81 research outputs found
Radio-continuum observations of a giant radio source QSO J0443.8-6141
We report the discovery of a giant double-lobed (lobe-core-lobe)
radio-continuum structure associated with QSO J0443.8-6141 at z=0.72. This
QSO was originally identified during the follow-up of a sample of ROSAT All
Sky Survey sources at radio and optical frequencies. With a linear size of
~0.77 Mpc, QSO J0443.8-6141 is classified as a giant radio source (GRS);
based on its physical properties, we classify QSO J0443.8-6141 as a FR II
radio galaxy. High-resolution observations are required to reliably identify
GRSs; the next generation of southern sky radio and optical surveys will be
crucial to increasing our sample of these objects
Rise in 2017-2018 measles morbidity in Serbia and northwest Russia
In 2017, the WHO registered 23,927 measles cases in 44 out of 53 countries in the European region. In 2018, measles incidence rate increased up to 82,599 cases registered in 48 countries of the region, with a large number of measles-associated deaths. Overall, 72 measles fatalities were registered in 10 European countries, including Serbia (15 cases). Aim of the study: to characterize 2017-2018 epidemiological upsurge of measles incidence rate observed in the Republic of Serbia (RS) and the Northwestern Federal District (NWFD) of the Russian Federation. Materials and methods. During the 2017-2018 season, 944 serum samples were collected from patients with measles, rubella, or exanthematous diseases in the NWFD and tested in the Laboratory of Virology at the St. Petersburg Regional Centre for Measles Surveillance (SPbRC). In 2017-2018, 2,946 serum samples from the Republic of Serbia were analyzed in the SPbRC by using ELISA with IgM measles test system (Vector-Best, Russia; or Siemens, Germany). Urine and swab samples were examined by RT-PCR and used for isolation and genotyping of measles viruses. Results. From 2017 to 2018, 5,798 measles cases were registered in the RS, among which 2,946 were laboratory-confirmed (serological testing and/or PCR). Unvaccinated subjects or those with unknown vaccination status accounted for majority of the cases. Children under 5 years of age and adults aged 30 years and over dominated among measles patients. During this season, 15 deaths were reported. Several genotypes of measles virus circulated in the RS, e.g. B3 Dublin, D8 Gir Somnath, and D8 Herborn. In 2018, 109 measles cases were recorded in the NWFD, 5 of which were imported from abroad. Among patients, adults comprised 64.2%, wherein 74.3% were covered by unvaccinated subjects or those with unknown vaccination status. Rise in measles incidence rate linked to multiple importations of various measles virus genotypes: B3 Kabul; B3 Dublin; D8 Frankfurt; D8 Cambridge; and D8 Gir Somnath
Two evolved supernova remnants with newly identified Fe-rich cores in the Large Magellanic Cloud*
Aims. We present a multi-wavelength analysis of the evolved supernova remnants MCSNR J0506−7025 and MCSNR J0527−7104 in the Large Magellanic Cloud.
Methods. We used observational data from XMM-Newton, the Australian Telescope Compact Array, and the Magellanic Cloud Emission Line Survey to study their broad-band emission and used Spitzer and H i data to gain a picture of the environment into which the remnants are expanding. We performed a multi-wavelength morphological study and detailed radio and X-ray spectral analyses to determine their physical characteristics.
Results. Both remnants were found to have bright X-ray cores, dominated by Fe L-shell emission, which is consistent with reverse shock-heated ejecta with determined Fe masses in agreement with Type Ia explosion yields. A soft X-ray shell, which is consistent with swept-up interstellar medium, was observed in MCSNR J0506−7025, suggestive of a remnant in the Sedov phase. Using the spectral fit results and the Sedov self-similar solution, we estimated the age of MCSNR J0506−7025 to be ~16−28 kyr, with an initial explosion energy of (0.07−0.84) × 1051 erg. A soft shell was absent in MCSNR J0527−7104, with only ejecta emission visible in an extremely elongated morphology that extends beyond the optical shell. We suggest that the blast wave has broken out into a low density cavity, allowing the shock heated ejecta to escape. We find that the radio spectral index of MCSNR J0506−7025 is consistent with the standard −0.5 for supernova remnants. Radio polarisation at 6 cm indicates a higher degree of polarisation along the western front and at the eastern knot with a mean fractional polarisation across the remnant of P ≅ (20 ± 6)%.
Conclusions. The detection of Fe-rich ejecta in the remnants suggests that both resulted from Type Ia explosions. The newly identified Fe-rich cores in MCSNR J0506−7025 and MCSNR J0527−7104 make them members of the expanding class of evolved Fe-rich remnants in the Magellanic Clouds
An analysis of the FIR/RADIO Continuum Correlation in the Small Magellanic Cloud
The local correlation between far-infrared (FIR) emission and radio-continuum
(RC) emission for the Small Magellanic Cloud (SMC) is investigated over scales
from 3 kpc to 0.01 kpc. Here, we report good FIR/RC correlation down to ~15 pc.
The reciprocal slope of the FIR/RC emission correlation (RC/FIR) in the SMC is
shown to be greatest in the most active star forming regions with a power law
slope of ~1.14 indicating that the RC emission increases faster than the FIR
emission. The slope of the other regions and the SMC are much flatter and in
the range of 0.63-0.85. The slopes tend to follow the thermal fractions of the
regions which range from 0.5 to 0.95. The thermal fraction of the RC emission
alone can provide the expected FIR/RC correlation. The results are consistent
with a common source for ultraviolet (UV) photons heating dust and Cosmic Ray
electrons (CRe-s) diffusing away from the star forming regions. Since the CRe-s
appear to escape the SMC so readily, the results here may not provide support
for coupling between the local gas density and the magnetic field intensity.Comment: 19 pages, 7 Figure
Optical Spectra of SNR Candidates in NGC 300
We present moderate-resolution (<5A) long-slit optical spectra of 51 nebular
objects in the nearby Sculptor Group galaxy NGC 300 obtained with the 2.3 meter
Advanced Technology Telescope at Siding Spring Observatory, Australia. Adopting
the criterion of [SII]/Ha>=0.4 to confirm supernova remnants (SNRs) from
optical spectra, we find that of 28 objects previously proposed as SNRs from
optical observations, 22 meet this criterion with six showing [SII]/Ha of less
than 0.4. Of 27 objects suggested as SNRs from radio data, four are associated
with the 28 previously proposed SNRs. Of these four, three (included in the 22
above) meet the criterion. In all, 22 of the 51 nebular objects meet the
[SII]/Ha criterion as SNRs while the nature of the remaining 29 objects remains
undetermined by these observations.Comment: Accepted for publication in Astrophysics & Space Scienc
ALMA CO Observations of Gamma-Ray Supernova Remnant N132D in the Large Magellanic Cloud:Possible Evidence for Shocked Molecular Clouds Illuminated by Cosmic-Ray Protons
Hydrocortisone release from tablets based on bioresorbable poly(ether-ester-urethane)s
The Mopra Southern Galactic Plane CO Survey-data release 4-complete survey
We present observations of the Mopra carbon monoxide (CO) survey of the Southern Galactic Plane, covering Galactic longitudes spanning
l = 250◦ (−110◦) to l = 355◦ (−5◦), with a latitudinal coverage of at least |b| 210 deg2. These data have been
taken at 0.6 arcmin spatial resolution and 0.1 km s−1 spectral resolution, providing an unprecedented view of the molecular gas clouds of
the Southern Galactic Plane in the 109–115 GHz J = 1 − 0 transitions of 12CO, 13CO, C18O, and C17O.K. O. Cubuk ... G. Rowell ... et al
Letter of interest for a neutrino beam from Protvino to KM3NeT/ORCA
The Protvino accelerator facility located in the Moscow region, Russia, is in a good position to offer a rich experimental research program in the field of neutrino physics. Of particular interest is the possibility to direct a neutrino beam from Protvino towards the KM3NeT/ORCA detector, which is currently under construction in the Mediterranean Sea 40 km offshore Toulon, France. This proposal is known as P2O. Thanks to its baseline of 2595 km, this experiment would yield an unparalleled sensitivity to matter effects in the Earth, allowing for the determination of the neutrino mass ordering with a high level of certainty after only a few years of running at a modest beam intensity of ≈ 90 kW. With a prolonged exposure (≈1500 kWyear), a 2σ sensitivity to the leptonic CP-violating Dirac phase can be achieved. A second stage of the experiment, comprising a further intensity upgrade of the accelerator complex and a densified version of the ORCA detector (Super-ORCA), would allow for up to a 6σ sensitivity to CP violation and a 10º−17º resolution on the CP phase after 10 years of running with a 450 kW beam, competitive with other planned experiments. The initial composition and energy spectrum of the neutrino beam would need to be monitored by a near detector, to be constructed several hundred meters downstream from the proton beam target. The same neutrino beam and near detector set-up would also allow for neutrino-nucleus cross section measurements to be performed. A short-baseline sterile neutrino search experiment would also be possible
Unexpected circular radio objects at high Galactic latitude
Large scale structure and cosmolog
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