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Arxiv_Daily_Notice/2025-05-08-Arxiv-Daily-Paper.md

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+# Showing new listings for Thursday, 8 May 2025
+Auto update Star Formation & Molecular Cloud papers at about 2:30am UTC (10:30am Beijing time) every weekday.
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+
+阅读 `Usage.md`了解如何使用此repo实现个性化的Arxiv论文推送
+
+See `Usage.md` for instructions on how to personalize the repo. 
+
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+Keyword list: ['star formation', 'star-forming', 'molecular cloud', 'interstellar medium', 'cloud', 'clump', 'core', 'filament', 'atomic gas', 'N-PDF']
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+Excluded: ['galaxies', 'galaxy cluster', ' AGN ']
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+
+### Today: 5papers 
+#### The ALMA-ATOMS Survey: Exploring Protostellar Outflows in HC$_3$N
+ - **Authors:** Ariful Hoque, Tapas Baug, Lokesh K. Dewangan, Mika Juvela, Anandmayee Tej, Paul F. Goldsmith, Pablo García, Amelia M. Stutz, Tie Liu, Chang Won Lee, Fengwei Xu, Patricio Sanhueza, N. K. Bhadari, K. Tatematsu, Xunchuan Liu, Hong-Li Liu, Yong Zhang, Xindi Tang, Guido Garay, Ke Wang, Siju Zhang, L. Viktor Tóth, Hafiz Nazeer, Jihye Hwang, Prasanta Gorai, Leonardo Bronfman, Swagat Ranjan Das, Tirthendu Sinha
+ - **Subjects:** Subjects:
+Astrophysics of Galaxies (astro-ph.GA)
+ - **Arxiv link:** https://arxiv.org/abs/2505.04164
+
+ - **Pdf link:** https://arxiv.org/pdf/2505.04164
+
+ - **Abstract**
+ We present the first systematic study of bipolar outflows using HC$_3$N as a tracer in a sample of 146 massive star-forming regions from ALMA-ATOMS survey. Protostellar outflows arise at the initial stage of star formation as a consequence of active accretion. In general, these outflows play a pivotal role in regulating the star formation processes by injecting energetic material in the parent molecular clouds. In such process, lower velocity components of outflows contain a significant portion of the energy. However, extraction of those component is difficult as the corresponding gas is often mixed with that of the ambient cloud. In our sample, we identified 44 bipolar outflows and one explosive outflow in HC$_3$N (J=11--10). The host clumps of these outflows are found to be at different evolutionary stages, suggesting that outflows in HC$_3$N are detectable in different stages of star formation. Also, the non-correlation of HC$_3$N outflows with clump evolutionary stages suggests that HC$_3$N is an unbiased tracer of outflows. Analyses revealed that HC$_3$N performs slightly better in detecting low-velocity components of outflows than traditionally employed tracers like SiO. The derived outflow parameters (i.e outflow mass, momentum, and energy) show moderate correlations with clump mass and luminosity. Our analysis of outflow opening angles and position-velocity diagrams across the outflow lobes show that, HC$_3$N is not only a good tracer of low-velocity outflows, but can also detect high-velocity collimated outflows. Overall, this study indicates that HC$_3$N can be used as a complementary outflow tracer along with the traditionally known outflow tracers, particularly in the detection of the low-velocity components of outflows.
+#### Dust enrichment and growth in their earliest stages of protoplanetary disk formation
+ - **Authors:** E. I. Vorobyov (1), V. G. Elbakyan (2), A. Skliarevskii (3), V. Akimkin (4), I. Kulikov (5) ((1) University of Vienna, Department of Astrophysics, Vienna, Austria, (2) Fakultät für Physik, Universität Duisburg-Essen, Duisburg, Germany, (3) Research Institute of Physics, Southern Federal University, Rostov-on-Don, Russia, (4) Institute of Astronomy, Russian Academy of Sciences, Moscow, Russia, (5) Institute of Computational Mathematics and Mathematical Geophysics SB RAS, Novosibirsk, Russia)
+ - **Subjects:** Subjects:
+Earth and Planetary Astrophysics (astro-ph.EP)
+ - **Arxiv link:** https://arxiv.org/abs/2505.04233
+
+ - **Pdf link:** https://arxiv.org/pdf/2505.04233
+
+ - **Abstract**
+ Aims. Dust enrichment and growth during the initial stages of protoplanetary disk formation were numerically investigated. A particular objective was to determine the effects of various growth barriers, which were mimicked by setting a series of upper permissible limits on maximum dust sizes. Methods. We used the ngFEOSAD code to simulate the three-dimensional dynamics of gas and dust in the polytropic approximation starting from the gravitational collapse of a slowly rotating Bonnor-Ebert sphere to $\approx 12$ kyr after the first hydrostatic core and disk formation. Results. We found that dust growth starts in the contracting cloud in the evolution stage that precedes disk formation and the disk begins to form in an environment that is already enriched in grown dust. The efficiency of dust growth in the disk is limited by dust growth barriers. For dust grains with maximum size < 100 $\mu$m these are likely electrostatic or bouncing barriers, and for larger grains the fragmentation and drift barriers play the major role. The disk midplane becomes quickly enriched with dust, while the vertically integrated distribution of dust shows notable local variations around the canonical 1:100 dust-to-gas mass ratio. These positive and negative deviations are likely caused by local hydrodynamic flows, since the globally integrated dust-to-gas ratio deviates negligibly from the initial 1:100 value. We note that care should be taken when considering models with a fixed dust size, as it may attain a profound negative radial gradient already in the very early stages of disk formation. Models with a constant Stokes number may be preferable in this context. Conclusions. The early dust enrichment and growth may facilitate planet formation as suggested by observations of protoplanetary disk substructures.
+#### Spectroscopic investigations of a filament reconnecting with coronal loops during a two-ribbon solar flare
+ - **Authors:** Reetika Joshi, Jaroslav Dudík, Brigitte Schmieder, Guillaume Aulanier, Ramesh Chandra
+ - **Subjects:** Subjects:
+Solar and Stellar Astrophysics (astro-ph.SR)
+ - **Arxiv link:** https://arxiv.org/abs/2505.04479
+
+ - **Pdf link:** https://arxiv.org/pdf/2505.04479
+
+ - **Abstract**
+ In the standard 2D model of eruption, the eruption of a magnetic flux rope is associated with magnetic reconnection occurring beneath it. However, in 3D, additional reconnection geometries are possible, in particular the AR-RF, where external reconnection involving the overlying arcades (A) and erupting flux rope (R) turns into another arcade and a flare loop (F). This process results in the drifting of the legs of the erupting flux rope. We investigated spectroscopic signatures of such AR-RF reconnection occurring in an erupting filament reconnecting with coronal arcades during a two-ribbon flare. The evolution of the erupting filament eruption is examined using observations by the Atmospheric Imaging Assembly (AIA) and the Interface Region Imaging Spectrograph (IRIS). As the filament rises into the corona, it reconnects with the surrounding arcade of coronal loops with localized brightenings, resulting in the disappearance of the coronal loops and formation of a hot flux rope, showing slipping motion of its footpoints extending to the previous footpoints of the coronal loops (AR-RF reconnection) as predicted by the 3D extensions to the Standard solar flare model. These brightenings are accompanied by the presence of strong blue-shifts in both the IRIS Si IV and Mg II lines, upto about 200 km/s. The lines are also extremely wide, with non-thermal widths above 100 km/s. Furthermore, a strongly non-Gaussian profile of the most blue-shifted component is detected at the start of the AR-RF reconnection, indicating the presence of accelerated particles and MHD turbulence, and associated with the appearance of hot plasma in the AIA 94 A passband. For the first time, an observation has been reported in which the IRIS slit successfully captures AR-RF reconnection between a filament and overlying arcades, resulting in strong blue-shifts and very broad line profiles.
+#### A disturbance in the force. How force fluctuations hinder dynamical friction and induce core stalling
+ - **Authors:** Pierfrancesco Di Cintio, Bruno Marcos
+ - **Subjects:** Subjects:
+Astrophysics of Galaxies (astro-ph.GA); Statistical Mechanics (cond-mat.stat-mech); Plasma Physics (physics.plasm-ph)
+ - **Arxiv link:** https://arxiv.org/abs/2505.04505
+
+ - **Pdf link:** https://arxiv.org/pdf/2505.04505
+
+ - **Abstract**
+ Dynamical friction is an important phenomena in stellar dynamics resulting in the slowing down of a test particle upon many two-body scatters with background particles. Chandrasekhar's original formulation, developed for idealized infinite and homogeneous systems, has been found to be sufficiently accurate even in models of finite extent and radially dependent density profiles. However, in some cases $N-$body simulations evidenced a breakdown of Chandrasekhar's formalism. In particular, in the case of cored stellar systems, the analytical predictions underestimate the rate of in-fall of the test particle. Several explanations for such discrepancy have been proposed so far, in spite of this it remains unclear whether the origin is a finite N effect or an effect arising from the resonance of the orbits of the test and field particles, which is independent on $N$, such as dynamical buoyancy. Here we aim at shedding some light on this issue with tailored numerical experiments. We perform ad hoc simulations of a massive tracer initially placed on a low eccentricity orbit in spherical equilibrium models with increasing resolution. We use an $N-$body code where the self-consistent interaction among the background particles can be substituted with the effect of the static smooth potential of the system's continuum limit, so that the higher order contributions to the dynamical friction arising from the formation of a wake can be neglected if needed. We find that, contrary to what reported in the previous literature, a suppression of dynamical friction happens in both cuspy and cored models. When neglecting the interaction among field particles we observe in both cases a clear $N^{-1/2}$ scaling of the radius at which dynamical friction ceases to be effective. This hints towards a granularity-induced origin of the so-called core-stalling of the massive tracer in cored models.
+#### Linear Thermal Instability of a Condensing Gas-Particle Mixture
+ - **Authors:** Kecheng Stephon Qian (Berkeley), Eugene Chiang (Berkeley)
+ - **Subjects:** Subjects:
+Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
+ - **Arxiv link:** https://arxiv.org/abs/2505.04618
+
+ - **Pdf link:** https://arxiv.org/pdf/2505.04618
+
+ - **Abstract**
+ We study the stability of a hot saturated gas coexisting with condensed particles in an optically thin medium. Such a situation may obtain downstream of a shock, at condensation fronts, or in vaporizing impacts. We show that the gas-particle mixture is subject to a thermal instability whereby a region of lower temperature and higher condensate density cools faster to condense faster. If the region of runaway condensation has a sound-crossing time shorter than its cooling time, then it accretes more mass, in gas and particles, from its higher pressure surroundings. Numerical integration of the linearized perturbation equations demonstrates that this radiation-condensation instability can create particle clumps and voids out of a secularly cooling gas. Provided radiation can escape to cool particle overdensities, thermal instability can help assemble chondrite parent bodies out of the vaporized debris of asteroid collisions, and form planetesimals generally.
+
+
+by olozhika (Xing Yuchen). 
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+2025-05-08