The presence of gamma rays in space was known before they were
... however the main definition of a gamma ray is that its source has to be from the nucleus of an atom and not from one of the electrons surrounding the nucleus. This means X-rays which are generated from electrons can have same energies as gamma rays, but it is important to make a distinction between ...
... however the main definition of a gamma ray is that its source has to be from the nucleus of an atom and not from one of the electrons surrounding the nucleus. This means X-rays which are generated from electrons can have same energies as gamma rays, but it is important to make a distinction between ...
Chandra The Role of Modeling in the Calibration of ’s Optics
... The Chandra X-ray observatory, launched in 1999, is the result of more than two decades of design, engineering, and manufacturing effort. At its heart is a set of four Wolter type I optics, fabricated of Zerodur and polished to a surface roughness of 1.3 − 3Å,1 designed to provide better than 100 a ...
... The Chandra X-ray observatory, launched in 1999, is the result of more than two decades of design, engineering, and manufacturing effort. At its heart is a set of four Wolter type I optics, fabricated of Zerodur and polished to a surface roughness of 1.3 − 3Å,1 designed to provide better than 100 a ...
?! XMM-Newton ready for the next decade?!!!! Chandra calibration meeting
... -->linear build up model in calibration New RGS effective area CCFs based on linear increase with time of pure carbon contamination layer Fixed polynomial blazar power-law correction Improved Crab nebula model corrected RGS flux constant within ± 5 % Marcus G. F. Kirsch XMM-Newton Page 10 ...
... -->linear build up model in calibration New RGS effective area CCFs based on linear increase with time of pure carbon contamination layer Fixed polynomial blazar power-law correction Improved Crab nebula model corrected RGS flux constant within ± 5 % Marcus G. F. Kirsch XMM-Newton Page 10 ...
The destruction and survival of polycyclic aromatic hydrocarbons in
... In Spitzer observations of Tauri stars and their disks, features of polycyclic aromatic hydrocarbons (PAHs) are detected in less than 10% of the objects, although the stellar photosphere is sufficiently hot to excite PAHs. To explain the deficiency, we discuss PAH destruction by photons, assuming that ...
... In Spitzer observations of Tauri stars and their disks, features of polycyclic aromatic hydrocarbons (PAHs) are detected in less than 10% of the objects, although the stellar photosphere is sufficiently hot to excite PAHs. To explain the deficiency, we discuss PAH destruction by photons, assuming that ...
Document
... us to estimate their black hole masses. - The galaxy masses have been estimated from their SED - z~2 obscured AGNs have MBH/Mstar lower than the local relation, in contrast with unobscured AGNs ...
... us to estimate their black hole masses. - The galaxy masses have been estimated from their SED - z~2 obscured AGNs have MBH/Mstar lower than the local relation, in contrast with unobscured AGNs ...
Present Carbon and Oxygen data with efficiency numbers
... The Constellation-X mission will provide an instrument with large effective collecting area and high spectral resolution relative to past and current x-ray observatories. An overview of the mission and science goals is given by Tananbaum, et al.1, and can be found on the web at http://constellation. ...
... The Constellation-X mission will provide an instrument with large effective collecting area and high spectral resolution relative to past and current x-ray observatories. An overview of the mission and science goals is given by Tananbaum, et al.1, and can be found on the web at http://constellation. ...
Lecture 3, Optical and UV Astronomy
... UV Detectors UV detectors need to be “solar blind” (not sensitive to visible photons). UV detectors are often based on UV sensitive photocathodes amplified by stacks of microchannel plates (also used in X-ray). Microchannel plate: electron multiplier made of a thin disk of leadoxide glass with a la ...
... UV Detectors UV detectors need to be “solar blind” (not sensitive to visible photons). UV detectors are often based on UV sensitive photocathodes amplified by stacks of microchannel plates (also used in X-ray). Microchannel plate: electron multiplier made of a thin disk of leadoxide glass with a la ...
"Characterization of 3D-integrated Active Pixel Sensor for X-ray Detection."
... signal losses of any type have to be negligible. Since the signal is very small, the noise level also needs to be very low. When an entire array is clocked out, pixel nonuniformities of all kinds mask the intrapixel X-ray performance and make it difficult to diagnose the limits of the technology, wh ...
... signal losses of any type have to be negligible. Since the signal is very small, the noise level also needs to be very low. When an entire array is clocked out, pixel nonuniformities of all kinds mask the intrapixel X-ray performance and make it difficult to diagnose the limits of the technology, wh ...
part 2
... The X-ray study of rotation-powered or radio pulsars has had a close link with Xray astronomy from its very beginning. After the discovery of Sco X−1 as the first extra-solar X-ray source by rocket-borne Geiger counters (Giacconi et al. 1962), the next source of celestial X-rays identified was the C ...
... The X-ray study of rotation-powered or radio pulsars has had a close link with Xray astronomy from its very beginning. After the discovery of Sco X−1 as the first extra-solar X-ray source by rocket-borne Geiger counters (Giacconi et al. 1962), the next source of celestial X-rays identified was the C ...
Supernova neutrinos at ICARUS
... General expectations: 1. Prompt e much harder to observe (reduced x interactions) 2. Harder e flux, due to mixing 3. e , enhances energy transfer from neutrino flux to matter behind the stalled shock ...
... General expectations: 1. Prompt e much harder to observe (reduced x interactions) 2. Harder e flux, due to mixing 3. e , enhances energy transfer from neutrino flux to matter behind the stalled shock ...
Ch 05
... Hooker reflectors he then designed the 200” Hale telescope for the Mt. Palomar Obs. Using funds from the ...
... Hooker reflectors he then designed the 200” Hale telescope for the Mt. Palomar Obs. Using funds from the ...
Section 7 The Electromagnetic Spectrum
... to be able to study these events, they must use X-ray telescopes. These must be based in space, above Earth’s atmosphere. For example, the Chandra X-Ray Observatory is currently in orbit around Earth. It is peering out into the universe, collecting the X-ray emissions of extremely high-temperature e ...
... to be able to study these events, they must use X-ray telescopes. These must be based in space, above Earth’s atmosphere. For example, the Chandra X-Ray Observatory is currently in orbit around Earth. It is peering out into the universe, collecting the X-ray emissions of extremely high-temperature e ...
TeV gamma rays from blazars beyond z= 1?
... scenarios the gamma-ray production spectra cannot be harder than E −1.5 , it was claimed that the EBL must be quite low, based on the observations of blazars H 2356– 309 (z = 0.165) and 1ES 1101–232 (z = 0.186) by the HESS collaboration [1]. The derived upper limits appeared to be rather close to th ...
... scenarios the gamma-ray production spectra cannot be harder than E −1.5 , it was claimed that the EBL must be quite low, based on the observations of blazars H 2356– 309 (z = 0.165) and 1ES 1101–232 (z = 0.186) by the HESS collaboration [1]. The derived upper limits appeared to be rather close to th ...
NIRCam - STScI
... physical size of today’s 35mm sensor…. • You only need to spend $33K to get nearly as many pixels as NIRCam So what do you get for your extra $100M for a NIRCam? -- a camera that works from 0.6 to 5 microns, not just from 0.36 microns to 0.8 microns and which can survive the space environment ...
... physical size of today’s 35mm sensor…. • You only need to spend $33K to get nearly as many pixels as NIRCam So what do you get for your extra $100M for a NIRCam? -- a camera that works from 0.6 to 5 microns, not just from 0.36 microns to 0.8 microns and which can survive the space environment ...
High Energy Gamma Rays from Protons Hitting
... real. Our spectral shape is not consistent with the Egret γ ray data of MayerHasselwander et. al. [14], which shows a peak near to 1 GeV. However, there are hints that the M-H data may be due to a source other than SgA* [15, 16]. At very high energies our mini-jet model should be a good approximatio ...
... real. Our spectral shape is not consistent with the Egret γ ray data of MayerHasselwander et. al. [14], which shows a peak near to 1 GeV. However, there are hints that the M-H data may be due to a source other than SgA* [15, 16]. At very high energies our mini-jet model should be a good approximatio ...
A systematic study of X-ray variability in the ROSAT all
... variability studies of individual sources using the RASS data (Schmitt 1994), however, up to now no systematic search for variability in the total all-sky survey data has been carried out. The first great advantage of the RASS data set is that it is unbiased in the sense that no specific objects or ...
... variability studies of individual sources using the RASS data (Schmitt 1994), however, up to now no systematic search for variability in the total all-sky survey data has been carried out. The first great advantage of the RASS data set is that it is unbiased in the sense that no specific objects or ...
REQUIRED PERFORMANCES FOR FUTURE LUNAR AND
... resolution of the neutron measurement technique is currently quite coarse due to the use of omnidirectional neutron sensors without the usage of bulky collimators. Omni-directional techniques rely only on the geometrical cut off of the sensor FOV, restricting us to the FWHM spatial resolution equal ...
... resolution of the neutron measurement technique is currently quite coarse due to the use of omnidirectional neutron sensors without the usage of bulky collimators. Omni-directional techniques rely only on the geometrical cut off of the sensor FOV, restricting us to the FWHM spatial resolution equal ...
Cygnus X-1
... Cygnus X-1 is one of the most likely candidates as being a black hole. Cygnus X-1 is about 14,000 light years away from earth. So this means that what we are seeing, is many, many, years old. It is a very inconsistent source for X-ray emissions. The emissions of X-rays for Cygnus X-1 flicker in hund ...
... Cygnus X-1 is one of the most likely candidates as being a black hole. Cygnus X-1 is about 14,000 light years away from earth. So this means that what we are seeing, is many, many, years old. It is a very inconsistent source for X-ray emissions. The emissions of X-rays for Cygnus X-1 flicker in hund ...
Chapter 1
... • Many objects emit radio waves, from long wave to microwaves. • Radio telescopes generally look like large satellite dishes. • They can operate during the day and night. • Large facilities in Puerto Rico, West Virginia, and New Mexico. ...
... • Many objects emit radio waves, from long wave to microwaves. • Radio telescopes generally look like large satellite dishes. • They can operate during the day and night. • Large facilities in Puerto Rico, West Virginia, and New Mexico. ...
The ROSAT galactic plane survey: ASTRONOMY AND
... observed X-ray population of active coronae is compared with that predicted by stellar population models having resolution in age, folded with the most recent X-ray luminosity functions and the applications of such studies are shortly reviewed. We also put constraints on the contribution to the gala ...
... observed X-ray population of active coronae is compared with that predicted by stellar population models having resolution in age, folded with the most recent X-ray luminosity functions and the applications of such studies are shortly reviewed. We also put constraints on the contribution to the gala ...
Chapter 5 - Astronomy
... or electronic light detectors. 2. Charge-coupled device (CCD) is an electronic “film” that serves as a light detector. It works by collecting electrons excited into higher energy states when the detector is struck by incident photons. The data collected is formed into images by a computer. 3. Photom ...
... or electronic light detectors. 2. Charge-coupled device (CCD) is an electronic “film” that serves as a light detector. It works by collecting electrons excited into higher energy states when the detector is struck by incident photons. The data collected is formed into images by a computer. 3. Photom ...
E. Waxman, Weizmann Institute Lecture notes for the 2008 SLAC Summer institute:
... I.4 Transient sources * There is no known steady source that satisfies the power constraint, L>1045.5Γ2erg/s, within a distance of several hundred Mpc (recall that d(Ep=1020eV)~100Mpc). This implies that the sources must be transient. That is, the duration T of their activity should be shorter than ...
... I.4 Transient sources * There is no known steady source that satisfies the power constraint, L>1045.5Γ2erg/s, within a distance of several hundred Mpc (recall that d(Ep=1020eV)~100Mpc). This implies that the sources must be transient. That is, the duration T of their activity should be shorter than ...
The coronal temperatures of low-mass main
... threshold in rotation, given that saturation happens at a single mass-independent value of RX . It would further imply that all saturated stars have similar coronal temperatures. On the other hand, if either LX or FX are the relevant parameters, then it would indicate that among stars that lie above ...
... threshold in rotation, given that saturation happens at a single mass-independent value of RX . It would further imply that all saturated stars have similar coronal temperatures. On the other hand, if either LX or FX are the relevant parameters, then it would indicate that among stars that lie above ...
A New Measurement of the Fusion Reaction 14N(p,γ)
... Stars create the light we observe from energy liberated by nuclear fusion reactions. For most of their lives, stars exist as main-sequence objects quiescently burning hydrogen. At temperatures present in stars slightly larger than the Sun, the CN cycle dominates hydrogen burning and thus a star’s ma ...
... Stars create the light we observe from energy liberated by nuclear fusion reactions. For most of their lives, stars exist as main-sequence objects quiescently burning hydrogen. At temperatures present in stars slightly larger than the Sun, the CN cycle dominates hydrogen burning and thus a star’s ma ...
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.