78 research outputs found
Investigation of CTA 1 with Suzaku Observation
We report on an 105 ks Suzaku observation of the supernova remnant CTA 1
(G119.5+10.2). The Suzaku soft X-ray observation was carried out with both
timing mode and imaging mode. A ~ 10' extended feature, which is interpreted as
a bow-shock component of the pulsar wind nebula (PWN), is revealed in this deep
observation for the first time. The nebular spectrum can be modelled by a
power-law with a photon index of ~ 1.8 which suggests a slow synchrotron
cooling scenario. The photon index is approximately constant across this
extended feature. We compare and discuss our observations of this complex
nebula with previous X-ray investigations. We do not obtain any significant
pulsation from the central pulsar in the soft (0.2-12 keV) and hard (10-60 keV)
X-ray data. The non-detection is mainly due to the loss of the precise imaging
ability to accurately determine the source contribution. The spectra of XIS and
HXD can be directly connected without a significant spectral break according to
our analysis. Future observations of NuSTAR and Astro-H would be able to
resolve the contamination and provide an accurate hard X-ray measurement of CTA
1.Comment: 9 pages, 7 figures, accepted by MNRA
The impact of hyperhidrosis on patients' daily life and quality of life : A qualitative investigation
Background: An understanding of the daily life impacts of hyperhidrosis and how patients deal with them, based on qualitative research, is lacking. This study investigated the impact of hyperhidrosis on the daily life of patients using a mix of qualitative research methods. Methods: Participants were recruited through hyperhidrosis patient support groups such as the Hyperhidrosis Support Group UK. Data were collected using focus groups, interviews and online surveys. A grounded theory approach was used in the analysis of data transcripts. Data were collected from 71 participants, out of an initial 100 individuals recruited. Results: Seventeen major themes capturing the impacts of hyperhidrosis were identified; these covered all areas of life including daily life, psychological well-being, social life, professional /school life, dealing with hyperhidrosis, unmet health care needs and physical impact. Conclusions: Psychosocial impacts are central to the overall impacts of hyperhidrosis, cutting across and underlying the limitations experienced in other areas of life.Peer reviewe
Multi-Wavelength Observations Of A New Redback Millisecond Pulsar 4FGL J1910.7-5320
We present the study of multi-wavelength observations of an unidentified
Fermi Large Area Telescope (LAT) source, 4FGL J1910.7-5320, a new candidate
redback millisecond pulsar binary. In the 4FGL 95% error region of 4FGL
J1910.7-5320, we find a possible binary with a 8.36-hr orbital period from the
Catalina Real-Time Transient Survey (CRTS), confirmed by optical spectroscopy
using the SOAR telescope. This optical source was recently independently
discovered as a redback pulsar by the TRAPUM project, confirming our
prediction. We fit the optical spectral energy distributions of 4FGL
J1910.7-5320 with a blackbody model, inferring a maximum distance of 4.1 kpc by
assuming that the companion fills its Roche-lobe with a radius of R = 0.7R_sun.
Using a 12.6 ks Chandra X-ray observation, we identified an X-ray counterpart
for 4FGL J1910.7-5320, with a spectrum that can be described by an absorbed
power-law with a photon index of 1.0+/-0.4. The spectrally hard X-ray emission
shows tentative evidence for orbital variability. Using more than 12 years of
Fermi-LAT data, we refined the position of the {\gamma}-ray source, and the
optical candidate still lies within the 68% positional error circle. In
addition to 4FGL J1910.7-5320, we find a variable optical source with a
periodic signal of 4.28-hr inside the 4FGL catalog 95% error region of another
unidentified Fermi source, 4FGL J2029.5-4237. However, the {\gamma}-ray source
does not have a significant X-ray counterpart in a 11.7 ks Chandra observation,
with a 3-{\sigma} flux upper limit of 2.4*10^-14 erg cm^-2 s^-1 (0.3-7 keV).
Moreover, the optical source is outside our updated Fermi-LAT 95% error circle.
These observational facts all suggest that this new redback millisecond pulsar
powers the {\gamma}-ray source 4FGL J1910.7-5320 while 4FGL J2029.5-4237 is
unlikely the {\gamma}-ray counterpart to the 4.28-hr variable.Comment: Accepted for publication in Ap
The Greenland Telescope: Antenna Retrofit Status and Future Plans
Since the ALMA North America Prototype Antenna was awarded to the Smithsonian
Astrophysical Observatory (SAO), SAO and the Academia Sinica Institute of
Astronomy & Astrophysics (ASIAA) are working jointly to relocate the antenna to
Greenland. This paper shows the status of the antenna retrofit and the work
carried out after the recommissioning and subsequent disassembly of the antenna
at the VLA has taken place. The next coming months will see the start of the
antenna reassembly at Thule Air Base. These activities are expected to last
until the fall of 2017 when commissioning should take place. In parallel,
design, fabrication and testing of the last components are taking place in
Taiwan
Environmental supply chain management in the seafood industry: past, present and future approaches
This review discusses and analyses previous results in identification, development and implementation of cleaner production strategies within the seafood industry. The relevant peer reviewed articles were identified from a structured keyword search and analysed by both supply chain stage (capture and aquaculture, transport, processing, storage and retail), and examination of the cleaner production strategies implemented. Results found entities along the seafood supply chain generally worked separately to improve cleaner production processes and outputs to grow their own businesses. Whilst this approach can be beneficial, it ignores the broader cleaner production potential benefits gained when applied across multiple supply chain entities. The most effective cleaner production strategies for improved environmental performance in each sector of the supply chain were identified with the potential to reduce unnecessary handling, energy usage, storage costs and waste production. To ensure the greatest reduction in environmental impact, a whole of supply chain management system that incorporates life cycle assessment modelling is recommended
A ring-like accretion structure in M87 connecting its black hole and jet
The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation1,2. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which was interpreted as gravitationally lensed emission around a central black hole3. Here we report images of M87 obtained in 2018, at a wavelength of 3.5 mm, showing that the compact radio core is spatially resolved. High-resolution imaging shows a ring-like structure of [Formula: see text] Schwarzschild radii in diameter, approximately 50% larger than that seen at 1.3 mm. The outer edge at 3.5 mm is also larger than that at 1.3 mm. This larger and thicker ring indicates a substantial contribution from the accretion flow with absorption effects, in addition\ua0to the gravitationally lensed ring-like emission. The images show that the edge-brightened jet connects to the accretion flow of the black hole. Close to the black hole, the emission profile of the jet-launching region is wider than the expected profile of a black-hole-driven jet, suggesting the possible presence of a wind associated with the accretion flow
A Ring-Like Accretion Structure in M87 Connecting Its Black Hole and Jet
The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation1,2. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which was interpreted as gravitationally lensed emission around a central black hole3. Here we report images of M87 obtained in 2018, at a wavelength of 3.5 mm, showing that the compact radio core is spatially resolved. High-resolution imaging shows a ring-like structure of 8.4+0.5−1.1 Schwarzschild radii in diameter, approximately 50% larger than that seen at 1.3 mm. The outer edge at 3.5 mm is also larger than that at 1.3 mm. This larger and thicker ring indicates a substantial contribution from the accretion flow with absorption effects, in addition to the gravitationally lensed ring-like emission. The images show that the edge-brightened jet connects to the accretion flow of the black hole. Close to the black hole, the emission profile of the jet-launching region is wider than the expected profile of a black-hole-driven jet, suggesting the possible presence of a wind associated with the accretion flow
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