RULING OUT IC/CMB X-RAYS IN PKS 0637-752 AND THE IMPLICATIONS FOR TEV EMISSION FROM LARGE-SCALE QUASAR JETS

We consider the emission processes in the large-scale jets of powerful quasars based on the results obtained with the VLA, Spitzer, Hubble, and Chandra. We show that two archetypal jets, 3C 273 and PKS 1136–135, have two distinct spectral components on large-scales: (1) the low-energy (LE) synchrotron spectrum extending from radio to infrared, and (2) the high-energy (HE) component arising from optical and extending to X-rays. The X-ray emission in quasar jets is often attributed to inverse-Compton scattering of cosmic microwave background (CMB) photons by radio-emitting electrons in a highly relativistic jet. However, recent data prefer synchrotron radiation by a second distinct electron population as the origin of the HE component. We anticipate that optical polarimetry with Hubble will establish the synchrotron nature of the HE component. Gamma-ray observations with GLAST (renamed as the Fermi Gamma-ray Space Telescope), as well as future TeV observations, are expected to place important constraints on the jet models.

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CrisDi School: disseminating crystallography in Piedmont, Italy

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314087221 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C1277-C1277

Author(s):

Domenica Marabello ◽

Angelo Agostino ◽

Piera Benna ◽

Giovanna Dinardo ◽

Carlo Lamberti ◽

...

Keyword(s):

Large Scale ◽

Kinetic Studies ◽

Research Centre ◽

Main Task ◽

X Rays ◽

X Ray Diffraction ◽

Time Resolved ◽

New Methodologies ◽

The University ◽

Basic Level

The Interdepartmental Research Centre for the Development of Crystallography (CrisDi) aims to be an institution of reference for researchers at the University of Turin interested on the field of diffraction (X-rays, neutrons and electrons), to promote the knowledge and dissemination of crystallography, and to facilitate the access to available laboratory instrumentation (diffractometers and TEM) and to large scale facilities (synchrotron and neutron sources). CrisDi hosts scientists with interest in the fields of solid state chemistry and physics, organic, inorganic, organometallic and theoretical chemistry, mineralogy, biology, pharmaceutical and agricultural sciences. The Centre encourages the design and the development of new methodologies and applications, and supports the enhancement of the available instruments. The submission of proposals at large scale instruments is encouraged specially for young researchers and PhD students. The cultural and scientific interchange among crystallographers coming from different disciplines is strongly encouraged by CrisDi. A main task of the CrisDi is the annual organization of a post-grade level School with a series of courses dedicated to: (i) basic level crystallography (symmetry, theory of diffraction, crystal-chemistry), diffraction techniques (single crystal and powder X-ray diffraction, neutron and electron scattering); (ii) advanced level (high temperature and high pressure structural studies, macromolecular crystallography, time resolved crystallography and kinetic studies); (iii) spectroscopic approaches (XAFS, XANES, XES and NMR) in crystallography. The school, which is held every year in May for about 20 ECTS equivalent, has no tuition fees and is also open to non-academia people.

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A young and obscured AGN embedded in the giant radio galaxy Mrk 1498

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2265 ◽

2019 ◽

Cited By ~ 3

Author(s):

L Hernández-García ◽

F Panessa ◽

L Bassani ◽

G Bruni ◽

F Ursini ◽

...

Keyword(s):

Large Scale ◽

Radio Galaxy ◽

Conclusive Evidence ◽

X Rays ◽

Nuclear Activity ◽

X Ray ◽

Multi Wavelength ◽

Tidal Streams ◽

A Minor ◽

Extended Emission

Abstract Mrk 1498 is part of a sample of galaxies with extended emission line regions (extended outwards up to a distance of ∼7 kpc) suggested to be photo-ionized by an AGN that has faded away or that is still active but heavily absorbed. Interestingly, the nucleus of Mrk 1498 is at the center of two giant radio lobes with a projected linear size of 1.1 Mpc. Our multi-wavelength analysis reveals a complex nuclear structure, with a young radio source (Giga-hertz Peaked Spectrum) surrounded by a strong X-ray nuclear absorption, a mid-infrared spectrum that is dominated by the torus emission, plus a circum-nuclear extended emission in the [OIII] image (with radius of ∼ 1 kpc), most likely related to the ionization of the AGN, aligned with the small and large scale radio jet and extended also at X-rays. In addition a large-scale extended emission (up to ∼ 10 kpc) is only visible in [OIII]. These data show conclusive evidence of a heavily absorbed nucleus and has recently restarted its nuclear activity. To explain its complexity, we propose that Mrk 1498 is the result of a merging event or secular processes, such as a minor interaction, that has triggered the nuclear activity and produced tidal streams. The large-scale extended emission that gives place to the actual morphology could either be explained by star formation or outflowing material from the AGN.

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Worsening bone scan in the evaluation of antitumor response during hormonal therapy of breast cancer.

Journal of Clinical Oncology ◽

10.1200/jco.1995.13.5.1123 ◽

1995 ◽

Vol 13 (5) ◽

pp. 1123-1128 ◽

Cited By ~ 82

Author(s):

C L Vogel ◽

J Schoenfelder ◽

I Shemano ◽

D F Hayes ◽

R A Gams

Keyword(s):

Breast Cancer ◽

Disease Progression ◽

Retrospective Analysis ◽

Hormonal Therapy ◽

Bone Scan ◽

Large Scale ◽

Response To Therapy ◽

X Rays ◽

Cancer Trial ◽

Radiology Reports

PURPOSE Scintigraphic flare in association with response to therapy has been well described in the medical literature. During the course of a recent breast cancer trial, it became apparent that several patients with worsening bone scan but no other clinical evidence of disease progression might have potentially benefited from continued therapy, but had therapy discontinued. A retrospective analysis of this issue was performed to assess the magnitude and scope of this problem. MATERIALS AND METHODS A total of 648 patients with hormone receptor-positive or unknown advanced breast cancer were treated as part of a large-scale trial of first-line hormonal therapy. Patients were assessed for response to therapy, including response duration, progression-free interval (PFI), overall survival, and quality of life. The retrospective analysis presented here was performed to assess whether patients with a possible scintigraphic flare within the first 16 weeks of therapy might have had therapy discontinued prematurely due to a worsening bone scan attributable to tumor flare, rather than due to disease progression. RESULTS Analysis of the hormonal trial showed that of 376 assessable patients 108 (29%) with bone disease had a possible scintigraphic flare by week 8 or 16 of the trial, based on data on the case report forms and radiology reports (bone scans and x-rays). Of these, 69 patients (64%) were continued on study therapy, which resulted in clinical benefit in 50 (72%) of those patients. In contrast, 39 patients (36%) with possible scintigraphic flare were removed from the trial. CONCLUSION We conclude that changes in bone scintigraphy that mimic progressive disease early in the course of hormonal treatment of patients with breast cancer metastatic to bone may represent scintigraphic flare associated with response. Thus, clinicians must be cognizant of the phenomenon of scintigraphic flare to avoid premature discontinuation of a potentially beneficial treatment.

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Large Scale Jets in Class I and Class II Radio Sources and Quasars

Highlights of Astronomy ◽

10.1017/s1539299600008078 ◽

1989 ◽

Vol 8 ◽

pp. 409-416

Author(s):

G.V. Bicknell

Keyword(s):

Interstellar Medium ◽

Surface Brightness ◽

Large Scale ◽

External Medium ◽

Class Ii ◽

Class I ◽

Radio Sources ◽

Speed Of Light ◽

Slow Surface ◽

Quasar Jets

ABSTRACTThe physics of large scale jets in class I and class II extragalactic radio sources and quasars is discussed. Class I jets appear to be turbulent, transonic jets which entrain the interstellar medium. The related jet deceleration causes a slow surface brightness decline which is usually observed. Class II jets are supersonic and terminate in an advancing shock against the external medium. Both types of jet are initially light but the ratio of jet density to external density of class I jets increases owing to entrainment. It is quite plausible that quasar jets are hypersonic and light and this may solve problems of confinement. The velocities of class I jets are of the order of a few thousand kilometers per second. Class II and quasar jets may be at least mildly relativistic. However, it is not clear whether the velocities of large scale jets in powerful sources are close to the speed of light. Recent depolarization measurements provide an interesting focus for discussion of this question.

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SPINE-compatible `carboloops': a new microshaped vitreous carbon sample mount for X-ray and neutron crystallography

Acta Crystallographica Section F Structural Biology Communications ◽

10.1107/s2053230x14005901 ◽

2014 ◽

Vol 70 (5) ◽

pp. 681-684 ◽

Cited By ~ 3

Author(s):

Filippo Romoli ◽

Estelle Mossou ◽

Maxime Cuypers ◽

Peter van der Linden ◽

Philippe Carpentier ◽

...

Keyword(s):

Large Scale ◽

Production Quality ◽

Vitreous Carbon ◽

Scale Production ◽

X Rays ◽

Macromolecular Crystallography ◽

X Ray ◽

Large Scale Production ◽

Custom Design ◽

High Standards

A novel vitreous carbon mount for macromolecular crystallography, suitable for neutron and X-ray crystallographic studies, has been developed. The technology described here is compatible both with X-ray and neutron cryo-crystallography. The mounts have low density and low background scattering for both neutrons and X-rays. They are prepared by laser cutting, allowing high standards of production quality, the ability to custom-design the mount to specific crystal sizes and large-scale production.

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P183 Osteitis condensans ilii or axial spondyloarthritis: a diagnostic challenge!

Rheumatology ◽

10.1093/rheumatology/keab247.178 ◽

2021 ◽

Vol 60 (Supplement_1) ◽

Author(s):

Sadaf Saeed ◽

Muhammad Safwan Jamal ◽

Dave Ostry ◽

Graham Robinson ◽

Rajiv Sengupta

Keyword(s):

Large Scale ◽

Axial Spondyloarthritis ◽

Cancer Surveillance ◽

Imaging Features ◽

X Rays ◽

Electronic Patient Records ◽

Diagnostic Challenge ◽

Pet Ct ◽

Initial Imaging ◽

Osteitis Condensans Ilii

Abstract Background/Aims Osteitis condensans ilii (OCI) is a rare cause of chronic non-inflammatory axial lower back pain. It has become an important differential diagnosis of axial spondyloarthritis. Bone marrow oedema can be present in 48% of patients. Although 'aunt minnie' appearance on MRI is pathognomonic, specialised imaging like SPECT/PET CT can be considered in difficult cases to confirm the diagnosis. We reviewed case notes of patients with incidental diagnosis of OCI on imaging and followed their clinical progression to see if the diagnosis was modified later. Methods Retrospective radiological database analysis was performed to find imaging reported as OCI or osteitis from 2015-2020. Electronic patient records were analyzed and data was compiled through Microsoft Excel. Results Data from 24 patients was reviewed. Most patients were females (91.7%), with a median age of 43 years (range 19-79 years). CT and MRI were the chief modalities of imaging (46% and 38% respectively) while 20% had plain x-rays of the pelvis. The main indications for imaging were pelvic or hip girdle pain (58.3%), cancer surveillance (25%), abdominal pain (6%), and infection (6%). 20% had an underlying rheumatological diagnosis of which 8% had spondyloarthritis. 12.5% of patients had seronegative features of spondyloarthritis and 8.3% were HLA B27 positive. Approximately 40% of patients were seen by the Rheumatology team for further assessment after imaging and 12.5% of patients were diagnosed with axial spondyloarthritis and remained under follow-up. Conclusion OCI can mimic sacroiliitis on imaging. Although only a minority of patients with OCI reported on initial imaging were subsequently diagnosed with axial spondyloarthritis, thorough clinical assessment and multidisciplinary discussion can reduce the chance of a missed axial spondyloarthritis diagnosis. Further large-scale studies are required to find the exact incidence of spondyloarthritis in patients with imaging features of OCI. Disclosure S. Saeed: None. M. Jamal: None. D. Ostry: None. G. Robinson: None. R. Sengupta: None.

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The Munich Compact Light Source: initial performance measures

Journal of Synchrotron Radiation ◽

10.1107/s160057751600967x ◽

2016 ◽

Vol 23 (5) ◽

pp. 1137-1142 ◽

Cited By ~ 65

Author(s):

Elena Eggl ◽

Martin Dierolf ◽

Klaus Achterhold ◽

Christoph Jud ◽

Benedikt Günther ◽

...

Keyword(s):

Light Source ◽

Large Scale ◽

Source Size ◽

Relativistic Electrons ◽

X Rays ◽

Beam Hardening ◽

X Ray ◽

Inverse Compton Scattering ◽

Inverse Compton ◽

Compact Light Source

While large-scale synchrotron sources provide a highly brilliant monochromatic X-ray beam, these X-ray sources are expensive in terms of installation and maintenance, and require large amounts of space due to the size of storage rings for GeV electrons. On the other hand, laboratory X-ray tube sources can easily be implemented in laboratories or hospitals with comparatively little cost, but their performance features a lower brilliance and a polychromatic spectrum creates problems with beam hardening artifacts for imaging experiments. Over the last decade, compact synchrotron sources based on inverse Compton scattering have evolved as one of the most promising types of laboratory-scale X-ray sources: they provide a performance and brilliance that lie in between those of large-scale synchrotron sources and X-ray tube sources, with significantly reduced financial and spatial requirements. These sources produce X-rays through the collision of relativistic electrons with infrared laser photons. In this study, an analysis of the performance, such as X-ray flux, source size and spectra, of the first commercially sold compact light source, the Munich Compact Light Source, is presented.

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X-rays from magnetic massive OB stars

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314002427 ◽

2013 ◽

Vol 9 (S302) ◽

pp. 330-333

Author(s):

V. Petit ◽

D. H. Cohen ◽

Y. Nazé ◽

M. Gagné ◽

R. H. D. Townsend ◽

...

Keyword(s):

Magnetic Fields ◽

Large Scale ◽

Massive Stars ◽

Magnetic Activity ◽

Magnetic Characteristics ◽

Driving Mechanism ◽

X Rays ◽

X Ray ◽

Ob Stars ◽

Strong Winds

AbstractThe magnetic activity of solar-type and low-mass stars is a well known source of coronal X-ray emission. At the other end of the main sequence, X-rays emission is instead associated with the powerful, radiatively driven winds of massive stars. Indeed, the intrinsically unstable line-driving mechanism of OB star winds gives rise to shock-heated, soft emission (~0.5 keV) distributed throughout the wind. Recently, the latest generation of spectropolarimetric instrumentation has uncovered a population of massive OB-stars hosting strong, organized magnetic fields. The magnetic characteristics of these stars are similar to the apparently fossil magnetic fields of the chemically peculiar ApBp stars. Magnetic channeling of these OB stars' strong winds leads to the formation of large-scale shock-heated magnetospheres, which can modify UV resonance lines, create complex distributions of cooled Halpha emitting material, and radiate hard (~2-5 keV) X-rays. This presentation summarizes our coordinated observational and modelling efforts to characterize the manifestation of these magnetospheres in the X-ray domain, providing an important contrast between the emission originating in shocks associated with the large-scale fossil fields of massive stars, and the X-rays associated with the activity of complex, dynamo-generated fields in lower-mass stars.

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Field of researches and applications domains for compact and large-scale DPF devices: Current assets, problems and essentials

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194514603147 ◽

2014 ◽

Vol 32 ◽

pp. 1460314

Author(s):

V. A. Gribkov

Keyword(s):

Large Scale ◽

Intermediate Energy ◽

X Rays ◽

Intermediate Energies ◽

Low Energies ◽

Plasma Diode ◽

Radiation Material ◽

Dynamic Quality ◽

Very High ◽

Radiation Material Science

Examination of the most important processes taking place in Dense Plasma Focus (DPF) device that lead to the production of very bright flashes of neutrons and X-rays is presented. It is shown that the current abruption (CA) phenomenon accompanied by the plasma-diode formation plays the key role in these events. Issues of matching of different primary loads with plasma inductive storage and subsequently with plasma diode are discussed. It is shown that at the intermediate energies it is possible to attain the perfect matching. Results in some applications of medium-sized DPF obtained recently in radiation material science, dynamic quality control, biology and medicine are presented. It is shown that for better matching at very high energies the classical intermediate energy compressing element can be used. Besides schemes with laser support switching are discussed. Extrapolations of DPF phenomena to very high and very low energies with their feasibility are examined. Envisioned applications of such huge and tiny DPF devices in power production, medicine and electronics are discussed.

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