Recent Optical Observations of the X-Ray Source H0139-68; an AM-Herculis Type Binary System

1982 ◽  
Vol 4 (4) ◽  
pp. 425-428
Author(s):  
A.J. Pickles ◽  
N. Visvanathan
Keyword(s):  
Binary System ◽  
Low Energy ◽  
Optical Observations ◽  
Short Time Scale ◽  
Optical Identification ◽  
Time Resolved ◽  
X Ray ◽  
Short Time ◽  
Energy Detectors ◽  
Optical Spectrophotometry

The soft X-ray source HO 139-68 was originally detected with the low energy detectors of the HEAO A-2 experiment, and confirmed by later IPC observations (Agarwal et al. 1981). The X-ray observations show flux variations in the 0.15 – 0.4 keV band of a factor of two, or timescales of a few hours, with evidence for short time-scale flickering. Following communication of the source position to us by Agarwal and Riegler, we obtained time-resolved optical spectrophotometry of a star close to the X-ray position, using the IDPCA on the MSO 1.9m telescope. The spectrophotometry and later polarisation observations confirm the optical identification and that the source is an AM-Herculis type binary system, with a late type dwarf secondary overflowing its Roche lobe in a magnetically constrained funnel onto a magnetic white dwarf (WD) primary (Visvanathan and Pickles 1982).

New insight into the origin of the GeV flare in the binary system PSR B1259-63/LS 2883 from the 2017 periastron passage

2020 ◽  
Vol 497 (1) ◽  
pp. 648-655
Author(s):  
M Chernyakova ◽  
D Malyshev ◽  
S Mc Keague ◽  
B van Soelen ◽  
J P Marais ◽  
...  
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Energy Release ◽  
Broad Band ◽  
Strong Shock ◽  
Optical Observations ◽  
X Rays ◽  
X Ray ◽  
Inverse Compton ◽  
Pulsar Wind

ABSTRACT PSR B1259-63 is a gamma-ray binary system hosting a radio pulsar orbiting around an O9.5Ve star, LS 2883, with a period of ∼3.4 yr. The interaction of the pulsar wind with the LS 2883 outflow leads to unpulsed broad-band emission in the radio, X-rays, GeV, and TeV domains. While the radio, X-ray, and TeV light curves show rather similar behaviour, the GeV light curve appears very different with a huge outburst about a month after a periastron. The energy release during this outburst seems to significantly exceed the spin-down luminosity of the pulsar and both the GeV light curve and the energy release vary from one orbit to the next. In this paper, we present for the first time the results of optical observations of the system in 2017, and also reanalyse the available X-ray and GeV data. We present a new model in which the GeV data are explained as a combination of the bremsstrahlung and inverse Compton emission from the unshocked and weakly shocked electrons of the pulsar wind. The X-ray and TeV emission is produced by synchrotron and inverse Compton emission of energetic electrons accelerated on a strong shock arising due to stellar/pulsar winds collision. The brightness of the GeV flare is explained in our model as a beaming effect of the energy released in a cone oriented, during the time of the flare, in the direction of the observer.

The soft X-ray diffuse background observed with the HEAO 1 low-energy detectors

1992 ◽  
Vol 399 ◽  
pp. 694 ◽  
Author(s):  
G. P. Garmire ◽  
J. A. Nousek ◽  
K. M. V. Apparao ◽  
D. N. Burrows ◽  
R. L. Fink ◽  
...  
Keyword(s):  
Low Energy ◽  
X Ray ◽  
Diffuse Background ◽  
Energy Detectors

scholarly journals IPS Observations of Short-Time Scale Interplanetary Activity

1996 ◽  
Vol 154 ◽  
pp. 225-228
Author(s):  
Pradeep Gothoskar ◽  
A. Pramesh Rao
Keyword(s):  
Time Scale ◽  
Solar Maximum ◽  
Component Model ◽  
Scintillation Index ◽  
Short Time Scale ◽  
High Time Resolution ◽  
The Sun ◽  
X Ray ◽  
Average Mass ◽  
Short Time

AbstractWe have carried out a program of continuous Interplanetary Scintillation (IPS) monitoring of the interplanetary activity using Ooty Radio Telescope (ORT). From May 1990 to March 1991, during the 22nd solar maximum, a few radio sources were monitored to provide long stretches of IPS data with a high-time resolution of few minutes. These observations covered 0.3 to 0.8 AU region (12° to 70° elongations) around the sun at several heliographic latitudes. During the observation, we detected 33 short-time scale IPS events which had significant variation in the scintillation index and solar wind velocity. These were considered to be due to travelling interplanetary disturbances.A multi-component model of plasma density enhancement was developed to estimate the geometry and physical properties of these IPS events. Detailed analysis of 20 of these events suggests, 1. fast IPS events were interplanetary signatures of Coronal Mass Ejections (CMEs), 2. the average mass and energy of these events was ~ 1016 gm and 1033 erg respectively, 3. 80% of IPS events were associated with X-ray flares on the sun and 50% were associated with geomagnetic activity at earth. Detailed study of the multi-component model suggests IPS observations at smaller elongations (hence at higher radio frequencies) are more suited to detect fast-moving interplanetary disturbances such as produced by CMEs.

Time-resolved measurement of X-ray emission from Al2O3 targets induced by low-energy ion bombardment

2006 ◽  
Vol 38 (12-13) ◽  
pp. 1641-1645
Author(s):  
Minghui Song ◽  
Masaki Takeguchi ◽  
Kazuo Furuya
Keyword(s):  
Ion Bombardment ◽  
Low Energy ◽  
Time Resolved ◽  
X Ray

Search for short time-scale periodicity in the X-ray flux of 4U1700 – 37

Nature ◽  
1979 ◽  
Vol 279 (5713) ◽  
pp. 508-509
Author(s):  
G. BRANDUARDI ◽  
A. K. DUPREE ◽  
P. W. SANFORD ◽  
G. S. G. POLLARD
Keyword(s):  
Time Scale ◽  
Short Time Scale ◽  
X Ray ◽  
Short Time

scholarly journals X-RAY AND OPTICAL OBSERVATIONS OF THE UNIQUE BINARY SYSTEM HD 49798/RX J0648.0-4418

2011 ◽  
Vol 737 (2) ◽  
pp. 51 ◽  
Author(s):  
S. Mereghetti ◽  
N. La Palombara ◽  
A. Tiengo ◽  
F. Pizzolato ◽  
P. Esposito ◽  
...  
Keyword(s):  
Binary System ◽  
Optical Observations ◽  
X Ray

scholarly journals X-ray observations of the nova shell IPHASX J210204.7+471015*

2021 ◽  
Author(s):  
J A Toalá ◽  
G Rubio ◽  
E Santamaría ◽  
M A Guerrero ◽  
S Estrada-Dorado ◽  
...  
Keyword(s):  
Time Series ◽  
Binary System ◽  
Binary Star ◽  
Optical Observations ◽  
X Ray ◽  
Imaging Camera ◽  
Nova Shells ◽  
Intermediate Polars ◽  
Time Series Analyses ◽  
Nova Shell

Abstract We present the analysis of XMM-Newton European Photon Imaging Camera (EPIC) observations of the nova shell IPHASX J210204.7+471015. We detect X-ray emission from the progenitor binary star with properties that resemble those of underluminous intermediate polars such as DQ Her: an X-ray-emitting plasma with temperature of TX = (6.4 ± 3.1) × 106 K, a non-thermal X-ray component, and an estimated X-ray luminosity of LX = 1030 erg s−1. Time series analyses unveil the presence of two periods, the dominant with a period of 2.9 ± 0.2 hr, which might be attributed to the spin of the white dwarf, and a secondary of 4.5 ± 0.6 hr that is in line with the orbital period of the binary system derived from optical observations. We do not detect extended X-ray emission as in other nova shells probably due to its relatively old age (130–170 yr) or to its asymmetric disrupted morphology which is suggestive of explosion scenarios different to the symmetric ones assumed in available numerical simulations of nova explosions.

scholarly journals Optical Observations of Pulsars

1981 ◽  
Vol 95 ◽  
pp. 221-234
Author(s):  
F. Graham Smith
Keyword(s):  
Ultra Violet ◽  
Optical Observations ◽  
Crab Pulsar ◽  
Radio Pulsars ◽  
Optical Identification ◽  
Absorption Effect ◽  
Time Resolved ◽  
Pulse Cycle ◽  
Infra Red ◽  
Minimum Intensity

Optical identification of radio pulsars has only been achieved for the Crab and Vela Pulsars. The luminosity limits for others could be considerably improved: better astrometry and time-resolved photometry could reach mv = 27. The limits for pulsars with unknown periods, for example in extragalactic nebulae, are usually about mv = 20. The luminosity falls rapidly with increasing period: if it follows a power law the index is minus ten at least.The optical spectrum of the Crab Pulsar falls toward the infra-red and is flat in the ultra-violet. No self-absorption effect is seen in the infra-red. New observations of the minimum intensity and of the polarisation show a highly linearly polarised component continuing through the whole pulse cycle.

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