RAS_WEB (Page 32)

Remnant masses from 1D+ core-collapse supernovae simulations: bimodal neutron star mass distribution and black holes in the low-mass gap Luca Boccioli, Giacomo Fragione arXiv:2404.05927v1 Announce Type: new Abstract: The explosion of core-collapse supernovae (CCSNe) is an extremely challenging problem, and there are still large uncertainties regarding which stars lead to successful explosions that leave behind a neutron star, and which ones will form a black hole instead. In this paper, we simulate 341 progenitors at three different metallicities using spherically symmetric simulations that include neutrino-driven convection via a mixing-length theory. We use these simulations to improve previously derived explosion criteria based on the density andRead More →

Chondrule Destruction via Dust Collisions in Shock Waves Yuji Matsumoto, Kosuke Kurosawa, Sota Arakawa arXiv:2404.05954v1 Announce Type: new Abstract: A leading candidate for the heating source of chondrules and igneous rims is shock waves. This mechanism generates high relative velocities between chondrules and dust particles. We have investigated the possibility of the chondrule destruction in collisions with dust particles behind a shock wave using a semianalytical treatment. We find that the chondrules are destroyed during melting in collisions. We derive the conditions for the destruction of chondrules and show that the typical size of the observed chondrules satisfies the condition. We suggest that the chondruleRead More →

Resolution enhancement of SOHO/MDI Magnetograms Ying Qin, Kai-Fan Ji, Hui Liu, Xiao-Guang Yu arXiv:2404.05968v1 Announce Type: new Abstract: Research on the solar magnetic field and its effects on solar dynamo mechanisms and space weather events has benefited from the continual improvements in instrument resolution and measurement frequency. The augmentation and assimilation of historical observational data timelines also play a significant role in understanding the patterns of solar magnetic field variation. Within the realm of astronomical data processing, superresolution reconstruction refers to the process of using a substantial corpus of training data to learn the nonlinear mapping between low-resolution and high-resolution images,thereby achieving higher-resolution astronomical images.Read More →

On Variation of Light Curves and Broad Emission Lines for Periodic QSOs from co-rotating Supermassive binary black holes in elliptical orbits Junqiang Ge, Youjun Lu, Changshuo Yan, Jifeng Liu arXiv:2404.05975v1 Announce Type: new Abstract: Context. Periodic QSOs are considered as candidates of supermassive binary black hole (BBH) systems in galactic centers. Further confirmation of these candidates may require different lines of observational evidences. Aims. Assuming the Doopler boosting scenario, in this paper we investigate the (coherent) variations of both broad emission lines (BELs) and continuum light curves for active BBH systems surrounding by a circumbinary broad line region (cBLR) and focus on their dependence onRead More →

Tests of the Kerr Hypothesis with MAXI J1803-298 Using Different RELXILL_NK Flavors Jie Liao, M. Ghasemi-Nodehi, Lang Cui, Ashutosh Tripathi, Yong-Feng Huang, Xiang Liu arXiv:2404.06020v1 Announce Type: new Abstract: Iron line spectroscopy has been one of the leading methods not only for measuring the spins of accreting black holes but also for testing fundamental physics. Basing on such a method, we present an analysis of a dataset observed simultaneously by NuSTAR and NICER for the black hole binary candidate MAXI J1803-298, which shows prominent relativistic reflection features. Various relxill_nk flavors are utilized to test the Kerr black hole hypothesis. The results obtained from our analysisRead More →

Relativistic imprints on dispersion measure space distortions Shohei Saga, David Alonso arXiv:2404.06049v1 Announce Type: new Abstract: We investigate the three-dimensional clustering of sources emitting electromagnetic pulses traveling through cold electron plasma, whose radial distance is inferred from their dispersion measure. As a distance indicator, dispersion measure is systematically affected by inhomogeneities in the electron density along the line of sight and special and general relativistic effects, similar to the case of redshift surveys. We present analytic expressions for the correlation function of fast radio bursts (FRBs), and for the galaxy-FRB cross-correlation function, in the presence of these dispersion measure-space distortions. We find that the evenRead More →

Weak lensing combined with the kinetic Sunyaev Zel’dovich effect: A study of baryonic feedback L. Bigwood, A. Amon, A. Schneider, J. Salcido, I. G. McCarthy, C. Preston, D. Sanchez, D. Sijacki, E. Schaan, S. Ferraro, N. Battaglia, A. Chen, S. Dodelson, A. Roodman, A. Pieres, A. Ferte, A. Alarcon, A. Drlica-Wagner, A. Choi, A. Navarro-Alsina, A. Campos, A. J. Ross, A. Carnero Rosell, B. Yin, B. Yanny, C. Sanchez, C. Chang, C. Davis, C. Doux, D. Gruen, E. S. Rykoff, E. M. Huff, E. Sheldon, F. Tarsitano, F. Andrade-Oliveira, G. M. Bernstein, G. Giannini, H. T. Diehl, H. Huang, I. Harrison, I. Sevilla-Noarbe, I. Tutusaus,Read More →

Estimating the lateral speed of a fast shock driven by a coronal mass ejection at the location of solar radio emissions S. Normo, D. E. Morosan, E. K. J. Kilpua, J. Pomoell arXiv:2404.06102v1 Announce Type: new Abstract: Fast coronal mass ejections (CMEs) can drive shock waves capable of accelerating electrons to high energies. These shock-accelerated electrons act as sources of electromagnetic radiation, often in the form of solar radio bursts. Recent findings suggest that radio imaging of solar radio bursts can provide a means to estimate the lateral expansion of CMEs and associated shocks in the low corona. Our aim is to estimate the expansionRead More →

REPUBLIC: A variability-preserving systematic-correction algorithm for PLATO’s multi-camera light curves Oscar Barrag’an, Suzanne Aigrain, James McCormac arXiv:2404.06132v1 Announce Type: new Abstract: Space-based photometry missions produce exquisite light curves that contain a wealth of stellar variability on a wide range of timescales. Light curves also typically contain significant instrumental systematics — spurious, non-astrophysical trends that are common, in varying degrees, to many light curves. Empirical systematics-correction approaches using the information in the light curves themselves have been very successful, but tend to suppress astrophysical signals, particularly on longer timescales. Unlike its predecessors, the PLATO mission will use multiple cameras to monitor the same stars. We presentRead More →

Radial and vertical constraints on the icy origin of H$_{2}$CO in the HD 163296 Protoplanetary Disk Claudio Hern’andez-Vera, Viviana V. Guzm’an, Elizabeth Artur de la Villarmois, Karin I. "Oberg, L. Ilsedore Cleeves, Michiel R. Hogerheijde, Chunhua Qi, John Carpenter, Edith C. Fayolle arXiv:2404.06133v1 Announce Type: new Abstract: H$_2$CO is a small organic molecule widely detected in protoplanetary disks. As a precursor to grain-surface formation of CH$_3$OH, H$_2$CO is considered an important precursor of O-bearing organic molecules that are locked in ices. Still, since gas-phase reactions can also form H$_2$CO, there remains an open question on the channels by which organics form in disks, and howRead More →

Thin Accretion disks in GR-MHD simulations Indu K. Dihingia, Christian Fendt arXiv:2404.06140v1 Announce Type: new Abstract: We review some recent results of general relativistic magnetohydrodynamic (GR-MHD) simulations considering the evolution of geometrically thin disks around a central black hole. Thin disk GR-MHD simulations complement the widely used MAD (Magnetically Arrested Disk) or SANE (Standard And Normal Evolution) approaches of evolving from an initial disk torus. In particular, we discuss the dynamical evolution of the disk, its role in the formation of disk winds or jets, the impact of disk resistivity, and its potential role in generating magnetic flux by an internal disk dynamo. The mainRead More →

The radius variations of accreting main sequence stars and mass transfer instability Zi-Qi Zhao, Zhen-Wei Li, Lin Xiao, Hong-Wei Ge, Zhan-Wen Han arXiv:2404.06148v1 Announce Type: new Abstract: Many previous works studied the dynamical timescale mass transfer stability criteria based on the donor response with neglecting the stellar structure of the accretor. In this letter, we investigate the radial response of accretors with mass accumulation and its effect on the binary mass transfer stability. We perform a series of detailed stellar evolution simulations with different types of accretors and obtain the radial variations of stars accreting at different rates. Since the time within which the donorRead More →

Non-Gaussianities in primordial black hole formation and induced gravitational waves Shi Pi arXiv:2404.06151v1 Announce Type: new Abstract: The most promising mechanism of generating primordial black holes (PBHs) is by the enhancement of power spectrum of the primordial curvature perturbation, which is usually accompanied by the the enhancement of non-Gaussianity that crucially changes the abundance of PBHs. In this review I will discuss how non-Gaussianity is generated in single field inflation as well as in the curvaton scenario, and then discuss how to calculate PBH mass function with such non-Gaussianities. I also show non-Gaussianity only has mild effects on the induced gravitational waves (GWs), which givesRead More →

Understanding the thermal and magnetic properties of a X-class flare in the low solar atmosphere F. Ferrente, C. Quintero Noda, F. Zuccarello, S. L. Guglielmino arXiv:2404.06231v1 Announce Type: new Abstract: We analyse the spatial distribution and vertical stratification of the physical parameters of the solar atmosphere when an X-class flare occurs. We made use of observations acquired by the Interferometric Bidimensional Spectropolarimeter instrument when observing the full Stokes parameters for the Fe I 6173 A and Ca II 8542 A transitions. We analysed the observed spectra using the newly developed DeSIRe code to infer the atmospheric parameters at photospheric and chromospheric layers over the entireRead More →

The Rubin Observatory’s Legacy Survey of Space and Time DP0.2 processing campaign at CC-IN2P3 Quentin Le Boulc’h, Fabio Hernandez, Gabriele Mainetti arXiv:2404.06234v1 Announce Type: new Abstract: The Vera C. Rubin Observatory, currently in construction in Chile, will start performing the Legacy Survey of Space and Time (LSST) in 2025 for 10 years. Its 8.4-meter telescope will survey the southern sky in less than 4 nights in six optical bands, and repeatedly generate about 2 000 exposures per night, corresponding to a data volume of about 20 TiB every night. Three data facilities are preparing to contribute to the production of the annual data releases: theRead More →

Redshift drift in a universe with structure III: Numerical relativity Sofie Marie Koksbang, Asta Heinesen, Hayley J. Macpherson arXiv:2404.06242v1 Announce Type: new Abstract: Measurements of the cosmic redshift drift – the change in redshift of a source over time – will enable independent detection of cosmological expansion thanks to the immense precision soon reached by new facilities such as the Square Kilometer Array Observatory and the Extremely Large Telescope. We conduct the first ever redshift drift computation in fully relativistic cosmological simulations, with the simulations performed with the Einstein Toolkit. We compute the redshift drift over the full skies of 50 synthetic observers in theRead More →

Dynamical dark energy in light of cosmic distance measurements I: a demonstration using simulated datasets Gan Gu, Xiaoma Wang, Xiaoyong Mu, Shun Yuan, Gong-Bo Zhao arXiv:2404.06303v1 Announce Type: new Abstract: We develop methods to extract key dark energy information from cosmic distance measurements including the BAO scales and supernovae luminosity distances. Demonstrated using simulated datasets of the complete DESI, LSST and Roman surveys designed for BAO and SNe distance measurements, we show that using our method, the dynamical behaviour of the energy, pressure, equation of state (with its time derivative) of dark energy and the cosmic deceleration function can all be accurately recovered from high-qualityRead More →

Constraining the Coronal Properties of AB Dor in the Radio Regime C. E. Brasseur, M. M. Jardine, G. A. J. Hussain arXiv:2404.06304v1 Announce Type: new Abstract: We present a multiwavelength study of AB Doradus, combining modelling that incorporates a spectropolarimetric magnetic field map with 8.4 GHz radio interferometry to measure the coronal extent and density of this young star. We use the surface magnetic field map to produce a 3D extrapolation of AB Dor’s coronal magnetic field. From this model we create synthetic radio images throughout the stellar rotation period which we can compare with the interferometric radio observations. Our models reproduce the two-lobe structureRead More →

Dynamical dark energy in light of cosmic distance measurements II: a study using current observations Xiaoma Wang, Gan Gu, Xiaoyong Mu, Shuo Yuan, Gong-Bo Zhao arXiv:2404.06310v1 Announce Type: new Abstract: We extract key information of dark energy from current observations of BAO, OHD and $H_0$, and find hints of dynamical behaviour of dark energy. In particular, a dynamical dark energy model whose equation of state crosses $-1$ is favoured by observations. We also find that the Universe has started accelerating at a lower redshift than expected.arXiv:2404.06310v1 Announce Type: new Abstract: We extract key information of dark energy from current observations of BAO, OHD and $H_0$,Read More →

The AstraLux-TESS high-spatial resolution imaging survey. Search for stellar companions of 215 planet candidates from TESS J. Lillo-Box, M. Morales-Calder’on, D. Barrado, O. Balsalobre-Ruza, A. Castro-Gonz’alez, I. Mendigut’ia, N. Hu’elamo, B. Montesinos, M. Vioque arXiv:2404.06316v1 Announce Type: new Abstract: Chance-aligned sources or blended companions can cause false positives in planetary transit detections or simply bias the determination of the candidate properties. In the era of high-precision space-based photometers, the need for high-spatial resolution images has demonstrated to be critical for validating and confirming transit signals. This already applied to the Kepler mission, it is now applicable to the TESS survey and will be critical forRead More →