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Telescopic sunspot observations began in 1610 and captured subsequent solar cycles. In combination with proxy reconstructions on an annual scale, these data sets indicate a gradual transition between regular solar cycles and the Maunder Minimum. The telescopic sunspot observations missed the beginning of the first telescopic solar cycle (Solar Cycle −13), leaving room for considerable uncertainty as to its temporal evolution. Before these early telescopic observations, however, Kepler made solar observations using camerae obscurae and recorded a sunspot group in three solar drawings in 1607. Here, we make use of Kepler’s sunspot drawings and descriptive texts to identify his observational sites and time stamps. We have deprojected his sunspot drawings and compared the reported positions with our calculations of the inclination of the solar equator as seen from these sites at that time. These results locate the reported sunspot group near the solar equator eastward from the central meridian. This contrasts with telescopic sunspot drawings from the 1610s that show sunspot groups in the higher heliographic latitudes. Therefore, what Kepler saw was probably a sunspot group from Solar Cycle −14, rather than one from Solar Cycle −13. These records allow us to place the beginning of Solar Cycle −13 between 1607 and 1610. In comparison with the ^14 C-based solar-cycle reconstructions, our result supports regular solar-cycle durations around the 1610s, rather than any suggested extreme extensions of the solar-cycle duration(s) around the 1610s.

Since the last IAEA-FEC in 2021, significant progress on the development of long pulse steady state scenario and its related key physics and technologies have been achieved, including the reproducible 403 s long-pulse steady-state H-mode plasma with pure radio frequency (RF) power heating. A thousand-second time scale (∼1056 s) fully non-inductive plasma with high injected energy up to 1.73 GJ has also been achieved. The EAST operational regime of high β _P has been significantly extended ( H _98y2 > 1.3, β _P ∼ 4.0, β _N ∼ 2.4 and n _e / n _GW ∼ 1.0) using RF and neutral beam injection (NBI). The full edge localized mode suppression using the n = 4 resonant magnetic perturbations has been achieved in ITER-like standard type-I ELMy H-mode plasmas with q _95 ≈ 3.1 on EAST, extrapolating favorably to the ITER baseline scenario. The sustained large ELM control and stable partial detachment have been achieved with Ne seeding. The underlying physics of plasma-beta effect for error field penetration, where toroidal effect dominates, is disclosed by comparing the results in cylindrical theory and MARS-Q simulation in EAST. Breakdown and plasma initiation at low toroidal electric fields (

As an inaugural investigation under the X-ray Winds In Nearby-to-distant Galaxies (X-WING) program, we assembled a data set comprising 132 active galactic nuclei (AGNs) spanning redshifts z ∼ 0–4 characterized by blueshifted absorption lines indicative of X-ray winds. Through an exhaustive review of previous research, we compiled the outflow parameters for 583 X-ray winds, encompassing key attributes such as outflow velocities ( V _out ), ionization parameters ( ξ ), and hydrogen column densities. By leveraging the parameters V _out and ξ , we systematically categorized the winds into three distinct groups: ultrafast outflows (UFOs), low-ionization parameter (low-IP) UFOs, and warm absorbers (WAs). Strikingly, a discernible absence of linear correlations in the outflow parameters, coupled with distributions approaching instrumental detection limits, was observed. Another notable finding was the identification of a velocity gap around V _out ∼ 10,000 km s ^−1 . This gap was particularly evident in the winds detected via absorption lines within the ≲2 keV band, indicating disparate origins for low-IP UFOs and WAs. In cases involving Fe xxv /Fe xxvi lines, where the gap might be attributed to potential confusion between emission/absorption lines and the Fe K-edge, the possibility of UFOs and galactic-scale WAs being disconnected is considered. An examination of the outflow and dust sublimation radii revealed a distinction: UFOs appear to consist of dust-free material, whereas WAs likely comprise dusty gas. From 2024, the X-Ray Imaging and Spectroscopy Mission is poised to alleviate observational biases, providing insights into the authenticity of the identified gap, a pivotal question in comprehending AGN feedback from UFOs.

We find a candidate for new permanent-magnet materials with the 1–16 stoichiometry on the basis of first-principles calculations utilizing a materials database. An extremely iron-rich NdFe _16 compound shows exceptionally high saturation magnetization with an adequate magnetocrystalline anisotropy energy and Curie temperature. Although it has an excessive formation energy in its binary composition, introducing interstitial light elements into NdFe _16 successfully decreases the formation energy while maintaining its superior magnetic properties. The density of states explains the alteration of magnetization from incorporating light elements.

We present the study on the relationship between supermassive black holes (SMBHs) and their host galaxies using our variability-selected active galactic nuclei (AGNs) sample ( i _AB ≤ 25.9 and z ≤ 4.5) constructed from the Hyper Suprime-Cam Subaru Strategic Program Ultradeep survey in the COSMOS field. We estimated the black hole (BH) mass ( M _BH = 10 ^5.5−10 M _⊙ ) based on the single-epoch virial method and the total stellar mass ( M _star = 10 ^10−12 M _⊙ ) by separating the AGN component with spectral energy distribution fitting. We found that the redshift evolution of the BH–stellar mass ratio ( M _BH / M _star ) depends on the M _BH , which is caused by no significant correlation between M _BH and M _star . Variable AGNs with massive SMBHs ( M _BH > 10 ^9 M _⊙ ) at 1.5 < z < 3 show considerably higher BH–stellar mass ratios (> ∼1%) than the BH–bulge ratios ( M _BH / M _bulge ) observed in the local Universe for the same BH range. This implies that there is a typical growth path of massive SMBHs, which is faster than the formation of the bulge component as final products seen in the present day. For the low-mass SMBHs ( M _BH < 10 ^8 M _⊙ ) at 0.5 < z < 3, on the other hand, variable AGNs show similar BH–stellar mass ratios with the local objects (∼0.1%), but smaller than those observed at z > 4. We interpret that host galaxies harboring less massive SMBHs at intermediate redshift have already acquired sufficient stellar mass, although high- z galaxies are still in the early stage of galaxy formation relative to those at the intermediate/local Universe.

We studied the optical variability of 241 BL Lacertae (BL Lacs) and 83 flat-spectrum radio quasars (FSRQs) from the 4LAC catalog using data from the Tomo-e Gozen Northern Sky Transient Survey, with ∼50 epochs per blazar on average. We excluded blazars whose optical variability may be underestimated due to the influence of their host galaxy based on their optical luminosity ( L _O ). FSRQs with γ -ray photon index greater than 2.6 exhibit very low optical variability, and their distribution of standard deviation of repeated photometry is significantly different from that of the other FSRQs (Kolmogorov–Smirnov test p -value equal to 5 × 10 ^−6 ). Among a sample of blazars at any particular cosmological epoch, those with lower γ -ray luminosity ( L _γ ) tend to have lower optical variability, and those FSRQs with a γ -ray photon index greater than 2.6 tend to have low L _γ . We also measured the structure function of optical variability and found that the amplitude of the structure function for FSRQs is higher than previously measured and higher than that of BL Lacs at multiple time lags. Additionally, the amplitude of the structure function of FSRQs with high γ -ray photon index is significantly lower than that of FSRQs with low γ -ray photon index. The structure function of FSRQs of high γ -ray photon index shows a characteristic timescale of more than 10 days, which may be the variability timescale of the accretion disk. In summary, we infer that the optical component of FSRQs with high γ -ray photon index may be dominated by the accretion disk.

Impact experiments were conducted at a velocity of ∼0.2–1.0 km s ^−1 using fine particles with several microns or submicrons in size. For metal (Cu) plate targets, as observed in previous impact experiments using projectiles with sizes larger than tens of micron, our experiments with the fine particles also show that projectile materials can remain in the crater. For brittle (SiO _2 glass) plate targets, though previous impact experiments using projectiles with sizes larger than tens of microns have shown the spallation and ejection of projectile materials, our experiments with the fine particles show that irreversible inelastic deformation of targets occurred and that projectile materials can remain in the crater. This is explained by the absorption of impact energy determined via the competition between deformation and crack propagation. The deformation thus contributes to the energy absorption even for brittle materials at small sizes. Compiling our results and previous data, we found that sticking can occur in collisions with particles up to at least 1 cm for ductile (metal) targets and 10 μ m for brittle targets at several hundred meters per second. As an application, we evaluated the size distribution of dust grains in a debris disk where the sticking of fine particles is assumed to occur. We demonstrated that the collisional sticking modified the size distribution, resulting in the decrease of spectral energy distribution at millimeter wavelengths, consistent with the photometry data of this debris disk. This suggests that the sticking of fine particles occurs in this debris disk.

Aiming to improve the battery performance of lithium-ion batteries (LIBs), modification of the cathodes and anodes of LIBs using laser beams to prepare through-holes, non-through-holes or ditches arranged in grid and line patterns has been proposed by many researchers and engineers. In this study, a laser processing system attached to rollers, which realizes this modification without large changes in the present mass-production system, was developed. The laser system apparatus comprises roll-to-roll equipment and laser equipment. The roll-to-roll equipment mainly consists of a hollow cylinder with openings on its circumferential surface. Cathode and anode electrodes for LIBs are wound around the cylinder in the longitudinal direction of the electrodes. A pulsed beam reflected from the central axis of the cylinder can continuously open a large number of through-holes in the thin electrodes. Through-holes were formed at a rate of 100 000 holes per second on lithium iron phosphate cathodes and graphite anodes with this system. The through-holed cathodes and anodes prepared with this system exhibited higher C-rate performance than nontreated cathodes and anodes.

“Changing-look active galactic nuclei” (CLAGNs) are known to change their apparent types between types 1 and 2, usually accompanied by a drastic change in their luminosity on timescales of years. However, it is still unclear whether materials in broad-line regions (BLRs) in CLAGNs appear and disappear during the type-transition or remain at the same location while the line production is simply activated or deactivated. Here we present our X-ray–optical monitoring results of a CLAGN, NGC 3516, by Suzaku, Swift, and ground telescopes, with our primary focus on the narrow Fe–K α emission line, which is an effective probe of the BLR materials. We detected significant variations of the narrow Fe–K α line on a timescale of tens of days during the type-2 (faint) phase in 2013–2014, and conducted “narrow Fe–K α reverberation mapping,” comparing its flux variation with those of the X-ray continuum from a corona and B -band continuum from an accretion disk. We derived, as a result, a time lag of ${10.1}_{-5.6}^{+5.8}$ days (1 σ errors) for the Fe–K α line behind the continuum, which is consistent with the location of the BLR determined in optical spectroscopic reverberation mapping during the type-1 (bright) phase. This finding shows that the BLR materials remained at the same location without emitting optical broad lines during the type-2 phase. Considering the drastic decrease of the radiation during the type-transition, our result is possibly inconsistent with the hotly discussed formation models of the BLR, which propose that the radiative pressure from an accretion disk should be the main driving force.

Random number generation has become an indispensable part of information processing: it is essential for many numerical algorithms, security applications, and in securing fairness in everyday life. Random number generators (RNGs) find application in many devices, ranging from dice and roulette wheels, via computer algorithms, lasers to quantum systems, which inevitably capitalize on their physical dynamics at respective spatio-temporal scales. Herein, to the best of our knowledge, we propose the first mathematically proven true RNG (TRNG) based on a mechanical system, particularly the triple linkage of Thurston and Weeks. By using certain parameters, its free motion has been proven to be an Anosov flow, from which we can show that it has an exponential mixing property and structural stability. We contend that this mechanical Anosov flow can be used as a TRNG, which requires that the random number should be unpredictable, irreproducible, robust against the inevitable noise seen in physical implementations, and the resulting distribution’s controllability (an important consideration in practice). We investigate the proposed system’s properties both theoretically and numerically based on the above four perspectives. Further, we confirm that the random bits numerically generated pass the standard statistical tests for random bits.

To move the performance of lithium-ion batteries into the next stage, the modification of the structure of cells is the only choice except for the development of materials exhibiting higher performance. In this review paper, the employment of through-holing structures of anodes and cathodes prepared with a picosecond pulsed laser has been proposed. The laser system and the structure for improving the battery performance were introduced. The performance of laminated cells constructed with through-holed anodes and cathodes was reviewed from the viewpoints of the improvement of high-rate performance and energy density, removal of unbalanced capacities on both sides of the current collector, even greater high-rate performance by hybridizing cathode materials and removal of irreversible capacity. In conclusion, the points that should be examined and the problem for the through-holed structure to be in practical use are summarized.

We present the study on the relationship between supermassive black holes (SMBHs) and their host galaxies using our variability-selected active galactic nuclei (AGNs) sample (i AB ≤ 25.9 and z ≤ 4.5) constructed from the Hyper Suprime-Cam Subaru Strategic Program Ultradeep survey in the COSMOS field. We estimated the black hole (BH) mass (M BH = 105.5−10 M ⊙) based on the single-epoch virial method and the total stellar mass (M star = 1010−12 M ⊙) by separating the AGN component with spectral energy distribution fitting. We found that the redshift evolution of the BH–stellar mass ratio (M BH/ M star) depends on the M BH, which is caused by no significant correlation between M BH and M star. Variable AGNs with massive SMBHs (M BH > 109 M ⊙) at 1.5 < z < 3 show considerably higher BH–stellar mass ratios (> ∼1%) than the BH–bulge ratios (M BH/ M bulge) observed in the local Universe for the same BH range. This implies that there is a typical growth path of massive SMBHs, which is faster than the formation of the bulge component as final products seen in the present day. For the low-mass SMBHs (M BH < 108 M ⊙) at 0.5 < z < 3, on the other hand, variable AGNs show similar BH–stellar mass ratios with the local objects (∼0.1%), but smaller than those observed at z > 4. We interpret that host galaxies harboring less massive SMBHs at intermediate redshift have already acquired sufficient stellar mass, although high- z galaxies are still in the early stage of galaxy formation relative to those at the intermediate/local Universe. [ABSTRACT FROM AUTHOR]