Observational evidence for mass ejection during soft X-ray dips in GRS 1915+105

Outflows from low-mass young stellar objects are thought to draw upon the energy released by accretion onto T Tauri stars. I briefly summarize the evidence for this accretion and outline present estimates of mass accretion rates. Young stars show a very large range of accretion rates, and this has important implications for both mass ejection and for the structure of stellar magnetospheres which may truncate T Tauri disks.

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Wave Activity and Prominence Eruption

International Astronomical Union Colloquium ◽

10.1017/s0252921100047813 ◽

1998 ◽

Vol 167 ◽

pp. 314-317 ◽

Cited By ~ 1

Author(s):

F. Baudin ◽

K. Bocchialini ◽

C. Delannee ◽

S. Koutchmy ◽

G. Stellmacher ◽

...

Keyword(s):

Dissipation Rate ◽

Wave Activity ◽

Observational Evidence ◽

Loop System ◽

Mhd Waves ◽

Plasma Instabilities ◽

Important Ingredient ◽

X Ray ◽

Convective Structures ◽

Energy And Momentum

AbstractObservational evidence of 3 and 5 min vertical oscillations of a filament on the disk are recorded. Wave activity was observed before, during and after a filament disappearance, inside and around the filament. Both an Hα brightening and, later, a blowing out of a faint soft X-ray (Yohkoh) loop system occuring in connection with a flare were noticed. The wave activity seems to be a dynamically important ingredient of this erupting prominence.Propagating MHD waves and convective structures bring their energy and momentum from the photosphere towards the chromosphere up to the coronal heights where they are partially reflected and/or dissipated. The transition from the laminar to the turbulent state of the whole prominence enhances the dissipation rate of the external waves inside this system, adding energy to produce the heating and lifting of the plasma. Internal plasma instabilities could trigger this transition in the framework of a prominence disappearance.

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MHD simulations of magnetospheric response to a strong solar wind density pulse

10.5194/egusphere-egu21-8329 ◽

2021 ◽

Author(s):

Andrey Samsonov ◽

Jennifer A. Carter ◽

Graziella Branduardi-Raymont ◽

Steven Sembay

Keyword(s):

Solar Wind ◽

Dynamic Pressure ◽

Solar Wind Density ◽

Ionospheric Currents ◽

X Ray ◽

Interplanetary Coronal Mass Ejection ◽

Explorer Mission ◽

The One ◽

Mass Ejection ◽

Present Simulation

<p>On 16-17 June 2012, an interplanetary coronal mass ejection with an extremely high solar wind density (~100 cm<sup>-3</sup>) and mostly strong northward (or eastward) interplanetary magnetic field (IMF) interacted with the Earth&#8217;s magnetosphere. We have simulated this event using global MHD models. We study the magnetospheric response to two solar wind discontinuities. The first is characterized by a fast drop of the solar wind dynamic pressure resulting in rapid magnetospheric expansion. The second is a northward IMF turning which causes reconfiguration of the magnetospheric-ionospheric currents. We discuss variations of the magnetopause position and locations of the magnetopause reconnection in response to the solar wind variations. In the second part of our presentation, we present simulation results for the forthcoming SMILE (Solar wind Magnetosphere Ionosphere Link Explorer) mission. SMILE is scheduled for launch in 2024. We produce two-dimensional images that derive from the MHD results of the expected X-ray emission as observed by the SMILE Soft X-ray Imager (SXI).&#160;We discuss how SMILE observations may help to study events like the one presented in this work.</p>

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On pulsar-driven mass ejection in low-mass X-ray binaries

Research in Astronomy and Astrophysics ◽

10.1088/1674-4527/11/12/007 ◽

2011 ◽

Vol 11 (12) ◽

pp. 1457-1468 ◽

Cited By ~ 1

Author(s):

Lei Fu ◽

Xiang-Dong Li

Keyword(s):

X Ray ◽

Low Mass ◽

Mass Ejection ◽

X Ray Binaries

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The Supersoft X-Ray Transient ASASSN-16oh as a Thermonuclear Runaway without Mass Ejection

The Astrophysical Journal ◽

10.3847/2041-8213/ab2887 ◽

2019 ◽

Vol 879 (1) ◽

pp. L5 ◽

Cited By ~ 2

Author(s):

Yael Hillman ◽

Marina Orio ◽

Dina Prialnik ◽

Michael Shara ◽

Pavol Bezák ◽

...

Keyword(s):

X Ray ◽

Thermonuclear Runaway ◽

Mass Ejection

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Radio and X‐Ray Studies of a Coronal Mass Ejection Associated with a Very Slow Prominence Eruption

The Astrophysical Journal ◽

10.1086/303519 ◽

1997 ◽

Vol 475 (1) ◽

pp. 348-360 ◽

Cited By ~ 30

Author(s):

N. Gopalswamy ◽

Y. Hanaoka ◽

M. R. Kundu ◽

S. Enome ◽

J. R. Lemen ◽

...

Keyword(s):

Coronal Mass Ejection ◽

X Ray ◽

Mass Ejection

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Motion of dust particles in dry snow under temperature gradient metamorphism

The Cryosphere ◽

10.5194/tc-13-2345-2019 ◽

2019 ◽

Vol 13 (9) ◽

pp. 2345-2359 ◽

Cited By ~ 1

Author(s):

Pascal Hagenmuller ◽

Frederic Flin ◽

Marie Dumont ◽

François Tuzet ◽

Isabel Peinke ◽

...

Keyword(s):

Time Series ◽

Temperature Gradient ◽

Pore Space ◽

Observational Evidence ◽

Climate Forcing ◽

Dust Particles ◽

Snow Surface ◽

X Ray ◽

Arctic Regions ◽

Radiative Impact

Abstract. The deposition of light-absorbing particles (LAPs) such as mineral dust and black carbon on snow is responsible for a highly effective climate forcing, through darkening of the snow surface and associated feedbacks. The interplay between post-depositional snow transformation (metamorphism) and the dynamics of LAPs in snow remains largely unknown. We obtained time series of X-ray tomography images of dust-contaminated samples undergoing dry snow metamorphism at around −2 ∘C. They provide the first observational evidence that temperature gradient metamorphism induces dust particle motion in snow, while no movement is observed under isothermal conditions. Under temperature gradient metamorphism, dust particles can enter the ice matrix due to sublimation–condensation processes and spread down mainly by falling into the pore space. Overall, such motions might reduce the radiative impact of dust in snow, in particular in arctic regions where temperature gradient metamorphism prevails.

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An Observational Evidence of the Common Envelope Phase

International Astronomical Union Colloquium ◽

10.1017/s0252921100151826 ◽

2004 ◽

Vol 194 ◽

pp. 37-38

Author(s):

Marek J. Sarna ◽

Jeremy J. Drake

Keyword(s):

Abundance Ratio ◽

Observational Evidence ◽

Coronal Emission ◽

X Ray ◽

Common Envelope ◽

Transmission Grating ◽

Processed Material ◽

The Common ◽

Red Giant ◽

First Time

AbstractChandra Low Energy Transmission Grating Spectrograph observations of the pre-cataclysmic binary V471 Tau have been used to estimate the C/N abundance ratio of the K dwarf component for the first time. While the white dwarf component dominates the spectrum longward of 50 Å, at shorter wavelengths the observed X-ray emission is entirely due to coronal emission from the K dwarf. The H-like 2p 2Р3/2, 1/2 → 1s 2S1/2 resonance lines of С and N yield an estimate of their logarithmic abundance ratio relative to the Sun of [C/N]= –0.38 ± 0.15—half of the currently accepted solar value. We interpret this result as the first clear observational evidence for the presumed common envelope phase of this system, during which the surface of the K dwarf was contaminated by CN-cycle processed material dredged up into the red giant envelope

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Observational evidence for intermediate-mass black holes

International Journal of Modern Physics D ◽

10.1142/s021827181730021x ◽

2017 ◽

Vol 26 (11) ◽

pp. 1730021 ◽

Cited By ~ 84

Author(s):

Mar Mezcua

Keyword(s):

Black Holes ◽

Galaxy Formation ◽

Globular Clusters ◽

High Redshift ◽

Galactic Nuclei ◽

Observational Evidence ◽

Intermediate Mass ◽

X Ray ◽

Mass Scaling ◽

Intermediate Mass Black Holes

Intermediate-mass black holes (IMBHs), with masses in the range [Formula: see text]–[Formula: see text][Formula: see text]M[Formula: see text], are the link between stellar-mass BHs and supermassive BHs (SMBHs). They are thought to be the seeds from which SMBHs grow, which would explain the existence of quasars with BH masses of up to 10[Formula: see text][Formula: see text]M[Formula: see text] when the Universe was only 0.8 Gyr old. The detection and study of IMBHs has thus strong implications for understanding how SMBHs form and grow, which is ultimately linked to galaxy formation and growth, as well as for studies of the universality of BH accretion or the epoch of reionization. Proving the existence of seed BHs in the early Universe is not yet feasible with the current instrumentation; however, those seeds that did not grow into SMBHs can be found as IMBHs in the nearby Universe. In this review, I summarize the different scenarios proposed for the formation of IMBHs and gather all the observational evidence for the few hundreds of nearby IMBH candidates found in dwarf galaxies, globular clusters, and ultraluminous X-ray sources, as well as the possible discovery of a few seed BHs at high redshift. I discuss some of their properties, such as X-ray weakness and location in the BH mass scaling relations, and the possibility to discover IMBHs through high velocity clouds, tidal disruption events, gravitational waves, or accretion disks in active galactic nuclei. I finalize with the prospects for the detection of IMBHs with up-coming observatories.

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