z
... evolution in MBH-MGAL ratio with redshift - with relationship ~2-4x higher at z~2 and perhaps higher at z~2-6: factor ~4 based on Merloni et al. (2010) Evolution perhaps only significant at highest masses (>3x108 solar masses): see Di Matteo talk (also Merloni et al. 2010) ...
... evolution in MBH-MGAL ratio with redshift - with relationship ~2-4x higher at z~2 and perhaps higher at z~2-6: factor ~4 based on Merloni et al. (2010) Evolution perhaps only significant at highest masses (>3x108 solar masses): see Di Matteo talk (also Merloni et al. 2010) ...
EM spectrum telescopes,HR star info-domenico
... giant mirror. These mirrors are computer controlled to make a parabolic shape. • The KECK telescope in Hawaii is currently the largest telescope in the world with a ...
... giant mirror. These mirrors are computer controlled to make a parabolic shape. • The KECK telescope in Hawaii is currently the largest telescope in the world with a ...
Lecture 2. Isolated Neutron Stars – I.
... UHURU 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. ...
... UHURU 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. ...
Construction and Operation of an Axion Helioscope
... We are preparing and evaluating a design for a detector sensitive to axions and other light particles with a two-photon interaction vertex. Such particles would be pro duced in the solar interior by Primakoff conversion of blackbody photons and could be detected by their reconversion into x-rays (a ...
... We are preparing and evaluating a design for a detector sensitive to axions and other light particles with a two-photon interaction vertex. Such particles would be pro duced in the solar interior by Primakoff conversion of blackbody photons and could be detected by their reconversion into x-rays (a ...
Testing Models of Coronal Heating, X
... Testing Models of Coronal Heating, X-Ray Emission, and Winds . . . ...
... Testing Models of Coronal Heating, X-Ray Emission, and Winds . . . ...
Phenomenon of total external reflection of x rays
... traditional branch of x-ray optics which is being used increasingly in research and physics, astrophysics, and biology.4 We are speaking here of wavelengths in the range 300 A >A > 1 A, so that it is important to consider the irregularities which unavoidably remain on an optical surface after any ty ...
... traditional branch of x-ray optics which is being used increasingly in research and physics, astrophysics, and biology.4 We are speaking here of wavelengths in the range 300 A >A > 1 A, so that it is important to consider the irregularities which unavoidably remain on an optical surface after any ty ...
A wide Chandra view of the core of the Perseus cluster
... This volume is about 5.6 × 104 kpc3 , or about 21.5 times that of the inner N bubble, which has a radius of 8.5 kpc. The external pressure drops by a factor of 3 between the centre and 10 arcmin radius where the trough resides (Fig. 12), which is a pressure of about ne Te ∼ 7×105 K cm−3 . Adiabatic ...
... This volume is about 5.6 × 104 kpc3 , or about 21.5 times that of the inner N bubble, which has a radius of 8.5 kpc. The external pressure drops by a factor of 3 between the centre and 10 arcmin radius where the trough resides (Fig. 12), which is a pressure of about ne Te ∼ 7×105 K cm−3 . Adiabatic ...
Astronomy Astrophysics − Astrophysical parameters of the peculiar X-ray transient
... Context. The current generation of X-ray satellites has discovered many new X-ray sources that are difficult to classify within the well-described subclasses. The hard X-ray source IGR J11215−5952 is a peculiar transient, displaying very short X-ray outbursts every 165 days. Aims. To characterise the ...
... Context. The current generation of X-ray satellites has discovered many new X-ray sources that are difficult to classify within the well-described subclasses. The hard X-ray source IGR J11215−5952 is a peculiar transient, displaying very short X-ray outbursts every 165 days. Aims. To characterise the ...
A STRONGLY MAGNETIZED PULSAR WITHIN THE GRASP OF THE MILKY... SUPERMASSIVE BLACK HOLE Rea ,
... template for the timing analysis (which might artificially affect the phase shift), instead using two parallel methods: fitting a sinusoid to the profile at the fundamental period and fitting the highest peak in all the observations with a Gaussian. We used 12 phase bins to produce a folded pulse pr ...
... template for the timing analysis (which might artificially affect the phase shift), instead using two parallel methods: fitting a sinusoid to the profile at the fundamental period and fitting the highest peak in all the observations with a Gaussian. We used 12 phase bins to produce a folded pulse pr ...
Ch a n d
... Warm Absorbers Influenced By Soft Photons From An AGN Accretion Disk Susmita Chakravorty Harvard Smithsonian CfA A warm absorber (WA) is the ionized gas in the line of sight to the central region of the active galactic nuclei (AGN). The thermal properties and the ionization state of the WA is determ ...
... Warm Absorbers Influenced By Soft Photons From An AGN Accretion Disk Susmita Chakravorty Harvard Smithsonian CfA A warm absorber (WA) is the ionized gas in the line of sight to the central region of the active galactic nuclei (AGN). The thermal properties and the ionization state of the WA is determ ...
The Be/X-ray transient V0332153: evidence for a tilt between the
... discuss the evolution of the circumstellar envelope. Owing to the low inclination of the system, parameters are strongly constrained. We find strong evidence for a tilt of the orbital plane with respect to the circumstellar disc (presumably on the equatorial plane). Even though the periastron distan ...
... discuss the evolution of the circumstellar envelope. Owing to the low inclination of the system, parameters are strongly constrained. We find strong evidence for a tilt of the orbital plane with respect to the circumstellar disc (presumably on the equatorial plane). Even though the periastron distan ...
Slides - GSI IndiCo
... values can be obtain from β decay experiments. -Weak interaction processAbsolute B(GT) values - Beta decay studies are limited in the low excitation energy regions. ...
... values can be obtain from β decay experiments. -Weak interaction processAbsolute B(GT) values - Beta decay studies are limited in the low excitation energy regions. ...
ppt - WISH
... high-z galaxy clusters? 1. Growth of structures: the measurement of cosmological parameters. - independent of the geometric methods such as SNe distance, CMB, BAO - One of the very few ways to test GR at ...
... high-z galaxy clusters? 1. Growth of structures: the measurement of cosmological parameters. - independent of the geometric methods such as SNe distance, CMB, BAO - One of the very few ways to test GR at ...
L171 COULD BLACK HOLE X-RAY BINARIES BE DETECTED IN
... we have tRGB ⱗ 10 9 yr. This is still shorter than the interaction timescale tex ⯝ 3 # 10 9 yr estimated for a cluster like NGC 6397. Therefore, for all clusters where exchanges are important (or where post-exchange–like binaries are formed through TC with RGs), we find tMT /tex K 1. Next, we consid ...
... we have tRGB ⱗ 10 9 yr. This is still shorter than the interaction timescale tex ⯝ 3 # 10 9 yr estimated for a cluster like NGC 6397. Therefore, for all clusters where exchanges are important (or where post-exchange–like binaries are formed through TC with RGs), we find tMT /tex K 1. Next, we consid ...
X-ray astronomy detector
X-ray astronomy detectors are instruments that detect X-rays for use in the study of X-ray astronomy.X-ray astronomy is an observational branch of astronomy which deals with the study of X-ray emission from celestial 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 part of space science.X-ray astronomy detectors have been designed and configured primarily for energy and occasionally for wavelength detection using a variety of techniques usually limited to the technology of the time.