arXiv - PHYS - Solar and Stellar Astrophysics最新文献

{"title":"Powerful flares and magneto-elastic oscillations of magnetars","authors":"D. G. YakovlevIoffe Institute","doi":"arxiv-2409.11178","DOIUrl":"https://doi.org/arxiv-2409.11178","url":null,"abstract":"Magnetars are neutron stars with superstrong magnetic fields which can exceed\u00001e15 G. Some magnetars (the so-called soft gamma-repeaters) demonstrate\u0000occasionally very powerful processes of energy release, which result in\u0000exceptionally strong flares of electromagnetic radiation. It is believed that\u0000these flares are associated with the presence of superstrong magnetic fields.\u0000Despite many hypotheses, the mechanism of these flares remains a mystery. In\u0000afterglows of the flares, one has often observed quasi-periodic oscillations\u0000(QPOs) of magnetar emission. They are interpreted as stellar vibrations,\u0000excited by the flares, which are useful for exploring the nature of magnetar\u0000activity. The incompleteness of theories employed to interpret magnetar QPOs is\u0000discussed.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spot Modeling through Multiband Photometry Analysis of V1298 Tau","authors":"Alfredo Biagini, Antonino Petralia, Claudia Di Maio, Lorenzo Betti, Emanuele Pace, Giuseppina Micela","doi":"arxiv-2409.11034","DOIUrl":"https://doi.org/arxiv-2409.11034","url":null,"abstract":"Context. Stellar activity consists of different phenomena, mainly spots and\u0000faculae, and it is one of the main sources of noise in exoplanetary\u0000observations because it affects both spectroscopic and photometric\u0000observations. If we want to study young active planetary systems we need to\u0000model the activity of the host stars in order to remove astrophysical noise\u0000from our observational data. Aims. We modelled the contribution of stellar\u0000spots in photometric observations. Through the use of multiband photometry, we\u0000aim to extract the geometric properties of the spots and constrain their\u0000temperature. Methods. We analyzed multiband photometric observations acquired\u0000with the 80 cm Marcon telescope of the Osservatorio Polifunzionale del Chianti\u0000of V1298 Tau, assuming that the photometric modulation observed in different\u0000bands should be due to cold spots. Results. We constrained the effective\u0000temperature of the active regions present on the surface of V1298 Tau, which is\u0000composed by the contemporary presence of spots and faculae. We tested our\u0000hypothesis on solar data, verifying that we measure the size of the dominant\u0000active region and its averaged effective temperature.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Colour-Based Disentangling of Mira Variables and Ultra-Cool Dwarfs","authors":"Aleksandra Avdeeva, Kefeng Tan, Santosh Joshi, Dana Kovaleva, Harinder P. Singh, Ali Luo, Oleg Malkov","doi":"arxiv-2409.11266","DOIUrl":"https://doi.org/arxiv-2409.11266","url":null,"abstract":"Despite having different astronomical characteristics, the studies of mira\u0000variables and ultra-cool dwarfs frequently show similar red colors, which could\u0000cause leading to photometric misclassification. This study uses photometric\u0000data from the WISE, 2MASS, and Pan-STARRS surveys to construct color-based\u0000selection criteria for red dwarfs, brown dwarfs, and Mira variables. On\u0000analyzing the color indices, we developed empirical rules that separate these\u0000objects with an overall classification accuracy of approximately 91%-92%. While\u0000the differentiation between red dwarfs and both Mira variables and brown dwarfs\u0000is effective, challenges remain in distinguishing Mira variables from brown\u0000dwarfs due to overlapping color indices. The robustness of our classification\u0000technique was validated by a bootstrap analysis, highlighting the significance\u0000of color indices in large photometric surveys for stellar classification.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MHD waves in the partially ionized plasma: from single to multi-fluid approach","authors":"Elena Khomenko, David Martínez-Gómez","doi":"arxiv-2409.11528","DOIUrl":"https://doi.org/arxiv-2409.11528","url":null,"abstract":"This Chapter outlines the basic properties of waves in solar partially\u0000ionized plasmas. It provides a summary of the main sets of equations, from the\u0000single-fluid formalism, to the multi-fluid one, giving examples for purely\u0000hydrogen, and for hydrogen-helium plasmas. It then discusses the solutions for\u0000waves under the single-fluid frame: the influence of the ambipolar diffusion,\u0000diamagnetic effect, and the Hall effect on the propagation, dissipation, and\u0000mode conversion of the magnetohydrodynamic waves. The Chapter continues by\u0000outlining the wave solutions in the multi-fluid formalism: the influence of the\u0000elastic inter-particle collisions into the propagation, damping and dissipation\u0000of different magnetohydrodynamic modes. Both parts discuss linear and\u0000non-linear wave solutions, and the effects of the gravitational stratification\u0000of the solar atmosphere.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stable Case BB/BC Mass Transfer to Form GW190425-like Massive Binary Neutron Star Mergers","authors":"Ying Qin, Jin-Ping Zhu, Georges Meynet, Bing Zhang, Fa-Yin Wang, Xin-Wen Shu, Han-Feng Song, Yuan-Zhu Wang, Liang Yuan, Zhen-Han-Tao Wang, Rui-Chong Hu, Dong-Hong Wu, Shuang-Xi Yi, Qing-Wen Tang, Jun-Jie Wei, Xue-Feng Wu, En-Wei Liang","doi":"arxiv-2409.10869","DOIUrl":"https://doi.org/arxiv-2409.10869","url":null,"abstract":"On April 25th, 2019, the LIGO-Virgo Collaboration discovered a\u0000Gravitational-wave (GW) signal from a binary neutron star (BNS) merger, i.e.,\u0000GW190425. Due to the inferred large total mass, the origin of GW190425 remains\u0000unclear. We perform detailed stellar structure and binary evolution\u0000calculations that take into account mass-loss, internal differential rotation,\u0000and tidal interactions between a He-rich star and a NS companion. We explore\u0000the parameter space of the initial binary properties, including initial NS and\u0000He-rich masses and initial orbital period. We find that the immediate\u0000post-common-envelope progenitor system, consisting of a primary\u0000$sim2.0,M_odot$ ($sim1.7,M_odot$) NS and a secondary He-rich star with an\u0000initial mass of $sim3.0-5.5,M_odot$ ($sim5.5-6.0,M_odot$) in a close\u0000binary with an initial period of $sim0.08-0.5,{rm{days}}$ ($sim\u00000.08-0.4,{rm{days}}$), that experiences stable Case BB/BC mass transfer (MT)\u0000during binary evolution, can reproduce the formation of GW190425-like BNS\u0000events. Our studies reveal that the secondary He-rich star of the GW190425's\u0000progenitor before its core collapse can be efficiently spun up through tidal\u0000interaction, finally remaining as a NS with rotational energy even reaching\u0000$sim10^{52},{rm{erg}}$, which is always much higher than the neutrino-driven\u0000energy of the supernova (SN) explosion. If the newborn secondary NS is a\u0000magnetar, we expect that GW190425 can be the remnant of a magnetar-driven SN,\u0000e.g., a magnetar-driven ultra-stripped SN, a superluminous SN, or a broad-line\u0000Type Ic SN. Our results show that GW190425 could be formed through the isolated\u0000binary evolution, which involves a stable Case BB/BC MT just after the common\u0000envelope phase. On top of that, we show the He-rich star can be tidally spun\u0000up, potentially forming a spinning magnetized NS (magnetar) during the second\u0000SN explosion.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gravity or turbulence? VII. The Schmidt-Kennicutt law, the star formation efficiency, and the mass density of clusters from gravitational collapse rather than turbulent support","authors":"Manuel Zamora-Aviles, Vianey Camacho, Javier Ballesteros-Paredes, Enrique Vázquez-Semadeni, Aina Palau, Carlos Román-Zúñiga, Andrés Hernández-Cruz, Gilberto C. Gómez, Fabián Quesada-Zúñiga, Raúl Naranjo-Romero","doi":"arxiv-2409.11588","DOIUrl":"https://doi.org/arxiv-2409.11588","url":null,"abstract":"We explore the Schmidt-Kennicutt (SK) relations and the star formation\u0000efficiency per free-fall time ($eff$), mirroring observational studies, in\u0000numerical simulations of filamentary molecular clouds undergoing gravitational\u0000contraction. We find that {it a)} collapsing clouds accurately replicate the\u0000observed SK relations for galactic clouds and {it b)} the so-called efficiency\u0000per free-fall time ($eff$) is small and constant in space and in time, with\u0000values similar to those found in local clouds. This constancy is a consequence\u0000of the similar radial scaling of the free-fall time and the internal mass in\u0000density structures with spherically-averaged density profiles near $r^{-2}$. We\u0000additionally show that {it c)} the star formation rate (SFR) increases rapidly\u0000in time; {it d)} the low values of $eff$ are due to the different time\u0000periods over which $tauff$ and $tausf$ are evaluated, together with the fast\u0000increasing SFR, and {it e)} the fact that star clusters are significantly\u0000denser than the gas clumps from which they form is a natural consequence of the\u0000fast increasing SFR, the continuous replenishment of the star-forming gas by\u0000the accretion flow, and the near $r^{-2}$ density profile generated by the\u0000collapse Finally, we argue that the interpretation of $eff$ as an efficiency\u0000is problematic because its maximum value is not bounded by unity, and because\u0000the total gas mass in the clouds is not fixed, but rather depends on the\u0000environment where clouds are embedded. In summary, our results show that the SK\u0000relation, the typical observed values of $eff$, and the mass density of\u0000clusters arise as a natural consequence of gravitational contraction.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Spectro-Polarimeter (SP) of the Andrei B. Severny Solar Tower Telescope (STT) at the Crimean Astrophysical Observatory: Optical Design and Implementation","authors":"Alexander Kutsenko, Valery Terebizh, Andrei Dolgopolov, Valentina Abramenko, Andrei Plotnikov, Dmitriy Semyonov, Vladimir Skiruta, Vyacheslav Lopukhin","doi":"arxiv-2409.11289","DOIUrl":"https://doi.org/arxiv-2409.11289","url":null,"abstract":"The Spectro-Polarimeter (SP) is a new instrument installed at the upgraded\u0000Andrei B. Severny Solar Tower Telescope (STT) at the Crimean Astrophysical\u0000Observatory. The instrument is a traditional echelle slit dual-beam\u0000spectropolarimeter with temporal modulation of the polarization. STT-SP\u0000provides simultaneous spectropolarimetric observations of the Sun within three\u000015 Angstrom wide spectral ranges around photospheric Fe I 5250, Fe I 5324, and\u0000chromospheric Mg I b2 5172 spectral lines. The spectral resolution of the\u0000instrument reaches 70,000 with the seeing-constrained slit width of 1 arcsec.\u0000The field-of-view of STT-SP is 200 arcsec allowing one to map a moderate size\u0000active region within a single raster scan. The instrument will provide new\u0000opportunities in the analysis of magnetic fields and thermodynamics of the\u0000lower atmosphere of the Sun. In this paper we describe the optical design of\u0000STT-SP and present the preliminary results acquired during the commissioning of\u0000the instrument.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linking Transients to their Host Galaxies: II. A Comparison of Host Galaxy Properties and Rate Dependencies across Supernova Types","authors":"Yu-Jing Qin, Ann Zabludoff","doi":"arxiv-2409.11461","DOIUrl":"https://doi.org/arxiv-2409.11461","url":null,"abstract":"We use the latest dataset of supernova (SN) host galaxies to investigate how\u0000the host properties -- stellar mass, star formation rate, metallicity, absolute\u0000magnitude, and colour -- differ across SN types, with redshift-driven selection\u0000effects controlled. SN Ib and Ic host galaxies, on average, are more massive,\u0000metal-rich, and redder than SN II hosts. For subtypes, SN Ibn and Ic-BL have\u0000bluer hosts than their normal SN Ib and Ic siblings; SN IIb has consistent host\u0000properties with SN Ib, while hosts of SN IIn are more metal-rich than those of\u0000SN II. Hydrogen-deficient superluminous supernovae feature bluer and lower\u0000luminosity hosts than most subtypes of core-collapse supernova (CC SN).\u0000Assuming simple proportionality of CC SN rates and host star formation rates\u0000(SFRs) does not recover the observed mean host properties; either a population\u0000of long-lived progenitors or a metallicity-dependent SN production efficiency\u0000better reproduces the observed host properties. Assuming the latter case, the\u0000rates of SN II are insensitive to host metallicity, but the rates of SN Ib and\u0000Ic are substantially enhanced in metal-rich hosts by a factor of ~10 per dex\u0000increase in metallicity. Hosts of SN Ia are diverse in their observed\u0000properties; subtypes including SN Ia-91T, Ia-02cx, and Ia-CSM prefer\u0000star-forming hosts, while subtypes like SN Ia-91bg and Ca-rich prefer quiescent\u0000hosts. The rates of SN Ia-91T, Ia-02cx, and Ia-CSM are closely dependent on, or\u0000even proportional to, their host SFRs, indicating relatively short-lived\u0000progenitors. Conversely, the rates of SN Ia-91bg and Ca-rich transients are\u0000proportional to the total stellar mass, favoring long-lived progenitors.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Connecting the Low to High Corona: Propagating Disturbances as Tracers of the Near-Sun Solar Wind","authors":"Nathalia Alzate, Simone Di Matteo, Huw Morgan, Nicholeen Viall, Angelos Vourlidas","doi":"arxiv-2409.11352","DOIUrl":"https://doi.org/arxiv-2409.11352","url":null,"abstract":"We revisit a quiet 14-day period of solar minimum during January 2008 and\u0000track sub-streamer propagating disturbances (PDs) from low heights in\u0000STEREO/EUVI to the extended corona through STEREO/COR1 and into STEREO/COR2\u0000along nonradial paths that trace the structure of the underlying streamers.\u0000Using our recently developed method for generating nonradial Height-Time\u0000profiles of outward PDs (OPDs) and inward PDs (IPDs), we obtained their\u0000velocities along the radial and position angle directions. Our analysis of 417\u0000unique OPDs revealed two classes: slow and fast OPDs. Slow OPDs form\u0000preferentially at $approx$1.6 $R_odot$ closer to the streamer boundaries,\u0000with asymmetric occurrence rates, and show speeds of $16.4_{-8.4}^{+26.6}km/s$\u0000at 1.5 $R_odot$ and accelerate up to $200.1_{-57.9}^{+71.1}km/s$ at 7.5\u0000$R_odot$. Fast OPDs form preferentially at $approx$ 1.6 $R_odot$ and at\u0000$approx$3.0 $R_odot$ both at the streamer boundaries and slightly more often\u0000within them. They show speeds of $87.8_{-24.8}^{+59.1}km/s$ at 1.5 $R_odot$ up\u0000to $197.8_{-46.7}^{+61.8}km/s$ at 7.5 $R_odot$. IPDs are observed forming at\u0000$approx$1.8 $R_odot$ with speeds of tens of $km/s$, mostly concentrated in\u0000the aftermath of a CME eruption. We present an example in which we show that\u0000periodic brightness variations related to OPDs remained in the range of 98 to\u0000128 min, down to $approx$2.0 $R_odot$, well within the field of view of COR1.\u0000The velocity profiles of slow OPDs for heliocentric height below 3.0 $R_odot$\u0000show good agreement with speeds more closely related to the bulk solar wind\u0000obtained via interplanetary scintillation.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A search for mode coupling in magnetic bright points","authors":"Arthur Berberyan, Peter H. Keys, David B. Jess, Damian J. Christian","doi":"arxiv-2409.11553","DOIUrl":"https://doi.org/arxiv-2409.11553","url":null,"abstract":"Context. Magnetic bright points (MBPs) are one of the smallest manifestations\u0000of the magnetic field in the solar atmosphere and are observed to extend from\u0000the photosphere up to the chromosphere. As such, they represent an excellent\u0000feature to use in searches for types of magnetohydrodynamic (MHD) waves and\u0000mode coupling in the solar atmosphere. Aims. In this work, we aim to study wave\u0000propagation in the lower solar atmosphere by comparing intensity oscillations\u0000in the photosphere with the chromosphere via a search for possible mode\u0000coupling, in order to establish the importance of these types of waves in the\u0000solar atmosphere, and their contribution to heating the chromosphere. Methods.\u0000Observations were conducted in July 2011 with the ROSA and the HARDCam\u0000instruments at the Dunn Solar Telescope. We used wavelet analysis to identify\u0000traveling MHD waves and derive frequencies in the G-band and H$alpha$wave\u0000bands. We isolated a large sample of MBPs using an automated tracking algorithm\u0000throughout our observations. Two dozen of the brightest MBPs were selected from\u0000the sample for further study. Results. We find oscillations in the G-band MBPs,\u0000with frequencies between 1.5 and 3.6 mHz. Corresponding MBPs in the lower solar\u0000chromosphere observed in H$alpha$ show a frequency range of 1.4 to 4.3 mHz. In\u0000about 38% of the MBPs, the ratio of H$alpha$ to G-band frequencies was near\u0000two. Thus, these oscillations show a form of mode coupling where the transverse\u0000waves in the photosphere are converted into longitudinal waves in the\u0000chromosphere. Conclusions. From simple estimates we find an energy flux of\u0000$approx$45 $times 10^{3}$ W m$^{-2}$ and show that the energy flowing through\u0000MBPs is enough to heat the chromosphere, and mode coupling is important in\u0000helping us understand the types of MHD waves in the lower solar atmosphere and\u0000the overall energy budget.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}