Merger Stage Research Articles

The merger of falling tones: A perception study in Taiyuan Jin Chinese

Traditionally, there are five lexical tones in Taiyuan dialect including one rising tone and four falling tones, but previous studies have shown that some speakers merged the four falling tones Ping Sheng (T1)/ Shang Sheng (T2)/ Yin Ru (T4)/ Yang Ru (T5) in production. The current study investigates how 25 participants (14 females) with different age groups perceive four falling tones by means of discrimination and identification tasks. Both accuracy rate and reaction time are measured. Results show that: (i) the stabilization sequence in perception is as follows: T2>T1>T4>T5, indicating that T2 is the most stable tone while T5 is the most susceptible to merge with other tones. (ii) T4 and T5 exhibit the highest degree of merger, with a tendency to perceive T5 as T4. (iii) there are two stages of tone merger in Taiyuan dialect at the perceptual level. The pronounced confusion between T4 and T5 is at the first stage, with a primary trend of T5 merging into T4. And the confusion among T1 and the entering tones (Yin and Yang Ru) is at the second stage, indicating a possibility that the entering tones are more likely to merge with the non-entering tone, T1, after the loss of the glottal coda.

Coalescence Dynamics of Oil Droplets on an Air-Water Interface Driven by Surface Waves

This study reports the unique phenomenon of the coalescence of oil droplets floating over the water surface. For the first time, the coalescence has been initiated through the creation of externally generated low-amplitude surface waves. We used a simple and cost-effective method to manifest the surface waves over the free surface of water to study the merging dynamics. The time-lapse images depict the entire stage of parent droplets merging. The study reveals that the coalescence time required for the complete transformation of parent droplets into the resultant droplet increases as the number of parent droplets over the free surface of water increases. We studied the time-dependent variation in the velocity of two non-identical parent droplets. The experiment reveals that the smaller droplet propagates faster than the larger droplet over a free surface of water. The peak velocities of the two droplets are 2.0 cm/s and 1.07 cm/s, respectively. The point of deposition of droplets does not influence the coalescence phenomenon; whether the droplets are deposited at the center of the petri dish or the wall, they still show coalescence. However, the droplets that are deposited near the center of the petridish propagate faster compared to those deposited near the wall due to the higher intensity of vibration at the center.

Oxygen Abundance Throughout the Dwarf Starburst Galaxy IC 10

Measurements of oxygen abundance throughout galaxies provide insight to the formation histories and ongoing processes. Here we present a study of the gas-phase oxygen abundance in the H ii regions and diffuse gas of the nearby starburst dwarf galaxy, IC 10. Using the Keck Cosmic Web Imager at W. M. Keck Observatory, we map the central region of IC 10 from 3500 to 5500 Å. The auroral [O III] 4363 Å line is detected with a high signal-to-noise ratio in 12 of 46 H II regions observed, allowing for direct measurement of the oxygen abundance, yielding a median and standard deviation of 12+log(O/H)=8.37±0.25 . We investigate trends between these directly measured oxygen abundances and other H II region properties, finding weak negative correlations with the radius, velocity dispersion, and luminosity. We also find weak negative correlations between the oxygen abundance and the derived quantities of turbulent pressure and ionized gas mass, and a moderate correlation with the derived dynamical mass. Strong line, R 23 abundance estimates are used in the remainder of the H II regions and on a resolved spaxel-by-spaxel basis. There is a large offset between the abundances measured with R 23 and the auroral line method. We find that the R 23 method is unable to capture the large range of abundances observed via the auroral line measurements. The extent of this variation in the measured abundances further indicates a poorly mixed interstellar medium in IC 10, which is not typical of dwarf galaxies and may be partly due to the ongoing starburst, accretion of pristine gas, or a late stage merger.

Optimized Parallel Sorting of 2D Arrays Using Row-Major Division and Final Merging Strategy

In this paper, we present a novel approach to sorting 2D arrays that leverages row-major order partitioning followed by a single, parallelized merging stage. We demonstrate how this method optimizes cache usage and reduces overhead in high-performance computing environments. Our results indicate significant performance improvements compared to traditional parallel sorting techniques, particularly in large-scale datasets

Merging galaxies in isolated environments

Context. It is now well known that certain massive galaxies undergo enormous enhancements in their star formation rate (SFR) when they undergo major mergers. These enhancements can be as high as 100 times the SFR of unperturbed galaxies of the same stellar mass. Previous works have found that the size of this boost in star formation (SF) is related to the morphology of and the proximity to the companion. The same trend has also been observed for the fraction of active galactic nuclei (AGN), where galaxies that are closer together tend to have higher AGN fractions. Aims. We aim to analyse the SF enhancement and AGN fraction evolution during the merger process by using a more timeline-like merger sequence. Additionally, we aim to determine the relation between the SF enhancement in mergers and the morphology of the galaxies involved. Methods. Taking advantage of the stellar masses (M*) and SFRs of the ∼600 nearby isolated mergers obtained in our previous study, we calculated the distance of each of our galaxies from the star-forming main sequence (MS; specific SFR (sSFR)/sSFRMS), which werefer to as the SF mode. We then analysed how the SF mode varies during the merger process as a function of morphology and M*. Additionally, we analysed the AGN content of our mergers, using multiple diagnostics based on emission line ratios and WISE colours. Results. We observed that, overall, merging galaxies show an SF mode that is governed by their morphology. Spirals typically show high SF mode values, while highly disturbed (HD) galaxies are generally even more enhanced (median values of +0.8 dex and +1.08 dex above the MS, respectively). In contrast, elliptical and lenticular galaxies show the lowest SF modes, as expected. However, even they show SF enhancement compared to their unperturbed counterparts. For example, their median SF mode is just within the 1-sigma scatter of the MS, and this can occur even before the galaxies have coalesced. We observed a trend for the SF mode to gradually increase with increasing merger stage. We did not find a clear dependency of the observed AGN fraction on the merger stage for the majority of our classification methods. Conclusions. We find mergers can significantly enhance SF in galaxies of all morphologies. For early-type galaxies, this could suggest that some gas was present prior to the merger, which may be triggered to form stars by the tidal interaction. As the SF enhancement continues throughout the merger process, this suggests that the enhancement may be a long-lived event, contrary to the short starbursts seen in some models.

Enhancing image recognition robustness in early weed detection through optimal training data curation

Abstract Using convolutional neural networks (CNNs) for image recognition is effective for early weed detection. However, the impact of training data curation, specifically concerning morphological changes during the early growth phases of weeds, on recognition robustness remains unclear. We focused on four weed species (giant ragweed [Ambrosia trifida L.], red morningglory [Ipomoea coccinea L.], pitted morningglory [Ipomoea lacunosa L.], and burcucumber [Sicyos angulatus L.]) with varying cotyledon and true leaf shapes. Creating 16 models in total, we employed four dataset patterns with different growth stage combinations, two image recognition algorithms (object detection: You Look Only Once [YOLO] v5 and image classification: Visual Geometry Group [VGG] 19), and two conditions regarding the number of species treated (four and two species). We evaluated the effects of growth stage training on weed recognition success using two datasets. One evaluation revealed superior results with a single class/species training dataset, achieving >90% average precision for detection and classification accuracy under most conditions. The other dataset revealed that merging different growth stages with different shapes as a class effectively prevented misrecognition among different species when using YOLOv5. Both results suggest that integrating different shapes in a plant species as a single class is effective for maintaining robust recognition success amid temporal morphological changes during the early growth stage. This finding not only enhances early detection of weed seedlings but also bolsters the robustness of general plant species identification.

In Situ PL Probes the Effect of 2D SnSe Nanosheets on the Crystallization Process of CsPbI2Br Perovskite Solar Cells.

Reducing defects in the active layer is important for improving the crystalline quality of all-inorganic perovskite solar cells (PSCs). Exploring novel additives is one of the most promising approaches to minimize active layer defects. In this work, two-dimensional (2D) SnSe nanosheets with excellent optoelectronic properties are prepared using an ultrasonic exfoliation method. The prepared 2D SnSe nanosheets are introduced into a CsPbI2Br precursor, which reduces the defect formation at grain boundaries and enhances the crystallinity of CsPbI2Br perovskites. We use the in situ photoluminescence (PL) technique to investigate the role of 2D materials in the crystallization process. The results show that SnSe nanosheets primarily shorten the grain boundary merging time and reduce the defect generation during the grain boundary merging stage, thereby regulating the crystallization of perovskite. In addition, SnSe nanosheets passivate uncoordinated Pb atoms at grain boundaries by Se atoms, further reducing the defect density in perovskite. As a result, PSCs exhibit a higher power conversion efficiency (PCE) of 14.24% and a Voc of 1.22 V. This study highlights the role of 2D materials in enhancing the crystalline quality and PCE of PSCs.

Exploring the impact of galactic interactions and mergers on the central oxygen abundance of APEX/EDGE–CALIFA galaxies

ABSTRACT In this study, we explore the impact of the galactic interaction/mergers on the central oxygen abundance. We analyse 234 star-forming galaxies included in the Calar Alto Legacy Integral Field Area survey with integrated molecular gas observations from the Atacama Pathfinder EXperiment millimeter telescope and the CARMA interferometer. This database has the most optical integral field spectroscopy data with CO data for yet, with integrated measurements within $\sim 1~{R_{\rm{eff}}}$. Our sample includes 125 isolated galaxies (control sample) and 109 galaxies in different merging stages. We find that despite whether the merging galaxies show an increase or decrease in their molecular gas fraction, the oxygen abundance does not vary significantly, in comparison to our control sample. Therefore, the enhancement and suppression of oxygen abundance are similar in both isolated galaxies and interacting/merging galaxies. On the contrary, regardless of the merger stage (including isolated sample), galaxies that present an increase in their specific star formation rate present a metallicity dilution. We suggest that both internal and external events affect the chemical composition of merging galaxies.

New Observational Recipes for Measuring Dynamical States of Galaxy Clusters

During cluster assembly, a cluster’s virialization process leaves behind signatures that can provide information on its dynamical state. However, no clear consensus yet exists on the best way to achieve this. Therefore, we attempt to derive improved recipes for classifying the dynamical states of clusters in observations using cosmological simulations. The cluster halo mass and their subhalos’ mass are used to 1014 M ⊙ h −1 and 1010 M ⊙ h −1 to calculate five independent dynamical state indicators. We experiment with recipes by combining two to four indicators for detecting specific merger stages, like recent and ancient mergers. These recipes are made by plotting merging clusters and a control sample of relaxed clusters in multiple-indicator parameter space, then applying a rotation matrix method to derive the best way to separate mergers from the control sample. The success of the recipe is quantified using the success rate and overlap percentage of the merger and control histograms along the newly rotated x-axis. This provides us with recipes using different numbers of combined indicators and for different merger stages. Among the recipes, the stellar mass gap and center offset are the first and second most dominant of the indicators, and using more indicators improves the effectiveness of the recipe. When applied to observations, our results show good agreement with literature values of cluster dynamical states.

Galaxy merger challenge: A comparison study between machine learning-based detection methods

Aims. Various galaxy merger detection methods have been applied to diverse datasets. However, it is difficult to understand how they compare. Our aim is to benchmark the relative performance of merger detection methods based on machine learning (ML). Methods. We explore six leading ML methods using three main datasets. The first dataset consists of mock observations from the IllustrisTNG simulations, which acts as the training data and allows us to quantify the performance metrics of the detection methods. The second dataset consists of mock observations from the Horizon-AGN simulations, introduced to evaluate the performance of classifiers trained on different, but comparable data to those employed for training. The third dataset is composed of real observations from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) survey. We also compare mergers and non-mergers detected by the different methods with a subset of HSC-SSP visually identified galaxies. Results. For the simplest binary classification task (i.e. mergers vs. non-mergers), all six methods perform reasonably well in the domain of the training data. At the lowest redshift explored 0.1 < ɀ < 0.3, precision and recall generally range between ~70% and 80%, both of which decrease with increasing ɀ as expected (by ~5% for precision and ~10% for recall at the highest ɀ explored 0.76 < ɀ < 1.0). When transferred to a different domain, the precision of all classifiers is only slightly reduced, but the recall is significantly worse (by ~20–40% depending on the method). Zoobot offers the best overall performance in terms of precision and F1 score. When applied to real HSC observations, different methods agree well with visual labels of clear mergers, but can differ by more than an order of magnitude in predicting the overall fraction of major mergers. For the more challenging multi-class classification task to distinguish between pre-mergers, ongoing-mergers, and post-mergers, none of the methods in their current set-ups offer good performance, which could be partly due to the limitations in resolution and the depth of the data. In particular, ongoing-mergers and post-mergers are much more difficult to classify than pre-mergers. With the advent of better quality data (e.g. from JWST and Euclid), it is of great importance to improve our ability to detect mergers and distinguish between merger stages.

CO Observations of Early-mid Stage Major Mergers in the MaNGA Survey

We present a study of the molecular gas in early-mid stage major mergers, with a sample of 43 major-merger galaxy pairs selected from the Mapping Nearby Galaxies at Apache Point Observatory survey and a control sample of 195 isolated galaxies selected from the xCOLD GASS survey. Adopting kinematic asymmetry as a new effective indicator to describe the merger stage, we aim to study the role of molecular gas in the merger-induced star formation enhancement along the merger sequence of galaxy pairs. We obtain the molecular gas properties from CO observations with the James Clerk Maxwell Telescope, Institut de Radioastronomie Milimetrique 30 m telescope, and the MaNGA-ARO Survey of CO Targets survey. Using these data, we investigate the differences in molecular gas fraction ( fH2 ), star formation rate (SFR), star formation efficiency (SFE), molecular-to-atomic gas ratio ( MH2 /M H i ), total gas fraction (f gas), and the SFE of total gas (SFEgas) between the pair and control samples. In the full pair sample, our results suggest the fH2 of paired galaxies is significantly enhanced, while the SFE is comparable to that of isolated galaxies. We detect significantly increased fH2 and MH2 /M H i in paired galaxies at the pericenter stage, indicating an accelerated transition from atomic gas to molecular gas due to interactions. Our results indicate that the elevation of fH2 plays a major role in the enhancement of global SFR in paired galaxies at the pericenter stage, while the contribution of enhanced SFE in specific regions requires further explorations through spatially resolved observations of a larger sample spanning a wide range of merger stages.

Effects of wind speed, spacing distance and heat release rate on the combustion and flame merging characteristics of two extra-thin line fires

This paper investigated the mutual interaction between two extra-thin line fires under different wind speeds of 0.4, 0.6, 0.8, 1.0 and 1.2 m/s by using a small-scale wind tunnel. The experiments involved the spacing distances of 5, 10, 15, 20, 25, 30, 35 and 40 cm, and the heat release rates of 19.4, 25.7 and 32.7 kW, respectively. The results show that the flame merging probability increase, as the wind speed or the heat release rate increases. Compared with the two rectangular or square fires, the flame height and flame length will be smaller at the same heat release rate for the extra-thin line fires. Meanwhile, the line fires will decrease the flame merging, making the downstream flame temperature smaller than that of the upstream at the relatively larger wind speed or heat release rate. The interesting finding is that, with the increase of the heat release rate, the flame inclination angle will increase in the fully merging stage, which is opposite to that of square fires. Correspondingly, the flame merging model is built on the influences of the buoyancy force and inertial force of the horizontal wind, which can give the good explanation on this behavior.

Effects of confined distance and wire spacing on flame spread over double electrical wires for the layout design in buildings

In this study, the flame merging and flame spread behaviors over two identical parallel electrical wires (the ratios of copper core diameter to entire wire diameter are: 6mm/10 mm and 8mm/12 mm for typeⅠand typeⅡ, respectively) were experimentally investigated under different wire spacings (3∼18 mm) and confined distances(10∼30 mm). The results show that the smaller confined distance D will promote the merging, making the wire spacing s increase for the fully merging. With the increase of D, the flame width and flame spread rate Vf will increase.While the flame height will be stretched at smaller D. And Vf is larger than that of single wire at the same D for different wire spacings.The interesting finding is that a pool fire is formed at the middle of the wire spacing when s and D are small, which will enhance the flame spread.The heat flux feedback of components including of the conductive heat flux q˙c″, the first single flame heat flux q˙f1″, the second flame heat flux q˙f2″, the pool fire heat flux q˙pf″ and the gypsum board heat flux q˙g″ are quantitatively analyzed. At the intermittent and non merging stages, the convective and radiative heat fluxes q˙vf2″ and q˙rf2″ will decrease largely due to the interaction weakened greatly. Based on the heat transfer analysis, a flame spread model is established, which can well predict the flame spread rate.These findings can give the useful suggestions on the layout design of electrical wires in confined space in buildings.

Clumpy star formation and an obscured nuclear starburst in the luminous dusty z = 4 galaxy GN20 seen by MIRI/JWST

Dusty star-forming galaxies emit most of their light at far-infrared to millimeter wavelengths as their star formation is highly obscured. Far-infrared and millimeter observations have revealed their dust, neutral and molecular gas properties. The sensitivity of JWST at rest-frame optical and near-infrared wavelengths now allows the study of the stellar and ionized gas content. We investigate the spatially resolved distribution and kinematics of the ionized gas in GN20, a dusty star-forming galaxy at z = 4.0548. We present deep MIRI/MRS integral field spectroscopy of the near-infrared rest-frame emission of GN20. We detect spatially resolved Paα, out to a radius of 6 kpc, distributed in a clumpy morphology. The star formation rate derived from Paα (144 ± 9 M⊙ yr−1) is only 7.7 ± 0.5% of the infrared star formation rate (1860 ± 90 M⊙ yr−1). We attribute this to very high extinction (AV = 17.2 ± 0.4 mag, or AV, mixed = 44 ± 3 mag), especially in the nucleus of GN20, where only faint Paα is detected, suggesting a deeply buried starburst. We identify four, spatially unresolved, clumps in the Paα emission. Based on the double peaked Paα profile, we find that each clump consists of at least two sub-clumps. We find mass upper limits consistent with them being formed in a gravitationally unstable gaseous disk. The ultraviolet bright region of GN20 does not have any detected Paα emission, suggesting an age of more than 10 Myr for this region of the galaxy. From the rotation profile of Paα, we conclude that the gas kinematics are rotationally dominated and the vrot/σm = 3.8 ± 1.4 is similar to low-redshift luminous infrared galaxies. From the Paα kinematics, we cannot distinguish between a rotational profile of a large disk and a late stage merger mimicking a disk. We speculate that GN20 is in the late stage of a major merger, where the clumps in a large gas-rich disk are created by the major merger, while the central starburst is driven by the merger event.

Deformable vector fields warping for modelling of irregular breathing.

Purpose
4D computed tomography (4DCT) is the clinical standard to image organ motion in radiotherapy, although it is limited in imaging breathing variability. We propose a method to transfer breathing motion across longitudinal imaging datasets to include intra-patient variability and verify its performance in lung cancer patients. 
Methods 
Five repeated control 4DCTs for 6 non-small cell lung cancer patients were combined into multi-breath datasets (m4DCT) by merging stages of deformable image registration to isolate respiratory motion. The displacement of the centre of mass of the primary tumour and its volume changes were evaluated to quantify intra-patient differences. Internal target volumes defined on the m4DCT were compared with those conventionally drawn on the 4DCT.
Results 
Motion analysis suggests no discontinuity at the junction between successive breaths, confirming the method's ability to merge repeated imaging into a continuum. Motion (variability) is primarily in superior-inferior direction and goes from 14.4 mm (8.7 mm) down to 0.1 mm (0.6 mm), respectively for tumours located in the lower lobes or most apical ones. On average, up to 65% and 74% of the tumour volume was subject to expansion or contraction in the inhalation and exhalation phases. These variations lead to an enlargement of the ITV up to 8% of its volume in our dataset.
Conclusion 
4DCT can be extended to model variable breathing motion by adding synthetic phases from multiple time-resolved images. The inclusion of this improved knowledge of patients' breathing allows better definition of treatment volumes and their margins for radiation therapy.&#xD.

EFT corrections to scalar and vector quasinormal modes of rapidly rotating black holes

Quasinormal modes characterize the final stage of a black hole merger. In this regime, spacetime curvature is high, making these modes effective tools to probe potential corrections to general relativity. In this paper, we utilize the effective field theory framework to compute the leading-order correction to massless scalar and electromagnetic quasinormal modes. Proceeding perturbatively in the size of the effective field theory length scale, we describe a general method to compute the frequencies for Kerr black holes of any spin. In the electromagnetic case, we study both parity even and parity odd effective field theory corrections, and, surprisingly, prove that the two have the same spectrum. Furthermore, we find that, the corrected frequencies separate into two families, corresponding to the two polarizations of light. The corrections pertaining to each family are equal and opposite. Our results are validated through several consistency checks. Published by the American Physical Society 2024

Effects of single and simultaneous Fe, He ions irradiations on CoCrFeMnNi high entropy alloy

Simultaneous irradiation was performed on CoCrFeMnNi high entropy alloy (HEA) at room temperature using Fe ions and He ions, and single Fe ions irradiation and single He ions irradiation were used as comparisons. The synergistic effect of the two ions on irradiation-induced defects such as dislocation loops and He bubbles, as well as the effect of irradiation damage on the nano-hardness were investigated. As the irradiation dose increased, a distribution with small and dense dislocation loops was first formed in CoCrFeMnNi HEA, and then these dislocation loops merged and grew. However, compared to pure metal, CoCrFeMnNi HEA entered the dislocation loop merging stage at a higher threshold dose due to its higher defect recombination capacity and higher critical stress of initial dislocation motion. Compared with the single Fe ions irradiation, the addition of He in the simultaneous irradiation accelerated the merging and growth of dislocation loops and decreased the density of dislocation loops. At the same He dose, simultaneous irradiation produced a higher vacancy concentration than single He ions irradiation, which increased He mobility, leading to wider He bubble layer and larger He bubble size. CoCrFeMnNi HEA hardened after irradiation with all three parameters in the order of single He ions irradiation > single Fe ions irradiation > simultaneous Fe+He ions irradiation. This study provided a deeper understanding of the irradiation damage mechanism of HEA in complex irradiation environment.

Experimental study on upward fire spread of polyurethane foam under double fire source conditions with different restricted facade Structures

This paper examines the impact of insulation material (PU) fire spread characteristics under dual fire source conditions considering various restricted facade Structures. It is found that the merging tendency is affected by the flame inclination angle θ1 and mapping length L. Additionally, the flame merging behavior is determined by the combined effects of the chimney effect, inter-flame air entrainment, and heat transfer changes caused by the restricted angle. The Inter-flame air entrainment λ was introduced to confirm that there is a positive correlation between flame height and Inter-flame air entrainment in the large-angle restricted facade Structures (θ=120°,150°，180°). By introducing the hydraulic diameter Deff* to compare the experimental data with the previous flame pulsation frequency model, the proposed f=0.5g/Deff* model can further improve the accuracy of the prediction results. During the flame merging stage, the axial temperature field distribution on the PU board surface was compared. The study found that the restricted facade Structures resulting in a cooling effect due to fresh air entrainment at the bottom with the chimney effect. As a result, the small-angle restricted facade Structures (θ=30°，60°，90°) led to an upper-high and lower-low distribution of axial temperature.

Merging galaxies in isolated environments. I. Multiband photometry, classification, stellar masses, and star formation rates

Extragalactic surveys provide significant statistical data for the study of crucial galaxy parameters (e.g. stellar mass, M$_*$, and star formation rate ,SFR) used to constrain galaxy evolution under different environmental conditions. These quantities are derived using manual or automatic methods for galaxy detection and flux measurement in imaging data at different wavelengths. The reliability of these automatic measurements, however, is subject to mis-identification and poor fitting due to the morphological irregularities present in resolved nearby galaxies (e.g. clumps, tidal disturbances, star- forming regions) and its environment (galaxies in overlap). Our aim is to provide accurate multi-wavelength photometry (from the UV to the IR, including GALEX, SDSS, and WISE) in a sample of $ 600$ nearby (z<0.1) isolated mergers, as well as estimations of M$_*$ and SFR. We performed photometry following a semi-automated approach using SExtractor, confirming by visual inspection that we successfully extracted the light from the entire galaxy, including tidal tails and star-forming regions. We used the available SED fitting code MAGPHYS in order to estimate M$_*$ and SFR. We provide the first catalogue of isolated merging galaxies of galaxy mergers including aperture-corrected photometry in 11 bands (FUV, NUV, u, g, r, i, z, W1, W2, W3, and W4), morphological classification, merging stage, M$_*$, and SFR. We found that SFR and M$_*$ derived from automated catalogues can be wrong by up to three orders of magnitude as a result of incorrect photometry. Contrary to previous methods, our semi-automated method can reliably extract the flux of a merging system completely. Even when the SED fitting often smooths out some of the differences in the photometry, caution using automatic photometry is suggested as these measurements can lead to large differences in M$_*$ and SFR estimations.

UNITED CITIES OF THE MOSCOW REGION: THE RESULT OF EVOLUTIONARY DEVELOPMENT OR ADMINISTRATIVE TRANSFORMATIONS

Using the example of the Moscow region and based on the analysis of various information, including data from cellular operators, we studied a poorly explored phenomenon of absorption of some cities (towns) by others. The objectives of the article included the development of an approach to the study of united cities (towns), including an assessment of the preservation of their self-sufficiency as autonomous centers, as well as the identification of factors and stages of integration.It is revealed that in the Soviet period the unification of cities (towns) in the Moscow region occurred as a result of the evolutionary development of neighboring centers and their merger. In recent decades the inclusion of cities (towns) into neighboring centers is mainly the result of artificial amalgamation during the current stage of municipal reform. Based on the example of the three largest takeover cases of recent times (Khimki - Skhodnya, Balashikha - Zheleznodorozhny, Podolsk - Klimovsk), and using the data of cellular operators, we analysed the borders, population numbers and the system of external relations of the population. It is shown that all united cities (towns) under consideration continue to be independent centers (in terms of population size and density, and their role as local centers of labor gravity).The study of the absorbed cities (towns) of the Moscow region made it possible to identify the stages of their integration. It is revealed that after formal administrative subordination, the united center goes through the stages of infrastructural and socio-cultural merger, ending with the stage of complete absorption. It is shown that under the influence of a number of factors (geographical proximity, population size, economic structure, etc.), merger processes can accelerate or slow down.A methodology proposed in the article is aimed at forming an approach to the study of absorbed cities (towns). The latter disappear from the field of view of official statistics and specialists, despite their continued functioning as independent centers for a long time.