Astronomy & Astrophysics最新文献

{"title":"Old massive clusters (and a nuclear star cluster?) in the tidal tails of NGC 5238","authors":"M. Bellazzini, F. Annibali, M. Correnti, M. Gatto, M. Marinelli, R. Pascale, E. Sacchi, M. Tosi, M. Cignoni, J. M. Cannon, L. Schisgal, G. Bortolini, A. Aloisi, G. Beccari, C. Nipoti","doi":"10.1051/0004-6361/202451810","DOIUrl":"https://doi.org/10.1051/0004-6361/202451810","url":null,"abstract":"New, deep HST photometry allowed us to identify and study eight compact and bright (<i>M<i/><sub><i>V<i/><sub/> ≤ −5.8) star clusters in the outskirts of the star-forming isolated dwarf galaxy NGC 5238 (<i>M<i/><sub>*<sub/> ≃ 10<sup>8<sup/> <i>M<i/><sub>⊙<sub/>). Five of these clusters are new discoveries, and six appear projected onto and/or aligned with the tidal tails recently discovered around this galaxy. The clusters are partially resolved into stars, and their colour magnitude diagrams reveal a well-developed red giant branch, implying ages older than 1–2 Gyr. Their integrated luminosity and structural parameters are typical of classical globular clusters, and one of them, with <i>M<i/><sub><i>V<i/><sub/> = −10.56 ± 0.07, is as bright as <i>ω<i/> Cen, the brightest globular cluster in the Milky Way. Since the properties of this cluster are in the range spanned by those of nuclear star clusters we suggest that it may be the nuclear remnant of the disrupted satellite of NGC 5238 that produced the observed tidal tails.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142452331","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":"Retrieved atmospheric properties of the sub-stellar object VHS 1256 b with HST, VLT, and JWST spectra","authors":"Anna Lueber, Kevin Heng, Brendan P. Bowler, Daniel Kitzmann, Johanna M. Vos, Yifan Zhou","doi":"10.1051/0004-6361/202451301","DOIUrl":"https://doi.org/10.1051/0004-6361/202451301","url":null,"abstract":"Motivated by the observed ~30% variations in flux from the L7 dwarf VHS 1256 b, we subjected its time-resolved <i>Hubble<i/> Space Telescope (HST) WFC3 spectra (measured in two epochs: 2018 and 2020), as well as medium-resolution Very Large Telescope (VLT) X-shooter and Early Release Science <i>James Webb<i/> Space Telescope (JWST) spectra to a suite of both standard Bayesian (nested sampling) and machine-learning (random forest) retrievals. We find that both HST and VLT data require vertically varying abundance profiles of water in order to model the spectra accurately. Despite the large flux variations observed in the HST data, the temporal variability cannot be attributed to a single varying atmospheric property. The retrieved atmospheric quantities are consistent with being invariant across time. However, we find that model grids offer relatively poor fits to the measured HST spectra and are unsuitable for quantifying the temporal variability of atmospheric properties. Additionally, our analysis of JWST spectra using model grids indicates consistency in terms of the retrieved properties across different wavelength channels. Despite the temporal variability in flux, the retrieved properties between HST and VLT, as well those as between HST and JWST, are consistent within the respective posterior uncertainties. Such an outcome bodes well for future retrieval analyses of exoplanetary atmospheres, which are expected to exhibit weaker flux variations.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142452339","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 [O I] fine structure line profiles in Mon R2 and M17 SW: The puzzling nature of cold foreground material identified by [12C II] self-absorption","authors":"C. Guevara, J. Stutzki, V. Ossenkopf-Okada, U. Graf, Y. Okada, N. Schneider, P. F. Goldsmith, J. P. Pérez-Beaupuits, S. Kabanovic, M. Mertens, N. Rothbart, R. Güsten","doi":"10.1051/0004-6361/202450530","DOIUrl":"https://doi.org/10.1051/0004-6361/202450530","url":null,"abstract":"<i>Context.<i/> Recent studies of the optical depth comparing [<sup>12<sup/>C II] and [<sup>13<sup/>C II] line profiles in Galactic star-forming regions have revealed strong self-absorption in [<sup>12<sup/>C II] by low excitation foreground material. This implies a high column density for C<sup>+<sup/>, corresponding to equivalent <i>A<i/><sub>V<sub/> values of a few (up to about 10) mag.<i>Aims.<i/> As the nature and origin of such a great column of cold C<sup>+<sup/> foreground gas are difficult to determine, it is essential to constrain the physical conditions of this material.<i>Methods.<i/> We conducted high-resolution observations of [O I] 63 μm and [O I] 145 μm lines in M17 SW and Mon R2. The [O I] 145 μm transition traces warm PDR-material, while the [O I] 63 μm line traces the foreground material, as manifested by the absorption dips.<i>Results.<i/> A comparison of both [O I] line profiles with [C II] isotopic lines confirm warm PDR-origin background emission and a significant column of cold foreground material, causing the self-absorption to be visible in the [<sup>12<sup/>C II] and [O I] 63 μm profiles. In M17 SW, the C<sup>+<sup/> and O<sup>0<sup/> column densities are comparable for both layers. Mon R2 exhibits larger O<sup>0<sup/> columns compared to C<sup>+<sup/>, indicating additional material where the carbon is neutral or in molecular form. Small-scale spatial variations in the foreground absorption profiles and the large column density (~10<sup>18<sup/> cm<sup>−2<sup/>) of the foreground material suggest the emission is coming from high-density regions associated with the cloud complex – and not a uniform diffuse foreground cloud.<i>Conclusions.<i/> The analysis confirms that the previously detected intense [C II] foreground absorption is attributable to a large column of low-excitation dense atomic material, where carbon is ionized and oxygen is in a neutral atomic form.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448315","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 patchy CO2 exosphere on Ganymede revealed by the James Webb Space Telescope","authors":"Dominique Bockelée-Morvan, Olivier Poch, François Leblanc, Vladimir Zakharov, Emmanuel Lellouch, Eric Quirico, Imke de Pater, Thierry Fouchet, Pablo Rodriguez-Ovalle, Lorenz Roth, Frédéric Merlin, Stefan Duling, Joachim Saur, Adrien Masson, Patrick Fry, Samantha Trumbo, Michael Brown, Richard Cartwright, Stéphanie Cazaux, Katherine de Kleer, Leigh N. Fletcher, Zachariah Milby, Audrey Moingeon, Alessandro Mura, Glenn S. Orton, Bernard Schmitt, Federico Tosi, Michael H. Wong","doi":"10.1051/0004-6361/202451599","DOIUrl":"https://doi.org/10.1051/0004-6361/202451599","url":null,"abstract":"Jupiter’s icy moon Ganymede has a tenuous exosphere produced by sputtering and possibly sublimation of water ice. To date, only atomic hydrogen and oxygen have been directly detected in this exosphere. Here, we present observations of Ganymede’s CO<sub>2<sub/> exosphere obtained with the <i>James Webb<i/> Space Telescope. CO<sub>2<sub/> gas is observed over different terrain types, mainly over those exposed to intense Jovian plasma irradiation, as well as over some bright or dark terrains. Despite warm surface temperatures, the CO<sub>2<sub/> abundance over equatorial subsolar regions is low. CO<sub>2<sub/> vapor has the highest abundance over the north polar cap of the leading hemisphere, reaching a surface pressure of 1 pbar. From modeling we show that the local enhancement observed near 12 h local time in this region can be explained by the presence of cold traps enabling CO<sub>2<sub/> adsorption. However, whether the release mechanism in this high-latitude region is sputtering or sublimation remains unclear. The north polar cap of the leading hemisphere also has unique surface-ice properties, probably linked to the presence of the large atmospheric CO<sub>2<sub/> excess over this region. These CO<sub>2<sub/> molecules might have been initially released in the atmosphere after the radiolysis of CO<sub>2<sub/> precursors, or from the sputtering of CO<sub>2<sub/> embedded in the H<sub>2<sub/>O ice bedrock. Dark terrains (regiones), more widespread on the north versus south polar regions, possibly harbor CO<sub>2<sub/> precursors. CO<sub>2<sub/> molecules would then be redistributed via cold trapping on ice-rich terrains of the polar cap and be diurnally released and redeposited on these terrains. Ganymede’s CO<sub>2<sub/> exosphere highlights the complexity of surface-atmosphere interactions on Jupiter’s icy Galilean moons.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448316","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":"Eddington ratios of dust-obscured quasars at z ≲ 1: Evidence supporting dust-obscured quasars as young quasars","authors":"Dohyeong Kim, Yongjung Kim, Myungshin Im, Eilat Glikman, Minjin Kim, Tanya Urrutia, Gu Lim","doi":"10.1051/0004-6361/202450290","DOIUrl":"https://doi.org/10.1051/0004-6361/202450290","url":null,"abstract":"Dust-obscured quasars have been suspected of being the intermediate-stage galaxies between merger-driven star-forming galaxies and unobscured quasars. This merger-driven galaxy evolution scenario suggests that dust-obscured quasars exhibit higher Eddington ratios (<i>λ<i/><sub>Edd<sub/>) than those of unobscured quasars. However, their high dust obscuration poses challenges to accurately measuring their <i>λ<i/><sub>Edd<sub/> using commonly employed bolometric luminosity (<i>L<i/><sub>bol<sub/>) and black hole mass (<i>M<i/><sub>BH<sub/>) estimators based on the ultraviolet or optical luminosity. Recently, new estimators for <i>L<i/><sub>bol<sub/> and <i>M<i/><sub>BH<sub/> based on mid-infrared continuum luminosity (<i>L<i/><sub>MIR<sub/>) were established, which are less affected by dust obscuration. These estimators enable the study of a large number of dust-obscured quasars across a wide redshift range. In this study, we measure the <i>λ<i/><sub>Edd<sub/> values of 30 dust-obscured quasars at <i>z<i/> ≲ 1, the largest sample size to date, using the <i>L<i/><sub>MIR<sub/>-based <i>L<i/><sub>bol<sub/> and <i>M<i/><sub>BH<sub/> estimators. Our findings reveal that dust-obscured quasars exhibit significantly higher <i>λ<i/><sub>Edd<sub/> values compared to unobscured quasars. Moreover, we confirm that the enhanced <i>λ<i/><sub>Edd<sub/> values of dust-obscured quasars maintain consistency across the redshift span of 0 to 1. Our results strongly support the picture that dust-obscured quasars are in an earlier stage than unobscured quasars on the merger-driven galaxy evolutionary track.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448312","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":"Metallicity-dependent kinematics and orbits in the Milky Way’s nuclear stellar disc","authors":"F. Nogueras-Lara, N. Nieuwmunster, M. Schultheis, M. C. Sormani, F. Fragkoudi, B. Thorsbro, R. M. Rich, N. Ryde, J. L. Sanders, L. C. Smith","doi":"10.1051/0004-6361/202450946","DOIUrl":"https://doi.org/10.1051/0004-6361/202450946","url":null,"abstract":"<i>Context<i/>. The nuclear stellar disc (NSD) is a flat and dense stellar structure at the centre of the Milky Way. Previous work has identified the presence of metal-rich and metal-poor stars in the NSD, suggesting that they have different origins. The recent publication of photometric, metallicity, proper motion, and orbital catalogues allows the NSD stellar population to be characterised with unprecedented detail.<i>Aims<i/>. We aim to explore the proper motions and orbits of NSD stars with different metallicities to assess whether they have different origins and to better understand the metallicity distribution in the NSD.<i>Methods<i/>. We distinguished between metal-rich and metal-poor stars by applying a Gaussian mixture model, as done in previous work, and analysed the proper motions, orbits, and spatial distribution of stars with different metallicities.<i>Results<i/>. We find that metal-rich stars exhibit a lower velocity dispersion, suggesting that they trace a kinematically cooler component compared to metal-poor ones. Furthermore, z-tube orbits are predominant among metal-rich stars, while chaotic/box orbits are more common among metal-poor ones. We also find that metal-rich and metal-poor stars show a similar extinction and are present throughout the analysed regions. As a secondary result, we detected a metallicity gradient in the metal-rich population with higher metallicity towards the centre of the NSD and a tentative gradient for the metal-poor stars, which is consistent with previous studies that did not distinguish between the two populations.<i>Conclusions<i/>. Our results suggest that metal-rich stars trace the NSD, whereas metal-poor ones are related to the Galactic bar and probably constitute Galactic bar interlopers and/or are NSD stars that originated from accreted clusters. The detected metallicity gradients aligns with the currently accepted inside-out formation of the NSD.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448355","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":"Flare-related plasma motions in the outer atmosphere of the RS CVn-type star II Peg","authors":"Dongtao Cao, Shenghong Gu","doi":"10.1051/0004-6361/202450931","DOIUrl":"https://doi.org/10.1051/0004-6361/202450931","url":null,"abstract":"Analogous to solar flares, stellar flares are dramatic explosions in the atmosphere, which may be accompanied by prominence eruptions, coronal mass ejections (CMEs), and other forms of plasma motion. Based on time-resolved spectroscopic observations of the RS CVn-type star II Peg, we aim to search for the potential plasma motions associated with flares. In these observations, we detected part of the gradual decay phase of an optical flare, for which we find a lower limit on the energy of the H<i>α<i/> line of 6.03 × 10<sup>33<sup/> erg. Converting this H<i>α<i/> energy, we find a bolometric white-light energy of 3.10 × 10<sup>35<sup/> erg. Moreover, a secondary peak is also observed. After removing a quiescence reference, the H<i>α<i/> residual shows an asymmetric behavior, including both a blueshifted and a redshifted emission component. The former component has a bulk velocity of about −180 km s<sup>−1<sup/> and extends its velocity to more than −350 km s<sup>−1<sup/>. This phenomenon is likely caused by a prominence eruption event or a chromospheric evaporation process. The latter emission component has a bulk velocity of 130–70 km s<sup>−1<sup/> and extends its velocity to nearly 400 km s<sup>−1<sup/>. We attribute the redshifted emission component to one or a combination of several possible scenarios: flare-driven coronal rain, chromospheric condensation, backward-directed prominence eruption close to the stellar limb, or falling material in a prominence eruption. The minimum masses of the moving plasmas resulting in the blueshifted and redshifted emission components are estimated to be 0.56 × 10<sup>20<sup/> g and 1.74 × 10<sup>20<sup/> g, respectively.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443998","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":"Stringent upper limits of minor species at the cloud top of Venus: PH3, HCN, and NH3","authors":"T. Encrenaz, T. K. Greathouse, R. Giles, T. Widemann, B. Bézard, F. Lefèvre, M. Lefèvre, W. Shao, H. Sagawa, E. Marcq, A. Arredondo","doi":"10.1051/0004-6361/202451495","DOIUrl":"https://doi.org/10.1051/0004-6361/202451495","url":null,"abstract":"<i>Aims.<i/> Following several reports announcing the detection or non-detection of minor species above the clouds of Venus, we have searched for other possible signatures of PH<sub>3<sub/>, HCN, and NH<sub>3<sub/> in the infrared range.<i>Methods.<i/> Since 2012, we have performed ground-based observations of Venus in the thermal infrared at various wavelengths to monitor the behavior of SO<sub>2<sub/> and H<sub>2<sub/>O at the cloud top. We have identified spectral intervals where transitions of PH<sub>3<sub/> (around 955 cm<sup>−1<sup/>), HCN (around 747 cm<sup>−1<sup/>), and NH<sub>3<sub/> (around 951cm<sup>−1<sup/>) are present.<i>Results.<i/> From the absence of any feature at these frequencies, we derive, on the disk-integrated spectrum, a 3-<i>σ<i/> upper limit of 3 ppbv for the PH<sub>3<sub/> mixing ratio, 0.5 ppbv for HCN, and 0.3 ppbv for NH<sub>3<sub/>, assuming that these species have a constant mixing ratio throughout the atmosphere. Maps of the Venus disk recorded at the center position of the lines show that there is no evidence for local detection anywhere over the Venus disk.<i>Conclusions.<i/> Our results bring new constraints on the maximum abundance of these species at the cloud top and in the lower mesosphere of Venus.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440304","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":"G321.3–3.9: A new supernova remnant observed with multi-band radio data and in the SRG/eROSITA All-Sky Surveys","authors":"S. Mantovanini, W. Becker, A. Khokhriakova, N. Hurley-Walker, G. E. Anderson, L. Nicastro","doi":"10.1051/0004-6361/202348962","DOIUrl":"https://doi.org/10.1051/0004-6361/202348962","url":null,"abstract":"<i>Aims.<i/> G321.3–3.9 was first identified as a partial shell at radio frequencies a few decades ago. Although it continued to be observed, no additional studies were undertaken until recently.<i>Methods.<i/> In this paper, we present results from a large selection of radio and X-ray data that cover the position of G321.3–3.9. We confirmed G321.3–3.9 as a new supernova remnant (SNR) using data collected by several radio surveys, spanning a frequency range from 200 to 2300 MHz. Stacked eROSITA data from four consecutive all-sky surveys (eRASS:4) provide spectro-imaging information in the energy band 0.2–8.0 keV.<i>Results.<i/> G321.3–3.9 has an elliptical shape with major and minor axes of approximately . From CHIPASS and S-PASS data, we calculate a spectral index <i>α<i/> = −0.8 ± 0.2, consistent with synchrotron emission from an expanding shell in the radiative phase. The eROSITA data show an X-ray diffuse structure filling almost the entire radio shell. Based on our spectral analysis, we found the temperature to be approximately 0.6 keV and the column absorption density about 10<sup>21<sup/> cm<sup>−2<sup/>. Comparing this absorption density to optical extinction maps, we estimated the distance to fall within the range of (1.0–1.7) kpc, considering the 1σ uncertainty range.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440306","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":"Slowly positively drifting bursts generated by large-scale magnetic reconnection","authors":"Alena Zemanová, Marian Karlický, Jaroslav Dudík, Jana Kašparová, Ján Rybák","doi":"10.1051/0004-6361/202450641","DOIUrl":"https://doi.org/10.1051/0004-6361/202450641","url":null,"abstract":"<i>Context.<i/> The slowly positively drifting bursts (SPDBs) are rarely observed in radio emission of solar flares.<i>Aims.<i/> To understand how the SPDBs are generated, we studied the radio observations at 600–5000 MHz together with the imaging observations made in ultraviolet (UV) and extreme ultraviolet (EUV) during the SPDB-rich C8.7 flare of 2014 May 10 (SOL2014-05-10T0702).<i>Methods.<i/> Because the SPDBs propagate towards locations of higher plasma density, we studied their associations with individual flare kernels, located either within the flare core itself, or distributed at longer distances, but connected to the flaring region by large-scale hot loops. For each kernel we constructed light curves using 1600 Å and 304 Å observations and compared these light curves with the temporal evolution of radio flux at 1190 MHz, representing all observed groups of SPDBs. We also analysed the UV/EUV observations to understand the evolution of magnetic connectivity during the flare.<i>Results.<i/> The flare starts with a growing hot sigmoid observed in 131 Å. As the sigmoid evolves, it extends to and interacts with a half dome present within the active region. The evolving sigmoid reconnects at the respective hyperbolic flux tube, producing large-scale magnetic connections and an EUV swirl. Three groups of SPDBs are observed during this large-scale magnetic reconnection, along with a group of narrow-band type III bursts. The light curves of a kernel corresponding to the footpoint of spine line analogue show good agreement with the radio flux at 1190 MHz, indicating that the SPDBs are produced by the large-scale magnetic reconnection at the half dome. In addition, one of the kernels appeared in the neighbouring active region and also showed a similar evolution to the radio flux, implying that beams of accelerated particles can synchronize radio and UV/EUV light curves across relatively large distances.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440305","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}