Astronomy & Astrophysics最新文献

{"title":"The young exoplanetary system TOI-4562: Confirming the presence of a third body in the system","authors":"V. Fermiano, R. K. Saito, V. D. Ivanov, C. Caceres, L. A. Almeida, J. Aires, J. C. Beamin, D. Minniti, T. Ferreira, L. Andrade, B. W. Borges, L. de Almeida, F. Jablonski, W. Schlindwein","doi":"10.1051/0004-6361/202451935","DOIUrl":"https://doi.org/10.1051/0004-6361/202451935","url":null,"abstract":"<i>Context.<i/> Young planetary systems represent an opportunity to investigate the early stages of (exo)planetary formation because the gravitational interactions have not yet significantly changed the initial configuration of the system.<i>Aims.<i/> TOI-4562 b is a highly eccentric temperate Jupiter analogue orbiting a young F7V-type star of < 700 Myr in age with an orbital period of <i>P<i/><sub>orb<sub/> ∼ 225 days and an eccentricity of <i>e<i/> = 0.76, and is one of the largest known exoplanets to have formed in situ.<i>Methods.<i/> We observed a new transit of TOI-4562 b using the 0.6-m Zeiss telescope at the Pico dos Dias Observatory (OPD/LNA) in Minas Gerais, Brazil, and combine our data with Transiting Exoplanet Survey Satellite (TESS) and archive data, with the aim being to improve the ephemerides of this interesting system.<i>Results.<i/> The <i>O<i/> − <i>C<i/> diagram for the new ephemeris is consistent with the presence of a giant planet in an outer orbit around TOI-4562. TOI-4562 c is a planet with a mass of <i>M<i/> = 5.77 <i>M<i/><sub>Jup<sub/>, an orbital period of <i>P<i/><sub>orb<sub/> = 3990 days, and a semi-major axis of <i>a<i/> = 5.219 AU.<i>Conclusions.<i/> We report the discovery of TOI-4562 c, the exoplanet with the longest orbital period discovered to date via the transit timing variation (TTV) method. The TOI-4562 system is in the process of violent evolution with intense dynamical changes – judging by its young age and high eccentricity – and is therefore a prime target for studies of formation and evolution of planetary systems.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142385742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The solar beryllium abundance revisited with 3D non-LTE models","authors":"A. M. Amarsi, D. Ogneva, G. Buldgen, N. Grevesse, Y. Zhou, P. S. Barklem","doi":"10.1051/0004-6361/202451778","DOIUrl":"https://doi.org/10.1051/0004-6361/202451778","url":null,"abstract":"The present-day abundance of beryllium in the solar atmosphere provides clues about mixing mechanisms within stellar interiors. However, abundance determinations based on the Be II313.107 nm line are prone to systematic errors due to imperfect model spectra. These errors arise from missing continuous opacity in the UV, a significant unidentified blend at 313.102 nm, departures from local thermodynamic equilibrium (LTE), and microturbulence and macroturbulence fudge parameters associated with one-dimensional (1D) hydrostatic model atmospheres. Although these factors have been discussed in the literature, no study has yet accounted for all of them simultaneously. To address this, we present 3D non-LTE calculations for neutral and ionised beryllium in the Sun. We used these models to derive the present-day solar beryllium abundance, calibrating the missing opacity on high resolution solar irradiance data and the unidentified blend on the centre-to-limb variation. We find a surface abundance of 1.21 ± 0.05 dex, which is significantly lower than the value of 1.38 dex that has been commonly adopted since 2004. Taking the initial abundance via CI chondrites, our result implies that beryllium has been depleted from the surface by an extra 0.11 ± 0.06 dex, or 22 ± 11%, on top of any effects of atomic diffusion. This is in tension with standard solar models, which predict negligible depletion, as well as with contemporary solar models that have extra mixing calibrated on the abundances of helium and lithium, which predict excessive depletion. These discrepancies highlight the need for further improvements to the physics in solar and stellar models.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142385735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rotation state, colors, and albedo of the mission-accessible tiny near-Earth asteroid 2001 QJ142","authors":"Jin Beniyama, Alexey V. Sergeyev, David J. Tholen, Marco Micheli","doi":"10.1051/0004-6361/202451414","DOIUrl":"https://doi.org/10.1051/0004-6361/202451414","url":null,"abstract":"<i>Context.<i/> Characterizing mission-accessible asteroids using telescopic observations is fundamental for target-selection and planning for spacecraft missions. Near-Earth asteroids on Earth-like orbits are of particular importance for applications such as asteroid mining. <i>Aims.<i/> 2001 QJ<sub>142<sub/> is a tiny (<i>D<i/> ≤ 100 m) near-Earth asteroid on an Earth-like orbit with a semimajor axis of 1.06 au, orbital eccentricity of 0.09, and orbital inclination of 3.10°. We aim to characterize 2001 QJ<sub>142<sub/> using ground-based observations with future spacecraft missions in mind.<i>Methods.<i/> We performed visible multicolor photometry of 2001 QJ<sub>142<sub/> using the TriCCS on the Seimei 3.8 m telescope in February 2024. We also revisited the images taken with the Suprime-Cam on the Subaru 8.2 m telescope in August 2012.<i>Results.<i/> Visible color indices of 2001 QJ<sub>142<sub/> indicate that 2001 QJ<sub>142<sub/> is a C- or X-complex asteroid. We detect a possible fast rotation with a period of about 10 min, which is consistent with a previous report. The geometric albedo of 2001 QJ<sub>142<sub/> is derived to be about 0.3 from a slope of its photometric phase curve, which is consistent with an albedo derived from thermal observations with updated physical quantities. A straightforward interpretation is that 2001 QJ<sub>142<sub/> is either an E- or M-type asteroid, although surface properties of such tiny fast-rotating asteroids are not well understood.<i>Conclusions.<i/> We infer that 2001 QJ<sub>142<sub/> is a fast-rotating mission-accessible E- or M-type near-Earth asteroid. More characterizations of tiny asteroids are particularly important for a deeper understanding of their nature.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142385736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A detailed study of the very high-energy Crab pulsar emission with the LST-1","authors":"K. Abe, S. Abe, A. Abhishek, F. Acero, A. Aguasca-Cabot, I. Agudo, N. Alvarez Crespo, L. A. Antonelli, C. Aramo, A. Arbet-Engels, C. Arcaro, M. Artero, K. Asano, P. Aubert, A. Baktash, A. Bamba, A. Baquero Larriva, L. Baroncelli, U. Barres de Almeida, J. A. Barrio, I. Batkovic, J. Baxter, J. Becerra Gonzáilez, E. Bernardini, J. Bernete Medrano, A. Berti, P. Bhattacharjee, C. Bigongiari, E. Bissaldi, O. Blanch, G. Bonnoli, P. Bordas, G. Brunelli, A. Bulgarelli, I. Burelli, L. Burmistrov, M. Buscemi, M. Cardillo, S. Caroff, A. Carosi, M. S. Carrasco, F. Cassol, N. Castrejón, D. Cauz, D. Cerasole, G. Ceribella, Y. Chai, K. Cheng, A. Chiavassa, M. Chikawa, G. Chon, L. Chytka, G. M. Cicciari, A. Cifuentes, J. L. Contreras, J. Cortina, H. Costantini, P. Da Vela, M. Dalchenko, F. Dazzi, A. De Angelis, M. de Bony de Lavergne, B. De Lotto, R. de Menezes, L. Del Peral, C. Delgado, J. Delgado Mengual, D. della Volpe, M. Dellaiera, A. Di Piano, F. Di Pierro, R. Di Tria, L. Di Venere, C. Díaz, R. M. Dominik, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, L. Eisenberger, D. Elsässer, G. Emery, J. Escudero, V. Fallah Ramazani, F. Ferrarotto, A. Fiasson, L. Foffano, L. Freixas Coromina, S. Fröse, Y. Fukazawa, R. Garcia López, C. Gasbarra, D. Gasparrini, L. Gavira, D. Geyer, J. Giesbrecht Paiva, N. Giglietto, F. Giordano, P. Gliwny, N. Godinovic, R. Grau, D. Green, J. Green, S. Gunji, P. Günther, J. Hackfeld, D. Hadasch, A. Hahn, T. Hassan, K. Hayashi, L. Heckmann, M. Heller, J. Herrera Llorente, K. Hirotani, D. Hoffmann, D. Horns, J. Houles, M. Hrabovsky, D. Hrupec, D. Hui, M. Iarlori, R. Imazawa, T. Inada, Y. Inome, K. Ioka, M. Iori, I. Jimenez Martinez, J. Jiménez Quiles, J. Jurysek, M. Kagaya, V. Karas, H. Katagiri, J. Kataoka, D. Kerszberg, Y. Kobayashi, K. Kohri, A. Kong, H. Kubo, J. Kushida, M. Lainez, G. Lamanna, A. Lamastra, L. Lemoigne, M. Linhoff, F. Longo, R. López-Coto, M. López-Moya, A. López-Oramas, S. Loporchio, A. Lorini, J. Lozano Bahilo, P. L. Luque-Escamilla, P. Majumdar, M. Makariev, M. Mallamaci, D. Mandat, M. Manganaro, G. Manicò, K. Mannheim, S. Marchesi, M. Mariotti, P. Marquez, G. Marsella, J. Martí, O. Martinez, G. Martínez, M. Martínez, A. Mas-Aguilar, G. Maurin, D. Mazin, E. Mestre Guillen, S. Micanovic, D. Miceli, T. Miener, J. M. Miranda, R. Mirzoyan, T. Mizuno, M. Molero Gonzalez, E. Molina, T. Montaruli, A. Moralejo, D. Morcuende, A. Morselli, V. Moya, H. Muraishi, S. Nagataki, T. Nakamori, A. Neronov, L. Nickel, M. Nievas Rosillo, L. Nikolic, K. Nishijima, K. Noda, D. Nosek, V. Novotny, S. Nozaki, M. Ohishi, Y. Ohtani, T. Oka, A. Okumura, R. Orito, J. Otero-Santos, P. Ottanelli, E. Owen, M. Palatiello, D. Paneque, F. R. Pantaleo, R. Paoletti, J. M. Paredes, M. Pech, M. Pecimotika, M. Peresano, F. Pfeiffle, E. Pietropaolo, M. Pihet, G. Pirola, C. Plard, F. Podobnik, E. Pons, E. Prandini, C. Priyadarshi, M. Prouza, R. Rando, W. Rhode, M. Ribó, C. Righi, V. Rizi, G. Rodriguez Fernandez, M. D. Rodríguez Frías, T. Saito, S. Sakurai, D. A. Sanchez, H. Sano, T. Šarić, Y. Sato, F. G. Saturni, V. Savchenko, F. Schiavone, B. Schleicher, F. Schmuckermaier, J. L. Schubert, F. Schussler, T. Schweizer, M. Seglar Arroyo, T. Siegert, R. Silvia, J. Sitarek, V. Sliusar, J. Strišković, M. Strzys, Y. Suda, H. Tajima, H. Takahashi, M. Takahashi, J. Takata, R. Takeishi, P. H. T. Tam, S. J. Tanaka, D. Tateishi, T. Tavernier, P. Temnikov, Y. Terada, K. Terauchi, T. Terzic, M. Teshima, M. Tluczykont, F. Tokanai, D. F. Torres, P. Travnicek, S. Truzzi, A. Tutone, M. Vacula, P. Vallania, J. van Scherpenberg, M. Vázquez Acosta, G. Verna, I. Viale, A. Vigliano, C. F. Vigorito, E. Visentin, V. Vitale, V. Voitsekhovskyi, G. Voutsinas, I. Vovk, T. Vuillaume, R. Walter, L. Wan, M. Will, T. Yamamoto, R. Yamazaki, P. K. H. Yeung, T. Yoshida, T. Yoshikoshi, W. Zhang, N. Zywucka","doi":"10.1051/0004-6361/202450059","DOIUrl":"https://doi.org/10.1051/0004-6361/202450059","url":null,"abstract":"<i>Context.<i/> To date, three pulsars have been firmly detected by imaging atmospheric Cherenkov telescopes (IACTs). Two of them reached the TeV energy range, challenging models of very high-energy (VHE) emission in pulsars. More precise observations are needed to better characterize pulsar emission at these energies. The LST-1 is the prototype of the large-sized telescopes, which will be part of the Cherenkov Telescope Array Observatory (CTAO). Its improved performance over previous IACTs makes it well suited for studying pulsars.<i>Aims.<i/> In this work we study the Crab pulsar emission with the LST-1, improving upon and complementing the results from other telescopes. Crab pulsar observations can also be used to characterize the potential of the LST-1 to study other pulsars and detect new ones.<i>Methods.<i/> We analyzed a total of ∼103 hours of gamma-ray observations of the Crab pulsar conducted with the LST-1 in the period from September 2020 to January 2023. The observations were carried out at zenith angles of less than 50 degrees. To characterize the Crab pulsar emission over a broader energy range, a new analysis of the <i>Fermi<i/>/LAT data, including ∼14 years of observations, was also performed.<i>Results.<i/> The Crab pulsar phaseogram, long-term light curve, and phase-resolved spectra are reconstructed with the LST-1 from 20 GeV to 450 GeV for the first peak and up to 700 GeV for the second peak The pulsed emission is detected with a significance level of 15.2<i>σ<i/>. The two characteristic emission peaks of the Crab pulsar are clearly detected (> 10<i>σ<i/>), as is the so-called bridge emission between them (5.7<i>σ<i/>). We find that both peaks are described well by power laws, with spectral indices of ∼3.44 and ∼3.03, respectively. The joint analysis of <i>Fermi<i/>/LAT and LST-1 data shows a good agreement between the two instruments in their overlapping energy range. The detailed results obtained from the first observations of the Crab pulsar with the LST-1 show the potential that CTAO will have to study this type of source.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142385737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New evidence supporting past dust ejections from active asteroid (4015) Wilson–Harrington","authors":"Sunho Jin, Masateru Ishiguro, Jooyeon Geem, Hiroyuki Naito, Jun Takahashi, Hiroshi Akitaya, Daisuke Kuroda, Seitaro Urakawa, Seiko Takagi, Tatsuharu Oono, Tomohiko Sekiguchi, Davide Perna, Simone Ieva, Yoonsoo P. Bach, Ryo Imazawa, Koji S. Kawabata, Makoto Watanabe, Hangbin Jo","doi":"10.1051/0004-6361/202451225","DOIUrl":"https://doi.org/10.1051/0004-6361/202451225","url":null,"abstract":"<i>Context.<i/> (4015) Wilson-Harrington (hereafter, WH) was discovered as a comet in 1949 but has a dynamical property consistent with that of a near-Earth asteroid. Although there is a report that the 1949 activity is associated with an ion tail, the cause of the activity has not yet been identified.<i>Aims.<i/> This work aims to reveal the mysterious comet-like activity of the near-Earth asteroid.<i>Methods.<i/> We conducted new polarimetric observations of WH from May 2022 to January 2023, reanalyses of the photographic plate images taken at the time of its discovery in 1949, and dust tail simulation modelings, where the dust terminal velocity and ejection epoch are taken into account.<i>Results.<i/> We found that this object shows polarization characteristics similar to those of low-albedo asteroids. We derived the geometric albedo ranging from <i>p<sub>V<sub/><i/> = 0.076 ± 0.010 to <i>p<sub>V<sub/><i/> = 0.094 ± 0.018 from our polarimetry (the values vary depending on the data used for fitting and the slope-albedo relationship coefficients). In addition, the 1949 image showed an increase in brightness around the nucleus. Furthermore, we found that the color of the tail is consistent with sunlight, suggesting that the 1949 activity is associated with dust ejection. From the dust tail analysis, ~9 × 10<sup>5<sup/> kg of material was ejected episodically at a low velocity equivalent to or even slower than the escape velocity.<i>Conclusions.<i/> We conclude that WH is most likely an active asteroid of main belt origin and that the activity in 1949 was likely triggered by mass shedding due to fast rotation.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142385738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Are all starbursts equal? Star-formation-rate profiles in merger versus secular starbursts","authors":"Mallory D. Thorp, Sara L. Ellison, Ana Galicia","doi":"10.1051/0004-6361/202451662","DOIUrl":"https://doi.org/10.1051/0004-6361/202451662","url":null,"abstract":"<i>Aims.<i/> Galaxy interactions can trigger drastic changes in the resolved star-forming properties of their constituents, but it remains unclear as to whether those changes are discernible from secular starburst triggers. In this Letter we investigate whether or not post-merger galaxies create unique star-forming trends on a kiloparsec scale.<i>Methods.<i/> We present radial trends in star-formation-rate (SFR) surface density (Σ<sub>SFR<sub/>) for 150 post-merger galaxies with moderate to extremely heightened global SFRs using observations from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey. We juxtapose these profiles with those of noninteracting galaxies (excluding both galaxy pairs and post-merger galaxies) with similarly enhanced global SFRs.<i>Results.<i/> Post-merger galaxies have a much stronger central starburst than isolated galaxies with similar global star-formation enhancements. Indeed, isolated starburst galaxies (SBs) lack a marked central enhancement and instead show a fairly uniform enhancement in Σ<sub>SFR<sub/> with radius. Moreover, the difference in central star formation between post-merger galaxies and noninteracting galaxies is more radially extended and pronounced when the global enhancement in star formation is larger. We conclude that post-merger galaxies create a unique signature in their resolved star-forming properties that is distinct from secular processes that can trigger similar global SFR enhancements.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing the physics of star formation (ProPStar)","authors":"Jaime E. Pineda, Juan D. Soler, Stella Offner, Eric W. Koch, Dominique M. Segura-Cox, Roberto Neri, Michael Kuffmeier, Alexei V. Ivlev, Maria Teresa Valdivia-Mena, Olli Sipilä, Maria Jose Maureira, Paola Caselli, Nichol Cunningham, Anika Schmiedeke, Caroline Gieser, Michael Chen, Silvia Spezzano","doi":"10.1051/0004-6361/202451208","DOIUrl":"https://doi.org/10.1051/0004-6361/202451208","url":null,"abstract":"<i>Context.<i/> Turbulence is a key component of molecular cloud structure. It is usually described by a cascade of energy down to the dissipation scale. The power spectrum for subsonic incompressible turbulence is ∝<i>k<i/><sup>−5/3<sup/>, while for supersonic turbulence it is ∝<i>k<i/><sup>−2<sup/>.<i>Aims.<i/> We determine the power spectrum in an actively star-forming molecular cloud, from parsec scales down to the expected magnetohydrodynamic (MHD) wave cutoff (dissipation scale).<i>Methods.<i/> We analyzed observations of the nearby NGC 1333 star-forming region in three different tracers to cover the different scales from ∼10 pc down to 20 mpc. The largest scales are covered with the low-density gas tracer <sup>13<sup/>CO (1–0) obtained with a single dish, the intermediate scales are covered with single-dish observations of the C<sup>18<sup/>O (3–2) line, while the smallest scales are covered in H<sup>13<sup/>CO<sup>+<sup/> (1–0) and HNC (1–0) with a combination of NOEMA interferometer and IRAM 30m single-dish observations. The complementarity of these observations enables us to generate a combined power spectrum covering more than two orders of magnitude in spatial scale.<i>Results.<i/> We derive the power spectrum in an active star-forming region spanning more than 2 decades of spatial scales. The power spectrum of the intensity maps shows a single power-law behavior, with an exponent of 2.9 ± 0.1 and no evidence of dissipation. Moreover, there is evidence that the power spectrum of the ions to have more power at smaller scales than the neutrals, which is opposite to the theoretical expectations.<i>Conclusions.<i/> We show new possibilities for studying the dissipation of energy at small scales in star-forming regions provided by interferometric observations.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gravitational collapse at low to moderate Mach numbers: The relationship between star formation efficiency and the fraction of mass in the massive object","authors":"Jorge Saavedra-Bastidas, Dominik R. G. Schleicher, Ralf S. Klessen, Sunmyon Chon, Kazuyuki Omukai, Thomas Peters, Lewis R. Prole, Bastián Reinoso, Rafeel Riaz, Paulo Solar","doi":"10.1051/0004-6361/202450409","DOIUrl":"https://doi.org/10.1051/0004-6361/202450409","url":null,"abstract":"The formation of massive objects via gravitational collapse is relevant both for explaining the origin of the first supermassive black holes and in the context of massive star formation. Here, we analyze simulations of the formation of massive objects pursued by different groups and in various environments, concerning the formation of supermassive black holes, primordial stars, as well as present-day massive stars. We focus here particularly on the regime of small virial parameters, that is, low ratios of the initial kinetic to gravitational energy, low to moderate Mach numbers, and the phase before feedback is very efficient. We compare the outcomes of collapse under different conditions using dimensionless parameters, particularly the star formation efficiency <i>є<i/><sub>*<sub/>, the fraction ƒ<sub>*<sub/> of mass in the most massive object relative to the total stellar mass, and the fraction ƒ<sub>tot<sub/> of mass of the most massive object as a function of the total mass. We find that in all simulations analyzed here, ƒ<sub>tot<sub/> increases as a function of <i>є<i/><sub>*<sub/>, although the steepness of the increase depends on the environment. The relation between ƒ<sub>*<sub/> and <i>є<i/><sub>*<sub/> is found to be more complex and also strongly depends on the number of protostars present at the beginning of the simulations. We show that a collision parameter, estimated as the ratio of the system size divided by the typical collision length, allows us to approximately characterize whether collisions are important. A high collision parameter implies a steeper increase in the relation between ƒ<sub>tot<sub/> and <i>є<i/><sub>*<sub/>. We analyze the statistical correlation between the dimensionless quantities using the Spearman coefficient and further confirm via a machine learning analysis that good predictions of ƒ<sub>*<sub/> can be obtained from <i>є<i/><sub>*<sub/> together with a rough estimate of the collision parameter. This suggests that a good estimate of the mass of the most massive object can be obtained once the maximum efficiency for a given environment is known and an estimate for the collision parameter has been determined.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Euclid: Constraining linearly scale-independent modifications of gravity with the spectroscopic and photometric primary probes★","authors":"N. Frusciante, F. Pace, V. F. Cardone, S. Casas, I. Tutusaus, M. Ballardini, E. Bellini, G. Benevento, B. Bose, P. Valageas, N. Bartolo, P. Brax, P. G. Ferreira, F. Finelli, K. Koyama, L. Legrand, L. Lombriser, D. Paoletti, M. Pietroni, A. Rozas-Fernández, Z. Sakr, A. Silvestri, F. Vernizzi, H. A. Winther, N. Aghanim, L. Amendola, N. Auricchio, R. Azzollini, M. Baldi, D. Bonino, E. Branchini, M. Brescia, J. Brinchmann, S. Camera, V. Capobianco, C. Carbone, J. Carretero, M. Castellano, S. Cavuoti, A. Cimatti, R. Cledassou, G. Congedo, L. Conversi, Y. Copin, L. Corcione, F. Courbin, M. Cropper, A. Da Silva, H. Degaudenzi, J. Dinis, F. Dubath, X. Dupac, S. Dusini, S. Farrens, S. Ferriol, P. Fosalba, M. Frailis, E. Franceschi, S. Galeotta, B. Gillis, C. Giocoli, A. Grazian, F. Grupp, L. Guzzo, S. V. H. Haugan, W. Holmes, F. Hormuth, A. Hornstrup, K. Jahnke, S. Kermiche, A. Kiessling, M. Kilbinger, T. Kitching, M. Kunz, H. Kurki-Suonio, S. Ligori, P. B. Lilje, I. Lloro, E. Maiorano, O. Mansutti, O. Marggraf, K. Markovic, F. Marulli, R. Massey, E. Medinaceli, M. Meneghetti, G. Meylan, M. Moresco, L. Moscardini, E. Munari, S. M. Niemi, J. Nightingale, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, W. J. Percival, V. Pettorino, G. Polenta, M. Poncet, L. Popa, F. Raison, R. Rebolo, A. Renzi, J. Rhodes, G. Riccio, E. Romelli, R. Saglia, D. Sapone, B. Sartoris, A. Secroun, G. Seidel, C. Sirignano, G. Sirri, L. Stanco, C. Surace, P. Tallada-Crespí, A. N. Taylor, I. Tereno, R. Toledo-Moreo, F. Torradeflot, E. A. Valentijn, L. Valenziano, T. Vassallo, G. A. Verdoes Kleijn, Y. Wang, A. Zacchei, G. Zamorani, J. Zoubian, V. Scottez","doi":"10.1051/0004-6361/202347526","DOIUrl":"https://doi.org/10.1051/0004-6361/202347526","url":null,"abstract":"<i>Context<i/>. The future <i>Euclid<i/> space satellite mission will offer an invaluable opportunity to constrain modifications to Einstein’s general relativity at cosmic scales. In this paper, we focus on modified gravity models characterised, at linear scales, by a scale-independent growth of perturbations while featuring different testable types of derivative screening mechanisms at smaller non-linear scales.<i>Aims<i/>. We considered three specific models, namely Jordan-Brans-Dicke, a scalar-tensor theory with a flat potential, the normal branch of Dvali-Gabadadze-Porrati (nDGP) gravity, a braneworld model in which our Universe is a four-dimensional brane embedded in a five-dimensional Minkowski space-time, and <i>k<i/>-mouflage gravity, an extension of <i>k<i/>-essence scenarios with a universal coupling of the scalar field to matter. In preparation for real data, we provide forecasts from spectroscopic and photometric primary probes by <i>Euclid<i/> on the cosmological parameters and the additional parameters of the models, respectively, <i>ω<i/><sub>BD<sub/>, Ω<sub>гc<sub/> and <i>ϵ<i/><sub>2,0<sub/>, which quantify the deviations from general relativity. This analysis will improve our knowledge of the cosmology of these modified gravity models.<i>Methods<i/>. The forecast analysis employs the Fisher matrix method applied to weak lensing (WL); photometric galaxy clustering (GC<sub>ph<sub/>), spectroscopic galaxy clustering (GC<sub>sp<sub/>) and the cross-correlation (XC) between GC<sub>ph<sub/> and WL. For the <i>Euclid<i/> survey specifications, we define three scenarios that are characterised by different cuts in the maximum multipole and wave number, to assess the constraining power of non-linear scales. For each model we considered two fiducial values for the corresponding model parameter.<i>Results<i/>. In an optimistic setting at 68.3% confidence interval, we find the following percentage relative errors with <i>Euclid<i/> alone: for log<sub>10<sub/> <i>ω<i/><sub>BD<sub/>, with a fiducial value of <i>ω<i/><sub>BD<sub/> = 800, 27.1% using GC<sub>sp<sub/> alone, 3.6% using GC<sub>ph<sub/>+WL+XC and 3.2% using GC<sub>ph<sub/>+WL+XC+GC<sub>sp<sub/>; for log<sub>10<sub/> Ω<sub>гc<sub/>, with a fiducial value of Ω<sub>гc<sub/> = 0.25, we find 93.4, 20 and 15% respectively; and finally, for <i>ϵ<i/><sub>2,0<sub/> = −0.04, we find 3.4%, 0.15%, and 0.14%. From the relative errors for fiducial values closer to their ΛCDM limits, we find that most of the constraining power is lost. Our results highlight the importance of the constraining power from non-linear scales.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accretion versus core-filament collision","authors":"Fumitaka Nakamura, Quang Nguyen-Luong, Kousuke Ishihara, Aoto Yoshino","doi":"10.1051/0004-6361/202450854","DOIUrl":"https://doi.org/10.1051/0004-6361/202450854","url":null,"abstract":"<i>Context.<i/> Recent millimetre and sub-millimetre observations have unveiled elongated and asymmetric structures around protostars. These structures, referred to as streamers, often exhibit coherent velocity gradients, seemingly indicating a directed gas flow towards the protostars. However, their origin and role in star formation remain uncertain.<i>Aims.<i/> The protostellar core Per-emb-2, located in Barnard 1, has a relatively large streamer of 10<sup>4<sup/> au that is more prominent in emission from carbon-chain molecules. We aim to unveil the formation mechanism of this streamer.<i>Methods.<i/> We conducted mapping observations towards Per-emb-2 using the Nobeyama 45 m telescope. We targeted carbon-chain molecular lines such as CCS, HC<sub>3<sub/>N, and HC<sub>5<sub/>N at 45 GHz.<i>Results.<i/> Using astrodendro, we identified one protostellar and four starless cores, including three new detections, on the <i>Herschel<i/> column density map. The starless and protostellar cores are more or less gravitationally bound. We discovered strong CCS and HC<sub>3<sub/>N emissions extending from the north to the south, appearing to bridge the gap between the protostellar core and the starless core to its north. This bridge spans 3 × 10<sup>4<sup/> au with velocities of 6.5–7.0 km s<sup>−1<sup/>. The velocity gradient of the bridge is opposite that of the streamer. Thus, the streamer is unlikely to be connected to the bridge, suggesting that the former does not have an accretion origin.<i>Conclusions.<i/> We propose that a collision between a spherical core and the filament has shaped the density structure in this region, consequently triggering star formation within the head-tail-shaped core. In this core-filament collision scenario, the collision appears to have fragmented the filament into two structures. The streamer is a bow structure, while the bridge is a remnant of the shock-compressed filament. Thus, we conclude that the Per-emb-2 streamer does not significantly contribute to the mass accumulation towards the protostar.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}