Evidence for x Rays From Sources Outside the Solar System

Giacconi, R.; Gursky, H.; Paolini, F. R.; Rossi, Bruno

doi:10.1103/physrevlett.9.439

Cited by 806 publications

(446 citation statements)

References 2 publications

Supporting

Mentioning

435

Contrasting

Unclassified

Order By: Relevance

“…A personal "guess" about the most likely outcome for the operation of the km 3 telescopes, is that they will play for neutrino astronomy a role similar to what the first X-ray rocket of Rossi and Giacconi [1,2] played for X-ray astronomy in 1962. That first glimpse of the X-ray sky revealed one single point source, the AGN Sco-X1 (that a the moment was in a high state of activity), and obtained evidence for an isotropic X-ray light glow of the sky.…”

Section: Discussionmentioning

confidence: 99%

“…A well known consequence of the approximate Feynman scaling of the hadronic interaction inclusive cross sections is the fact that if the parent c.r. have a power law spectrum of form φ cr ≃ K cr E −α , and their interaction probability is energy independent 2 the ν spectrum, to a good approximation, 2 In the most general case c.r. of different rigidity p/Z diffuse in different ways inside the source and have different is also a power law of the same slope.…”

Section: Neutrinos Photons and Cosmic Raysmentioning

confidence: 97%

See 1 more Smart Citation

Perspectives of high-energy neutrino astronomy

Lipari

2006

Nuclear Instruments and Methods in Physics Research Section A:

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Section: Neutrinos Photons and Cosmic Raysmentioning

confidence: 97%

Perspectives of high-energy neutrino astronomy

Lipari

2006

Nuclear Instruments and Methods in Physics Research Section A:

View full text Add to dashboard Cite

“…Sco X-1 was the first, persistently bright, extrasolar X-ray source to be discovered (Giacconi et al 1962). It lies at a distance of 2.8 kpc (Bradshaw et al 1999), has an orbital period of 18.9 hours (Gottlieb et al 1975;Cowley & Crampton 1975;Hynes & Britt 2012), and contains a 0.4M M-type companion (Steeghs & Casares 2002).…”

Section: Introductionmentioning

confidence: 99%

Sco X-1 revisited withKepler, MAXI and HERMES: outflows, time-lags and echoes unveiled

Scaringi

Maccarone

Hynes

et al. 2015

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

Sco X-1 has been the subject of many multi-wavelength studies in the past, being the brightest persistent extra-solar X-ray source ever observed. Here we revisit Sco X-1 with simultaneous short cadence Kepler optical photometry and MAXI X-ray photometry over a 78 day period, as well as optical spectroscopy obtained with HERMES. We find Sco X-1 to be highly variable in all our datasets. The optical fluxes are clearly bimodal, implying the system can be found in two distinct optical states. These states are generally associated with the known flaring/normal branch X-ray states, although the flux distributions associated with these states overlap. Furthermore, we find that the optical power spectrum of Sco X-1 differs substantially between optical luminosity states. Additionally we find rms-flux relations in both optical states, but only find a linear relation during periods of low optical luminosity. The full optical/X-ray discrete correlation function displays a broad ≈ 12.5 hour optical lag. However during the normal branch phase the X-ray and optical fluxes are anti-correlated, whilst being correlated during the flaring branch. We also performed a Cepstrum analysis on the full Kepler light curve to determine the presence of any echoes within the optical light curve alone. We find significant echo signals, consistent with the optical lags found using the discrete cross-correlation. We speculate that whilst some of the driving X-ray emission is reflected by the disk, some is absorbed and re-processed on the thermal timescale, giving rise to both the observed optical lags and optical echoes.

show abstract

“…Prior to the historic discovery (Giacconi et al 1962) of a remarkably bright X-ray source in the constellation of Scorpius, in June 1962, most astronomers considered that observations in the ultraviolet and gamma ray bands offered the best promise for exploiting the exciting potential of space research. X-ray observations were expected to focus on the study of active stars, with fluxes scaled from that of the solar corona, the only known X-ray source at that time.…”

Section: The Origins Of X-ray Astronomymentioning

confidence: 99%

Searching for Black Holes in Space

Pounds

2013

Space Sci Rev

View full text Add to dashboard Cite

Although General Relativity had provided the physical basis of black holes, evidence for their existence had to await the Space Era when X-ray observations first directed the attention of astronomers to the unusual binary stars Cygnus X-1 and A0620-00. Subsequently, a number of faint Ariel 5 and Uhuru X-ray sources, mainly at high Galactic latitude, were found to lie close to bright Seyfert galaxies, suggesting the nuclear activity in AGN might also be driven by accretion in the strong gravity of a black hole. Detection of rapid X-ray variability with EXOSAT later confirmed that the accreting object in AGN was almost certainly a supermassive black hole.

show abstract

Evidence for x Rays From Sources Outside the Solar System

Cited by 806 publications

References 2 publications

Perspectives of high-energy neutrino astronomy

Perspectives of high-energy neutrino astronomy

Sco X-1 revisited withKepler, MAXI and HERMES: outflows, time-lags and echoes unveiled

Searching for Black Holes in Space

Contact Info

Product

Resources

About