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Related papers: Complex Magnetospheric Accretion Flows in Low Accr…

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An investigation of the magnetospheric accretion and outflow signatures in sub-stellar objects is a natural extension of similar studies conducted on classical T Tauri stars (CTTS), and helps understand if brown dwarfs (BDs) follow the same…

Solar and Stellar Astrophysics · Physics 2013-07-08 B. Riaz

We investigate accretion onto a central star, with the size, rotation rate, and magnetic dipole of a young stellar object, to study the flow pattern (velocity and density) of the fluid within and outside of the disc. We perform resistive…

Solar and Stellar Astrophysics · Physics 2023-06-14 R. Mishra , M. Čemeljić , W. Kluźniak

Study of observed spin evolution of long-period X-ray pulsars challenges quasi-spherical and Keplerian disk accretion scenarios. It suggests that the magnetospheric radius of the neutron stars is substantially smaller than Alfven radius and…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Nazar Ikhsanov , Nina Beskrovnaya , Yury Likh

We present medium-resolution (R~7000) near-infrared echelle spectroscopic data for 36 MYSOs drawn from the Red MSX Source (RMS) survey. This is the largest sample observed at this resolution at these wavelengths of MYSOs to date. The…

Solar and Stellar Astrophysics · Physics 2017-09-14 R. Pomohaci , R. D. Oudmaijer , S. L. Lumsden , M. G. Hoare , I. Mendigutia

We present hydrodynamical simulations to model the accretion flow from a polar circumbinary disc onto a high eccentricity ($e=0.78$) binary star system with near unity mass ratio ($q=0.83$), as a model for binary HD 98800 BaBb. We compare…

Earth and Planetary Astrophysics · Physics 2022-06-01 Jeremy L. Smallwood , Stephen H. Lubow , Rebecca G. Martin

We use the Millennium Simulation series to study the relation between the accretion history (MAH) and mass profile of cold dark matter halos. We find that the mean density within the scale radius, r_{-2} (where the halo density profile has…

The magnetic field of the classical T Tauri star V2129 Oph can be modeled approximately by superposing slightly tilted dipole and octupole moments, with polar magnetic field strengths of 0.35kG and 1.2kG respectively (Donati et al. 2007).…

Solar and Stellar Astrophysics · Physics 2015-05-14 Marina M. Romanova , Min Long , Frederick K. Lamb , Akshay K. Kulkarni , Jean-Francois Donati

We consider the implications of recent infrared and radio observations of the nucleus of NGC 4258. There is no direct evidence that the nucleus has been steadily accreting on the viscous timescale of the outer masing disk, which is >~ 10^9…

Astrophysics · Physics 2009-10-30 Charles F. Gammie , Ramesh Narayan , Roger Blandford

We present kinematics of 35 highly r-process-enhanced ([Eu/Fe] >= +0.7) metal-poor (-3.8 < [Fe/H] < -1.4) field stars. We calculate six-dimensional positions and velocities, evaluate energies and integrals of motion, and compute orbits for…

Solar and Stellar Astrophysics · Physics 2018-10-17 Ian U. Roederer , Kohei Hattori , Monica Valluri

The problem of the late accretion phase of the evolution of an axisymmetric, isothermal magnetic disk surrounding a forming star has been formulated in a companion paper. The "central sink approximation" is used to circumvent the problem of…

Astrophysics · Physics 2009-11-10 Konstantinos Tassis , Telemachos Ch. Mouschovias

Within the magnetospheric radius, the geometry of accretion flow in X-ray pulsars is shaped by a strong magnetic field of a neutron star. Starting at the magnetospheric radius, accretion flow follows field lines and reaches the stellar…

High Energy Astrophysical Phenomena · Physics 2024-02-21 A. A. Mushtukov , A. Ingram , V. F. Suleimanov , N. DiLullo , M. Middleton , S. S. Tsygankov , M. van der Klis , S. Portegies Zwart

It has been shown that during the outburst of accretion activity observed in UX Ori type star RZ Psc in 2013, the accretion rate increased approximately by an order of magnitude. This means that the accretion process at the late stages of…

Solar and Stellar Astrophysics · Physics 2023-02-20 D. V. Dmitriev , V. P. Grinin , I. S. Potravnov , T. A. Ermolaeva

Light curves of young star systems show photometric variability due to different kinematic, and physical processes. One of the main contributors to the photometric variability is the changing mass accretion rate, which regulates the…

Solar and Stellar Astrophysics · Physics 2022-10-26 Eleonora Fiorellino , Gabriella Zsidi , Agnes Kospal , Peter Abraham , Attila Bodi , Gaitee Hussain , Carlo F. Manara , Andras Pal

Stars collect most of their mass during the protostellar stage, yet the accretion luminosity and stellar parameters, which are needed to compute the mass accretion rate, are poorly constrained for the youngest sources. The aim of this work…

We present Hubble Space Telescope ultraviolet spectroscopy of the recurrent nova T Pyxidis obtained more than 5 years after its 2011 outburst indicating that the system might not have yet reached its deep quiescent state. The ultraviolet…

Solar and Stellar Astrophysics · Physics 2018-08-08 Patrick Godon , Edward Sion , Robert Williams , Sumner Starrfield

We analyze the variability in accretion-related emission lines for 40 Classical T Tauri stars to probe the extent of accretion variations in young stellar objects. Our analysis is based on multi-epoch high-resolution spectra for young stars…

Solar and Stellar Astrophysics · Physics 2015-05-13 Duy Cuong Nguyen , Alexander Scholz , Marten H. van Kerkwijk , Ray Jayawardhana , Alexis Brandeker

The full disk, full of gas and dust, determines the upper limit of planet masses, and its lifetime is critical for planet formation, especially for giant planets. In this work, we studied the evolutionary timescales of the full disks of T…

Solar and Stellar Astrophysics · Physics 2023-12-25 Hasitieer Haerken , Guang-Wei Li , Min Li , Fuqing Duan , Yongheng Zhao

We used the WINERED spectrograph to perform near-infrared high-resolution spectroscopy (resolving power $R = 28$,000) of 13 young intermediate-mass stars in the Taurus star-forming region. Based on the presence of near- and mid-infrared…

Interpreting the short-timescale variability of the accreting, young, low-mass stars known as Classical T Tauri stars remains an open task. Month-long, continuous light curves from the Transiting Exoplanet Survey Satellite (\textit{TESS})…

Solar and Stellar Astrophysics · Physics 2022-08-24 Connor E. Robinson , Catherine C. Espaillat , Joseph E. Rodriguez

Two new magnetic white dwarf accretion binaries with extremely low mass-transfer rates have been discovered in the course of the Sloan Digital Sky Survey. Measured magnetic fields are 42 MG and 57 MG, and one system orbits with a period of…

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