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The physical mechanisms behind the fragmentation of high-mass dense clumps into compact star-forming cores and the properties of these cores are fundamental topics that are heavily investigated in current astrophysical research. The ALMAGAL survey provides the opportunity to study this process at an unprecedented level of detail and statistical significance, featuring high-angular resolution 1.38 mm ALMA observations of 1013 massive dense clumps at various Galactic locations. These clumps cover a wide range of distances (~2–8 kpc), masses (~10²–10⁴M_⊙), surface densities (0.1–10 g cm⁻²), and evolutionary stages (luminosity over mass ratio indicator of ~0.05 <L/M <450L_⊙/M_⊙). Here, we present the catalog of compact sources obtained with theCuTExalgorithm from continuum images of the full ALMAGAL clump sample combining ACA-7 m and 12 m ALMA arrays, reaching a uniform high median spatial resolution of ~1400 au (down to ~800 au). We characterize and discuss the revealed fragmentation properties and the photometric and estimated physical parameters of the core population. The ALMAGAL compact source catalog includes 6348 cores detected in 844 clumps (83% of the total), with a number of cores per clump between 1 and 49 (median of 5). The estimated core diameters are mostly within ~800–3000 au (median of 1700 au). We assigned core temperatures based on theL/Mof the hosting clump, and obtained core masses from 0.002 to 345M_⊙(complete above 0.23 M_⊙), exhibiting a good correlation with the core radii (M ∝ R^2.6). We evaluated the variation in the core mass function (CMF) with evolution as traced by the clumpL/M, finding a clear, robust shift and change in slope among CMFs within subsamples at different stages. This finding suggests that the CMF shape is not constant throughout the star formation process, but rather it builds (and flattens) with evolution, with higher core masses reached at later stages. We found that all cores within a clump grow in mass on average with evolution, while a population of possibly newly formed lower-mass cores is present throughout. The number of cores increases with the core masses, at least until the most massive core reaches ~10M_⊙. More generally, our results favor a clump-fed scenario for high-mass star formation, in which cores form as low-mass seeds, and then gain mass while further fragmentation occurs in the clump. 

Context. A large fraction of stars form in clusters containing high-mass stars, which subsequently influences the local and galaxy-wide environment. Aims. Fundamental questions about the physics responsible for fragmenting molecular parsec-scale clumps into cores of a few thousand astronomical units (au) are still open, that only a statistically significant investigation with ALMA is able to address; for instance: the identification of the dominant agents that determine the core demographics, mass, and spatial distribution as a function of the physical properties of the hosting clumps, their evolutionary stage and the different Galactic environments in which they reside. The extent to which fragmentation is driven by clumps dynamics or mass transport in filaments also remains elusive. Methods. With the ALMAGAL project, we observed the 1.38 mm continuum and lines toward more than 1000 dense clumps in our Galaxy, withM≥ 500 M_⊙, Σ ≥ 0.1 g cm⁻²andd≤ 7.5 kiloparsec (kpc). Two different combinations of ALMA Compact Array (ACA) and 12-m array setups were used to deliver a minimum resolution of ∼1000 au over the entire sample distance range. The sample covers all evolutionary stages from infrared dark clouds (IRDCs) to H IIregions from the tip of the Galactic bar to the outskirts of the Galaxy. With a continuum sensitivity of 0.1 mJy, ALMAGAL enables a complete study of the clump-to-core fragmentation process down toM∼ 0.3 M_⊙across the Galaxy. The spectral setup includes several molecular lines to trace the multiscale physics and dynamics of gas, notably CH₃CN, H₂CO, SiO, CH₃OH, DCN, HC₃N, and SO, among others. Results. We present an initial overview of the observations and the early science product and results produced in the ALMAGAL Consortium, with a first characterization of the morphological properties of the continuum emission detected above 5σin our fields. We used “perimeter-versus-area” and convex hull-versus-area metrics to classify the different morphologies. We find that more extended and morphologically complex (significantly departing from circular or generally convex) shapes are found toward clumps that are relatively more evolved and have higher surface densities. Conclusions. ALMAGAL is poised to serve as a game-changer for a number of specific issues in star formation: clump-to-core fragmentation processes, demographics of cores, core and clump gas chemistry and dynamics, infall and outflow dynamics, and disk detections. Many of these issues will be covered in the first generation of papers that closely follow on the present publication. 

We present a comparison of the Milky Way’s star formation rate (SFR) surface density (∑_SFR) obtained with two independent state-of-the-art observational methods. The first method infers Σ_SFRfrom observations of the dust thermal emission from interstellar dust grains in far-infrared wavelengths registered in theHerschelinfrared Galactic Plane Survey (Hi-GAL). The second method determines Σ_SFRby modeling the current population of O-, B-, and A-type stars in a 6 kpc × 6 kpc area around the Sun. We find an agreement between the two methods within a factor of two for the mean SFRs and the SFR surface density profiles. Given the broad differences between the observational techniques and the independent assumptions in the methods for computing the SFRs, this agreement constitutes a significant advance in our understanding of the star formation of our Galaxy and implies that the local SFR has been roughly constant over the past 10 Myr. 

The first measurements of proton emission accompanied by neutron emission in the electromagnetic dissociation (EMD) of ${}^{208}\mathrm{Pb}$nuclei in the ALICE experiment at the Large Hadron Collider are presented. The EMD protons and neutrons emitted at very forward rapidities are detected by the proton and neutron zero degree calorimeters of the ALICE experiment. The emission cross sections of zero, one, two, and three protons accompanied by at least one neutron were measured in ultraperipheral ${}^{208}\mathrm{Pb}\text{−}{}^{208}\mathrm{Pb}$collisions at a center-of-mass energy per nucleon pair $\sqrt{s_{NN}}=5.02\mathrm{TeV}$. The 0p and 3p cross sections are described by the RELDIS model within their measurement uncertainties, while the 1p and 2p cross sections are underestimated by the model by 17–25%. According to this model, these 0p, 1p, 2p, and 3p cross sections are associated, respectively, with the production of various isotopes of Pb, Tl, Hg, and Au in the EMD of ${}^{208}\mathrm{Pb}$. The cross sections of the emission of a single proton accompanied by the emission of one, two, or three neutrons in EMD were also measured. The data are significantly overestimated by the RELDIS model, which predicts that the (1p,1n), (1p,2n), and (1p,3n) cross sections are very similar to the cross sections for the production of the thallium isotopes ${}^{206,205,204}\mathrm{Tl}$. ©2025 CERN, for the ALICE Collaboration2025CERN 

Abstract The ALICE Collaboration at the CERN LHC has measured the inclusive production cross section of isolated photons at midrapidity as a function of the photon transverse momentum ($$p_{\textrm{T}}^{\gamma }$$ $p_{\text{T}}^{\gamma }$), in Pb–Pb collisions in different centrality intervals, and in pp collisions, at centre-of-momentum energy per nucleon pair of$$\sqrt{s_{\textrm{NN}}}~=~5.02$$ $\sqrt{s_{\text{NN}}}=5.02$ TeV. The photon transverse momentum range is between 10–14 and 40–140 GeV/$$c$$ $c$, depending on the collision system and on the Pb–Pb centrality class. The result extends to lower$$p_{\textrm{T}}^{\gamma }$$ $p_{\text{T}}^{\gamma }$than previously published results by the ATLAS and CMS experiments at the same collision energy. The covered pseudorapidity range is$$|\eta ^{\gamma } | <0.67$$ $|{\eta }^{\gamma }|<0.67$. The isolation selection is based on a charged particle isolation momentum threshold$$p_{\textrm{T}}^\mathrm{iso,~ch} = 1.5$$ $p_{\text{T}}^{\mathrm{iso},\mathrm{ch}}=1.5$ GeV/$$c$$ $c$within a cone of radii$$R=0.2$$ $R=0.2$and 0.4. The nuclear modification factor is calculated and found to be consistent with unity in all centrality classes, and also consistent with the HG-PYTHIA model, which describes the event selection and geometry biases that affect the centrality determination in peripheral Pb–Pb collisions. The measurement is compared to next-to-leading order perturbative QCD calculations and to the measurements of isolated photons and Z$$^{0}$$ $_{}^0$bosons from the CMS experiment, which are all found to be in agreement. 

Abstract ALICE is a large experiment at the CERN Large Hadron Collider. Located 52 meters underground, its detectors are suitable to measure muons produced by cosmic-ray interactions in the atmosphere. In this paper, the studies of the cosmic muons registered by ALICE during Run 2 (2015–2018) are described.The analysis is limited to multimuon events defined as events with more than four detected muons (N_μ> 4) and in the zenith angle range 0° < θ < 50°. The results are compared with Monte Carlo simulations using three of the main hadronic interaction models describing the air shower development in the atmosphere: QGSJET-II-04, EPOS-LHC, and SIBYLL 2.3d.The interval of the primary cosmic-ray energy involved in the measuredmuon multiplicity distribution is about4 × 10¹⁵<E_prim< 6 × 10¹⁶eV.In this interval none of the three models is able to describe precisely the trend of the composition of cosmic rays as the energy increases. However,QGSJET-II-04 is found to be the only model capable of reproducing reasonably well the muon multiplicity distribution, assuming a heavy composition of the primary cosmic raysover the whole energy range, while SIBYLL 2.3d and EPOS-LHC underpredict thenumber of muons in a large interval of multiplicity by more than 20% and 30%, respectively.The rate of high muon multiplicity events (N_μ> 100) obtainedwith QGSJET-II-04 and SIBYLL 2.3d is compatible with the data, while EPOS-LHC produces a significantly lower rate (55% of the measured rate). For both QGSJET-II-04 and SIBYLL 2.3d, the rate is close to the data when the composition is assumed to be dominated by heavy elements, an outcome compatible with the average energy E_prim∼ 10¹⁷eV of these events.This result places significant constraints on more exotic production mechanisms. 

A<sc>bstract</sc> Thep_T-differential cross section ofωmeson production in pp collisions at$$ \sqrt{s} $$ $\sqrt{s}$= 13 TeV at midrapidity (|y| <0.5) was measured with the ALICE detector at the LHC, covering an unprecedented transverse-momentum range of 1.6< p_T<50 GeV/c. The meson is reconstructed via theω→π⁺π⁻π⁰decay channel. The results are compared with various theoretical calculations: PYTHIA8.2 with the Monash 2013 tune overestimates the data by up to 50%, whereas good agreement is observed with Next-to-Leading Order (NLO) calculations incorporatingωfragmentation using a broken SU(3) model. Theω/π⁰ratio is presented and compared with theoretical calculations and the available measurements at lower collision energies. The presented data triples thep_Tranges of previously available measurements. A constant ratio ofC^ω/π0= 0.578 ± 0.006 (stat.) ± 0.013 (syst.) is found above a transverse momentum of 4 GeV/c, which is in agreement with previous findings at lower collision energies within the systematic and statistical uncertainties.