Wide-field all-sky monitor for X-ray astronomy

Author(s):  
Konstantin N. Borozdin ◽  
William C. Priedhorsky ◽  
Vadim A. Arefiev ◽  
Alexander S. Kaniovsky ◽  
Kevin Black ◽  
...  
Keyword(s):  
X Ray ◽  
2014 ◽  
Vol 10 (S312) ◽  
pp. 68-70 ◽  
Author(s):  
W. Yuan ◽  
S. Komossa ◽  
C. Zhang ◽  
H. Feng ◽  
Z.-X. Ling ◽  
...  

AbstractStars are tidally disrupted and accreted when they approach massive black holes (MBHs) closely, producing a flare of electromagnetic radiation. The majority of the (approximately two dozen) tidal disruption events (TDEs) identified so far have been discovered by their luminous, transient X-ray emission. Once TDEs are detected in much larger numbers, in future dedicated transient surveys, a wealth of new applications will become possible. Here, we present the proposed Einstein Probe mission, which is a dedicated time-domain soft X-ray all-sky monitor aiming at detecting X-ray transients including TDEs in large numbers. The mission consists of a wide-field micro-pore Lobster-eye imager (60° × 60°), and is designed to carry out an all-sky transient survey at energies of 0.5-4 keV. It will also carry a more sensitive telescope for X-ray follow-ups, and will be capable of issuing public transient alerts rapidly. Einstein Probe is expected to revolutionise the field of TDE research by detecting several tens to hundreds of events per year from the early phase of flares, many with long-term, well sampled lightcurves.


Author(s):  
Miranda Yew ◽  
Miroslav D. Filipović ◽  
Quentin Roper ◽  
Jordan D. Collier ◽  
Evan J. Crawford ◽  
...  

AbstractWe present a multi-frequency study of the intermediate spiral SAB(r)bc type galaxy NGC 6744, using available data from the Chandra X-Ray telescope, radio continuum data from the Australia Telescope Compact Array and Murchison Widefield Array, and Wide-field Infrared Survey Explorer infrared observations. We identify 117 X-ray sources and 280 radio sources. Of these, we find nine sources in common between the X-ray and radio catalogues, one of which is a faint central black hole with a bolometric radio luminosity similar to the Milky Way’s central black hole. We classify 5 objects as supernova remnant (SNR) candidates, 2 objects as likely SNRs, 17 as H ii regions, 1 source as an AGN; the remaining 255 radio sources are categorised as background objects and one X-ray source is classified as a foreground star. We find the star-formation rate (SFR) of NGC 6744 to be in the range 2.8–4.7 M⊙~yr − 1 signifying the galaxy is still actively forming stars. The specific SFR of NGC 6744 is greater than that of late-type spirals such as the Milky Way, but considerably less that that of a typical starburst galaxy.


2011 ◽  
Vol 196 (1) ◽  
pp. 6 ◽  
Author(s):  
Alan M. Levine ◽  
Hale V. Bradt ◽  
Deepto Chakrabarty ◽  
Robin H. D. Corbet ◽  
Robert J. Harris
Keyword(s):  
X Ray ◽  

IUCrJ ◽  
2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Hiroyuki Iwamoto

X-ray fiber diffraction is potentially a powerful technique to study the structure of fibrous materials, such as DNA and synthetic polymers. However, only rotationally averaged diffraction patterns can be recorded and it is difficult to correctly interpret them without the knowledge of esoteric diffraction theories. Here we demonstrate that, in principle, the non-rotationally averaged 3D structure of a fibrous material can be restored from its fiber diffraction pattern. The method is a simple puzzle-solving process and in ideal cases it does not require any prior knowledge about the structure, such as helical symmetry. We believe that the proposed method has a potential to transform the fiber diffraction to a 3D imaging technique, and will be useful for a wide field of life and materials sciences.


1999 ◽  
Author(s):  
Lothar Strueder ◽  
Robert Hartmann ◽  
Peter Holl ◽  
Josef Kemmer ◽  
Peter Klein ◽  
...  

2019 ◽  
Vol 15 (S341) ◽  
pp. 21-25
Author(s):  
M. J. I. Brown ◽  
K. J. Duncan ◽  
H. Landt ◽  
M. Kirk ◽  
C. Ricci ◽  
...  

AbstarctWe present ongoing work on the spectral energy distributions (SEDs) of active galactic nuclei (AGNs), derived from X-ray, ultraviolet, optical, infrared and radio photometry and spectroscopy. Our work is motivated by new wide-field imaging surveys that will identify vast numbers of AGNs, and by the need to benchmark AGN SED fitting codes. We have constructed 41 SEDs of individual AGNs and 80 additional SEDs that mimic Seyfert spectra. All of our SEDs span 0.09 to 30μm, while some extend into the X-ray and/or radio. We have tested the utility of the SEDs by using them to generate AGN photometric redshifts, and they outperform SEDs from the prior literature, including reduced redshift errors and flux density residuals.


2019 ◽  
Vol 26 (5) ◽  
pp. 1489-1495
Author(s):  
Andreas Koch ◽  
Johannes Risch ◽  
Wolfgang Freund ◽  
Theophilos Maltezopoulos ◽  
Marc Planas ◽  
...  

X-ray photon beam diagnostic imagers are located at 24 positions in the European XFEL beam transport system to characterize the X-ray beam properties, and to give feedback for tuning and optimization of the electron acceleration and orbit, the undulators, and the X-ray optics. One year of commissioning allowed experience to be gained with these imagers, which will be reported here. The sensitive Spontaneous Radiation imager is useful for various investigations in spontaneous radiation mode: for undulator adjustments and for low-signal imaging applications. The high-resolution Free-Electron Laser imager, 10 µm spatial resolution, is extensively used for the monitoring of beam position, spot size and shape, gain curve measurements, and also for beam-intensity monitoring. The wide field-of-view pop-in monitors (up to 200 mm) are regularly used for alignment and tuning of the various X-ray optical components like mirrors, slits and monochromators, and also for on-line beam control of a stable beam position at the instruments. The Exit Slit imager after the soft X-ray monochromator provides spectral information of the beam together with multi-channel plate based single-pulse gating. For particular use cases, these special features of the imagers are described. Some radiation-induced degradation of scintillators took place in this initial commissioning phase, providing useful information for better understanding of damage thresholds. Visible-light radiation in the beam pipe generated by upstream bending magnets caused spurious reflections in the optical system of some of the imagers which can be suppressed by aluminium-coated scintillating screens.


1990 ◽  
Vol 123 ◽  
pp. 463-468
Author(s):  
M. Matsuoka ◽  
N. Kawai ◽  
T. Imai ◽  
M. Yamauchi ◽  
A. Yoshida ◽  
...  

AbstractWe propose an X-ray all sky monitor for Japanese Experimental Module (JEM) on the space station. Considering practical circumstances, we show as a case study that the all sky monitor with slit hole cameras is most promising for monitoring the short-term and long-term X-ray transients. We call this all sky monitor as MAXI (Monitor of All-sky X-ray Image). Position determination of gamma-ray bursts could be achieved with accuracy less than one degree observing the X-ray component of the burst. Weak X-ray sources such as active galactic nuclei could be also monitored with time resolution less than one day. The X-ray all sky monitor will work to discover X-ray novae and transient phenomena and give us the alarm for further detailed observations. The obtained data will be also used for archival study.


1990 ◽  
Vol 123 ◽  
pp. 89-110
Author(s):  
H. V. Bradt ◽  
A. M. Levine ◽  
E. H. Morgan ◽  
R. A. Remillard ◽  
J. H. Swank ◽  
...  

AbstractThe capabilities of the X-ray Timing Explorer (XTE) are described with particular attention paid to current scientific problems it will address from galactic neutron star systems to active galactic nuclei. It features a low-background continuous 2-200 keV response with large apertures (a 0.63-m2 proportional counter array and a 0.16-m2 dual rocking NaI/CsI scintillation array). Rapid response (in hours) to temporal phenomena, e.g. transients, is obtained by virtue of a scanning all-sky monitor and rapid maneuverability. XTE will carry out detailed energy-resolved studies of phenomena close to neutron stars (e.g. QPO’s) because of its sub-millisecond timing (to 10 μs), its high telemetry rates (to 256 kb/s), and the high throughput of its data system (to ≳ 2 × 105 c s−1).


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