An exceptionally bright flare from SGR 1806–20 and the origins of
... dissipation of magnetic energy. Here we report the detection of a long (380 s) giant flare from SGR 1806–20, which was much more luminous than any previous transient event observed in our Galaxy. (In the first 0.2 s, the flare released as much energy as the Sun radiates in a quarter of a million yea ...
... dissipation of magnetic energy. Here we report the detection of a long (380 s) giant flare from SGR 1806–20, which was much more luminous than any previous transient event observed in our Galaxy. (In the first 0.2 s, the flare released as much energy as the Sun radiates in a quarter of a million yea ...
AMUSE-Virgo AGN Multi-wavelength Survey
... AMUSE, the team: E. Gallo, T. Treu, J.-H. Woo, J. Jacob, R. Antonucci, ...
... AMUSE, the team: E. Gallo, T. Treu, J.-H. Woo, J. Jacob, R. Antonucci, ...
Cosmological Transient Objects
... shine brighter than the host galaxy consisting of billions of stars. • In one month, a supernova can emit as much energy as Sun would emit in its entire life span of billions of years. • GRBs: biggest source of gamma-rays in universe and 100 times more energetic than supernovae. ...
... shine brighter than the host galaxy consisting of billions of stars. • In one month, a supernova can emit as much energy as Sun would emit in its entire life span of billions of years. • GRBs: biggest source of gamma-rays in universe and 100 times more energetic than supernovae. ...
Estimating the total radiative power output from the hot outer layers
... the chromosphere to the corona. Then, addition of these individual lines uxes gives the total radiative output. This would be a rather time-consuming method to employ and is currently impossible for targets other than the Sun, since even using IUE (International Ultraviolet Explorer), EUVE (Extreme ...
... the chromosphere to the corona. Then, addition of these individual lines uxes gives the total radiative output. This would be a rather time-consuming method to employ and is currently impossible for targets other than the Sun, since even using IUE (International Ultraviolet Explorer), EUVE (Extreme ...
Chandra HETGS Multiphase Spectroscopy Of The Young
... (Gagné et al. 1997). Hard, time-variable X-ray emission is not expected from O stars because they do not possess an outer convective envelope to drive a solar-type magnetic dynamo. Rather, the detection of a variable longitudinal magnetic field by Donati et al. (2002) confirms the basic picture of ...
... (Gagné et al. 1997). Hard, time-variable X-ray emission is not expected from O stars because they do not possess an outer convective envelope to drive a solar-type magnetic dynamo. Rather, the detection of a variable longitudinal magnetic field by Donati et al. (2002) confirms the basic picture of ...
Astronomy Astrophysics − Orbital phase-resolved spectroscopy of 4U 1538
... fitted the 2−20 keV energy spectrum with several successful models. We chose CompST (in xspec terminology; Sunyaev & Titarchuk 1980) as the representative model, i.e., a Comptonisation of cool photons on hot electrons modified by an absorbing column along our line of sight. Because MAXI/GSC does not ...
... fitted the 2−20 keV energy spectrum with several successful models. We chose CompST (in xspec terminology; Sunyaev & Titarchuk 1980) as the representative model, i.e., a Comptonisation of cool photons on hot electrons modified by an absorbing column along our line of sight. Because MAXI/GSC does not ...
Document
... Flare <15s to 1 hr, repeats hrs - days Amplitude up to 4 mag Opt is thermal brem at T ~ 107K, radio is non-thermal Between flares, spectrum is K-M with CaII, H emission ...
... Flare <15s to 1 hr, repeats hrs - days Amplitude up to 4 mag Opt is thermal brem at T ~ 107K, radio is non-thermal Between flares, spectrum is K-M with CaII, H emission ...
Far Ultraviolet Spectroscopic Explorer
... Search data set for interesting individual objects that represent rare classes of objects. ...
... Search data set for interesting individual objects that represent rare classes of objects. ...
Ch a n d
... various kinds of mass outflow. The impact of plasma onto the stellar surface from magnetospheric accretion streams, can be a dominant source of energy and momentum in the upper atmospheres of T Tauri stars. We present models in which turbulence is induced by these impacts, and waves then spread out ...
... various kinds of mass outflow. The impact of plasma onto the stellar surface from magnetospheric accretion streams, can be a dominant source of energy and momentum in the upper atmospheres of T Tauri stars. We present models in which turbulence is induced by these impacts, and waves then spread out ...
ULX accretion states
... (M82 X1 is perhaps unique exception so far) Many ULXs also have powerful winds (Mechanical power in addition to the X-ray emission) Some super-Eddington BHs may be jet dominated but radiatively faint (S26 in NGC7793) Relative power in the jet and radiation during super-Edd accretion is a fundamental ...
... (M82 X1 is perhaps unique exception so far) Many ULXs also have powerful winds (Mechanical power in addition to the X-ray emission) Some super-Eddington BHs may be jet dominated but radiatively faint (S26 in NGC7793) Relative power in the jet and radiation during super-Edd accretion is a fundamental ...
X-ray polarimetry in astrophysics
... • Toroidal magnetic field : The whole radiation does not produce a net polarization but due to light aberration the observer probes a small region with the magnetic field ordered in a specific direction. Therefore the polarization is high. • Random magnetic field : The polarization can still be high ...
... • Toroidal magnetic field : The whole radiation does not produce a net polarization but due to light aberration the observer probes a small region with the magnetic field ordered in a specific direction. Therefore the polarization is high. • Random magnetic field : The polarization can still be high ...
the magellanic clouds newsletter - Keele University Astrophysics
... age distribution of the LMC Cepheids is found to have a peak at log Age = 8.2 ± 0.1. This suggests that major star formation event took place at about 125–200 Myr ago which may have been triggered by a close encounter between the SMC and the LMC. Cepheids are found to be asymmetrically distributed t ...
... age distribution of the LMC Cepheids is found to have a peak at log Age = 8.2 ± 0.1. This suggests that major star formation event took place at about 125–200 Myr ago which may have been triggered by a close encounter between the SMC and the LMC. Cepheids are found to be asymmetrically distributed t ...
Jul y 9- 11,
... X-ray sources detected down to few times 1032 erg/s in fields with young ( 100 Myr) stellar populations of different ages. With these data we will a) derive the deepest X-ray luminosity functions for X-ray binaries (XRBs) in a low metallicity (0.2Zd ) star-forming galaxy, b) study how accreting XRB ...
... X-ray sources detected down to few times 1032 erg/s in fields with young ( 100 Myr) stellar populations of different ages. With these data we will a) derive the deepest X-ray luminosity functions for X-ray binaries (XRBs) in a low metallicity (0.2Zd ) star-forming galaxy, b) study how accreting XRB ...
Coevolution of SMBHs and host galaxies at high z
... Host-galaxy masses estimated from a variety of techniques: Host vel disp (em and abs lines), CO line ...
... Host-galaxy masses estimated from a variety of techniques: Host vel disp (em and abs lines), CO line ...
Lecture 2. Isolated Neutron Stars – I.
... 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. ...
... 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. ...
Discovery of Kilohertz Quasi-periodic Oscillations from 4U 1820
... occur. It may be possible to detect the buildup of an incipient scattering cloud by a detailed study of millisecond delays between the hard and soft X-ray flux, an investigation we will perform at a later date. A consequence of both BFMs is that the measured 275 Hz frequency difference can be interp ...
... occur. It may be possible to detect the buildup of an incipient scattering cloud by a detailed study of millisecond delays between the hard and soft X-ray flux, an investigation we will perform at a later date. A consequence of both BFMs is that the measured 275 Hz frequency difference can be interp ...
High-Energy Astrophysics with Gamma
... LIRGs and ULIRGs, following simple population analysis, are to be detected as gamma-ray sources Starburst activity – cosmic ray populations – difussion Detailed analysis for ULIRG Arp 220 confirms this. Many other LIRGs (several tens) may appear in the forthcoming catalogs first multiwavelength ...
... LIRGs and ULIRGs, following simple population analysis, are to be detected as gamma-ray sources Starburst activity – cosmic ray populations – difussion Detailed analysis for ULIRG Arp 220 confirms this. Many other LIRGs (several tens) may appear in the forthcoming catalogs first multiwavelength ...
Computation of the off-axis effective area of the New Hard X
... The launch of a number of X-ray telescopes[1],[2],[3],[4] is foreseen in the next years, most of them carrying optical modules able to effectively focus X-rays beyond the present limit of 10 keV. This will be made possible not only by the increase of the size of the optics, but also by the adoption ...
... The launch of a number of X-ray telescopes[1],[2],[3],[4] is foreseen in the next years, most of them carrying optical modules able to effectively focus X-rays beyond the present limit of 10 keV. This will be made possible not only by the increase of the size of the optics, but also by the adoption ...
Lecture9
... mass and the collapsed core will have mass larger than the neutron star maximum mass limit ~ 3M☉ So, if the remnant collapsed mass is larger than ~3M☉, the core keeps collapsing to singularity, and hence becomes a black hole. Note: Though nothing can come out of a black hole itself, the gas around t ...
... mass and the collapsed core will have mass larger than the neutron star maximum mass limit ~ 3M☉ So, if the remnant collapsed mass is larger than ~3M☉, the core keeps collapsing to singularity, and hence becomes a black hole. Note: Though nothing can come out of a black hole itself, the gas around t ...
3011800000631
... star surface (Kouveliotou et al., 1998). For some of the sources we have evidence for association with supernova remnants (SNR) indicating a young age, of some 104 yrs. If the neutron star’s initial rotation period was in the sub-second range, as inferred for the isolated radio pulsars, a magnetar r ...
... star surface (Kouveliotou et al., 1998). For some of the sources we have evidence for association with supernova remnants (SNR) indicating a young age, of some 104 yrs. If the neutron star’s initial rotation period was in the sub-second range, as inferred for the isolated radio pulsars, a magnetar r ...
don_lamb - New Views of the Universe
... of greatest remaining mystery of GRBs: The Nature of short GRBs Follow-up observations at X-ray, optical, and radio wavelengths have led to compelling evidence that short GRBs come from merging compact binaries (as David Eichler, Mario Livio, Tsvi Piran, and David Schramm conjectured in 1989) It ...
... of greatest remaining mystery of GRBs: The Nature of short GRBs Follow-up observations at X-ray, optical, and radio wavelengths have led to compelling evidence that short GRBs come from merging compact binaries (as David Eichler, Mario Livio, Tsvi Piran, and David Schramm conjectured in 1989) It ...
Neon and oxygen in low activity stars: towards a coronal unification
... to additionally increase jointly within allowed errors would provide a sufficient opacity increase. Several objections to this solution were raised, especially from solar observers. A reassessment of solar coronal data from the Solar Maximum Mission led to an upper limit of Ne/O = 0.18 ± 0.04 for acti ...
... to additionally increase jointly within allowed errors would provide a sufficient opacity increase. Several objections to this solution were raised, especially from solar observers. A reassessment of solar coronal data from the Solar Maximum Mission led to an upper limit of Ne/O = 0.18 ± 0.04 for acti ...
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.