bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autopsy of the Supernova Remnant Cassiopeia A
Authors: Milisavljevic Dan , Fesen Robert A. 
Published: January 2014

AbstractThree-dimensional kinematic reconstructions of optically emitting ejecta in the young Galactic supernova remnant Cassiopeia A (Cas A) are discussed. The reconstructions encompass the remnant's faint outlying ejecta knots, including the exceptionally high-velocity NE and SW streams of debris often referred to as ‘jets’. The bulk of Cas A's ejecta are arranged in several circular rings with diameters between approximately 30″ (0.5 pc) and 2′ (2 pc). We suggest that similar large-scale ejecta rings may be a common phenomenon of young core-collapse remnants and may explain lumpy emission line profile substructure sometimes observed in spectra of extragalactic core-collapse supernovae years after explosion. A likely origin for these large ejecta rings is post-explosion input of energy from plumes of radioactive 56Ni-rich ejecta that rise, expand, and compress non-radioactive material to form bubble-like structures.
Observations and discoveries of supernova remnants with GMRT
Authors: Roy Subhashis , Pal Sabyasachi 
Published: January 2014

AbstractWe have measured HI absorption distance to the youngest Galactic supernova remnant G1.9+0.3. Absorption by known anomalous velocity features near the Galactic centre (GC) puts a lower limit on its distance from Sun as 10 kpc, 2 kpc further away from the GC. We have found a small diameter (1.6′) shell like structure G354.4+0.0, that shows polarised emission in the NVSS. Based on its morphology, angular size, HI distance and its spectrum between 1.4 GHz and 330 MHz, it is perhaps the second youngest SNR in the Galaxy that is expanding in a dense environment of an HII region surrounding it. Our pilot observation of the inner Galactic 4th quadrant within 337° < l < 354° with a fixed Galactic latitude of 0.37° has confirmed G345.1−0.2 as an SNR.
Infrared [Fe II] and Dust Emissions from Supernova Remnants
Authors: Koo Bon-Chul 
Published: January 2014

AbstractSupernova remnants (SNRs) are strong thermal emitters of infrared radiation. The most prominent lines in the near-infrared spectra of SNRs are [Fe II] lines. The [Fe II] lines are from shocked dense atomic gases, so they trace SNRs in dense environments. After briefly reviewing the physics of the [Fe II] emission in SNR shocks, I describe the observational results which show that there are two groups of SNRs bright in [Fe II] emission: middle-aged SNRs interacting with molecular clouds and young core-collapse SNRs in dense circumstellar medium. The SNRs belonging to the former group are also bright in near-infrared H2 emission, indicating that both atomic and molecular shocks are pervasive in these SNRs. The SNRs belonging to the latter group have relatively small radii in general, implying that most of them are likely the remnants of SN IIL/b or SN IIn that had strong mass loss before the explosion. I also comment on the “[Fe II]-H2 reversal” in SNRs and on using the [Fe II]-line luminosity as an indicator of the supernova (SN) rate in galaxies. In the mid- and far-infrared regimes, thermal dust emission is dominant. The dust in SNRs can be heated either by collisions with gas species in a hot plasma or by radiation from a shock front. I discuss the characteristics of the infrared morphology of the SNRs interacting with molecular clouds and their dust heating processes. Finally, I give a brief summary of the detection of SN dust and crystalline silicate dust in SNRs.
Thermal X-ray Spectra of Supernova Remnants
Authors: Slane Patrick 
Published: January 2014

AbstractThe fast shocks that characterize supernova remnants heat circumstellar and ejecta material to extremely high temperatures, resulting in significant X-ray emission. The X-ray spectrum from an SNR carries a wealth of information about the temperature and ionization state of the plasma, the density distribution of the postshock material, and the composition of the ejecta. This, in turn, places strong constraints on the properties of the progenitor star, the explosive nucleosynthesis that produced the remnant, the properties of the environment into which the SNR expands, and the effects of particle acceleration on its dynamical evolution. Here I present results from X-ray studies SNRs in various evolutionary states, and highlight key results inferred from the thermal emission.
Supernovae driven galactic outflows
Authors: Nath Biman B. 
Published: January 2014

AbstractOutflows from galaxies play a crucial role in the evolution of galaxies and also affect the surrounding medium. The standard scenario of explaining these outflows with the help of supernovae driven wind has recently come under criticism, and other processes such as radiation pressure and cosmic-rays have been invoked. We examine the relative importance of supernovae as the driving mechanism of galactic outflows in light of these competing processes.
Fermi-LAT and WMAP observations of the supernova remnant Puppis A
Authors: Grondin Marie-Hélène , Hewitt John W. , Lemoine-Goumard Marianne , Reposeur Thierry ,   for the Fermi-LAT collaboration
Published: January 2014

AbstractThe supernova remnant (SNR) Puppis A (aka G260.4-3.4) is a middle-aged supernova remnant, which displays increasing X-ray surface brightness from West to East corresponding to an increasing density of the ambient interstellar medium at the Eastern and Northern shell. The dense IR photon field and the high ambient density around the remnant make it an ideal case to study in γ-rays. Gamma-ray studies based on three years of observations with the Large Area Telescope (LAT) aboard Fermi have revealed the high energy gamma-ray emission from SNR Puppis A. The γ-ray emission from the remnant is spatially extended, and nicely matches the radio and X-ray morphologies. Its γ-ray spectrum is well described by a simple power law with an index of ~2.1, and it is among the faintest supernova remnants yet detected at GeV energies. To constrain the relativistic electron population, seven years of Wilkinson Microwave Anisotropy Probe (WMAP) data were also analyzed, and enabled to extend the radio spectrum up to 93 GHz. The results obtained in the radio and γ-ray domains are described in detail, as well as the possible origins of the high energy γ-ray emission (Bremsstrahlung, Inverse Compton scattering by electrons or decay of neutral pions produced by proton interactions).
Probing the effects of hadronic acceleration at the SN 1006 shock front
Authors: Miceli Marco , Bocchino F. , Decourchelle A. , Maurin G. , Vink J. , Orlando S. , Reale F. , Broersen S. 
Published: January 2014

AbstractSupernova remnant shocks are strong candidates for being the source of energetic cosmic rays and hadron acceleration is expected to increase the shock compression ratio, providing higher post-shock densities. We exploited the deep observations of the XMM-Newton Large Program on SN 1006 to verify this prediction. Spatially resolved spectral analysis led us to detect X-ray emission from the shocked ambient medium in SN 1006 and to find that its density significantly increases in regions where particle acceleration is efficient. Our results provide evidence for the effects of acceleration of cosmic ray hadrons on the post-shock plasma in supernova remnants.
Three-dimensional simulations of the expanding remnant of SN 1987A
Authors: Potter Toby , Staveley-Smith Lister , Kirk John , Reville Brian , Bicknell Geoff , Sutherland Ralph , Wagner Alexander , Zanardo Giovanna 
Published: January 2014

AbstractSNR 1987A is the expanding remnant from the brightest supernova since the invention of the telescope. The remnant has been monitored extensively in the radio at variety of wavelengths and provides a wealth of data on which to base a simulation. Questions to be answered include estimating the efficiency of particle acceleration at shock fronts, determining the cause of the one-sided radio morphology for SNR 1987A and investigating the gas properties of the pre-supernova environment. We attempt to address these questions using a fully three-dimensional model of SNR 1987A.
Optical observations of supernova 2012aw
Authors: Bose Subhash , Kumar Brijesh , Sutaria Firoza , Roy Rupak , Kumar Brajesh , Bhatt Vijay K. , Chakraborti Sayan 
Published: January 2014

AbstractWe present optical UBVRI photometric and low-resolution spectroscopic follow-up observations of a type II SN 2012aw in a nearby (~10 Mpc) galaxy M95 during 4 to 270 days post-explosion. The evolution characteristics of optical brightness and color are found to have striking similarity with the archetypal type IIP SN 1999em. The mid-plateau MV is −16.7 mag and the ejected nickel mass is ~0.06 M⊙. The presence and evolution of optical spectral features during 7d to 104d are also similar to SN 1999em as well as other normal type IIP events. The mid-plateau photospheric velocity is around 4200 km s−1 which is same as that of SN 2004et at similar phases, indicating similar energy of explosion i.e. 2 × 1051 erg s−1.
Using the environment to understand supernova properties
Authors: Galbany Lluís , Stanishev Vallery , Mourão Ana 
Published: January 2014

AbstractWe present three studies that use supernova (SN) environments within host galaxies (HGs) to constrain SNe properties. These studies are ordered from an indirect approximation to a direct determination of the environmental parameters of the SN. We find correlations between the galactocentric distance and several parameters measured from both the SN light-curve (LC) and the host galaxy spectroscopy. We are able to recover and strength previous results pointing to a sequence on the progenitor mass of different SN types. We also confirm no significant difference in the elemental abundances of the environment where different SN types exploded, measured with a more powerful technique such as Integral Field Spectroscopy (IFS).
Multi-band optical light-curve behavior of core-collapse supernovae
Authors: Kumar Brijesh 
Published: January 2014

AbstractWe present survey results obtained from the UBVRI optical photometric follow-up of 19 bright core-collapse SNe during 2002-2012 using 1-m class optical telescopes operated by the Aryabhatta Research Institute of Observational Science (acronym ARIES), Nainital India. This homogeneous set of data have been used to study behavior of optical light/color curve, and to gain insight into objet-to-object peculiarity. We derive integrated luminosities for types IIP, Ibc and luminous SNe. Two peculiar type IIP events having photometric properties similar to normal IIP and spectroscopic properties similar to sub-lumnious IIP have been identified.
A comparative study of GRB-Supernovae
Authors: Resmi Lekshmi , Misra Kuntal 
Published: January 2014

AbstractOptical afterglow observations hold the indirect key to type-Ic Supernovae associated with Gamma Ray Bursts. In several cases where there is no spectroscopic confirmation available, presence of the supernova is inferred from the red bump seen in late afterglow light-curves. We do extensive afterglow modeling to extract the supernova contribution as residue. We compare the residual lightcurves of Supernovae associated with GRB041006, GRB030329, GRB050525A and GRB090618.
An XMM-Newton study of the mixed-morphology supernova remnant W28
Authors: Zhou Ping , Safi-Harb Samar , Chen Yang , Zhang Xiao 
Published: January 2014

AbstractWe perform an XMM-Newton study of the mixed-morphology supernova remnant (MMSNR) W28. The X-ray spectrum arising from the northeastern shell consists of a thermal component plus a non-thermal power-law component with a hard photon index (~1.5). Non-thermal bremsstrahlung is the most favourible origin of the hard X-ray emission. The gas in the SNR interior is centrally peaked and best described by a two-temperature thermal model. We found a non-uniform absorption column density and temperature profile for the central gas, indicating that the remnant is evolving in a non-uniform environment with denser material in the east. We argue that the cloudlet evaporation is an indispensable process to explain both the spectral properties and the clumpiness in the X-ray emission.
Kinematic Distances of SNRs W44 and 3C 391
Authors: Su Hongquan , Tian Wenwu , Zhu Hui , Xiang F. Y. 
Published: January 2014

AbstractWe extracted the neutral hydrogen absorption spectra of supernova remnants W44 (G34.7-0.4) and 3C 391 (G31.9+0.0) from the VLA Galactic Plane Survey data. The revised distance of W41 is about 3.3 kpc replacing the previous 3.0 kpc. Further, we confined the distance of G31.9+0.0 to about 7.2 kpc due to its interaction with its surrounding molecular clouds.
A combined GMRT/CLFST image of IC443 at 150 MHz
Authors: Mitra D. , Green D. A. , Rao A. Pramesh 
Published: January 2014

AbstractIC443 is a relatively large Galactic (≈45 arcmin) SNR with a high radio surface brightness. It has fine scale structure down to arcsec scales, and so is difficult to image on all angular scales with a single instrument. Here observations of IC443 at 151 MHz made with both the GMRT and the CLFST are combined to give a composite image of IC443 on all scales from >45 arcmin down to ≈20 arcsec.
Fast-Expanding Hi Shells Associated with Supernova Remnants in the I-GALFA Survey
Authors: Park Geumsook , Koo Bon-Chul , Gibson Steven J. , Kang Ji-hyun 
Published: January 2014

AbstractWe examine excess emission at high positive and negative velocities toward known Galactic supernova remnants (SNRs) in the “Inner-Galaxy Arecibo L-band Feed Array (I-GALFA)” Hi 21-cm survey data. The I-GALFA survey covers ℓ = 32° to 77°, and has a velocity range of ±700 km s−1 with high angular and velocity resolutions (4′ and 0.18 km s−1, respectively) and good sensitivity (0.2 K). The excess emission which is thought to be part of a fast-expanding Hi shell of a SNR is detected from four among 39 SNRs in the I-GALFA area: W44, G54.4–0.3, W51C, and CTB 80. Although the Hi shells of the four SNRs were already reported in low-resolution studies, the first detection of both sides of an expanding Hi shell associated with W44 is very inspiring. We discuss physical properties of these four SNRs and their statistical nature.
Observations of O vi Absorption from the Superbubbles of the Large Magellanic Cloud
Authors: Pradhan Ananta C. , Pathak Amit , Murthy Jayant , Ojha D. K. 
Published: January 2014

AbstractWe have presented the observations of O VI absorption at 1032 Å towards 22 sightlines in 10 superbubbles (SBs) of the Large Magellanic Cloud (LMC) using the data obtained from the Far Ultraviolet Spectroscopic Explorer (FUSE). The estimated abundance of O VI in the SBs varies from a minimum of (1.09 ±0.22)×1014 atoms/cm2 in SB N206 to a maximum of (3.71±0.23)×1014 atoms/cm2 in SB N70. We find about a 46% excess in the abundance of O VI in the SBs compared to the non-SB lines of sight. Even inside a SB, O VI column density (N(O VI)) varies by about a factor of 2 to 2.5. These data are useful in understanding the nature of the hot gas in SBs.
Heavy Elements Produced in Supernova Explosion and thier Propulsion in the ISM
Authors: Baruah Rulee 
Published: January 2014

AbstractWe study the r-process path at temperatures from 1.0–3.0 × 109K and neutron number density from 1020-1030cm−3. At low density of 1020 cm−3 and T9 = 2.0, the path contains all the elements as given by experimental data of Wapstra et al. (2003). The element 98Cf254 shown by supernova light curves is found in our results. We take iron (Z = 26) as seed for calculation of abundances for supernova.
Transdiagnostic cognitive behavioural therapy (CBT): case reports from Saudi Arabia
Authors: Alatiq Yousra 
Published: January 2014

AbstractTransdiagnostic cognitive behavioural therapy (CBT) focuses on the processes shared across disorders and can be applied to a wide range of mental health problems or comorbid conditions. The transdiagnostic approach provides the potential opportunity to improve access to CBT, particularly in countries such as Saudi Arabia, where the number of well-trained therapists is limited. This study aims to examine the feasibility and potential benefit of transdiagnostic CBT for Saudi patients. Case reports describe the outcome of transdiagnostic CBT for four female patients who presented a wide range of symptoms and conditions without conducting any specific diagnostic assessments. The results support the positive effect of this treatment method on depression, anxiety symptoms, and general functioning. Patient feedback and observable improvements also supported these outcomes. However, the results are limited by the small sample size and simple study design. Transdiagnostic CBT is a feasible treatment approach for patients in Saudi Arabia. However, to confirm this preliminary finding, more studies are required.
Design of multi-layered bandpass filter with independently controllable triple-passband response
Authors: Chen Yung-Wei , Wu Hung-Wei , Su Yan-Kuin 
Published: January 2014

In this paper, a new multi-layered triple-passband bandpass filter using embedded and stub-loaded stepped impedance resonators (SIRs) is proposed. The filter is designed to have triple-passband at 1.8, 2.4, and 3.5 GHz. The 1st and 2nd passbands (1.8/2.4 GHz) are simultaneously generated by controlling the impedance and length ratios of the embedded SIRs (on top layer). The 3rd passband (3.5 GHz) is generated by using the stub-loaded SIR (on bottom layer). Using the embedded SIR, the even modes can be tuned within very wide frequency range and without affecting the odd modes. Therefore, the design of multi-band filters with very close passbands can be easily achieved and having a high isolation between the passbands. The filter can provide the multi-path propagation to enhance the frequency response and achieving the compact circuit size. The measured results are in good agreement with the full-wave electromagnetic simulation results.
Constraint-induced sound therapy for sudden sensorineural hearing loss – behavioral and neurophysiological outcomes
Authors: Okamoto Hidehiko , Fukushima Munehisa , Teismann Henning , Lagemann Lothar , Kitahara Tadashi , Inohara Hidenori , Kakigi Ryusuke , Pantev Christo 
Published: January 2014

AbstractSudden sensorineural hearing loss is characterized by acute, idiopathic hearing deterioration. We report here the development and evaluation of “constraint-induced sound therapy”, which is based on a well-established neuro-rehabilitation approach and which is characterized by the plugging of the intact ear (“constraint”) and the simultaneous, extensive stimulation of the affected ear with music. The sudden sensorineural hearing loss patients who received the constraint-induced sound therapy in addition to the standard corticosteroid therapy showed significantly better recovery of hearing function compared to those who had only received corticosteroid treatments. Additionally, the brain activity obtained in a subgroup of patients suggested that the constraint-induced sound therapy could have prevented maladaptive auditory cortex reorganization. Constraint-induced sound therapy thus appears to be an effective, practical and safe treatment option for sudden sensorineural hearing loss.
CDS circuit with 0 to 18 dB, 9‐bit VGA functionality
Authors: Zhuang Haoyu , Zhu Zhangming , Yang Yintang , Liu Lianxi 
Published: January 2014

For processing charge coupled device (CCD) signals, a correlated double sampling (CDS) circuit must be used to eliminate noise. Usually, the amplitude of the CCD signals is uncertain, either too small or too large, hence a variable‐gain amplifier (VGA) is also needed to amplify the CCD signals. Traditionally, the CDS and the VGA are separated, each of which consumes much energy and large area. If only the CDS and the VGA would be combined together, much energy and area could be saved. Hence, a CDS with VGA functionality is proposed to achieve this goal. Besides, the VGA functionality provides a gain range of 0–18 dB, programmable with a 9 bit resolution, which is far better than the traditional ones. Also, the VGA gain curve follows a linear‐in‐dB characteristic, hence the VGA functionality has rather good linearity. Finally, the VGA gain curve demonstrates the good performance of the VGA functionality.
Low‐power 77–81 GHz CMOS LNA with excellent matching for automotive radars
Authors: Lin Y.‐S. , Lee G.‐L. , Wang C.‐C. 
Published: January 2014

A low‐power and wideband three‐stage 77–81 GHz low‐noise amplifier (LNA) using standard 90 nm CMOS technology is reported. The T‐match technique is utilised to achieve simultaneously wideband input and output impedance matching, wideband power gain (S21) and a wideband noise figure (NF). The LNA consumes 21.1 mW, achieving S11 better than −10 dB for the frequencies 62.3–82.4 GHz, S22 better than −10 dB for the frequencies 62.8–84.6 GHz, S12 better than −29 dB for the frequencies 72–84 GHz and a group delay variation smaller than ±4 ps for the frequencies 77–81 GHz. In addition, high and flat S21 of 13.1 ± 1.5 dB is achieved for the frequencies 72–84 GHz, which means the corresponding 3 dB bandwidth is 12 GHz. Furthermore, the LNA achieves a minimum NF of 6.2 dB at 78 GHz and a NF of 6.8 ± 0.6 dB for the frequencies 75–82 GHz, one of the best NF results ever reported for a CMOS LNA for 77–81 GHz automotive radar applications.
AlN/AlGaN HEMTs on AlN substrate for stable high‐temperature operation
Authors: Yafune N. , Hashimoto S. , Akita K. , Yamamoto Y. , Tokuda H. , Kuzuhara M. 
Published: January 2014

An AlN/AlGaN high‐electron‐mobility transistor (HEMT) fabricated on a free‐standing AlN substrate is demonstrated. A metal stack, composed of Zr/Al/Mo/Au, was found to show low contact resistivity for source and drain ohmic contacts. The fabricated AlN/AlGaN HEMT exhibited a maximum drain current of 38 mA/mm with a threshold voltage of −3.4 V. Negligible drain current degradation was observed at temperatures from 300 to 573 K, demonstrating that an AlN/AlGaN approach on an AlN substrate is promising for stable high‐temperature operation.
Activation of Mg implanted in GaN by multicycle rapid thermal annealing
Authors: Anderson T.J. , Feigelson B.N. , Kub F.J. , Tadjer M.J. , Hobart K.D. , Mastro M.A. , Hite J.K. , Eddy C.R. 
Published: January 2014

A long‐standing goal of GaN device research has been the development of a reliable, well‐controlled process for p‐GaN formation by ion implantation. Results to date have indicated an activation of 1% or less using high‐temperature rapid thermal annealing (RTA) techniques and coimplantation. Although Mg is a relatively deep acceptor, this is still much less than the theoretically achievable value (8.2% based on the 160 meV acceptor level). A multicycle RTA process is presented that is capable of achieving up to 8% activation of the Mg‐implanted GaN. This approaches the theoretical value, and represents a significant step in GaN device research.
Differential orthogonal space‐time block codes for four transmit antennas
Authors: Ben Slimane E. , Jarboui S. , Bouallègue A. 
Published: January 2014

A new high‐order differential space‐time block code (DSTBC) is introduced as an attractive alternative to the well‐known coherent space‐time block code (STBC) by providing both full space‐time diversity and blind detection. A differential detection based on the orthogonal STBC scheme is proposed. The proposed differential scheme is a generalisation of the recent DSTBC already designed for two transmit antennas. The proposed differential encoder consists of a specific trellis diagram that creates a positive correlation between successive differential data. At the receiver side, the well‐known Viterbi algorithm is applied using a specific metric that nearly compensates for the 3 dB penalty commonly introduced by the symbol by symbol differential schema, and shows a 0.5 dB performance loss only from the coherent STBC scheme.