Altair - the hottest `cool` star in X-rays
... 2.4 MK and its emission measure distribution (EMD) is dominated by rather cool plasma at temperatures in the range of 1 – 4 MK, additionally a weak hotter component seems to contribute at a few percent level. These properties are quite typical for weakly active stars and similar to those of the quie ...
... 2.4 MK and its emission measure distribution (EMD) is dominated by rather cool plasma at temperatures in the range of 1 – 4 MK, additionally a weak hotter component seems to contribute at a few percent level. These properties are quite typical for weakly active stars and similar to those of the quie ...
Discovery of 7-13 HZ quasi-periodic oscillations in the new X
... correlation between X-ray count rate and the QPO parameters. In the X-ray colorcolor diagram a two-branched structure was traced out. The QPO parameters are well correlated with the position of the source on these branches. During earlier observations on 1998 April 27, 28 and 29 the count rates were ...
... correlation between X-ray count rate and the QPO parameters. In the X-ray colorcolor diagram a two-branched structure was traced out. The QPO parameters are well correlated with the position of the source on these branches. During earlier observations on 1998 April 27, 28 and 29 the count rates were ...
Astrosat (India) - X-ray Astronomy Group at ISAS
... the acceleration processes and origin of cosmic rays in the case of SNRs. ...
... the acceleration processes and origin of cosmic rays in the case of SNRs. ...
X-ray effects on protoplanetary disks
... • The X-ray studies of young stars show that powerful magnetic flares are ubiquitous throughout the epoch of planet formation, 103 above solar levels. The astrophysics resembles gigantic solar flares. • X-rays can efficiently irradiate protoplanetary disks. X-ray evidence: IR evidence: ...
... • The X-ray studies of young stars show that powerful magnetic flares are ubiquitous throughout the epoch of planet formation, 103 above solar levels. The astrophysics resembles gigantic solar flares. • X-rays can efficiently irradiate protoplanetary disks. X-ray evidence: IR evidence: ...
The High Resolution Camera CXC Newsletter
... or outbursting (with subclasses short vs. long outbursts and activity periods). 129 sources could be classified as X-ray binaries due to their position in globular clusters or their strong time variability (see Fig. 2). We detected seven supernova remnants, one of which is a new candidate, and also ...
... or outbursting (with subclasses short vs. long outbursts and activity periods). 129 sources could be classified as X-ray binaries due to their position in globular clusters or their strong time variability (see Fig. 2). We detected seven supernova remnants, one of which is a new candidate, and also ...
The population of young stars in Orion A: X-rays and... Ignazio Pillitteri , S. J. Wolk , L. Allen
... are the RGB mosaics of X-ray images of EPIC on board XMM-Newton and IR images of IRAC on board Spitzer. The upper crowded field is the archive Iota Ori observation, in which the bright O-type star in the center has a soft spectrum, due to shock interaction of stellar winds and thus it appears quite ...
... are the RGB mosaics of X-ray images of EPIC on board XMM-Newton and IR images of IRAC on board Spitzer. The upper crowded field is the archive Iota Ori observation, in which the bright O-type star in the center has a soft spectrum, due to shock interaction of stellar winds and thus it appears quite ...
High Energy Processes in Young Stellar Objects
... • Gyrosymchrotron radio-continuum – Highly variable – Produced by mildly relativistic electrons with energy around 1 MeV spiraling in ~1 G fields (Dulk 1985) ...
... • Gyrosymchrotron radio-continuum – Highly variable – Produced by mildly relativistic electrons with energy around 1 MeV spiraling in ~1 G fields (Dulk 1985) ...
PowerPoint - Chandra X
... the explosion of a massive star in the Large Magellanic Cloud, a small galaxy about 160,000 light years from Earth. The colors in this image show low energy X-rays (red), intermediate energy X-rays (green) and high energy X-rays (blue). ...
... the explosion of a massive star in the Large Magellanic Cloud, a small galaxy about 160,000 light years from Earth. The colors in this image show low energy X-rays (red), intermediate energy X-rays (green) and high energy X-rays (blue). ...
A Chandra Observation of the Massive Star-Forming
... 38 ksec Chandra/ACIS-I observation (FOV~17'X17'), centered on the O3 star Pismis 24-1 (N35). Blue circles show regions used for photon extraction. ...
... 38 ksec Chandra/ACIS-I observation (FOV~17'X17'), centered on the O3 star Pismis 24-1 (N35). Blue circles show regions used for photon extraction. ...
What Are the Faint X-ray Transients Near the Galactic Center?
... X-ray Sources within 25 pc of Sgr A* ...
... X-ray Sources within 25 pc of Sgr A* ...
NASA`s X-ray Eye on the Universe
... Black Hole: Mass and Spin • Properties determine their effects on their surroundings • Spinning BH has a smaller “size” (event horizon is closer in) ...
... Black Hole: Mass and Spin • Properties determine their effects on their surroundings • Spinning BH has a smaller “size” (event horizon is closer in) ...
PPT
... Largest optical telescope ever to observe the Sun from space Diffraction-limited (0.2 – 0.3 arcsec) imaging in 388 – 668 nm Vector magnetic field measurement at the photosphere • X-Ray Telescope (XRT) Highest angular resolution imaging at > 3 MK corona Wide temperature coverage from below 1 MK to ab ...
... Largest optical telescope ever to observe the Sun from space Diffraction-limited (0.2 – 0.3 arcsec) imaging in 388 – 668 nm Vector magnetic field measurement at the photosphere • X-Ray Telescope (XRT) Highest angular resolution imaging at > 3 MK corona Wide temperature coverage from below 1 MK to ab ...
Hitomi Observation of the Highly Obscured High-Mass X-ray
... SXT+SXI and HXT+HXI spectra show negligible contribution of the Compton shoulder as in the previous observations (Ibarra et al. 2007, A&A, 465, 501). The spectra are fitted with an absorbed cut-off power-law and three gaussians to account for the fluorescence lines. Comparing the spectral parameters ...
... SXT+SXI and HXT+HXI spectra show negligible contribution of the Compton shoulder as in the previous observations (Ibarra et al. 2007, A&A, 465, 501). The spectra are fitted with an absorbed cut-off power-law and three gaussians to account for the fluorescence lines. Comparing the spectral parameters ...
Chandra and NIR Observations of Galactic HII Regions
... Massive Stars in M16 • The 11 O5 V - O9.5 V stars in NGC 6611 are all detected with Chandra, with LX in the range 5.3´1030 – 1.8x1032 ergs s-1, LX/Lbol in the range 1.4x10-8 – 6.8x10-8, and kT from 0.49–0.96 keV. • The 2-Myr old O stars in NGC 6611 have relatively soft X-ray spectra and low LX/Lbol ...
... Massive Stars in M16 • The 11 O5 V - O9.5 V stars in NGC 6611 are all detected with Chandra, with LX in the range 5.3´1030 – 1.8x1032 ergs s-1, LX/Lbol in the range 1.4x10-8 – 6.8x10-8, and kT from 0.49–0.96 keV. • The 2-Myr old O stars in NGC 6611 have relatively soft X-ray spectra and low LX/Lbol ...
Galactic Neighborhood and (Chandra-enabled) X-ray Astrophysics Q. Daniel Wang
... Approach 2: Deep large-scale X-ray mapping: • Individual observations have to be deep to remove enough background sources, which causes the cosmic variance. • To check physical properties of hot plasma near outer boundaries if they are present. Mkn 231, 0.5 Ms ACIS 0.5-8 keV Veilleux et al. 201 ...
... Approach 2: Deep large-scale X-ray mapping: • Individual observations have to be deep to remove enough background sources, which causes the cosmic variance. • To check physical properties of hot plasma near outer boundaries if they are present. Mkn 231, 0.5 Ms ACIS 0.5-8 keV Veilleux et al. 201 ...
PPT
... Doppler broadening of Fe: v/c = (kT/Mc2)1/2 = 1.3 x 10-4 (T/107 K)1/2 Absorption lines saturate, very hard to detect unless spectroscopic resolving power > 5000 (NB. Stellar rotation does not affect [increase] the line contrast) ...
... Doppler broadening of Fe: v/c = (kT/Mc2)1/2 = 1.3 x 10-4 (T/107 K)1/2 Absorption lines saturate, very hard to detect unless spectroscopic resolving power > 5000 (NB. Stellar rotation does not affect [increase] the line contrast) ...
High-Energy Astrophysics - University of Iowa Astrophysics
... • Extreme temperatures (X-ray emitting plasma) • Extreme densities (black holes and neutron stars) • Extreme magnetic fields (near neutron stars) • Extreme velocities (jets from black holes) • Extreme explosions (gamma-ray bursts) ...
... • Extreme temperatures (X-ray emitting plasma) • Extreme densities (black holes and neutron stars) • Extreme magnetic fields (near neutron stars) • Extreme velocities (jets from black holes) • Extreme explosions (gamma-ray bursts) ...
Astro2006_0526
... supercritical accretion disk and jets. Basing on observational data of SS433 and published 2D-simulations of supercritical accretion disks we estimate parameters of the funnel in the disk/wind of SS433 and discuss formation of the jets. We argue that the UV radiation of the SS433 disk (~50000 K, ~10 ...
... supercritical accretion disk and jets. Basing on observational data of SS433 and published 2D-simulations of supercritical accretion disks we estimate parameters of the funnel in the disk/wind of SS433 and discuss formation of the jets. We argue that the UV radiation of the SS433 disk (~50000 K, ~10 ...
Nobel Prize in Physics 2002: Riccardo Giaconni
... the tenuous gas between galaxies to the vicinity of ultra compact objects like neutron stars and black holes. First discovered by UHUR U, one common category of X-ray sources is stars in binary systems, from which strong and rapid (and sometimes periodic) bursts of X-ray are detected. In these syste ...
... the tenuous gas between galaxies to the vicinity of ultra compact objects like neutron stars and black holes. First discovered by UHUR U, one common category of X-ray sources is stars in binary systems, from which strong and rapid (and sometimes periodic) bursts of X-ray are detected. In these syste ...
The Ultraluminous X-ray Source in Holmberg IX and its Environment
... mass black holes (IMBHs) having 102 to 105 solar masses (Colbert & Mushotzky 1999) or non-isotropic emission beamed into our line-of-sight (King et al. 2001). Here, we are interested in one of these objects, Holmberg IX X-1, located at a distance of 3.6 Mpc in a dwarf galaxy companion of M81. Miller ...
... mass black holes (IMBHs) having 102 to 105 solar masses (Colbert & Mushotzky 1999) or non-isotropic emission beamed into our line-of-sight (King et al. 2001). Here, we are interested in one of these objects, Holmberg IX X-1, located at a distance of 3.6 Mpc in a dwarf galaxy companion of M81. Miller ...
Introduction - University of Iowa Astrophysics
... usually referred to as X-rays • Gamma-rays typically have energies above about 100 keV ...
... usually referred to as X-rays • Gamma-rays typically have energies above about 100 keV ...
Pounds K. - X-ray Astronomy and Cosmology group group
... • SL 723 (July 1968) and 724 (April 1969) with largest PCS to date, 2 x 1380 cm2 • spectra of brightest sources ...
... • SL 723 (July 1968) and 724 (April 1969) with largest PCS to date, 2 x 1380 cm2 • spectra of brightest sources ...
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.