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Related papers: Looking for outflows from brown dwarfs

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Young giant planets and brown dwarf companions emit near-infrared radiation that can be linearly polarized up to several percent. This polarization can reveal the presence of a circumsubstellar accretion disk, rotation-induced oblateness of…

We report on accretion- and outflow-related X-rays from T Tauri stars, based on results from the "XMM-Newton Extended Survey of the Taurus Molecular Cloud." X-rays potentially form in shocks of accretion streams near the stellar surface,…

The radiation fields external to the jets and originating from within a few parsecs from the black hole, are discussed in this paper. They are the direct radiation from an accretion disk in symbiosis with jets, the radiation field from the…

Astrophysics · Physics 2009-11-07 A. -C. Donea , R. J. Protheroe

Disks around brown dwarfs (BDs) are excellent laboratories to study the first steps of planet formation in cold and low-mass disk conditions. The radial-drift velocities of dust particles in BD disks are higher than in disks around more…

Earth and Planetary Astrophysics · Physics 2017-09-13 P. Pinilla , L. H. Quiroga-Nuñez , M. Benisty , A. Natta , L. Ricci , Th. Henning , G. van der Plas , T. Birnstiel , L. Testi , K. Ward-Duong

Ultraviolet observations of classical T Tauri Stars (cTTSs) have shown that there is a hot (Te ~ 80,000 K) and dense (ne ~ 1e10 cm-3) component associated with the large scale jet. This hot component is formed very close to the base of the…

Solar and Stellar Astrophysics · Physics 2015-05-20 Ana I. Gomez de Castro , Brigitta von Rekowski

Characterising stellar jet asymmetries is key to setting robust constraints on jet launching models and improving our understanding of the underlying mechanisms behind jet launching. We aim to characterise the asymmetric properties of the…

Solar and Stellar Astrophysics · Physics 2024-12-11 A. Murphy , E. T. Whelan , F. Bacciotti , D. Coffey , F. Comerón , J. Eislöffel , B. Nisini , S. Antoniucci , J. M. Alcalá , T. P. Ray

We have carried out a near-infrared imaging survey of luminous young stellar outflow candidates using the United Kingdom Infrared Telescope. Observations were obtained in the broad band K (2.2 mu) and through narrow band filters at the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Watson P. Varricatt , Christopher J. Davis , Suzanne Ramsay , Stephen P. Todd

The inner region of a luminous accretion disk is radiation pressure dominated. We estimate the surface temperature of a radiation pressure dominated accretion disk, \Theta=(c_s/r\Omega_K)^2<<(H/r)^2, which is significantly lower than that…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Xinwu Cao

AIMS: We examine whether ejection phenomena from accreting T Tauri stars can be described by only one type of self-collimated jet model. METHODS: We present analytical kinematic predictions valid soon after the Alfv\'en surface for all…

Astrophysics · Physics 2009-11-11 Jonathan Ferreira , Catherine Dougados , Sylvie Cabrit

We have carried out a spatio-kinematic study of the outflow from the classical T Tauri star DG Tau using the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST). A series of seven spatially offset long-slit…

We discuss the spectral energy distribution of three very low mass objects in Chamaeleon I for which ground-based spectroscopy and photometry as well as ISO measurements in the mid-infrared are available (Comeron et al. 2000; Persi et al.…

Astrophysics · Physics 2009-11-06 A. Natta , L. Testi

Crucial information on the mass accretion-ejection in young stars can be obtained from high spatial resolution images of jets in sources with recurrent accretion outbursts. Using the SPHERE/ZIMPOL instrument, we observed the young binary Z…

Mass loss through stellar jets is closely tied to the process of accretion through the disk. Understanding phenomena such as episodic ejections and outflow asymmetries can thus shed light on the mechanism of jet launching and its connection…

Solar and Stellar Astrophysics · Physics 2026-03-25 A. Murphy , E. T. Whelan , F. Bacciotti , A. Kirwan , D. Coffey , M. Birney , J. Eislöffel , H. Takami

Based on theoretical arguments and quasi-stationary radiative MHD calculations, a model for an accretion-powered jet is presented. It is argued that accretion disks around BHs consist of 1) a cold, Keplerian-rotating and weakly magnetized…

Astrophysics · Physics 2009-11-07 A. Hujeirat , M. Livio , M. Camenzind , A. Burkert

Using SpeX at the NASA Infrared Telescope Facility and the Spitzer Infrared Spectrograph, we have obtained infrared spectra from 0.7 to 30um for three young brown dwarfs in the TW Hydra Association (~10 Myr), 2M J1207-3932, 2M J1139-3159,…

We examine the conditions of the plasma along a sample of 'classical' Herbig-Haro jets located in the Orion and Vela star forming regions, through combined optical-infrared spectral diagnostics. Our sample includes HH 111, HH 34, HH 83, HH…

Astrophysical jets are present in a range of environments, including young stellar objects, X-ray binaries, and active galactic nuclei, but their formation is still not fully understood. As one of the nearest symbiotic binary stars, R…

Solar and Stellar Astrophysics · Physics 2023-04-19 Caroline D. Huang , Margarita Karovska , Warren Hack , John C. Raymond , Rodolfo Montez , Vinay L. Kashyap

We determine inner disk sizes and temperatures for four solar-type (1-2 M$_{\odot}$) classical T Tauri stars (AS 207A, V2508 Oph, AS 205A, and PX Vul) using 2.2 $\mu$m observations from the Keck Interferometer. Nearly contemporaneous…

Astrophysics · Physics 2009-11-10 J. A. Eisner , L. A. Hillenbrand , R. J. White , R. L. Akeson , A. I. Sargent

Irradiated brown dwarfs (BDs) provide natural laboratories to test our understanding of substellar and irradiated atmospheres. A handful of short-period BDs around white dwarfs (WDs) have been observed, but the uniquely intense UV-dominated…

Solar and Stellar Astrophysics · Physics 2021-01-06 Joshua D. Lothringer , Sarah L. Casewell

We studied the relation of accretion-jet power and disk luminosity, especially the jet efficiencies and disk radiative efficiencies for different accretion disks as well as black hole (BH) spin, in order to explore the origin of radio…

High Energy Astrophysical Phenomena · Physics 2021-10-25 Xiang Liu , Ning Chang , Xin Wang , Qi Yuan
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