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Related papers: Accretion and Outflow Activity in Brown Dwarfs

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We study the energetics of the accretion-induced outflow and then plausible jet around black holes/compact objects using a newly developed disc-outflow coupled model. Inter-connecting dynamics of outflow and accretion essentially upholds…

High Energy Astrophysical Phenomena · Physics 2009-09-28 Shubhrangshu Ghosh , Banibrata Mukhopadhyay , Vinod Krishan , Manoranjan Khan

We present a method of determining lower limits on the masses of pre-main-sequence (PMS) stars and so constraining the PMS evolutionary tracks. This method uses the red-shifted absorption feature observed in some emission-line profiles of T…

We have analyzed a broad-band optical and near-infrared spectrum of FU Tau A, a presumed young brown dwarf in the Taurus star forming region that has intrigued both theorists and observers by its over-luminosity in the HR diagram with…

Solar and Stellar Astrophysics · Physics 2015-06-12 B. Stelzer , J. M. Alcala , A. Scholz , A. Natta , S. Randich , E. Covino

Accretion disks of active galactic nuclei (AGN) have been proposed as promising sites for producing both (stellar-mass) compact object mergers and extreme mass ratio inspirals. Along with the disk-assisted migration/evolution process,…

High Energy Astrophysical Phenomena · Physics 2022-01-05 Zhen Pan , Huan Yang

In this review I summarise the observational connections between accretion and relativistic outflows -- jets -- in X-ray binaries. I argue that jets are likely to be a fairly ubiquitous property of X-ray binaries as a whole, an assertion…

Astrophysics · Physics 2007-05-23 Rob Fender

Aims : We re-examine the conditions required to steadily deviate an accretion flow from a circumstellar disc into a magnetospheric funnel flow onto a slow rotating young forming star. Methods : New analytical constraints on the formation of…

Astrophysics · Physics 2009-11-13 N. Bessolaz , C. Zanni , J. Ferreira , R. Keppens , J. Bouvier

We present numerical solutions of the collapse of prestellar cores that lead to the formation and evolution of circumstellar disks. The disk evolution is then followed for up to three million years. A variety of models of different initial…

Solar and Stellar Astrophysics · Physics 2015-05-13 E. I. Vorobyov , Shantanu Basu

Measurements of accretion rates onto planetary mass objects may distinguish between different planet formation mechanisms, which predict different accretion histories. In this Letter, we use \HST/WFC3 UVIS optical photometry to measure…

Solar and Stellar Astrophysics · Physics 2015-06-18 Yifan Zhou , Gregory J. Herczeg , Adam L. Kraus , Stanimir Metchev , Kelle Cruz

We report the statistical properties of stars, brown dwarfs and multiple systems obtained from the largest hydrodynamical simulation of star cluster formation to date that resolves masses down to the opacity limit for fragmentation (a few…

Astrophysics · Physics 2010-04-29 Matthew Bate

Classical T Tauri stars (CTTSs) are young stellar objects that accrete materials from their accretion disc influenced by their strong magnetic field. The magnetic pressure truncates the disc at a few stellar radii and forces the material to…

Solar and Stellar Astrophysics · Physics 2022-11-30 Kim Pouilly , Oleg Kochukhov , Ágnes Kóspál , Axel Hahlin , Andres Carmona , Péter Ábrahám

We present derived stellar and disc parameters for a sample of Taurus brown dwarfs both with and without evidence of an associated disc. These parameters have been derived using an online fitting tool (http://bd-server.astro.ex.ac.uk/),…

Solar and Stellar Astrophysics · Physics 2015-06-04 N. J. Mayne , Tim J. Harries , John Rowe , David M. Acreman

Low-mass pre-main sequence (PMS) stars are strong X-ray sources, because they possess hot corona like their older main-sequence counterparts. Unique to young stars, however, are X-rays from accretion and outflows, and both processes are of…

Solar and Stellar Astrophysics · Physics 2023-04-05 P. Christian Schneider , H. Moritz Günther , Sabina Ustamujic

We aim to characterize the U-band variability of young brown dwarfs in the Taurus Molecular Cloud and discuss its origin. We used the XMM-Newton Extended Survey of the Taurus Molecular Cloud, where a sample of 11 young bona fide brown…

Despite the prevalence of jets in accreting systems and their impact on the surrounding medium, the fundamental physics of how they are launched and collimated is not fully understood. Radio observations of local compact objects, including…

High Energy Astrophysical Phenomena · Physics 2018-10-17 Deanne L. Coppejans , James C. A. Miller-Jones , Elmar G. Koerding , Gregory R. Sivakoff , Michael P. Rupen

We investigate the structure and dynamics of the magnetospheric accretion region and associated outflows on a scale smaller than 0.1 au around the young transitional disk system GM Aur. We monitored the variability of the system on…

The processes of accretion of the gaseous blobs with different masses and densities onto strongly magnetized white dwarfs in the systems of polars have been modeled. We have proved that shot noise in blue wavelengths represents accretion of…

Astrophysics · Physics 2007-05-23 A. V. Halevin , I. L. Andronov , N. M. Shakhovskoy , S. V. Kolesnikov , N. I. Ostrova

Young stellar objects are thought to accrete material from their circumstellar disks through their strong stellar magnetospheres. We aim to directly probe the magnetospheric accretion region on a scale of a few 0.01 au in a young stellar…

Solar and Stellar Astrophysics · Physics 2020-05-06 J. Bouvier , K. Perraut , J. -B. Le Bouquin , G. Duvert , C. Dougados , W. Brandner , M. Benisty , J. -P. Berger , E. Alécian

We discuss results of global 3D MHD simulations of accretion on to a rotating magnetized star with a tilted dipole magnetic field, where the accretion is driven by the magneto-rotational instability (MRI). The simulations show that…

Solar and Stellar Astrophysics · Physics 2015-06-03 M. M. Romanova , G. V. Ustyugova , A. V. Koldoba , R. V. E. Lovelace

Variable accretion in young stellar objects reveals itself photometrically and spectroscopically over a continuum of timescales and amplitudes. Most dramatic are the large outbursts (e.g., FU Ori, V1647 Ori, and EX Lup type events), but…

Solar and Stellar Astrophysics · Physics 2023-11-20 William J. Fischer , Lynne A. Hillenbrand , Gregory J. Herczeg , Doug Johnstone , Ágnes Kóspál , Michael M. Dunham

I have performed a search for young low-mass stars and brown dwarfs (BDs) in 2 regions encompassing a total area of 4 deg^2 in the Taurus star-forming region, discovering 15 new members of Taurus. In addition, I present 7 new members…

Astrophysics · Physics 2008-11-26 K. L. Luhman
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