Monthly Notices of the Royal Astronomical Society最新文献

{"title":"Molecular clouds as hubs in spiral galaxies : gas inflow and evolutionary sequence","authors":"J W Zhou, Sami Dib, Timothy A Davis","doi":"10.1093/mnras/stae2101","DOIUrl":"https://doi.org/10.1093/mnras/stae2101","url":null,"abstract":"We decomposed the molecular gas in the spiral galaxy NGC 628 (M74) into multi-scale hub-filament structures using the CO (2−1) line by the dendrogram algorithm. All leaf structures as potential hubs were classified into three categories, i.e. leaf-HFs-A, leaf-HFs-B and leaf-HFs-C. leaf-HFs-A exhibit the best hub-filament morphology, which also have the highest density contrast, the largest mass and the lowest virial ratio. We employed the FILFINDER algorithm to identify and characterize filaments within 185 leaf-HFs-A structures, and fitted the velocity gradients around the intensity peaks. Measurements of velocity gradients provide evidence for gas inflow within these structures, which can serve as a kinematic evidence that these structures are hub-filament structures. The numbers of the associated 21 μm and Hα structures and the peak intensities of 7.7 μm, 21 μm and Hα emissions decrease from leaf-HFs-A to leaf-HFs-C. The spatial separations between the intensity peaks of CO and 21 μm structures of leaf-HFs-A are larger than those of leaf-HFs-C. These evidence indicate that leaf-HFs-A are more evolved than leaf-HFs-C. There may be an evolutionary sequence from leaf-HFs-C to leaf-HFs-A. Currently, leaf-HFs-C lack a distinct gravitational collapse process that would result in a significant density contrast. The density contrast can effectively measure the extent of the gravitational collapse and the depth of the gravitational potential of the structure which, in turn, shapes the hub-filament morphology. Combined with the kinematic analysis presented in previous studies, a picture emerges that molecular gas in spiral galaxies is organized into network structures through the gravitational coupling of multi-scale hub-filament structures. Molecular clouds, acting as knots within these networks, serve as hubs, which are local gravitational centers and the main sites of star formation.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"42 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Twenty-three new Heartbeat Star systems discovered based on TESS data","authors":"Min-Yu Li, Sheng-Bang Qian, Ai-Ying Zhou, Li-Ying Zhu, Wen-Ping Liao, Er-Gang Zhao, Xiang-Dong Shi, Fu-Xing Li, Qi-Bin Sun","doi":"10.1093/mnras/stae2057","DOIUrl":"https://doi.org/10.1093/mnras/stae2057","url":null,"abstract":"Heartbeat stars (HBSs) are ideal astrophysical laboratories to study the formation and evolution of binary stars in eccentric orbits and the internal structural changes of their components under strong tidal action. We discover 23 new HBSs based on TESS photometric data. The orbital parameters, including orbital period, eccentricity, orbital inclination, argument of periastron, and epoch of periastron passage of these HBSs are derived by using a corrected version of Kumar et al. model based on the Markov Chain Monte Carlo (MCMC) method. The preliminary results show that these HBSs have orbital periods in the range from 2.7 to 20 days and eccentricities in the range from 0.08 to 0.70. The eccentricity-period relation of these objects shows a positive correlation between eccentricity and period, and also shows the existence of orbital circularization. The Hertzsprung-Russell diagram shows that the HBSs are not all located in a particular area. The distribution of the derived parameters suggests a selection bias within the TESS survey towards HBSs with shorter periods. These objects are a very useful source to study the structure and evolution of eccentricity orbit binaries and to extend the TESS HBS catalog.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"79 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Baryon Acoustic Oscillation Theory and Modelling Systematics for the DESI 2024 results","authors":"Shi-Fan Chen, Cullan Howlett, Martin White, Patrick McDonald, Ashley J Ross, Hee-Jong Seo, Nikhil Padmanabhan, J Aguilar, S Ahlen, S Alam, O Alves, U Andrade, R Blum, D Brooks, X Chen, S Cole, K Dawson, A de la Macorra, Arjun Dey, Z Ding, P Doel, S Ferraro, A Font-Ribera, D Forero-Sánchez, J E Forero-Romero, C Garcia-Quintero, E Gaztañaga, S Gontcho A Gontcho, M M S Hanif, K Honscheid, T Kisner, A Kremin, A Lambert, M Landriau, M E Levi, M Manera, A Meisner, J Mena-Fernández, R Miquel, A Munoz-Gutierrez, E Paillas, N Palanque-Delabrouille, W J Percival, A Pérez-Fernández, F Prada, M Rashkovetskyi, M Rezaie, A Rosado-Marin, G Rossi, R Ruggeri, E Sanchez, D Schlegel, J Silber, G Tarlé, M Vargas-Magaña, B A Weaver, J Yu, S Yuan, R Zhou, Z Zhou","doi":"10.1093/mnras/stae2090","DOIUrl":"https://doi.org/10.1093/mnras/stae2090","url":null,"abstract":"This paper provides a comprehensive overview of how fitting of Baryon Acoustic Oscillations (BAO) is carried out within the upcoming Dark Energy Spectroscopic Instrument’s (DESI) 2024 results using its DR1 dataset, and the associated systematic error budget from theory and modelling of the BAO. We derive new results showing how non-linearities in the clustering of galaxies can cause potential biases in measurements of the isotropic (αiso) and anisotropic (αap) BAO distance scales, and how these can be effectively removed with an appropriate choice of reconstruction algorithm. We then demonstrate how theory leads to a clear choice for how to model the BAO and develop, implement and validate a new model for the remaining smooth-broadband (i.e., without BAO) component of the galaxy clustering. Finally, we explore the impact of all remaining modelling choices on the BAO constraints from DESI using a suite of high-precision simulations, arriving at a set of best-practices for DESI BAO fits, and an associated theory and modelling systematic error. Overall, our results demonstrate the remarkable robustness of the BAO to all our modelling choices and motivate a combined theory and modelling systematic error contribution to the post-reconstruction DESI BAO measurements of no more than 0.1% (0.2%) for its isotropic (anisotropic) distance measurements. We expect the theory and best-practices laid out to here to be applicable to other BAO experiments in the era of DESI and beyond.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"3 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Deciphering accretion-driven starquakes in recycled millisecond pulsars using gravitational waves","authors":"Sagnik Chatterjee, Kamal Krishna Nath, Ritam Mallick","doi":"10.1093/mnras/stae2087","DOIUrl":"https://doi.org/10.1093/mnras/stae2087","url":null,"abstract":"Recycled millisecond pulsars are susceptible to starquakes as they are continuously accreting matter from their binary companion. A starquake happens when the rotational frequency of the star crosses its breaking frequency. In this study, we perform a model analysis of an accreting neutron star suffering a starquake. We analyse two models: a spherical star with accreting mountains and a deformed star with accreting mountains. We find that as the star crosses the breaking frequency and suffers a starquake, there is a sudden change in the continuous gravitational wave signal arriving from it. The amplitude of the gravitational wave signal increases suddenly both for the spherical and deformed star. For the spherical star, the accreting matter entirely dictates the amplitude of the gravitational wave. For the deformed star, both the accreting matter and the deformation from spherical symmetry play a significant role in determining the amplitude of the gravitational wave signal. This sudden change in the continuous gravitational wave signal in recycled millisecond pulsars can be a unique signature for such pulsars undergoing a starquake.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"395 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Testing screened modified gravity with SDSS-IV-MaNGA","authors":"Ricardo G Landim, Harry Desmond, Kazuya Koyama, Samantha Penny","doi":"10.1093/mnras/stae2096","DOIUrl":"https://doi.org/10.1093/mnras/stae2096","url":null,"abstract":"Fifth forces are ubiquitous in modified gravity theories, and must be screened to evade stringent local tests. This can introduce unusual behaviour in galaxy phenomenology by affecting galaxies’ components differently. Here we use the SDSS-IV-MaNGA dataset to search for a systematic excess of gas circular velocity over stellar circular velocity, expected in thin-shell-screened theories in the partially screened regime. Accounting for asymmetric drift and calibrating our model on screened subsamples, we find no significant evidence for a screened fifth force. We bound the fifth-force strength to ΔG/GN < 0.1 for all astrophysical ranges, strengthening to ∼0.01 at Compton wavelength of 3 Mpc for the Hu-Sawicki model, for instance. This implies a stringent constraint on scalar–tensor theories, for example $f_{mathcal {R}0} lesssim 10^{-8}$ in Hu–Sawicki $f(mathcal {R})$ gravity.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"108 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Time-integrated constraint on neutrino flux of CHIME fast radio burst sources with 10-year IceCube point-source data","authors":"Jia-Wei Luo, Bing Zhang","doi":"10.1093/mnras/stae2071","DOIUrl":"https://doi.org/10.1093/mnras/stae2071","url":null,"abstract":"Despite numerous studies, the sources of IceCube cosmic neutrinos are mostly unidentified. Utilizing recently released IceCube neutrino and CHIME fast radio burst (FRB) catalogs, we examine the possibility of an association between neutrinos and CHIME/FRB catalog 1 FRBs for both the entire FRB population and individual FRBs using the unbinned maximum likelihood method. Our results do not directly support the possibility of the above-mentioned association with three weighting schemes: equal, total radio fluence, and event rate. We then attempt to constrain the diffuse muon neutrino flux upper limit from CHIME/FRB catalog 1 FRBs. After considering a completeness correction, we find the 95% diffuse muon neutrino flux upper limit at 100 TeV for all FRB sources in the universe to be ∼ 1.01 × 10−18GeV−1 cm−2s−1sr−1, or ∼ 70.3 % of the 10-year diffuse neutrino flux observed by IceCube. Our results match the non-detection results of other studies, but we do not rule out FRBs being a significant contributor to the diffuse neutrino flux measured by IceCube.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"31 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"HD 21520 b: a warm sub-Neptune transiting a bright G dwarf","authors":"Molly Nies, Ismael Mireles, François Bouchy, Diana Dragomir, Belinda A Nicholson, Nora L Eisner, Sergio G Sousa, Karen A Collins, Steve B Howell, Carl Ziegler, Coel Hellier, Brett Addison, Sarah Ballard, Brendan P Bowler, César Briceño, Catherine A Clark, Dennis M Conti, Xavier Dumusque, Billy Edwards, Crystal L Gnilka, Melissa Hobson, Jonathan Horner, Stephen R Kane, John Kielkopf, Baptiste Lavie, Nicholas Law, Monika Lendl, Colin Littlefield, Huigen Liu, Andrew W Mann, Matthew W Mengel, Dominic Oddo, Jack Okumura, Enric Palle, Peter Plavchan, Angelica Psaridi, Nuno C Santos, Richard P Schwarz, Avi Shporer, Robert A Wittenmyer, Duncan J Wright, Hui Zhang, David Watanabe, Jennifer V Medina, Joel Villaseñor, Eric B Ting, Jessie L Christiansen, Joshua N Winn, Keivan G Stassun, S Seager, David W Latham, George R Ricker","doi":"10.1093/mnras/stae2079","DOIUrl":"https://doi.org/10.1093/mnras/stae2079","url":null,"abstract":"We report the discovery and validation of HD 21520 b, a transiting planet found with TESS and orbiting a bright G dwarf (V=9.2, Teff = 5871 ± 62 K, R⋆ = 1.04 ± 0.02 R⊙). HD 21520 b was originally alerted as a system (TOI-4320) consisting of two planet candidates with periods of 703.6 and 46.4 days. However, our analysis supports instead a single-planet system with an orbital period of 25.1292 ± 0.0001 days and radius of 2.70 ± 0.09 R⊕. Three full transits in sectors 4, 30 and 31 match this period and have transit depths and durations in agreement with each other, as does a partial transit in sector 3. We also observe transits using CHEOPS and LCOGT. SOAR and Gemini high-resolution imaging do not indicate the presence of any nearby companions, and Minerva-Australis and CORALIE radial velocities rule out an on-target spectroscopic binary. Additionally, we use ESPRESSO radial velocities to obtain a tentative mass measurement of $7.9^{+3.2}_{-3.0}, M_{hbox{$oplus $}}$, with a 3-σ upper limit of 17.7 M⊕. Due to the bright nature of its host and likely significant gas envelope of the planet, HD 21520 b is a promising candidate for further mass measurements and for atmospheric characterization.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"43 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 X-ray polarization of the jet in the vela PWN","authors":"Kuan Liu, Fei Xie, En-Wei Liang","doi":"10.1093/mnras/stae2068","DOIUrl":"https://doi.org/10.1093/mnras/stae2068","url":null,"abstract":"In this paper, we studied the X-ray polarization of the jet in the Vela Pulsar Wind Nebula (PWN). After the background subtraction, we found a high degree of polarization in the helical jet region, close to the upper limit allowed by the synchrotron radiation mechanism. This result indicates the magnetic field is highly ordered, even though the jet’s morphology is curved and varies rapidly, which suggests that the magnetic collimation process for the jet doesn’t introduce significant turbulence. The polarization angle is perpendicular to the symmetry axis of the nebula, consistent with the results from the magnetohydrodynamic numerical simulations. This finding sheds light on the underlying mechanisms related to the dynamics and evolution of the jet structures.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"108 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"SPIRou monitoring of the protostar V347 Aur: Binarity, magnetic fields, pulsed dynamo and accretion","authors":"J-F Donati, P I Cristofari, A Carmona, K Grankin","doi":"10.1093/mnras/stae2076","DOIUrl":"https://doi.org/10.1093/mnras/stae2076","url":null,"abstract":"We present in this paper an analysis of near-infrared observations of the 0.3 M⊙ protostar V347 Aur collected with the SPIRou high-resolution spectropolarimeter and velocimeter at the 3.6-m Canada-France-Hawaii Telescope from October 2019 to April 2023. From a set of 79 unpolarized and circularly polarized spectra of V347 Aur to which we applied Least-Squares Deconvolution (LSD), we derived radial velocities and longitudinal fields, along with their temporal variations over our monitoring campaign of 1258 d. Our data show that V347 Aur is an eccentric binary system with an orbital period 154.6 ± 0.7 d, experiencing strong to extreme accretion events near periastron. The companion is a 29.0 ± 1.6${rm M}_{2!_{4}}$ brown dwarf, a rare member of the brown dwarf desert of close companions around M dwarfs. We detect weak longitudinal fields (<100 G) at the surface of V347 Aur, significantly weaker than those of more evolved prototypical T Tauri stars. These fields show small-amplitude rotational modulation, indicating a mainly axisymmetric parent large-scale magnetic topology, and larger fluctuations at half the orbital period, suggesting that what we dub a ‘pulsed dynamo’ triggered by orbital motion and pulsed accretion operates in V347 Aur. Applying Zeeman-Doppler imaging to our circularly polarised LSD profiles, we find that the large-scale field of V347 Aur is mainly toroidal for most of our observations, with the toroidal component switching sign near periastron and apoastron. The weak large-scale dipole (≃ 30 G) is not able to disrupt the disc beyond 1.3 R⋆ even at the lowest accretion rates, implying longitudinally distributed (rather than localized) accretion at the surface of the protostar.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"49 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Vortex dynamics in various solar magnetic field configurations","authors":"Arjun Kannan, Nitin Yadav","doi":"10.1093/mnras/stae1990","DOIUrl":"https://doi.org/10.1093/mnras/stae1990","url":null,"abstract":"We investigate vortex dynamics in three magnetic regions, viz., Quiet Sun, Weak Plage, and Strong Plage, using realistic three-dimensional simulations from a comprehensive radiation-magnetohydrodynamics (MHD) code, MURaM. We find that the spatial extents and spatial distribution of vortices vary for different set-ups even though the photospheric turbulence responsible for generating vortices has similar profiles for all three regions. We investigate kinetic and magnetic swirling strength and find them consistent with the Alfvén wave propagation. Using a flux tube expansion model and linear MHD wave theory, we find that the deviation in kinetic swirling strength from the theoretically expected value is the highest for the Strong Plage, least for the Weak Plage, and intermediate for the Quiet Sun at chromospheric heights. It suggests that Weak Plage is the most favoured region for chromospheric swirls, though they are of smaller spatial extents than in Quiet Sun. We also conjecture that vortex interactions within a single flux tube in Strong Plage lead to an energy cascade from larger to smaller vortices that further result in much lower values of kinetic swirling strength than other regions. Fourier spectra of horizontal magnetic fields at 1 Mm height also show the steep cascade from large to smaller scales for Strong Plage. These findings indicate the potential of vortex-induced torsional Alfvén waves to travel higher in the atmosphere without damping for weaker magnetic regions such as the Quiet Sun, whereas vortices would result in dissipation and heating due to the vortex interactions in narrow flux tubes for the strongly magnetized regions such as Strong Plage.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"152 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}