bluuebunny/crossref_metadata_2025_split huggingface dataset:
The formation of neutron star systems through accretion-induced collapse in white-dwarf binaries
Authors: Wang Bo , Liu Dongdong 
Published: September 2020

Abstract
The accretion-induced collapse (AIC) scenario was proposed 40 years ago as an evolutionary end state of oxygen-neon white dwarfs (ONe WDs), linking them to the formation of neutron star (NS) systems. However, there has been no direct detection of any AIC event so far, even though there exists a lot of indirect observational evidence. Meanwhile, the evolutionary pathways resulting in NS formation through AIC are still not thoroughly investigated. In this article, we review recent studies on the two classic progenitor models of AIC events, i.e., the single-degenerate model (including the ONe WD+MS/RG/He star channels and the CO WD+He star channel) and the double-degenerate model (including the double CO WD channel, the double ONe WD channel and the ONe WD+CO WD channel). Recent progress on these progenitor models is reviewed, including the evolutionary scenarios leading to AIC events, the initial parameter space for producing AIC events and the related objects (e.g., the pre-AIC systems and the post-AIC systems). For the single-degenerate model, the pre-AIC systems (i.e., the progenitor systems of AIC events) could potentially be identified as supersoft X-ray sources, symbiotics and cataclysmic variables (such as classical novae, recurrent novae, Ne novae and He novae) in the observations, whereas the post-AIC systems (i.e., NS systems) could potentially be identified as low-/intermediate-mass X-ray binaries, and the resulting low-/intermediate-mass binary pulsars, most notably millisecond pulsars. For the double-degenerate model, the pre-AIC systems are close double WDs with short orbital periods, whereas the post-AIC systems are single isolated NSs that may correspond to a specific kind of NS with peculiar properties. We also review the predicted rates of AIC events, the mass distribution of NSs produced via AIC and the gravitational wave (GW) signals from double WDs that are potential GW sources in the Galaxy in the context of future space-based GW detectors, such as LISA, TianQin, Taiji, etc. Recent theoretical and observational constraints on the detection of AIC events are summarized. In order to confirm the existence of the AIC process, and resolve this long-term issue presented by current stellar evolution theories, more numerical simulations and observational identifications are required.
Statistical relations between stellar spectral and luminosity classes and stellar effective temperature and surface gravity
Authors: Malkov Oleg , Kovaleva Dana , Sichevsky Sergey , Zhao Gang 
Published: September 2020

Abstract
We have determined new statistical relations to estimate the fundamental atmospheric parameters of effective temperature and surface gravity, using MK spectral classification, and vice versa. The relations were constructed based on the published calibration tables (for main sequence stars) and observational data from stellar spectral atlases (for giants and supergiants). These new relations were applied to field giants with known atmospheric parameters, and the results of the comparison of our estimations with available spectral classification have been quite satisfactory.
Lsyn – Esyn, p – δ relation in active galactic nucleus jets and implication for the physical origin of the Lp − Ep,z − Γ0 relation of gamma-ray bursts
Authors: Huang Xiao-Li , Liang En-Wei 
Published: September 2020

Abstract
High energy photon radiations of gamma-ray bursts (GRBs) and active galactic nuclei (AGNs) are dominated by their jet radiations. We examine whether the synchrotron radiations of jets in BL Lacs, flat spectrum radio quasars (FSRQs), and Narrow Line Seyfert 1 galaxies (NLS1s) follow the relation between the prompt gamma-ray emission and the initial Lorentz factor (Γ0) of GRBs. It is shown that the AGN sample does not agree with the L
p − E
p,z − Γ0 relation of GRBs. In addition, we obtain a tight relation of

L

syn

∝

E

syn
,
p

0.45
±
0.15

δ

3.50
±
0.25

for FSRQs and NLS1 galaxies, where L
syn is the luminosity at peak photon energy E
syn, p of the synchrotron radiations. This relation is different from the L
p − E
p,z − Γ0 relation of GRBs. The dependence of L
syn to δ is consistent with the expectation of the Doppler boosting effect for the FSRQs and NLS1 galaxies, but it is not for GRBs. We argue that Γ0 may be a representative of the kinetic power of the radiating region and the tight L
p − E
p, z − Γ0 relation is shaped by the radiation physics and the jet power together.
Periodicity in fast radio bursts due to forced precession by a fallback disk
Authors: Tong Hao , Wang Wei , Wang Hong-Guang 
Published: September 2020

Abstract
Recently, a 16-day periodicity in a fast radio burst was reported. We propose that this 16-day periodicity may be due to forced precession of the neutron star by a fallback disk. When the rotation axis is misaligned with respect to the normal direction of the disk plane, the neutron star will precess. The eccentricity of the neutron star may be due to rotation or strong magnetic field, or similar reasons. We found that the 16-day period may be understood using typical masses of the fallback disk. Polarization observations and information about the neutron star rotation period may help to discriminate different models. The possible precession observations in pulsars, magnetars and fast radio bursts may be understood together considering forced precession by a fallback disk.
A cold and diffuse giant molecular filament in the region of l = 41°, b = −1°
Authors: Lin Liang-Hao , Wang Hong-Chi , Su Yang , Li Chong , Yang Ji 
Published: September 2020

Abstract
Data of 12CO/13CO/C18O J = 1 → 0 emission toward the Galactic plane region of l = 35° to 45° and b = –5° to +5° are available with the Milky Way Imaging Scroll Painting (MWISP) project. Using the data, we found a giant molecular filament (GMF) around l ≈ 38° ∼ 42°, b ≈ –3.5° ∼ 0°, V
LSR ≈ 27 ∼ 40 km s−1, named the GMF MWISP G041–01. At a distance of 1.7 kpc, the GMF is about 160 pc long. With a median excitation temperature about 7.5 K and a median column density about 1021 cm−2, this GMF is very cold and very diffuse compared to known GMFs. Using the morphology in the data cube, the GMF is divided into four components among which three show filamentary structure. Masses of the components are 103 ∼ 104
M
⊙, with a total mass for the whole filament being about 7 × 104
M
⊙ from the local thermodynamic equilibrium method. 13CO cores inside each component are searched. Virial parameters are about 2.5 for these cores and have a power-law index of –0.34 against the mass. The mass fraction of dense cores traced by 13CO to the diffuse clouds traced by 12CO is about 7% for all components of the GMF. We found signatures of possible large scale filament-filament collision in the GMF.
An upgraded interpolator of the radial basis function network for spectral calculation based on empirical stellar spectral library
Authors: Cheng Lian-Tao , Zhang Feng-Hui 
Published: September 2020

Abstract
Stellar population synthesis is an important method in galaxy and star-cluster studies. In stellar population synthesis models, a stellar spectral library is necessary for the integrated spectra of the stellar population. Usually, the stellar spectral library is utilized for the transformation between the stellar atmospheric parameters and stellar spectrum. The empirical stellar spectral library has distinct advantages over the theoretical library. However, for the empirical spectral library, the distribution of stars is irregular in the stellar atmospheric parameter space, which makes the traditional interpolator difficult to get accurate results. In this work, we will provide an improved radial basis function interpolator which is implemented to obtain the interpolated stellar spectra based on the empirical stellar spectral library. For this interpolator, we use the relation between the standard variance σ in the Gaussian radial basis function and the density distribution of stars in the stellar atmospheric parameter space to give the prior constraint on this σ. Moreover, we also consider the anisotropic radial basis function by the advantage of the local dispersion of stars in the stellar atmospheric parameter space. Furthermore, we use the empirical stellar spectral library MILES to test this interpolator. On the whole, the interpolator has a good performance except for the edge of the low-temperature region. At last, we compare this interpolator with our work in 2018, and the interpolation result shows an obvious improvement. Users can apply this interpolator to retrieve the interpolated spectra based on the stellar spectral library quickly and easily.
The evolutionary status of chemically peculiar eclipsing binary star DV Boo
Authors: Kahraman Aliçavuş Filiz , Aliçvuş F. 
Published: September 2020

Abstract
Eclipsing binary systems are unique stellar objects to examine and understand stellar evolution and formation. Thanks to these systems, the fundamental stellar parameters (mass, radius) can be obtained very precisely. The existence of metallic-line (Am) stars in binaries is noticeably common. However, the known number of Am stars in eclipsing binaries is less. The Am stars in eclipsing binaries are extremely useful to deeply investigate the properties of Am stars, as eclipsing binaries are the only tool to directly derive the fundamental stellar parameters. Additionally, the atmospheric parameters and metallicities of such binary components could be obtained by a detailed spectroscopic study. Therefore, in this study, we present a comprehensive photometric and spectroscopic analysis of the eclipsing binary system DV Boo which has a possible Am component. The fundamental stellar parameters were determined by the analysis of radial velocity and photometric light curves. The atmospheric parameters of both binary components of DV Boo were derived considering the disentangled spectra. The chemical abundance analysis was carried out as well. As a result, we showed that the primary component exhibits a typical Am star chemical abundance distribution. The fundamental stellar parameters of the binary components were also obtained with an accuracy of <1% for masses and <3% for radii. The evolutionary status of DV Boo was examined utilizing the precisely obtained stellar parameters. The age of the system was found to be 1.00 ± 0.08 Gyr.
Investigating the relationship between cosmic curvature and dark energy models with the latest supernova sample
Authors: Gao Chao , Chen Yun , Zheng Jie 
Published: September 2020

Abstract
We investigate the relationship between cosmic curvature and model of dark energy (hereafter DE) with recent Type Ia supernovae (hereafter SNe Ia) data, i.e., the Pantheon sample including 1048 SNe Ia with 0.01 < z < 2.3. We obtain measurements of the dimensionless spatial curvature density today, i.e.,

Ω

k
0

=
−

0.062

−
0.169

+
0.189

,
−

0.004

−
0.134

+
0.228

,

0.127

−
0.276

+
0.280

and

0.422

−
0.338

+
0.213

at 68% confidence level (CL), respectively, in the scenarios of ΛCDM, ϕCDM (i.e., scalar field DE), ωCDM and ω
0
ωa
CDM models. In the scenario of ΛCDM model, a closed universe is preferred by the Pantheon sample, which is consistent with that from the Planck CMB spectra. However, the uncertainty of Ω
k0 from the Pantheon SNe sample is about 8 times larger than that from the Planck data, so the former one supports a closed universe at a much lower CL than that from the latter one. An open unverse is supported by the Pantheon sample at ∼32% and ∼78% CLs, respectively, in the ωCDM and ω
0
ω
aCDM models. Among these models, the ϕCDM model is the one which supports the flat universe most strongly. It shows that Ω
k0 is significantly dependent on the adopted model of DE, and there is a negative correlation between Ω
k0 and the equation of state of DE.
Multi-wavelength study of energetic processes during solar flare occurrence
Authors: Lata Soni Shirsh , Lal Yadav Manohar , Shyam Gupta Radhe , Prasad Mishra Adya 
Published: September 2020

Abstract
This paper is an attempt to understand the physical processes occurring in different layers of the solar atmosphere during a solar flare. For a complete understanding of the flare, we must analyze multi-wavelength datasets, as emission at different wavelengths originates from different layers in the solar atmosphere. Also, flares are transient and localized events observed to occur at all longitudes. With these considerations, we have carried out multi-wavelength analysis of two representative flare events. One event occurred close to the center of the solar disk and the other occurred close to the limb. In the former case, we examine emission from the lower layers of the solar atmosphere. Therefore the chromosphere, transition region and also photospheric magnetogram can be analyzed. On the other hand, in the near-limb event, coronal features can be clearly examined. In this paper, the first event studied is the M1.1 class flare from the active region NOAA 10649 located at S10E14 and the second event is the M1.4 class flare from the active region 10713 located at S12W90. In both cases, we have acquired excellent multi-wavelength data sets. The observations from multi-instrumental data clearly demonstrate that flares occur in the vicinity of sunspots. These are regions of strong magnetic field with mixed polarity.
Investigating the morphology of the supernova remnant G349.7+00.2 in the medium with a density gradient
Authors: Yan Jing-Wen , Lu Chun-Yan , Wen Lu , Yu Huan , Fang Jun 
Published: September 2020

Abstract
G349.7 + 00.2 is a young Galactic supernova remnant (SNR) with a mushroom morphology in radio and X-rays, and it has been detected across the entire electromagnetic spectrum from radio to high energy γ-rays. Moreover, the remnant is interacting with a molecular cloud based on the observations in the radio and infrared band. The reason for the formation of the periphery and the dynamical evolution of the remnant is investigated using 3D hydrodynamical (HD) simulations. Under the assumption that the supernova ejecta is evolved in the medium with a density gradient, the shell is composed of two hemispheres with different radii, and the smaller hemisphere is in relatively dense media. The resulting periphery of remnant is consistent with detected ones, and it can be concluded that the peculiar periphery of G349.7+00.2 can be reproduced as the remnants interacting with the medium with a density gradient.
AstroSat observation of the Be/X-ray binary Pulsar 3A 0726-260 (4U 0728-25)
Authors: Roy Jayashree , C. Agrawal Prahlad , Singari Baibhav , Misra Ranjeev 
Published: September 2020

Abstract
Results on timing and spectral properties of the Be/X-ray binary pulsar 3A 0726–260 (4U 0728–25) are presented. The binary was observed on 2016 May 6–7 with the Large Area X-ray Proportional Counter (LAXPC) and Soft X-ray Telescope (SXT) instruments onboard the AstroSat satellite. During this observation, the source was in non-flaring persistent state at a flux level of ∼ 8.6 ± 0.3 ×10−11 erg cm−2 s−1 in 0.4–20 keV. Strong X-ray pulsations with a period of 103.144±0.001 s are detected in 0.3–7 keV with the SXT and in 3–40 keV with the LAXPC. The pulse profile is energy dependent, and there is an indication that the pulse shape changes from a broad single pulse to a double pulse at higher energy. At energies above 20 keV, we report the first time detection of pulsation period 103.145±0.001 s and the double peaked pulse profile from the source. The energy spectrum of the source is derived from the combined analysis of the SXT and LAXPC spectral data in 0.4–20 keV. The best spectral fit is obtained by a power law model with a photon index (1.7±0.03) with high energy spectral cut-off at 12.9 ± 0.7 keV. A broad iron line at ∼ 6.3 keV is detected in the energy spectrum. We briefly discuss the implications of these results.
Determinants of low-carbon transport mode adoption: systematic review of reviews
Authors: Javaid Aneeque , Creutzig Felix , Bamberg Sebastian 
Published: September 2020

Abstract
Urban transport provides access to multiple services, structures and impedes daily life of residents, and translates into wellbeing considerations, sustainability impacts, and GHG emissions. Thus motivated, multiple disciplines, ranging from psychology to urban planning, are invested in understanding the potential for transitioning to low-carbon and sustainable urban transport systems. While each discipline has carved out a growing body of knowledge, a consistent cross-disciplinary understanding of psychological, sociological, and urban form determinants of urban mobility choices is, perhaps surprisingly so, still lacking. Here, we systematically review the reviews of several strands of literature and lay out the evidence for individual, social, and infrastructure level factors pertinent to urban mode choice. Synthesizing the results from 75 review papers, we find that all three dimensions (individual, social, and infrastructure) unambiguously interfere with mode choice. Individuals are most motivated to shift modes, if they are well informed, if personal norms match low-carbon mode use, and, most importantly, if they perceive to have personal control over decisions. Perceptions about common travel behaviour (descriptive social norms), especially if supported by perceived normative beliefs of others (injunctive norms), are highly influential to support mode shift. However, the overall margin of shift as induced by individual and social settings remains limited. Instead, the infrastructure factors explain large differences in mode choice. New shared mobility modes, and teleworking and shopping, add a long tail to modes chosen, but are no game changer. We conclude that a transition to low-carbon mobility requires low-carbon infrastructure, which leverages enthusiastic individuals’ concerns and empowers them for mode change, and that address safety concerns prevalent especially in cities of the Global South. The mode shift to low-carbon option can then be sustained and enhanced by social influence in the form of collective social norms.
Stratospheric contribution to the summertime high surface ozone events over the western united states
Authors: Wang Xinyue , Wu Yutian , Randel William , Tilmes Simone 
Published: September 2020

Abstract
The stratospheric influence on summertime high surface ozone (

O
3

) events is examined using a twenty-year simulation from the Whole Atmosphere Community Climate Model. We find that

O
3

transported from the stratosphere makes a significant contribution to the surface

O
3

variability where background surface

O
3

exceeds the 95th percentile, especially over western U.S. Maximum covariance analysis is applied to

O
3

anomalies paired with stratospheric

O
3

tracer anomalies to identify the stratospheric intrusion and the underlying dynamical mechanism. The first leading mode corresponds to deep stratospheric intrusions in the western and northern tier of the U.S., and intensified northeasterlies in the mid-to-lower troposphere along the west coast, which also facilitate the transport to the eastern Pacific Ocean. The second leading mode corresponds to deep intrusions over the Intermountain Regions. Both modes are associated with eastward propagating baroclinic systems, which are amplified near the end of the North Pacific storm tracks, leading to strong descents over the western U.S.
Enhanced realignment criterion vs linear entanglement witnesses
Authors: Sarbicki Gniewomir , Scala Giovanni , Chruściński Dariusz 
Published: September 2020

Abstract
It is shown that the enhanced (nonlinear) realignment criterion is equivalent to the family of linear criteria based on correlation tensor. These criteria generalize the original (linear) realignment criterium and give rise to the family of entanglement witnesses. An appropriate limiting procedure is proposed which leads to a novel class of witnesses which are as powerful as the enhanced realignment criterion.
Elementary band representations for (double)-line groups
Authors: Milošević I , Dmitrović S , Vuković T , Dimić A , Damnjanović M 
Published: September 2020

Abstract
Quantized topological invariants characterizing topological phases in quasi-1D materials are usually considered only on the basis of spatial inversion parity eigenvalues. However, symmetry of quasi-1D systems is far more complex and their complete topological characterisation can be obtained only on the basis of elementary band representations (EBRs) for the relevant symmetry groups. We derive complete sets of inequivalent EBRs for line groups (LG), the symmetry groups of all quasi-1D systems with either translational or helical periodicity. Besides, we determine also EBRs for double-LGs, accounting for spin degree of freedom. In order to illustrate applicability of the results obtained, we analyze electronic-band topology of a chiral single-wall carbon nanotube, using EBRs for relevant (double)-LG and discuss Su-Schrieffer–Heeger model from EBR-perspective.
A study on microstructural evolution and detwinning behavior of Ti–3Al–2.5V cold-rolled tube during annealing
Authors: Yu Yang , Chen Rong , Li Cheng-Lin , Ye Wenjun , Hui Songxiao 
Published: September 2020

Abstract
Near alpha titanium alloys have been widely used in the aerospace industry owing to their high special strength, low-density and excellent corrosion resistance. Ti–3Al–2.5V is a typical near alpha titanium alloy that was usually used in the form of a tube in aircraft due to its excellent cold workability. In the present study, the microstructural evolution and detwinning behavior of cold-rolled Ti–3Al–2.5V alloy tubes during annealing were investigated. Upon annealing, the microstructure evolution strongly depends on the annealing temperature and holding time, which play important roles in the kinetics of the static recovery and recrystallization. In addition, there are two independent detwinning mechanisms involved during annealing. The first one is that detwinning occurs along the twin shear direction at grain boundaries, resulting in a shortening effect. The second one is that detwinning occurs in the center of twins, resulting in a thinning effect of twins. The understanding of the detwinning behavior and microstructural evolution during annealing helps with the tube processing and their applications in aircraft.
A breathable waterborne poly-(urethane/urea) coating containing PO-EO-PO triblock copolymer
Authors: Chen Shu-Yi , Chen Chin-Wen , Cheng Ling-Chen , Chuang Fu-Sheng , Rwei Syang-Peng 
Published: September 2020

Abstract
A breathable waterborne poly-(urethane/urea) (WPU) coating for textiles was synthesized by a pre-polymer method with 4,4′-Diisocyanate dicyclohexylmethane (H12MDI), Poly(propylene oxide)-b-poly(ethylene oxide)-b-poly(propylene oxide) triblock diols (PO-EO-PO diols), and Polyteramethylene glycol (PTMG). The PO-EO-PO diols were incorporated into the WPU to improve the swelling issue of frequently observed in the polyethylene glycol (PEO) segments. The stability, mechanical property, thermal properties, and breathability of PO-EO-PO, including WPUs were investigated by varying PTMG/PO-EO-PO diol ratios. The PO-EO-PO incorporated WPUs showed excellent mechanical properties: 250% of tensile elongation and breaking stress of 15–27 MPa. The breathability reached 620–15 000 mm of water pressure resistance H2O and 2717–63 822 g H2O 24 h m−2 of vapor permeability. The highly breathable, WPU coating contained with different PO/EO fraction of PO-EO-PO diols will play an essential role in the garment-textile industry to convert to a greener process.