2. The X-ray-Radio correlation for bulgeless galaxies
... Correlations between the X-ray and Radio emissions are observed for both galaxies with Active Galactic Nuclei (AGN) and in Star Forming galaxies. For the first case, the Xray/Radio correlation seems to present different slopes for Radio-loud and Radio-quiet AGN and may be used to estimate the mass o ...
... Correlations between the X-ray and Radio emissions are observed for both galaxies with Active Galactic Nuclei (AGN) and in Star Forming galaxies. For the first case, the Xray/Radio correlation seems to present different slopes for Radio-loud and Radio-quiet AGN and may be used to estimate the mass o ...
Global Properties of Solar Flares
... The idea that a solar disturbance could affect a terrestrial instrument such as a compass seemed highly improbable at the time, but it turned out to be indeed a correct association, so this first observed flare served to suggest immediately the capability for a such a solar event to have widely felt ...
... The idea that a solar disturbance could affect a terrestrial instrument such as a compass seemed highly improbable at the time, but it turned out to be indeed a correct association, so this first observed flare served to suggest immediately the capability for a such a solar event to have widely felt ...
The effect of helium sedimentation on galaxy cluster masses and
... Sunyaev-Zel’dovich effect (SZE) may be used to infer the helium abundance in the ICM (Markevitch 2007); however, the limited resolution and sensitivity of current SZE interferometers have so far not enabled the measurement of the distribution of helium, even in the cluster cores where the sedimentati ...
... Sunyaev-Zel’dovich effect (SZE) may be used to infer the helium abundance in the ICM (Markevitch 2007); however, the limited resolution and sensitivity of current SZE interferometers have so far not enabled the measurement of the distribution of helium, even in the cluster cores where the sedimentati ...
potenza dei jet nei nuclei galattici attivi radio
... Figure 1.1: A schematic representation of an AGN’s Spectral Energy Distribution (SED), loosely based on the observed SEDs of radio-quiet quasars. The black solid curve represents the total SED and the various coloured curves (with an arbitrary offset) represent the individual components. The SED of ...
... Figure 1.1: A schematic representation of an AGN’s Spectral Energy Distribution (SED), loosely based on the observed SEDs of radio-quiet quasars. The black solid curve represents the total SED and the various coloured curves (with an arbitrary offset) represent the individual components. The SED of ...
X-ray astronomy of stellar coronae (Review)
... Although often narrowed down to some specific energy ranges, coronal emission is intrinsically a multi-wavelength phenomenon revealing itself from the meter-wave radio range to gamma rays. The most important wavelength regions from which we have learned diagnostically on stellar coronae include the ...
... Although often narrowed down to some specific energy ranges, coronal emission is intrinsically a multi-wavelength phenomenon revealing itself from the meter-wave radio range to gamma rays. The most important wavelength regions from which we have learned diagnostically on stellar coronae include the ...
H.E.S.S. observations of the binary system PSR B1259
... HESS J0632+057 (Aharonian et al. 2007), the first binary primarily discovered at TeV energies. This class can be extended by two more candidates: Cygnus X-1 (Albert et al. 2007), a stellarmass black hole binary detected at VHEs at the 4.1σ significance level, and HESS J1018-589 (HESS Collaboration e ...
... HESS J0632+057 (Aharonian et al. 2007), the first binary primarily discovered at TeV energies. This class can be extended by two more candidates: Cygnus X-1 (Albert et al. 2007), a stellarmass black hole binary detected at VHEs at the 4.1σ significance level, and HESS J1018-589 (HESS Collaboration e ...
The impact of surface temperature inhomogeneities on quiescent
... tions of 47 Tuc have been performed with the HRC-S detector (Cameron et al. 2007), which retains high (microsecond) timing resolution, though it has very poor spectral resolution. This dataset enables a search for pulsations from X7 and X5, which we report in this work, utilizing acceleration search ...
... tions of 47 Tuc have been performed with the HRC-S detector (Cameron et al. 2007), which retains high (microsecond) timing resolution, though it has very poor spectral resolution. This dataset enables a search for pulsations from X7 and X5, which we report in this work, utilizing acceleration search ...
OBSERVATIONS OF PHYSICAL PROCESSES IN
... cluster galaxies (BCGs) of those clusters. It has been known for a while that the state of the hot intracluster medium (ICM) gas in the core of a galaxy cluster, quantified as the central entropy of the gas, can be found in two particular states. Galaxy clusters with central entropies greater than 3 ...
... cluster galaxies (BCGs) of those clusters. It has been known for a while that the state of the hot intracluster medium (ICM) gas in the core of a galaxy cluster, quantified as the central entropy of the gas, can be found in two particular states. Galaxy clusters with central entropies greater than 3 ...
Two-Dimensional Integrated Circuits for Hybrid
... was varied between 5 fC and 20 fC in steps of 5 fC. For each amplitude setting, we varied the comparator threshold voltages in steps of 10 to 20 mV (depending on the amplitude) and counted for 5 ms at each step. From these data we determined, for each cell, the threshold at which the number of count ...
... was varied between 5 fC and 20 fC in steps of 5 fC. For each amplitude setting, we varied the comparator threshold voltages in steps of 10 to 20 mV (depending on the amplitude) and counted for 5 ms at each step. From these data we determined, for each cell, the threshold at which the number of count ...
UvA-DARE (Digital Academic Repository) Multi
... just a fraction of a second to a few seconds, than our own Sun will over its entire lifetime. This energy is generated by super hot plasma travelling at relativistic speeds. The plasma is ejected from near the horizon of a newly created black hole in the form of a narrow jet pointing straight toward ...
... just a fraction of a second to a few seconds, than our own Sun will over its entire lifetime. This energy is generated by super hot plasma travelling at relativistic speeds. The plasma is ejected from near the horizon of a newly created black hole in the form of a narrow jet pointing straight toward ...
Statistics of gamma-ray point sources below the Fermi detection limit
... We separate the sources based on their statistical properties. In the paper we consider three sources of gamma-rays at high latitudes. The first source is a diffuse source that varies over large angles. The main contribution to this source comes from the Galactic diffuse emission (π 0 production, ICS p ...
... We separate the sources based on their statistical properties. In the paper we consider three sources of gamma-rays at high latitudes. The first source is a diffuse source that varies over large angles. The main contribution to this source comes from the Galactic diffuse emission (π 0 production, ICS p ...
Slide 1
... • Properties (spectral state transitions, radio flares) similar to what is seen in stellar-mass BH binaries. ...
... • Properties (spectral state transitions, radio flares) similar to what is seen in stellar-mass BH binaries. ...
ON THE POLAR CAPS OF THE THREE MUSKETEERS1
... ( Bignami et al. 1983). The discovery of a common 237 ms pulsation clicked the identification, the first ever, of an unidentified -ray source with its X-ray counterpart ( Halpern & Holt 1992; Bertsch et al. 1992). The first good-quality spectral data on Geminga were collected by ROSAT. Halpern & Ru ...
... ( Bignami et al. 1983). The discovery of a common 237 ms pulsation clicked the identification, the first ever, of an unidentified -ray source with its X-ray counterpart ( Halpern & Holt 1992; Bertsch et al. 1992). The first good-quality spectral data on Geminga were collected by ROSAT. Halpern & Ru ...
Influence of extreme ultraviolet radiation on the Pv ionization fraction
... on the square of the density. Moreover, the ultraviolet P V resonance lines indicate a possible need for an even stronger reduction of hot star mass-loss rates, provided that P V is a dominant ionization stage of phosphorus, at least in some hot stars. The latter assumption is challenged by the poss ...
... on the square of the density. Moreover, the ultraviolet P V resonance lines indicate a possible need for an even stronger reduction of hot star mass-loss rates, provided that P V is a dominant ionization stage of phosphorus, at least in some hot stars. The latter assumption is challenged by the poss ...
Untitled - METU Astrophysics Home Page
... suggestions on these issues. I would like to thank my colleagues at METU Astrophysics Group for useful discussions and for their help at all levels of this tedious work. My deep gratitudes are to M. Miraç Serim for his great help, advice and insights related to data analysis and interpretation. It w ...
... suggestions on these issues. I would like to thank my colleagues at METU Astrophysics Group for useful discussions and for their help at all levels of this tedious work. My deep gratitudes are to M. Miraç Serim for his great help, advice and insights related to data analysis and interpretation. It w ...
PDF hosted at the Radboud Repository of the Radboud University
... Figure 3: Kepler’s supernova remnant (SN1604). Image is a combination of X-ray images from the Chandra space observatory and optical images from the Digitized Space Survey. Credit: X-ray: NASA/CXC/SAO/D.Patnaude, Optical: Digitized Space Survey (DSS) ...
... Figure 3: Kepler’s supernova remnant (SN1604). Image is a combination of X-ray images from the Chandra space observatory and optical images from the Digitized Space Survey. Credit: X-ray: NASA/CXC/SAO/D.Patnaude, Optical: Digitized Space Survey (DSS) ...
Systematic variation in the apparent burning area of thermonuclear
... 2009 The Authors. Journal compilation ...
... 2009 The Authors. Journal compilation ...
Section IV High-Energy Astrophysics and Cosmology
... presents the main basis for modern science of the polarized emission of cosmic objects including X-rays and gamma-rays. The accreting supermassive black holes (SMBH) in active galactic nuclei (AGN) are found in the center of modern astrophysics. The main problem is connected with determining the mas ...
... presents the main basis for modern science of the polarized emission of cosmic objects including X-rays and gamma-rays. The accreting supermassive black holes (SMBH) in active galactic nuclei (AGN) are found in the center of modern astrophysics. The main problem is connected with determining the mas ...
Numerical solution of the radiative transfer equation: X
... e-mail: [email protected] Dipartimento di Fisica, Università di Ferrara, via Saragat 1, 44100 Ferrara, Italy NASA, Goddard Space Flight Center, Greenbelt, MD 20771, USA ...
... e-mail: [email protected] Dipartimento di Fisica, Università di Ferrara, via Saragat 1, 44100 Ferrara, Italy NASA, Goddard Space Flight Center, Greenbelt, MD 20771, USA ...
Rich Clusters of Galaxies
... will generally assume that the mass is proportional to the number of galaxies. For example, what happens if we have two groups of galaxies each with N ~ 25 members that are projected together on the sky? With optical samples we have serious problems with the swamping of cluster galaxies by backgroun ...
... will generally assume that the mass is proportional to the number of galaxies. For example, what happens if we have two groups of galaxies each with N ~ 25 members that are projected together on the sky? With optical samples we have serious problems with the swamping of cluster galaxies by backgroun ...
X-ray narrow emission lines from the nuclear region of NGC 1365
... region and then would again be likely located at r ∼ 1015 cm from the source. Finally, Braito et al. (2014) suggest that the Mg XII emission and absorption lines in the highest flux part of their observation are reminiscent of a classical P-Cygni profile, and therefore could hint at a common origin ...
... region and then would again be likely located at r ∼ 1015 cm from the source. Finally, Braito et al. (2014) suggest that the Mg XII emission and absorption lines in the highest flux part of their observation are reminiscent of a classical P-Cygni profile, and therefore could hint at a common origin ...
X-ray spectra of highly magnetized neutron stars in binary systems
... CRSF in the spectrum. While one line at ∼50 keV has been observed by many instruments, a second line at ∼24 keV had been reported by Kretschmar et al. (1996), while other observers (Orlandini et al. 1997) could not detect this line. Using pulse phase resolved spectroscopy (in pulse phase resolved sp ...
... CRSF in the spectrum. While one line at ∼50 keV has been observed by many instruments, a second line at ∼24 keV had been reported by Kretschmar et al. (1996), while other observers (Orlandini et al. 1997) could not detect this line. Using pulse phase resolved spectroscopy (in pulse phase resolved sp ...
The X-ray emission from shock cooling zones in O star winds
... structure of a cooling zone behind the shock modifies the emission coefficient and the theoretical emergent X-ray spectrum. Such an investigation is the purpose of the present paper. We extend the concept of randomly distributed shocks embedded in the absorbing cool wind, as used by Hillier et al., ...
... structure of a cooling zone behind the shock modifies the emission coefficient and the theoretical emergent X-ray spectrum. Such an investigation is the purpose of the present paper. We extend the concept of randomly distributed shocks embedded in the absorbing cool wind, as used by Hillier et al., ...
The Early-time Optical Properties of Gamma
... initial gamma ray burst. In the standard model a typical long duration GRB is thought to be formed by the explosion of a compact source that generates an expanding relativistic fireball (Rees & Mészáros 1992). If the central engine remains active for some time several expanding shells with differe ...
... initial gamma ray burst. In the standard model a typical long duration GRB is thought to be formed by the explosion of a compact source that generates an expanding relativistic fireball (Rees & Mészáros 1992). If the central engine remains active for some time several expanding shells with differe ...
ROSAT Isolated Neutron Stars
... with a SNR in one case Persistent X-ray emitters, L ≈ 1035 erg/s Pulsations discovered both in GFs tails and persistent emission, P ≈ 5 -10 s Huge spindown rates, Ṗ/P ≈ 10-10 ss-1 (Kouveliotou et al. 1998; 1999) ...
... with a SNR in one case Persistent X-ray emitters, L ≈ 1035 erg/s Pulsations discovered both in GFs tails and persistent emission, P ≈ 5 -10 s Huge spindown rates, Ṗ/P ≈ 10-10 ss-1 (Kouveliotou et al. 1998; 1999) ...
History of X-ray astronomy
The history of X-ray astronomy begins in the 1920s, with interest in short wave communications for the U.S. Navy. This was soon followed by extensive study of the earth's ionosphere. By 1927, interest in the detection of X-ray and ultraviolet (UV) radiation at high altitudes inspired researchers to launch Goddard's rockets into the upper atmosphere to support theoretical studies and data gathering. The first successful rocket flight equipped with instrumentation able to detect solar ultraviolet radiation occurred in 1946. X-ray solar studies began in 1949. By 1973 a solar instrument package orbited on Skylab providing significant solar data.In 1965 the Goddard Space Flight Center program in X-ray astronomy was initiated with a series of balloon-borne experiments. In the 1970s this was followed by high altitude sounding rocket experiments, and that was followed by orbiting (satellite) observatories.The first rocket flight to successfully detect a cosmic source of X-ray emission was launched in 1962 by a group at American Science and Engineering (AS&E).X-ray wavelengths reveal information about the bodies (sources) that emit them.