This paper presents a preliminary investigation into the influence of radial behavior of disk outflow on the structure and dynamics of the broad line region (BLR) in active galactic nuclei (AGNs), with an emphasis on how the mass ejection rate contri...
There is growing evidence that many Be stars are parts of binary systems. As the B-type primaries are very fast rotators and their spectral lines may be distorted by the circumstellar material, it is not easy to measure their radial velocity directly...
The emission-line B-type stars constitute a heterogeneous group. Many of these stars show similar optical spectroscopic features and color indices, making it difficult to classify them adequately by means of photometric and spectroscopic techniques....
Fixed angular apertures sample different physical regions of nearby galaxies and can therefore bias optical emission-line diagnostics. We use 20,545 high-confidence emission-line galaxies observed by both the Dark Energy Spectroscopic Instrument (DES...
HD 50138 is a 6.6 mag emission-line B–type star, whose nature is still controversial. It has been thought to be a pre-main-sequence Herbig Be star and an evolved object with the B[e] phenomenon, possibly a mass-transferring binary system. Howev...
MWC 342 (V1972 Cyg) was discovered nearly 90 years ago as an early-type emission-line star. It was among the first hot stars whose strong infrared excess was detected in the early 1970s. Several mostly short-term photometric and spectroscopic studies...
The distinct behaviors of blue- and redshifted broad emission-line shifts, emitted by ionic species with varying ionization potentials in active galactic nuclei (AGN), can be elucidated by considering the balance between radiation and gravitational f...
The spectra of active galactic nuclei (AGNs) are often characterized by a wealth of emission lines with different profiles and intensity ratios that lead to a complicated classification. Their electromagnetic radiation spans more than 10 orders of ma...
Being ionized nebulae where star formation events take place, H ii regions are not only natural laboratories for studying physical processes of star formation and photoionization but also signatures reflecting evolution of their internal stellar popu...
Modeling emission lines from the millimeter to the UV and producing synthetic spectra is crucial for a good understanding of observations, yet it is an art filled with hazards. This is the proceedings of “Walking the Line”, a 3-day confer...
This paper describes recent studies of the FS CMa-type objects, a group of stars showing the B[e] phenomenon defined in 2007. The objects exhibit strong emission-line spectra with both permitted and forbidden lines suggesting the presence of a B-type...
AS 314 (V452 Sct) is a poorly studied early-type emission-line star, which exhibits an infrared excess at wavelengths longer than 10
An explicit spatial carbon emission map is of great significance for reducing carbon emissions through urban planning. Previous studies have proved that, at the city scale, the vector carbon emission maps can provide more accurate spatial carbon emis...
Apparel manufacturing is an industry with high energy consumption and carbon emissions. With the development of the low-carbon economy, low-carbon production in the apparel manufacturing industry become more and more imperative. The apparel industry...
In the post-transient stage of a 1-Torr pulsed argon discharge, a computationally assisted diagnostic technique is demonstrated for either inferring the electron energy distribution function (EEDF) if the metastable-atom density is known (i.e., measu...
Disassembly lines are widely utilized to disassemble end-of-life products. Most of the research focuses on the complete disassembly of obsolete products. However, there is a lack of studies on profit and on carbon emission saved. Hence, this study co...
This paper presents the development of a generic active distribution network (ADN) operation simulation framework that incorporates selected swarm optimization algorithms (SOAs) for the purpose of reducing CO2 emissions and line loss minimization thr...
This article reviews the principles and applications of passive spontaneous emission spectroscopy (SES) for the quantitative determination of alkali metal concentrations emitted from combustion processes. The combustion of fuels that contain a high a...
As a test of the time symmetry of forbidden-line emission processes, we measured the [OIII]
We present the results of photometric and spectroscopic observations of a poorly studied B-type supergiant with infrared excess, the hot post-AGB star IRAS 21546+4721. Based on our photometric observations in the
The investigation of emission line regions within active galaxies (AGNs) has a rich and extensive history, now extending to the use of AGNs and quasars as “standardizable” cosmological indicators, shedding light on the evolution of our un...
Knowledge of the conducted emissions in the frequency range 2–150 kHz contains some gaps related to the impact of the harmonics in the supply voltage on the nature of these emissions. It can be noticed that the conducted emissions from non-sinusoidal...
Objects with the B[e] phenomenon, whose defining features are the presence of forbidden emission lines and infrared excess coming from circumstellar dust, represent a broad range of evolutionary stages from pre-main-sequence to planetary nebulae. The...
Supermassive binary black holes (SMBBHs) are the anticipated byproducts of galaxy mergers and play a pivotal role in shaping galaxy evolution, gravitational wave emissions, and accretion physics. Despite their theoretical prevalence, direct observati...
Overall, climate concerns have been on the global agenda for many years now. However, the aviation sector’s impact on climate change has been receiving increased attention recently. This is primarily due to the adoption of the 2016 carbon offse...
Recently, significant attention has been paid to the large-scale use of renewable energy through high-voltage direct current (HVDC) because of its economic feasibility. At the same time, the growing demand for electricity and the increasing penetrati...
The B[e] phenomenon is manifested by a heterogeneous group of stars surrounded by gaseous and dusty circumstellar envelopes with similar physical conditions. Among these stars, the FS CMa-type objects are suspected to be binary systems, which could b...
The article presents a novel on-line partial discharge (PD) monitoring system for power transformers, whose functioning is based on the simultaneous use of three unconventional methods of PD detection: high-frequency (HF), ultra-high frequency (UHF),...
Overhead transmission lines are crucial components of power grid construction, and their carbon emissions significantly impact the low-carbon construction of the power grid. This study adopts a cradle-to-gate life cycle assessment (LCA) method, defin...
The main objective of the present study is the development of an “on-line” heating emissions modeling system based on simulated meteorological data and its integration with air quality modeling systems in order to improve their accuracy....
Strategically, the Republic of Croatia, with its economy focused on tourism, is directly connected to the sea and coastal area, and integrated management of this area contributes to the sustainable development strategy. Worldwide, the problem of atmo...
Boundary line models for N2O emissions from agricultural soils provide a means of estimating emissions within defined ranges. Boundary line models partition a two-dimensional region of parameter space into sub-regions by means of thresholds based on...
We report the recent results of a long-term spectroscopic and photometric monitoring of IRAS 17449+2320, a member of the least studied group of objects with the B[e] phenomenon called FS CMa-type objects. The main hypothesis for explaining the strong...
The quasar 3C 286, a well-known calibrator source in radio astronomy, was found to exhibit exceptional multiwavelength properties. Its rich and complex optical emission-line spectrum revealed its narrow-line Seyfert 1 (NLS1) nature. Given its strong...
For space-based atmospheric wind measurements, full-link simulation is critical for the optimization of the instrument indicators and the evaluation of the measurements’ performance. This paper presents observation simulations and error verific...
Simultaneous multi-band very long baseline interferometry (VLBI) observations at millimeter wavelengths have huge potential for various science cases. However, there exist difficulties in expanding the scientific targets, as the sensitivity of radio...
The Ne8+–He and –H2 collision systems are examined at impact speeds ranging between 0.17 and 0.4 a.u. Transition probabilities for electron capture are obtained using the two-center basis generator method performed within the independent-electron mod...
Direct metal deposition (DMD) can be used for the cladding of surfaces as well as repairing and additive manufacturing of parts and features. Process monitoring and control methods ensure a consistent quality during manufacturing. Monitoring by optic...
PSR B1259-63 is a gamma-ray binary system hosting a radio pulsar orbiting around a O9.5Ve star, LS 2883, with a period of ∼3.4 years. The interaction of the pulsar wind with the LS 2883 outflow leads to unpulsed broadband emission in the radio, X-ray...
A new spectroscopic study of HR 4049, a post-AGB star in a binary system, based on échelle spectra taken between 2019 and 2025 with the 0.81 m telescope of the Three College Observatory (North Carolina, USA) at a resolution of R ≈ 12,000...
Symbiotic stars, interacting binaries composed of a cool giant and a hot compact companion, exhibit complex variability across the electromagnetic spectrum. Over the past decades, large-scale photometric and spectroscopic surveys from ground- and spa...
The star
Be stars are rapidly rotating B-type stars surrounded by circumstellar disks formed from self-ejected material. Understanding the mechanisms driving mass ejection and disk formation, known as the Be phenomenon, requires a detailed investigation of th...
Be stars are characterized by the presence of a circumstellar Keplerian disk formed from material ejected from the rapidly rotating stellar surface. This article presents recent observational and theoretical progress on two central aspects of this ph...
We present the archive of spectroscopic photographic plates of the Universidad Católica historic observatory Manuel Foster. The archive includes more than 4800 plates covering the period of time from 1928 to 1991. The spectra present in the ar...
The IR spectra of Be stars display numerous hydrogen recombination lines, constituting a great resource for obtaining information on the physical and dynamic structures of different regions within the circumstellar envelope. Nevertheless, this spectr...
This review has two parts. The first one is devoted to the Barbier–Chalonge–Divan (BCD) spectrophotometric system, also known as the Paris spectral classification system. Although the BCD system has been applied and is still used for all...
Z Canis Majoris is a fascinating early-type binary with a Herbig Be primary and a FU Orionis-type secondary. Both of the stars exhibit sub-arcsecond jet-like ejecta. In addition, the primary is associated with the extended jet as well as with the lar...
Land urbanization (LU) is a defining feature of China’s urbanization process and has led to significant carbon emission challenges. To clarify the interaction mechanism between LU and carbon emissions (CEs), this study examines the temporal and...
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