scholarly journals Long-term evolutions of the cyclotron line energies in Her X-1, Vela X-1, and Cen X-3 as observed with Swift/BAT

2019 ◽  
Vol 484 (3) ◽  
pp. 3797-3805 ◽  
Author(s):  
L Ji ◽  
R Staubert ◽  
L Ducci ◽  
A Santangelo ◽  
S Zhang ◽  
...  
Keyword(s):  
Cyclotron Line

scholarly journals TheSwift-BAT monitoring reveals a long-term decay of the cyclotron line energy in Vela X-1

2016 ◽  
Vol 463 (1) ◽  
pp. 185-190 ◽  
Author(s):  
V. La Parola ◽  
G. Cusumano ◽  
A. Segreto ◽  
A. D'Aì
Keyword(s):  
Line Energy ◽  
Cyclotron Line

scholarly journals The X-ray Astronomy Satellite SAX

1990 ◽  
Vol 115 ◽  
pp. 302-306
Author(s):  
R.C. Butler
Keyword(s):  
Energy Range ◽  
Scintillation Counter ◽  
Broad Band ◽  
Wide Energy Range ◽  
Wide Field ◽  
X Ray ◽  
Wide Energy ◽  
Cyclotron Line ◽  
Galactic Sources

AbstractThe SAX satellite is forseen for launch at the end of 1992 to study the X-ray emission from galactic and extra-galactic sources in the energy range 0.1-200 keV. The payload consists of four concentrator/spectrometer systems (3 units 1-10keV, 1 unit 0.1-10keV), a high pressure gas scintillation proportional counter (3-120keV), a phoswich scintillation counter (15-200keV), and two wide field cameras (2-30keV). Together these instruments will perform the following:- - Broad band spectroscopy (E/ΔE=12) in the energy range 0.1-10 keV with imaging resolution of 1 arcmin- Continuum and cyclotron line spectroscopy (E/ΔE=5-20) in the wide energy range 3-200 keV- Variability studies of bright source energy spectra on time scales from milliseconds to days and months- Systematic long term source variability studies in selected regions of the sky down to a source intensity of 1 mCrab.

scholarly journals Cyclotron line energy in Hercules X-1: stable after the decay

2020 ◽  
Vol 642 ◽  
pp. A196
Author(s):  
R. Staubert ◽  
L. Ducci ◽  
L. Ji ◽  
F. Fürst ◽  
J. Wilms ◽  
...  
Keyword(s):  
High Precision ◽  
Line Energy ◽  
X Ray ◽  
Average Value ◽  
Pulse Phase ◽  
Flux Level ◽  
Cyclotron Line ◽  
The Continuum

We summarize the results of a dedicated effort made between 2012 and 2019 to follow the evolution of the cyclotron line in Her X-1 through repeated NuSTAR observations. The previously observed nearly 20-year-long decay of the cyclotron line energy has ended in 2012: from then on, the pulse-phase-averaged flux-corrected cyclotron line energy has remained stable and constant at an average value of Ecyc = (37.44 ± 0.07) keV (normalized to a flux level of 6.8 RXTE/ASM-cts s−1). The flux dependence of Ecyc discovered in 2007 is now measured with high precision, giving a slope of (0.675 ± 0.075) keV/(ASM-cts s−1), corresponding to an increase of 6.5% of Ecyc for an increase in flux by a factor of two. We also find that all line parameters as well as the continuum parameters show a correlation with X-ray flux. While a correlation between Ecyc and X-ray flux (both positive and negative) is now known for several accreting binaries with various suggestions for the underlying physics, the phenomenon of a long-term decay has so far only been seen in Her X-1 and Vela X-1, with far less convincing explanations.

scholarly journals Long-term change in the cyclotron line energy in Hercules X-1

2014 ◽  
Vol 572 ◽  
pp. A119 ◽  
Author(s):  
R. Staubert ◽  
D. Klochkov ◽  
J. Wilms ◽  
K. Postnov ◽  
N. I. Shakura ◽  
...  
Keyword(s):  
Line Energy ◽  
Term Change ◽  
Cyclotron Line

scholarly journals Study of the X-ray pulsar IGR J19294+1816 with NuSTAR: Detection of cyclotron line and transition to accretion from the cold disk

2019 ◽  
Vol 621 ◽  
pp. A134 ◽  
Author(s):  
Sergey S. Tsygankov ◽  
Victor Doroshenko ◽  
Alexander A. Mushtukov ◽  
Alexander A. Lutovinov ◽  
Juri Poutanen
Keyword(s):  
Energy Spectrum ◽  
Absorption Line ◽  
Orbital Period ◽  
Timing Analysis ◽  
Type I ◽  
Quiescent State ◽  
X Ray ◽  
Cyclotron Absorption ◽  
Cyclotron Line

In the work we present the results of two deep broadband observations of the poorly studied X-ray pulsar IGR J19294+1816 obtained with the NuSTAR observatory. The source was observed during Type I outburst and in the quiescent state. In the bright state a cyclotron absorption line in the energy spectrum was discovered at Ecyc = 42.8 ± 0.7 keV. Spectral and timing analysis prove the ongoing accretion also during the quiescent state of the source. Based on the long-term flux evolution, particularly on the transition of the source to the bright quiescent state with luminosity around 1035 erg s−1, we conclude that IGR J19294+1816 switched to the accretion from the “cold” accretion disk between Type I outbursts. We also report the updated orbital period of the system.

Therapy and prevention for mental health: What if mental diseases are mostly not brain disorders?

2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis
Keyword(s):  
Mental Health ◽  
Mental Disease ◽  
Brain Disorders ◽  
Social Stressors ◽  
Labor Education ◽  
Mental Diseases ◽  
Long Term Follow Up ◽  
Political Decisions

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

Brief summary of Kleť photographic search programme for minor planets

1999 ◽  
Vol 173 ◽  
pp. 189-192
Author(s):  
J. Tichá ◽  
M. Tichý ◽  
Z. Moravec
Keyword(s):  
Ccd Camera ◽  
Minor Planet ◽  
Minor Planets ◽  
Main Belt

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.

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