Formation History Research Articles

The Star Formation History of the Young Open Cluster NGC 2244: Study of the Binary Fraction

A star formation history (SFH) is the stellar record of the various processes that shaped a galaxy and star clusters since its birth to its current physical state. Studying the young open cluster NGC 2244, and in particular its massive stellar population, can improve our understanding of its formation mechanism, stellar evolution, feedback, and provide a basis for a better understanding of the formation of extragalactic star clusters. In this contribution, we present the first steps towards the derivation of the SFH of NGC 2244. We discuss the first results concerning the membership determination and the observed binary fractions of O- and B-type stars among NGC 2244. Finally, an overview of the forthcoming steps is also presented.

Stochastic Modeling of Star Formation Histories. III. Constraints from Physically Motivated Gaussian Processes

Galaxy formation and evolution involve a variety of effectively stochastic processes that operate over different timescales. The extended regulator model provides an analytic framework for the resulting variability (or “burstiness”) in galaxy-wide star formation due to these processes. It does this by relating the variability in Fourier space to the effective timescales of stochastic gas inflow, equilibrium, and dynamical processes influencing giant molecular clouds' creation and destruction using the power spectral density (PSD) formalism. We use the connection between the PSD and autocovariance function for general stochastic processes to reformulate this model as an autocovariance function, which we use to model variability in galaxy star formation histories (SFHs) using physically motivated Gaussian processes in log star formation rate (SFR) space. Using stellar population synthesis models, we then explore how changes in model stochasticity can affect spectral signatures across galaxy populations with properties similar to the Milky Way and present-day dwarfs, as well as at higher redshifts. We find that, even at fixed scatter, perturbations to the stochasticity model (changing timescales vs. overall variability) leave unique spectral signatures across both idealized and more realistic galaxy populations. Distributions of spectral features including Hα and UV-based SFR indicators, Hδ and Ca H and K absorption-line strengths, D n (4000), and broadband colors provide testable predictions for galaxy populations from present and upcoming surveys with the Hubble Space Telescope, James Webb Space Telescope, and Nancy Grace Roman Space Telescope. The Gaussian process SFH framework provides a fast, flexible implementation of physical covariance models for the next generation of spectral energy distribution modeling tools. Code to reproduce our results can be found at https://github.com/kartheikiyer/GP-SFH.

Chemodynamical Nature of the Anticenter Stream and Monoceros Ring

In the epoch of deep photometric surveys, a large number of substructures—e.g., overdensities and streams—have been identified. With the help of astrometry and spectroscopy, the community has revealed a complex picture of our Milky Way (MW) after investigating their origins. The off-plane substructures the Anticenter Stream (ACS) and Monoceros Ring (MNC), once considered as dissolving dwarf galaxies, were later found to share similar kinematics and metallicity with the Galactic outer thin disk. In this work, we aim to chemically tag ACS and MNC with high-accuracy abundances from the APOGEE survey. By extrapolating chemical abundance trends in the outer thin-disk region (10 < R GC < 18 kpc, 0 < ∣Z GC∣ < 3 kpc), we found that ACS and MNC stars show consistent chemical abundances as the extrapolating values for 12 elements, including C, N, O, Mg, Al, Si, K, Ca, Cr, Mn, Co, and Ni. The similar chemical patterns indicate that ACS and MNC have a similar star formation history as the MW outer thin disk, while we also excluded their dwarf galaxy association, as they are distinctive in multiple chemical spaces. The ages of ACS and MNC stars are consistent with the time of the first Sagittarius dSph passage, indicating their possible connection.

Middle Miocene volcanic flare up preceding and synchronous with the Langhian/Serravallian sea‐level decline in the North Pannonian Basin: Insights from 40Ar/39Ar dating, geo‐seismic analysis and 3D visualization of the subterranean Kráľová stratovolcano

AbstractThe Pannonian Basin System originated from the collision of the African and European tectonic plates, followed by the Miocene extensional collapse that led to the development of a back‐arc basins. Accurate dating is essential to comprehend the tectono‐volcanic evolution of the region, particularly in the under‐studied Danube Basin. Single‐grain 40Ar/39Ar dating has revealed that volcanic activity in the Danube Basin commenced around 14.1 million years ago, aligning with previous biostratigraphic and radioisotope data from nearby volcanic fields. The initial Middle Miocene pyroclastic deposits were generated by intermediate high K calc‐alkaline magmas, contributing significantly to the deposition of thick layers of fine vitric tuffs. The timing and chemistry of the volcanism are consistent with the Badenian rift phase in the Middle Miocene within the Carpathian–Pannonian region, suggesting an intraplate back‐arc volcanic environment. Three‐dimensional imaging has exposed the buried Kráľová stratovolcano, revealing its impressive scale with a thickness between 2620 and 5000 m and a base diameter of 18–30 km. Such dimensions place it among the ranks of the world's largest stratovolcanoes, indicating its substantial impact on the evolution of the Carpathian–Pannonian area. The complex formation history of the stratovolcano points to multiple phases of growth. Furthermore, the basin controlling Mojmírovce‐Rába fault's intersection with the stratovolcano implies that fault activity was subsequent to the volcanic activity, being younger than 14.1 million years. Regional age data consistently indicates that volcanic activity in the Danube Basin reached its zenith just prior to and during the lower/upper Badenian sea‐level fall (Langhian/Serravallian). K‐metasomatism is unique to the stratovolcanic structures and is not observed in the wider regional setting. This study supports the notion of an intricate, interconnected subterranean intrusive system within the stratovolcano, underscoring the complex interplay between geological structures and volcanic processes.

Outshining by Recent Star Formation Prevents the Accurate Measurement of High-z Galaxy Stellar Masses

We demonstrate that the inference of galaxy stellar masses via spectral energy distribution (SED) fitting techniques for galaxies formed in the first billion years after the Big Bang carries fundamental uncertainties owing to the loss of star formation history (SFH) information from the very first episodes of star formation in the integrated spectra of galaxies. While this early star formation can contribute substantially to the total stellar mass of high-redshift systems, ongoing star formation at the time of detection outshines the residual light from earlier bursts, hampering the determination of accurate stellar masses. As a result, order-of-magnitude uncertainties in stellar masses can be expected. We demonstrate this potential problem via direct numerical simulation of galaxy formation in a cosmological context. In detail, we carry out two cosmological simulations with significantly different stellar feedback models, which span a significant range in SFH burstiness. We compute the mock SEDs for these model galaxies at z = 7 via calculations of 3D dust radiative transfer, and then backward fit these SEDs with prospector SED fitting software. The uncertainties in derived stellar masses that we find for z > 7 galaxies motivate the development of new techniques and/or priors for SFH to model star formation in the early Universe.

Constraining the top-light initial mass function in the extended ultraviolet disk of M 83

Context. The universality or non-universality of the initial mass function (IMF) has significant implications for determining star formation rates and star formation histories from photometric properties of stellar populations. Aims. We reexamine whether the IMF is deficient in high-mass stars (top-light) in the low-density environment of the outer disk of M 83 and constrain the shape of the IMF therein. Methods. Using archival Galaxy Evolution Explorer (GALEX) far ultraviolet (FUV) and near ultraviolet (NUV) data and new deep OmegaCAM narrowband Hα imaging, we constructed a catalog of FUV-selected objects in the outer disk of M 83. We counted Hα-bright clusters and clusters that are blue in FUV−NUV in the catalog, measured the maximum flux ratio FHα/fλFUV among the clusters, and measured the total flux ratio ΣFHα/ΣfλFUV over the catalog. We then compared these measurements to predictions from stellar population synthesis models made with a standard Salpeter IMF, truncated IMFs, and steep IMFs. We also investigated the effect of varying the assumed internal extinction on our results. Results. We are not able to reproduce our observations with models using the standard Salpeter IMF or the truncated IMFs. It is only when assuming an average internal extinction of 0.10 &lt; AV &lt; 0.15 in the outer disk stellar clusters that models with steep IMFs (α &gt; 3.1) simultaneously reproduce the observed cluster counts, the maximum observed FHα/fλFUV, and the observed ΣFHα/ΣfλFUV. Conclusions. Our results support a non-universal IMF that is deficient in high-mass stars in low-density environments.

ՀԱՎԱՔԱԳՐՄԱՆ ԱՌԱՆՁՆԱՀԱՏԿՈՒԹՅՈՒՆՆԵՐԸ ՈՐՊԵՍ ՄՌԿ ԿԱՐԵՎՈՐԱԳՈՒՅՆ ԳՈՐԾԱՌՈՒՅԹ / FEATURES OF RECRUITMENT AS ONE OF THE MAIN FUNCTIONS OF MANAGING HUMAN RESOURCES

The purpose of this article is to present one of the HRM functions - recruitment, as well as to emphasize the importance of the function in HRM processes. In order to achieve the goal, the following tasks were set:  based on scientific materials, to research and present the evolution and formation history of recruitment, the stages of recruitment, the use of technologies in recruitment, modern trends and strategies of recruitment;  to explore and to emphasize the importance of organizational culture and the core recruiter’s because recruitment process is one of the fundamental functions of HR and helps to increase the effectiveness of the organization in the short and long term. With recruitment done properly, an organization has happier and more productive employees. The recruitment process creates a favorable working environment and good employee relations. Analysis, synthesis, induction, deduction and historical comparative methods were used during the research. The main conclusions made in the framework of the research are:  The recruitment process is highly dependent on the organizational culture;  Skill-based recruitment is replacing knowledge-based recruitment;  The entry of innovative technologies and artificial intelligence into recruitment is inevitable and helps to improve the recruitment process.

Dark Sage: Next-generation semi-analytic galaxy evolution with multidimensional structure and minimal free parameters

Abstract After more than five years of development, we present a new version of Dark Sage, a semi-analytic model (SAM) of galaxy formation that breaks the mould for models of its kind. Included among the major changes is an overhauled treatment of stellar feedback that is derived from energy conservation, operates on local scales, affects gas gradually over time rather than instantaneously, and predicts a mass loading factor for every galaxy. Building on the model’s resolved angular momentum structure of galaxies, we now consider the heating of stellar discs, delivering predictions for disc structure both radially and vertically. We add a further dimension to stellar discs by tracking the distribution of stellar ages in each annulus. Each annulus–age bin has its own velocity dispersion and metallicity evolved in the model. This allows Dark Sage to make structural predictions for galaxies that previously only hydrodynamic simulations could. We present the model as run on the merger trees of the highest-resolution gravity-only simulation of the MillenniumTNG suite. Despite its additional complexity relative to other SAMs, Dark Sage only has three free parameters, the least of any SAM, which we calibrate exclusively against the cosmic star formation history and the $z = 0$ stellar and H i mass functions using a particle-swarm optimisation method. The Dark Sage codebase, written in C and python, is publicly available at https://github.com/arhstevens/DarkSage.

RECURRENCE OF TRICHILEMMAL CYSTS ON THE SCALP: A CASE REPORT

Background: Trichilemmal cysts, benign lesions originating from the outer root sheath of hair follicles, commonly present as asymptomatic nodules on the scalp. Despite their typically non-threatening nature, cases of recurrence and familial clustering underscore the need for a comprehensive understanding of their clinical course and potential genetic influences. Case Presentation: We present a 44-year-old male with a lifelong history of trichilemmal cysts who sought surgical intervention due to discomfort caused by cyst formation on the scalp. Over a 15-year period, three cysts were surgically removed, with one inadvertently missing, leading to its progressive enlargement and the emergence of new cysts over the subsequent eight years. Magnetic resonance imaging revealed multiple well-defined cystic lesions with distinct margins, consistent with trichilemmal cysts. A second surgical procedure successfully excised all cysts, confirming the diagnosis through histopathological examination. Conclusion: The presented case highlights the challenges in managing recurrent trichilemmal cysts and emphasizes the importance of comprehensive surgical intervention. The benign nature of the lesions was reaffirmed through negative histopathological findings for dysplasia or malignancy. The family history of similar cystic formations raises intriguing questions about potential genetic predispositions and shared environmental factors. This case contributes valuable insights into the clinical dynamics of trichilemmal cysts and prompts further exploration into their genetic underpinnings.

SOME REFLECTIONS ON THE ISLAMIZATION OF KNOWLEDGE

Since the 1970s, Muslim intellectuals have offered alternatives to Euro-American dominance in the realm of knowledge. A new movement known as the “Islamization of Knowledge” was founded arguing for an epistemological revolution that hinged on the ideals of Tawhid (unity) and the sacralization of “secularized” disciplines and subjects. This article offers some critical reflections on this intriguing undertaking. In our view, the Islamization of Knowledge project was structured primarily around the idea of civilizational difference and a partial reading of the history of knowledge formation. The notion that knowledge can be “Islamized” or has been “secularized” is equally problematic because human knowledge incorporates both secular and sacred dimensions. Duality exists only in the minds and practices of knowledge producers and policymakers.

Дикі стада Bos taurus в Україні: огляд випадків та значення для розвитку ідей ревайлдингу

Examples of the formation of free groups of cattle (Bos taurus) are considered on the example of the Slobozhansky herd and two other groups remote from the Luhansk region—the Tendra and Chernobyl groups. The Luhansk herd was formed as a farming experiment; it existed from the early 1990s until around 2007, reaching ca. 40–50 animals in peak years, surviving cold winters and summer droughts well, but eventually being depopulated by poachers. Other groups were formed under different circumstances. The Tendra group is a herd of up to 100 animals that lived in the natural boundaries of an essentially island-like location; it was annually renewed with young animals, up to 30% of the herd, and animals were also taken from there for the needs of the military. The Chornobyl herd was formed from escaped cows and is constantly monitored. Finally, significant progress has been made in the Beremytsky Park as part of the international project Aurochs 2.0. The history of herd formation shows that animals are highly adaptable to exist without human care, provided that there is little or no human removal. These examples demonstrate the effectiveness of using different cow breeds for rewilding programmes.

A case report on the simultaneous occurrence of cancer in The Tongue and Breast

Squamous cell carcinoma (SCC) affecting the tongue commonly emerges along its lateral border, yet occurrences specifically on the dorsum, especially at the midline, are notably rare. This study delves into the incidence rates of SCC localized on the tongue, alongside an investigation into simultaneous lesions of the breast. 50-year-old female presented with an ulcerative growth on the left side of the tongue, accompanied by speech difficulty and chewing discomfort persisting for a month. Previous history included breast surgery five years prior, along with ongoing diabetes medication. No history of habits, trauma, or prior ulcer formation was reported. Clinical examination revealed a whitish-yellow, firm, ulcerative lesion extending on the left lateral tongue surface, measuring 7.2x3.1x2.5cm with an exophytic growth of 4.7x2.1cm. The lesion, extending to the dorsal tongue surface, displayed erythematous flooring interspersed with slough and pale mucosa. Limited tongue movement and palpable submandibular nodes were noted. Initial diagnostic findings indicated stage IV metastatic carcinoma of the tongue (T4aN2M1). pathology revealed severe epithelial dysplasia with an invasive pattern in the form of islands, demonstrating altered cellular features, pleomorphism, inflammatory infiltrate, vascularity, and areas of hemorrhage. Lymph nodal analysis showed metastatic deposits in one of three left level II B lymph nodes.

THE CONCEPT OF CORPORATE GOVERNANCE: THE HISTORY OF FORMATION

The purpose of the research. The article is devoted to the study of the history of formation of the concept of corporate governance. The historical period of development of the concept of corporate governance is no less important than the modern concept of corporate governance and it is necessary to study it, analyze the dynamics and trends. The purpose of the study is to analyze the formation of the concept of corporate governance in dynamics. Results. According to the results of the study, the author's view of the history of the emergence and development of corporate governance is presented. It is proved that the concept of corporate governance was not yet formed in the period of the Roman Empire. It seems more correct to define the period when the terminology began to be formed as associated with the beginning of the Industrial Revolution. Modern terminology is formed, but the understanding of the essence of corporate definition is not uniform. In general, opinions are divided into two groups: those who propose to include only participants of the corporation and management, and those who exclude subjects other than participants of the corporate legal entity and persons performing management. The author's conclusion that the expansion of the concept of corporate governance by increasing the subject composition of legal relations does not correspond to the essence, because the participation of other persons in corporate legal relations is secondary, indirect.

The UNCOVER Survey: A First-look HST+JWST Catalog of Galaxy Redshifts and Stellar Population Properties Spanning 0.2 ≲ z ≲ 15

The recent UNCOVER survey with the James Webb Space Telescope (JWST) exploits the nearby cluster A2744 to create the deepest view of our Universe to date by leveraging strong gravitational lensing. In this work, we perform photometric fitting of more than 50,000 robustly detected sources out to z ∼ 15. We show the redshift evolution of stellar ages, star formation rates, and rest-frame colors across the full range of 0.2 ≲ z ≲ 15. The galaxy properties are inferred using the Prospector Bayesian inference framework using informative Prospector-β priors on the masses and star formation histories to produce joint redshift and stellar populations posteriors. Additionally, lensing magnification is performed on the fly to ensure consistency with the scale-dependent priors. We show that this approach produces excellent photometric redshifts with σ NMAD ∼ 0.03, of a similar quality to the established photometric redshift code EAzY. In line with the open-source scientific objective of this Treasury survey, we publicly release the stellar population catalog with this paper, derived from our photometric catalog adapting aperture sizes based on source profiles. This release (the catalog and all related documentation are accessible via the UNCOVER survey web page: https://jwst-uncover.github.io/DR2.html#SPSCatalogs with a copy deposited to Zenodo at doi:10.5281/zenodo.8401181) includes posterior moments, maximum likelihood spectra, star formation histories, and full posterior distributions, offering a rich data set to explore the processes governing galaxy formation and evolution over a parameter space now accessible by JWST.

What Holes in the Gas Distribution of Nearly Face-on Galaxies Can Tell Us about the Host Disk Parameters: The Case of the NGC 628 Southeast Superbubble

Here we explore the impact of all major factors, such as the nonhomogeneous gas distribution, galactic rotation, and gravity, on the observational appearance of superbubbles in nearly face-on spiral galaxies. The results of our 3D numerical simulations are compared to the observed gas column density distribution in the largest southeast superbubble in the late-type spiral galaxy NGC 628. We make use of the star formation history inside the bubble derived from the resolved stellar population seen in Hubble Space Telescope images to obtain its energy and demonstrate that the results of numerical simulations are in good agreement with the observed gas surface density distribution. We also show that the observed gas column density distribution constrains the gaseous disk scale height and the midplane gas density if the energy input rate can be obtained from observations. This implies that observations of large holes in the interstellar gas distribution and their stellar populations have the potential power to solve the midplane gas density–gaseous disk scale height degeneracy problem in nearly face-on galaxies. The possible role of superbubbles in driving the secondary star formation in galaxies is also briefly discussed.

Disentangling Stellar Age Estimates from Galactic Chemodynamical Evolution

Stellar ages are key for determining the formation history of the Milky Way, but are difficult to measure precisely. Furthermore, methods that use chemical abundances to infer ages may entangle the intrinsic evolution of stars with the chemodynamical evolution of the Galaxy. In this paper, we present a framework for making probabilistic predictions of stellar ages, and then quantify the contribution of both stellar evolution and Galactic chemical evolution to those predictions using SHapley Additive exPlanations. We apply this interpretable prediction framework to both a simulated Milky Way sample containing stars in a variety of evolutionary stages and an APOGEE-mocked sample of red clump stars. We find that in the former case, stellar evolution is the dominant driver for age estimates, while in the latter case, the more restricted evolutionary information causes the model to proxy ages through the chemical evolution model. We show that as a result of the use of nonintrinsic Galactic chemical information, trends estimated with the predicted ages, such as the age–metallicity relation, can deviate from the truth.

Pure Spectroscopic Constraints on UV Luminosity Functions and Cosmic Star Formation History from 25 Galaxies at z spec = 8.61–13.20 Confirmed with JWST/NIRSpec

We present pure spectroscopic constraints on the UV luminosity functions and cosmic star formation rate (SFR) densities from 25 galaxies at z spec = 8.61–13.20. By reducing the JWST/NIRSpec spectra taken in multiple programs of Early Release Observation, Early Release Science, General Observer, and Director’s Discretionary Time observations with our analysis technique, we independently confirm 16 galaxies at z spec = 8.61–11.40, including new redshift determinations, and a bright interloper at z spec = 4.91 that was claimed as a photometric candidate at z ∼ 16. In conjunction with nine galaxies at redshifts up to z spec = 13.20 in the literature, we make a sample of 25 spectroscopically confirmed galaxies in total and carefully derive the best estimates and lower limits of the UV luminosity functions. These UV luminosity function constraints are consistent with the previous photometric estimates within the uncertainties and indicate mild redshift evolution toward z ∼ 12, showing tensions with some theoretical models of rapid evolution. With these spectroscopic constraints, we obtain firm lower limits of the cosmic SFR densities and spectroscopically confirm a high SFR density at z ∼ 12 beyond the constant star formation efficiency models, which supports earlier claims from the photometric studies. While there are no spectroscopically confirmed galaxies with very large stellar masses violating the ΛCDM model due to the removal of the bright interloper, we confirm star-forming galaxies at z spec = 11–13 with stellar masses much higher than model predictions. Our results indicate possibilities of high star formation efficiency (>5%), a hidden active galactic nucleus, a top-heavy initial mass function (possibly with Population III), and large scatter/variance. Having these successful and unsuccessful spectroscopy results, we suggest observational strategies for efficiently removing low-redshift interlopers for future JWST programs.

Preservation of bone organic fraction is not predictive of the preservation of bone inorganic fraction when assessing stable isotope analysis sample quality control measures

Stable isotope analysis of carbon (C), nitrogen (N), hydrogen (H), and oxygen (O) of archaeological bone has become an increasingly common research method for interpreting human behavior in the past. However, diagenesis of skeletal material can invalidate stable isotope ratios, thereby compromising interpretations. We examine patterns of bone diagenesis using infrared spectroscopy of bone bioapatite samples in relation to indicators of organic preservation quality indicators. We assess crystallinity, an indicator of bioapatite preservation, using the infrared splitting factor (IR-SF) and carbonate content (carbonate to phosphate ratio, C/P) calculated from infrared spectra. We then test the assumption that if the organic fraction of bone is preserved, the mineral fraction will also be unaffected by postmortem chemical alteration. We analyzed 454 bone bioapatite and extracted bone organic sample pairs from modern, historic, and prehistoric humans. Consistent with previous studies, we observed a strong, statistically significant negative linear relationship between IR-SF and C/P (r = −0.855, p < 0.001). Modern bone bioapatite samples unaltered by diagenesis have low IR-SF and high C/P values. There was no significant association between the collagen yield or atomic C:N ratio and IR-SF or C/P values. The range of variation in IR-SF and C/P values for samples with organic yields between 0 and >20 percent spanned the range of modern bone bioapatite unaltered by diagenesis as well as bone bioapatite significantly affected by diagenesis. The lack of predictive patterning between bone inorganic and organic diagenesis suggests that the depositional context and site formation history play critical and independent roles in the organic and mineral fraction of bone. Thus, the preservation of the organic fraction of bone is not predictive of the preservation of the inorganic fraction (e.g., bioapatite).

Genesis of Compulsory Licensing Norms in Universal International Legal Instruments

Compulsory licensing in intellectual property presents an institution of restriction of exclusive rights to the results of intellectual activity, which has a fairly long history of formation and development. Compulsory licensing replaced such a «rigid» mechanism for limiting the exclusive rights of the copyright holder as the rules on localization of patented objects, which were applied in the USA and European countries in the 19th — early 20th century. Compulsory licensing at the time of its origin was considered a «soft», «sparing» mechanism for limiting the exclusive rights of the copyright holder, which by the end of the 20th century acquired the features of a complex institution. This institution entails negative consequences, most often in the form of a decrease in foreign financing to an industry that has been subjected to acts of compulsory licensing, changes in the business climate, etc. Examining the genesis of the norms on compulsory licensing in universal international legal acts in the field of intellectual property, one can see that the international community in many acts has consolidated to some extent the institution of limitation of the exclusive right, which is an irrefutable proof of the value of compulsory licensing. The analysis of the institution of compulsory licensing both in Russian law and in a number of foreign countries allows us to come to the conclusion that the «negative concept» of compulsory licensing prevails.

Bursty star formation and galaxy–galaxy interactions in low-mass galaxies 1 Gyr after the Big Bang

ABSTRACT We use CANUCS JWST/NIRCam imaging of galaxies behind the gravitationally-lensing cluster MACS J0417.5-1154 to investigate star formation burstiness in low-mass (M⋆ ∼ 108 M⊙) galaxies at z ∼ 4.7–6.5. Our sample of 123 galaxies is selected using the Lyman break selection and photometric emission-line excess methods. Sixty per cent of the 123 galaxies in this sample have Hα-to-UV flux ratios that deviate significantly from the range of Hα-to-UV ratio values consistent with smooth and steady star formation histories. This large fraction indicates that the majority of low-mass galaxies is experiencing bursty star formation histories at high redshift. We also searched for interacting galaxies in our sample and found that they are remarkably common ($\sim 40~{{\ \rm per\ cent}}$ of the sample). Compared to non-interacting galaxies, interacting galaxies are more likely to have very low Hα-to-UV ratios, suggesting that galaxy–galaxy interactions enhance star formation burstiness and enable faster quenching (with time-scales of ≲100 Myr) that follows the rapid rise of star formation activity. Given the high frequency of galaxy–galaxy interactions and the rapid SFR fluctuations they appear to cause, we conclude that galaxy–galaxy interactions could be a leading cause of bursty star formation in low-mass, high-z galaxies. They could thus play a significant role in the evolution of the galaxy population at early cosmological times.