Detection of a Series of X‐Ray Dips Associated with a Radio Flare in GRS 1915+105

2001 ◽  
Vol 546 (2) ◽  
pp. 1075-1085 ◽  
Author(s):  
S. Naik ◽  
P. C. Agrawal ◽  
A. R. Rao ◽  
B. Paul ◽  
S. Seetha ◽  
...  
Keyword(s):  
X Ray ◽  
Radio Flare

scholarly journals Radio Flare Activity of RS CVn Stars

1980 ◽  
Vol 88 ◽  
pp. 403-403
Author(s):  
Paul A. Feldman
Keyword(s):  
Binary Star ◽  
Quantitative Model ◽  
Magnetic Activity ◽  
Flare Activity ◽  
Radio Observatory ◽  
X Ray ◽  
Rs Cvn Stars ◽  
Solar Magnetic Activity ◽  
Radio Flare ◽  
Systematic Program

For several years, a systematic program to observe RS CVn and similar binaries has been undertaken with the 46-m telescope of the Algonquin Radio Observatory. A number of large radio outbursts at 2.8 cm wavelength has been found from HR 1099, AR Lac, SZ Psc, UX Ari, and HR 5110. In several cases, simultaneous, or nearly simultaneous, observations of these stars were made by cooperating observers at (other) radio, optical, UV, and X-ray wavelengths. It is now clearly established that the mechanism responsible for the cm-wavelength radio emission is nonthermal gyrosynchrotron radiation in a volume whose characteristic dimension is comparable with the binary star separation. More generally, a semi-quantitative model for the radio flare activity of these stars seems to be possible using greatly scaled-up analogues of solar magnetic activity.

scholarly journals Radio and X-ray observations of an exceptional radio flare in the extreme z= 4.72 blazar GB B1428+4217

2006 ◽  
Vol 368 (2) ◽  
pp. 844-850 ◽  
Author(s):  
M. A. Worsley ◽  
A. C. Fabian ◽  
G. G. Pooley ◽  
C. J. Chandler
Keyword(s):  
X Ray ◽  
Radio Flare

scholarly journals 2006 May–July major radio flare episodes in Cygnus X-3: spectrotiming analysis of the X-ray data

2012 ◽  
Vol 429 (2) ◽  
pp. 1173-1188 ◽  
Author(s):  
K. I. I. Koljonen ◽  
M. L. McCollough ◽  
D. C. Hannikainen ◽  
R. Droulans
Keyword(s):  
X Ray ◽  
Radio Flare

scholarly journals Radio Flares in the Circinus X-1 System

1980 ◽  
Vol 88 ◽  
pp. 347-347
Author(s):  
G. D. Nicolson
Keyword(s):  
Mass Transfer ◽  
Radio Emission ◽  
Compact Object ◽  
Accretion Disc ◽  
X Ray ◽  
Long Period ◽  
Systematic Trend ◽  
Radio Flare

The 16.6 day periodic radio flares in Circinus X-l have been observed at 6 cm wavelength from February 1978 to May 1979. Two strong flares occurred in February 1978 followed by a long period of quiescence until flaring recurred in January 1979. The onset of the flares was however 18 hours earlier in the 16.6 day cycle than previous flares. Similar behaviour has been reported for the X-ray emission and it is concluded that both the X-ray and radio emission are caused by mass transfer at peristron in an eccentric binary with a 16.6 day period. Each radio flare generally shows a multipeaked structure with the first maximum being the strongest. There is also a systematic trend for the subsequent peaks to become weaker with each cycle and this suggests that the compact object precesses in relation to an accretion disc.

scholarly journals An Image of a Highly Relativistic Jet from a Large Flare in the X-Ray Binary Cyg X-3

1998 ◽  
Vol 164 ◽  
pp. 351-352 ◽  
Author(s):  
A. J. Mioduszewski ◽  
R. M. Hjellming ◽  
M. P. Rupen ◽  
E. B. Waltman ◽  
G. G. Pooley ◽  
...  
Keyword(s):  
Line Of Sight ◽  
Relativistic Jets ◽  
X Ray ◽  
Size Scale ◽  
Relativistic Jet ◽  
Large Flare ◽  
Radio Flare

AbstractA VLBA image of the X-ray binary Cyg X-3 made two days after a 10 Jy radio flare shows a one-sided, curved jet with a size scale of ≈60 mas. This seems to indicate a jet with a velocity of ≥0.89c with a inclination of a few degrees to the line of site, and indicates that some of events where Cyg X-3 flares above 3 Jy may come from highly relativistic jets close to the line of sight.

scholarly journals New Triggering Mechanism for Red Dwarf Flares

1983 ◽  
Vol 71 ◽  
pp. 609-611
Author(s):  
M.K. Das ◽  
J.N. Tandon
Keyword(s):  
Solar Flares ◽  
Galactic Cosmic Rays ◽  
Flare Activity ◽  
Radio Bursts ◽  
Triggering Mechanism ◽  
X Ray ◽  
Flare Stars ◽  
M Stars ◽  
Radio Band ◽  
Radio Flare

The flare phenomenon associated with dMe stars has received much attention in recent years (Gershberg 1975). Most of the flares have been detected in both optical and radio band (Lovell 1969; Kunkel 197U; Karpen et al, 1977). But as expected (Tandon 1976) only a few display weak soft X-ray emission (Karpen et al, 1977; Haisch and Linsky 1978)- Simultaneous X-ray, optical and radio observations of YZ CMi by Karpen et al (1977) shows no X-ray emission above 3σ level accompanying minor flares. Even coincident X-ray coverage with seven radio bursts shows no enhanced X-ray emission. Recently Haisch et al (1981) detected one well resolved X-ray flare on dM5e flare star Proxima Centauri and one coincident optical and radio flare out of five optical and twelve radio flare events. However, the X-ray flare on Proxima Centauri is not accompanied by any ultraviolet, optical or radio emission. Observations on flare stars show that they are more energetic, 102 - 103 times, than the corresponding solar flares. Considering the flare activity in dwarf M-stars to be similar but more energetic to that of a large solar flare, Tandon (1961) proposed red dwarf flares to be the source of low energy galactic cosmic rays. This hypothesis has been reexplored recently by Lovell (1974).

scholarly journals The X-ray spectral and timing properties of a major radio flare episode in Cygnus X-3

2012 ◽  
Vol 8 (S290) ◽  
pp. 237-238
Author(s):  
Karri I. I. Koljonen ◽  
Diana C. Hannikainen ◽  
Michael L. McCollough ◽  
Guy G. Pooley ◽  
Sergei A. Trushkin ◽  
...  
Keyword(s):  
Principal Component ◽  
Spectral Evolution ◽  
Thermal Component ◽  
X Ray ◽  
Emit Radiation ◽  
Orbital Phase ◽  
Timing Properties ◽  
Γ Rays ◽  
Spectral State ◽  
Radio Flare

AbstractThe microquasar Cygnus X-3 is known for massive outbursts that emit radiation from radio to γ-rays associated with jet ejection events. Using Principal Component Analysis to probe fast (~1 min) X-ray spectral evolution followed by subsequent spectral fits to the time-averaged spectra (~3 ks), we find that the overall X-ray variability during major outbursts can be attributed to two components. The spectral evolution of these components are best fitted with hybrid Comptonization and thermal bremsstrahlung components. Most of the X-ray variability is attributed to the hybrid Comptonization component. However, the spectral evolution of the thermal component is linked to a change in the X-ray spectral state. Phase-folding the fit results shows that the thermal component is restricted to two orbital phase regions opposite to each other, possibly indicating a flattened stellar wind from the Wolf-Rayet companion.

scholarly journals A Spectacular Radio Flare from XRF 050416a at 40 Days and Implications for the Nature of X‐Ray Flashes

2007 ◽  
Vol 661 (2) ◽  
pp. 982-994 ◽  
Author(s):  
A. M. Soderberg ◽  
E. Nakar ◽  
S. B. Cenko ◽  
P. B. Cameron ◽  
D. A. Frail ◽  
...  
Keyword(s):  
X Ray ◽  
Radio Flare

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

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