Chapter 2 Observing the Electromagnetic Spectrum
... the entire electromagnetic region, they too are sources of increasing ’pollution’ for ground-based observations, when recorded as streaks of light across long exposure wide-field images near to, or through (Figure 2.3) objects of interest. Of July, 2009 there were ∼900 operational satellites, with ∼ ...
... the entire electromagnetic region, they too are sources of increasing ’pollution’ for ground-based observations, when recorded as streaks of light across long exposure wide-field images near to, or through (Figure 2.3) objects of interest. Of July, 2009 there were ∼900 operational satellites, with ∼ ...
Magnetars: properties, origin and evolution
... stars: their characterizing property is the emission, in the X-ray and soft γ-ray range, of powerful short bursts which often reach super-Eddington luminosities. More rarely, they also emit intermediate and giant flares, the latter involving the release of up to about 1046 erg in less than half a se ...
... stars: their characterizing property is the emission, in the X-ray and soft γ-ray range, of powerful short bursts which often reach super-Eddington luminosities. More rarely, they also emit intermediate and giant flares, the latter involving the release of up to about 1046 erg in less than half a se ...
Here you can get a Science reprint
... GRO J1655-40 was launched far from its birthplace by an energetic SN explosion (2) at a runaway speed (3) of 120 km s⫺1. But so far there has been no observational evidence for a black hole formed without an energetic SN explosion. Cygnus X-1 (4) is a well-studied Galactic black hole candidate. The ...
... GRO J1655-40 was launched far from its birthplace by an energetic SN explosion (2) at a runaway speed (3) of 120 km s⫺1. But so far there has been no observational evidence for a black hole formed without an energetic SN explosion. Cygnus X-1 (4) is a well-studied Galactic black hole candidate. The ...
Astronomy Astrophysics Circumstellar emission in Be/X-ray binaries of the Magellanic
... 1998). These stars are surrounded by a circumstellar envelope that profoundly alters the emerging spectrum. Spectra of Be stars show some essential characteristics. 1) The Balmer lines are affected by the emission that is produced by bound-bound transitions in the envelope, which fills in the photos ...
... 1998). These stars are surrounded by a circumstellar envelope that profoundly alters the emerging spectrum. Spectra of Be stars show some essential characteristics. 1) The Balmer lines are affected by the emission that is produced by bound-bound transitions in the envelope, which fills in the photos ...
Formation of a Black Hole in the Dark - CEA-Irfu
... J1655-40 has a mass of (5.4 ± 0.3) MՎ (13) and was formed through an energetic supernova explosion and fall-back on a neutron star. The black hole in Cygnus X-1 which has a mass of (10.1 ± 5) MՎ (11) was formed through a low energy explosion or even by prompt implosion without a supernova. These obs ...
... J1655-40 has a mass of (5.4 ± 0.3) MՎ (13) and was formed through an energetic supernova explosion and fall-back on a neutron star. The black hole in Cygnus X-1 which has a mass of (10.1 ± 5) MՎ (11) was formed through a low energy explosion or even by prompt implosion without a supernova. These obs ...
The Sun as an X-Ray Star. III. Flares
... Y ohkoh/SXT, into templates of stellar coronal observations. Here we apply the method to several solar Ñares, for comparison with stellar X-ray Ñares. Eight Ñares, from weak (GOES class C5.8) to very intense ones (X9) are selected as representative of the Ñaring Sun. The emission measure distributio ...
... Y ohkoh/SXT, into templates of stellar coronal observations. Here we apply the method to several solar Ñares, for comparison with stellar X-ray Ñares. Eight Ñares, from weak (GOES class C5.8) to very intense ones (X9) are selected as representative of the Ñaring Sun. The emission measure distributio ...
M sun
... Holmberg II (Miller, Mushotzky & Neff 2005) NGC 5408 (Kaaret et al 2003; Soria, Fender et al 2006) NGC 7424 (Soria, Kuncic et al 2006) NGC 6946 (Swartz et al 2006, in prep) ...
... Holmberg II (Miller, Mushotzky & Neff 2005) NGC 5408 (Kaaret et al 2003; Soria, Fender et al 2006) NGC 7424 (Soria, Kuncic et al 2006) NGC 6946 (Swartz et al 2006, in prep) ...
Extraordinary Luminous Soft X-Ray Transient MAXI
... Figure 1. Images of MAXI J0158−744 taken by MAXI and Swift. (a) A part of the GSC all-sky image shown in Hammer-Aitoff projection of Galactic coordinates. Red, green, and blue color maps represent the intensities in 2–4, 4–10, and 10–20 keV bands, respectively. Grid lines are drawn every 1 hr and 10 ...
... Figure 1. Images of MAXI J0158−744 taken by MAXI and Swift. (a) A part of the GSC all-sky image shown in Hammer-Aitoff projection of Galactic coordinates. Red, green, and blue color maps represent the intensities in 2–4, 4–10, and 10–20 keV bands, respectively. Grid lines are drawn every 1 hr and 10 ...
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 ...
Chandra News The Secret X-ray Lives of Planetary Nebulae
... However, as an assortment of additional detections of diffuse emission trickled in over subsequent Chandra cycles (e.g., Montez et al. 2005), and XMMNewton joined in the hot bubble fun (Guerrero et al. 2002; Gruendl et al. 2006), it became clear that PN hot bubbles just aren’t hot enough. That is, s ...
... However, as an assortment of additional detections of diffuse emission trickled in over subsequent Chandra cycles (e.g., Montez et al. 2005), and XMMNewton joined in the hot bubble fun (Guerrero et al. 2002; Gruendl et al. 2006), it became clear that PN hot bubbles just aren’t hot enough. That is, s ...
The Gaseous Halo of NGC 891 Edmund Hodges-Kluck Joel Bregman
... lines with an impact parameter of 5 kpc • We also developed a new method to constrain Z in an imaging sense using dust-scattered light • Halos are dusty (Menard+2010); dust visible in: • Emission (mid-IR; sky is bright; stars) • Extinction (optical; Ménard+2010) • Scattering (σscat high in UV; sky i ...
... lines with an impact parameter of 5 kpc • We also developed a new method to constrain Z in an imaging sense using dust-scattered light • Halos are dusty (Menard+2010); dust visible in: • Emission (mid-IR; sky is bright; stars) • Extinction (optical; Ménard+2010) • Scattering (σscat high in UV; sky i ...
An extended X-ray object ejected from the PSR B1259
... the binary by the pulsar interaction with the decretion disk. The new data seem to support this scenario because the average projected velocity implies that the structure could indeed be launched near periastron. However, as K+14 pointed out, the fast, steady motion over such a large period of time ...
... the binary by the pulsar interaction with the decretion disk. The new data seem to support this scenario because the average projected velocity implies that the structure could indeed be launched near periastron. However, as K+14 pointed out, the fast, steady motion over such a large period of time ...
Modeling non-thermal emission from stellar bow shocks
... Assuming the velocity of this star is 67 km s−1 (Kobulnicky et al. 2010), the mass-loss rate 10−5 M⊙ yr−1 (Markova et al. 2004; Repolust et al. 2004), the stellar wind velocity 2300 km s−1 (Howarth et al. 1997), and that the standoff radius is R0 = 1.5 pc (Peri et al. 2012), from Eq. 1 we derive a m ...
... Assuming the velocity of this star is 67 km s−1 (Kobulnicky et al. 2010), the mass-loss rate 10−5 M⊙ yr−1 (Markova et al. 2004; Repolust et al. 2004), the stellar wind velocity 2300 km s−1 (Howarth et al. 1997), and that the standoff radius is R0 = 1.5 pc (Peri et al. 2012), from Eq. 1 we derive a m ...
Document
... should be < 1/30 of modified Urca • Coldest observed stars are more massive; their neutrino luminosity should be > 30 of modified Urca (any enhanced neutrino emission would do) • Neutron star masses at which neutrino cooling is enhanced are not constrained • The real physical model of neutron star i ...
... should be < 1/30 of modified Urca • Coldest observed stars are more massive; their neutrino luminosity should be > 30 of modified Urca (any enhanced neutrino emission would do) • Neutron star masses at which neutrino cooling is enhanced are not constrained • The real physical model of neutron star i ...
White dwarf binaries
... better known as cataclysmic variables (CVs) and are interacting binaries in that the white dwarf is accreting material from its (usually) cool, late-type companion star in a short (of the order of hours) orbital period. They are one of the few classes of object considered in this book that were actu ...
... better known as cataclysmic variables (CVs) and are interacting binaries in that the white dwarf is accreting material from its (usually) cool, late-type companion star in a short (of the order of hours) orbital period. They are one of the few classes of object considered in this book that were actu ...
Super-Eddington outburst in a binary system: V4641 Sgr Mikhail Revnivtsev, Marat Gilfanov
... • Usually the increase of optical brightness of X-ray Novae is caused by the contribution of the accretion disk • It is common for X-ray Novae to demonstrate ∆mv ∼ 5. But only if the X-ray Nova is the low mass X-ray binary ! Such huge change of the optical brightness was never observed in high mass ...
... • Usually the increase of optical brightness of X-ray Novae is caused by the contribution of the accretion disk • It is common for X-ray Novae to demonstrate ∆mv ∼ 5. But only if the X-ray Nova is the low mass X-ray binary ! Such huge change of the optical brightness was never observed in high mass ...
systems - Research in Astronomy and Astrophysics
... (2001). Numerous X-ray flares have been observed since then by both Chandra and XMM-Newton. Their variability time scales, including temporal structure on several-minute time scales during the flares, indicate that they arise much closer to the black hole than the quiescent emission, probably within ...
... (2001). Numerous X-ray flares have been observed since then by both Chandra and XMM-Newton. Their variability time scales, including temporal structure on several-minute time scales during the flares, indicate that they arise much closer to the black hole than the quiescent emission, probably within ...
From: BXSVR0::OWOCKI 12-JAN-2001 10:16:41.12 To: DCOHEN
... observed X-ray lines. If they are formed by recombination, then it seems likely the absorption opacity won't be too important. If formed by collisional excitation from a ground state, it seems it might be. What do you know about the formation mechanism for these observed lines. Do you think they cou ...
... observed X-ray lines. If they are formed by recombination, then it seems likely the absorption opacity won't be too important. If formed by collisional excitation from a ground state, it seems it might be. What do you know about the formation mechanism for these observed lines. Do you think they cou ...
IXO as an observatory in the large telescopes era
... the very phenomena where black holes grow by mass accretion, we need to uncover all populations of AGN over a broad range of redshifts, luminosities, and obscuration, to understand the whole growth history of supermassive black holes and their relation to galaxy formation. Theories suggest that a si ...
... the very phenomena where black holes grow by mass accretion, we need to uncover all populations of AGN over a broad range of redshifts, luminosities, and obscuration, to understand the whole growth history of supermassive black holes and their relation to galaxy formation. Theories suggest that a si ...
A relativistic iron emission line from the neutron star low-mass X
... Key words. line: identification – line: profiles – X-rays: individuals: GX 3+1 – X-rays: binaries – stars: neutron ...
... Key words. line: identification – line: profiles – X-rays: individuals: GX 3+1 – X-rays: binaries – stars: neutron ...
PDF Full-text
... C I, C II, but there are also many weaker emission lines of Fe II. Important transition region lines formed at temperatures of 60,000–250,000 K include the doublet lines of Si IV, C IV, and N V. These emission lines are superimposed on a UV continuum consisting mostly of recombination to Si I, Mg I, ...
... C I, C II, but there are also many weaker emission lines of Fe II. Important transition region lines formed at temperatures of 60,000–250,000 K include the doublet lines of Si IV, C IV, and N V. These emission lines are superimposed on a UV continuum consisting mostly of recombination to Si I, Mg I, ...
Sardinia_SA - Mullard Space Science Laboratory
... polars tend to emit at an approximately constant level, with occasional drops to fainter levels • There is a continuum of levels, but the states tend to be called “high”, “intermediate” and “low” • In low states the accretion rate drops, no reservoir in a disk, so the underlying stars can become vis ...
... polars tend to emit at an approximately constant level, with occasional drops to fainter levels • There is a continuum of levels, but the states tend to be called “high”, “intermediate” and “low” • In low states the accretion rate drops, no reservoir in a disk, so the underlying stars can become vis ...
PDF only - at www.arxiv.org.
... of the feedback process by which energy is transferred from the central massive black hole to the surrounding gas. The mechanism by which the filaments are stabilized against tidal shear and dissipation into the surrounding 4×107K gas has been unclear. Here we report new observations that resolve th ...
... of the feedback process by which energy is transferred from the central massive black hole to the surrounding gas. The mechanism by which the filaments are stabilized against tidal shear and dissipation into the surrounding 4×107K gas has been unclear. Here we report new observations that resolve th ...
![arXiv:1505.07406v1 [hep-ph] 27 May 2015](http://s1.studyres.com/store/data/007750137_1-1343a5635a0dda57ac4b2d01226e2ce5-300x300.png)
arXiv:1505.07406v1 [hep-ph] 27 May 2015
... gµν R being added to the determinantal action is analysed from a cosmological point of view. It corresponds to the most general action constructed from a rank two tensor that contains up to first order terms in curvature. This term can equally be seen as a conformal factor multiplying the metric gµν ...
... gµν R being added to the determinantal action is analysed from a cosmological point of view. It corresponds to the most general action constructed from a rank two tensor that contains up to first order terms in curvature. This term can equally be seen as a conformal factor multiplying the metric gµν ...
Comparison between the luminosity functions of X
... for all sources with a reliable Seyfert classification. There are 38 sources in the sample, of which 30 are classified as type2 and eight as type-1. We correct the X-ray luminosities for absorption using the observed column densities given in that paper. There are five Seyfert-2 galaxies which do no ...
... for all sources with a reliable Seyfert classification. There are 38 sources in the sample, of which 30 are classified as type2 and eight as type-1. We correct the X-ray luminosities for absorption using the observed column densities given in that paper. There are five Seyfert-2 galaxies which do no ...
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.