The rockets for extended-source X-ray spectroscopy

2021 ◽  
Author(s):  
Drew M. Miles ◽  
James H. Tutt ◽  
Randall L. McEntaffer ◽  
Ross McCurdy ◽  
Tyler B. Anderson ◽  
...  
Keyword(s):  
Extended Source ◽  
X Ray

scholarly journals Pyrolitic Graphite Mosaic Crystal Thickness and Mosaicity Optimization for an Extended Source Von Hamos X-ray Spectrometer

2019 ◽  
Vol 4 (2) ◽  
pp. 38 ◽  
Author(s):  
Alessandro Scordo ◽  
Catalina Curceanu ◽  
Marco Miliucci ◽  
Florin Sirghi ◽  
Johann Zmeskal
Keyword(s):  
High Energy ◽  
High Energy Resolution ◽  
Crystal Thickness ◽  
Special Role ◽  
Extended Source ◽  
X Ray ◽  
Peak Resolution ◽  
Slit System ◽  
Bragg Spectroscopy ◽  
Effective Source

Bragg spectroscopy, one of the best established experimental techniques for high energy resolution X-ray measurements, has always been limited to the measurement of photons produced from well collimated (tens of microns) or point-like sources; recently, the VOXES collaboration at INFN National Laboratories of Frascati developed a prototype of a high resolution and high precision X-ray spectrometer working also with extended isotropic sources. The realized spectrometer makes use of Highly Annealed Pyrolitic Graphite (HAPG) crystals in a “semi”-Von Hamos configuration, in which the position detector is rotated with respect to the standard Von Hamos one, to increase the dynamic energy range, and shows energy resolutions at the level of 0.1% for photon energies up to 10 keV and effective source sizes in the range 400–1200 μ m in the dispersive plane. Such wide effective source dimensions are achieved using a double slit system to produce a virtual point-like source between the emitting target and the crystal. The spectrometer performances in terms of reflection efficiency and peak resolution depend on several parameters, among which a special role is played by the crystal mosaicity and thickness. In this work, we report the measurements of the Cu(K α 1 , 2 ) and the Fe(K α 1 , 2 ) lines performed with different mosaicity and thickness crystals in order to investigate the influence of the parameters on the peak resolution and on the reflection efficiency mentioned above.

scholarly journals High-energy gamma-ray study of the dynamically young SNR G150.3+4.5

2020 ◽  
Vol 643 ◽  
pp. A28
Author(s):  
J. Devin ◽  
M. Lemoine-Goumard ◽  
M.-H. Grondin ◽  
D. Castro ◽  
J. Ballet ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Angular Size ◽  
High Energy ◽  
Maximum Energy ◽  
Primary Concern ◽  
Extended Source ◽  
X Ray ◽  
Sky Survey ◽  
Energy Gamma ◽  
Radio Band

Aims. The supernova remnant (SNR) G150.3+4.5 was recently discovered in the radio band; it exhibits a shell-like morphology with an angular size of ~ 3°, suggesting either an old or a nearby SNR. Extended γ-ray emission spatially coincident with the SNR was reported in the Fermi Galactic Extended Source Catalog, with a power-law spectral index of Γ = 1.91 ± 0.09. Studying particle acceleration in SNRs through their γ-ray emission is of primary concern to assess the nature of accelerated particles and the maximum energy they can reach. Methods. Using more than ten years of Fermi-LAT data, we investigate the morphological and spectral properties of the SNR G150.3+4.5 from 300 MeV to 3 TeV. We use the latest releases of the Fermi-LAT catalog, the instrument response functions and the Galactic and isotropic diffuse emissions. We use ROSAT all-sky survey data to assess any thermal and nonthermal X-ray emission, and we derive minimum and maximum distance to G150.3+4.5. Results. We describe the γ-ray emission of G150.3+4.5 by an extended component which is found to be spatially coincident with the radio SNR. The spectrum is hard and the detection of photons up to hundreds of GeV points towards an emission from a dynamically young SNR. The lack of X-ray emission gives a tight constraint on the ambient density n0 ≤ 3.6 × 10−3 cm−3. Since G150.3+4.5 is not reported as a historical SNR, we impose a lower limit on its age of t = 1 kyr. We estimate its distance to be between 0.7 and 4.5 kpc. We find that G150.3+4.5 is spectrally similar to other dynamically young and shell-type SNRs, such as RX J1713.7−3946 or Vela Junior. The broadband nonthermal emission is explained with a leptonic scenario, implying a downstream magnetic field of B = 5 μG and acceleration of particles up to few TeV energies.

A Geant4 tool for edge-illumination X-ray phase-contrast imaging

2022 ◽  
Vol 17 (01) ◽  
pp. C01043
Author(s):  
L. Brombal ◽  
L. Rigon ◽  
F. Arfelli ◽  
R.H. Menk ◽  
F. Brun
Keyword(s):  
Phase Contrast ◽  
Signal To Noise Ratio ◽  
Photon Counting ◽  
Spatial Coherence ◽  
Spot Size ◽  
Contrast Imaging ◽  
Extended Source ◽  
X Ray ◽  
Photon Counting Detector ◽  
Theoretical Predictions

Abstract The PEPI project is developing a new experimental facility integrating a chromatic photon-counting detector within an edge-illumination (EI) phase-contrast setup. In this context, a novel Geant4-based simulation tool has been introduced with the aim of defining the optimal design of the experimental setup. The code includes a custom X-ray refraction process and allows simulating the whole EI system, comprising a polychromatic and extended source, absorbing masks, substrates, their movement during acquisition, and X-ray detection. In this paper, a realistic spectral detector model is introduced and its energy response validated against experimental data acquired with synchrotron radiation at energies between 26 and 50 keV. Moreover, refraction and transmission images of a plastic phantom are reconstructed from simulation data and successfully compared with theoretical predictions. Finally, an optimization study aiming at finding the effect of the X-ray focal spot size (i.e. spatial coherence) on image quality is presented; the results suggest that, in the considered configuration, the system can tolerate source sizes up to 30 μm, while, for a fixed exposure time, the best signal-to-noise ratio in refraction images is found for source sizes in the order of 10 to 15 μm.

High Kα x-ray conversion efficiency from extended source gas jet targets irradiated by ultra short laser pulses

2008 ◽  
Vol 92 (24) ◽  
pp. 241504 ◽  
Author(s):  
N. L. Kugland ◽  
C. G. Constantin ◽  
P. Neumayer ◽  
H.-K. Chung ◽  
A. Collette ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Laser Pulses ◽  
Gas Jet ◽  
Extended Source ◽  
X Ray ◽  
Short Laser Pulses

An introduction to the Rockets for Extended-source X-ray Spectroscopy

2019 ◽  
Author(s):  
Drew M. Miles ◽  
Randall M. McEntaffer ◽  
James H. Tutt ◽  
Tyler Anderson ◽  
Matthew Weiss ◽  
...  
Keyword(s):  
Extended Source ◽  
X Ray

scholarly journals Inflowing gas in the central parsec of M81

2019 ◽  
Vol 488 (1) ◽  
pp. 1199-1210 ◽  
Author(s):  
Nick Devereux
Keyword(s):  
Hubble Space Telescope ◽  
Line Emission ◽  
Visible Spectrum ◽  
Emission Lines ◽  
Extended Source ◽  
Space Telescope ◽  
X Ray ◽  
Wide Range ◽  
Low Metallicity ◽  
Central Parsec

Abstract Spectroscopic observations of the Seyfert 1/Liner nucleus of M81, obtained recently with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope(HST), have revealed an ultraviolet (UV)–visible spectrum rich with emission lines of a variety of widths, ionization potentials, and critical densities, including several in the UV that have not previously been reported. Even at the highest angular resolution currently achievable with HST, the broad-line region of M81 cannot be uniquely defined on the basis of commonly used observables such as the full width at half-maximum of the emission lines, or ratios of various emission lines. Numerous broad forbidden lines complicate interpretation of the spectra. At least three separate line-emitting components are inferred. Firstly, a large, highly ionized, low-density, low-metallicity H+ region producing the broad Balmer lines. Located within the H+ region are smaller condensations spanning a wide range in density, and the source of forbidden line emission through collisional excitation of the respective ions. Intermingled with the H+ region and the condensations is a curious extended source of time-variable C iv λ1548 emission. Collectively, these observations can be qualitatively understood in the context of a shock-excited jet cavity within a large H+ region that is photoionized by the central UV–X-ray source. The H+ region contains ∼500 M⊙ of low-metallicity gas that is dynamically unstable to inflow. At the current rate, the available H+ gas can sustain the advection-dominated accretion flow that powers the central UV–X-ray source for 105 yr.

scholarly journals Radio Observations of the Supernova Remnant CTB109 (G109.2–1.0)

1983 ◽  
Vol 101 ◽  
pp. 455-458
Author(s):  
V. A. Hughes ◽  
R. H. Harten ◽  
C. Costain ◽  
L. Nelson ◽  
M. R. Viner
Keyword(s):  
Antenna Arrays ◽  
Supernova Remnant ◽  
Galactic Plane ◽  
Radio Observations ◽  
Extended Source ◽  
Radio Observatory ◽  
X Ray ◽  
Close Proximity ◽  
Strong Source ◽  
Cas A

The supernova remnant G109.2–1.0 was discovered at λ49cm by Hughes, Harten and van den Bergh (1981) during a survey of part of the Galactic plane. The northern part of it had been detected previously as the non-thermal radio source CTB109 by Wilson and Bolton (1960), and by Raghava Roa et al (1965), but the extended low brightness of the source and its close proximity to the very strong source Cas A, from which it is separated by ∼5′, excluded it from any further detailed study. It was discovered independently at X-ray wavelengths by Gregory and Fahlman (1980). Recently, the original WSRT radio observations have been found to be in error as a result of applying the CLEAN procedure to an extended source, and since the object appears to contain an X-ray pulsar (Fahlman and Gregory, 1981), it was decided to carry out a more detailed and extensive mapping of the remmant using different antenna arrays and frequencies. This paper describes the results obtained at λ49cm and λ21cm using the Westerbork Synthesis Radio Telescope (WSRT), at λ21cm using the aperture synthesis array at the Dominion Radio Astrophysical Observatory (DRAO) and at λ4.6cm using the 46m telescope of the Algonquin Radio Observatory (ARO). Thus, data has been obtained from three completely independent telescopes, using completely independent data reduction systems. Of importance is the fact that not only have wavelengths been chosen such that the larger dimensions of the array give a reasonable angular resolution of ≤1′, but also that the smallest spacing enables the larger angular dimensions of the remnant to be observed. This paper presents some of the results and a brief interpretation.

scholarly journals Geometry of the X-ray source 1H 0707–495

2020 ◽  
Vol 641 ◽  
pp. A89 ◽  
Author(s):  
Michał Szanecki ◽  
Andrzej Niedźwiecki ◽  
Chris Done ◽  
Łukasz Klepczarek ◽  
Piotr Lubiński ◽  
...  
Keyword(s):  
Black Hole ◽  
Power Law ◽  
Free Parameter ◽  
Accretion Disc ◽  
Black Hole Horizon ◽  
Gravitational Radius ◽  
Extended Source ◽  
X Ray ◽  
Source Geometry

Aims. We investigate the constraints on the size and location of the X-ray source in 1H 0707–495 determined from the shape of the relativistically smeared reflection from the accretion disc. Methods. We developed a new code to model an extended X-ray source and we applied this code to all archival XMM observations of 1H 0707–495. Results. In contrast to earlier works we find that the relativistic reflection in this source is not consistent with an extended uniform corona. Instead, we find that the X-ray source must be very compact, at most a gravitational radius in size, and located at most a few gravitational radii from the black-hole horizon. A uniform extended corona produces an emissivity that is similar to a twice-broken power-law, but the inner emissivity is fixed by the source geometry rather than being a free parameter. In 1H0707–495, the reflection from the inner disc is much stronger than expected for a uniformly extended source. Including the effect of ionised absorption from the wind does not change this conclusion, but including scattered emission (and more complex absorption) from the wind can dramatically change the reflection parameters.

scholarly journals The AGN Properties of the Starburst Galaxy NGC 7582

2009 ◽  
Vol 5 (S267) ◽  
pp. 134-134
Author(s):  
T. V. Ricci ◽  
J. E. Steiner ◽  
R. B. Menezes ◽  
A. Garcia-Rissmann ◽  
R. Cid-Fernandes
Keyword(s):  
Hot Spots ◽  
Optical Image ◽  
Starburst Galaxy ◽  
Extended Source ◽  
X Ray ◽  
Stellar Component

NGC 7582 was identified as a starburst galaxy in the optical (Veron et al. 1981) but its X-ray emission is typical of a Seyfert 1 galaxy (Ward et al. 1978). We analyzed a datacube on this object obtained with the GMOS-IFU on the Gemini-South telescope. After a subtraction of the stellar component using the starlight code (Cid Fernandes et al. 2005), we looked for optical signatures of the AGN. We detected a broad Hα component (Figure 1) in the source where Bianchi et al. (2007) identified the AGN in an HST optical image. We also found a broad Hβ feature (Figure 2), but its emission reveals a extended source. We suggest that it is the light of the AGN scattered in the ionization cone. We propose that NGC 7582 is a Seyfert 1 galaxy. A number of other “hot-spots” and Wolf–Rayet features were also identified.

scholarly journals A source of gamma rays coincident with the shell of the supernova remnant CTB 80

2021 ◽  
Vol 502 (1) ◽  
pp. 472-477
Author(s):  
M Araya ◽  
C Herrera
Keyword(s):  
Gamma Rays ◽  
Supernova Remnant ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Large Area ◽  
Extended Source ◽  
X Ray ◽  
Extended Radio ◽  
High Energy Emission

ABSTRACT CTB 80 (G69.0+2.7) is a relatively old (50–80 kyr) supernova remnant (SNR) with a complex radio morphology showing three extended radio arms and a radio and X-ray nebula near the location of the pulsar PSR B1951+32. We report on a study of the GeV emission in the region of CTB 80 with Fermi-Large Area Telescope data. An extended source with a size of 1.3°, matching the size of the infrared shell associated to the SNR, was discovered. The GeV emission, detected up to an energy of ∼20 GeV, is more significant at the location of the northern radio arm where previous observations imply that the SNR shock is interacting with ambient material. Both hadronic and leptonic scenarios can reproduce the multiwavelength data reasonably well. The hadronic cosmic ray energy density required is considerably larger than the local Galactic value and the gamma-ray leptonic emission is mainly due to bremsstrahlung interactions. We conclude that GeV particles are still trapped or accelerated by the SNR producing the observed high-energy emission when interacting with ambient material.

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