Results 71 to 80 of about 17,719 (230)

Properties of serendipitous X-ray flares discovered in XMM-Newton observations

, 2004
We present the results of a search of the XMM-Newton public data archive for stellar X-ray flares. We find eight flaring sources for which we identify 7 optical counterparts.
Allen, Barnes, Braes, Brown, Carl Foley, Chen, de Epstein, Dorman, Duncan Trenholme, Fuhrmeister, Gavin Ramsay, Glover, Golub, Jansen, Martres, Mewe, Micela, Moreton, Pallavicini, Panagi, Pearce, Perlman, Perryman, Pillitteri, Pillitteri, Priest, Prosser, Ramsay, Randich, Robichon, Serio, Shibata, Stern, Strüder, Tsikoudi, Wiramihardja, Švestka   +36 more
core   +1 more source

X-ray-heated models of stellar flare atmospheres - Theory and comparison with observations

The Astrophysical Journal Supplement Series, 1992
A sequence of five model atmospheres consisting of the photosphere, chromosphere, and transition region is computed. The models represent the response of the gas in a magnetically confined loop to intense flare energy release. It is assumed that the energy release is confined to the corona, and the effects of chromospheric evaporation and indirect ...
Suzanne L. Hawley, George H. Fisher
openaire   +1 more source

Scalable Room‐Temperature Terahertz Graphene Cameras

Small Methods, EarlyView.
ABSTRACT Terahertz (THz) imaging has emerged as a powerful tool for non‐destructive, label‐free analysis across several scientific disciplines, ranging from materials science to biomedical research. By capturing the spatial‐dependent information in a broad range of frequencies, this technique enables the identification of chemical composition ...
Lili Shi, Leonardo Viti, Miriam S. Vitiello   +2 more
wiley   +1 more source

Statistical Study of the Timing of the Appearance of Hα Postflare Loops: Simple Scaling Law Based on Radiative Cooling

The Astrophysical Journal
Recent Sun-as-a-star studies have shown that postflare loops can manifest as a secondary peak in the H α light curve, suggesting that stellar postflare loops are detectable.
Takato Otsu, Ayumi Asai, Kai Ikuta, Kazunari Shibata   +3 more
doaj   +1 more source

XMM-Newton survey of two Upper Scorpius regions [PDF]

, 2006
We study X-ray emission from young stars by analyzing deep XMM-Newton observations of two regions of the Upper Scorpius association, having an age of 5 Myr.
A. Maggio, Adams, Alexander, Anders, Ardila, Baraffe, Bouvier, Bouy, C. Argiroffi, Damiani, Damiani, de Geus, de Geus, E. Flaccomio, F. Favata, Favata, Favata, Favata, Favata, Favata, Favata, Favata, Feigelson, Flaccomio, Flaccomio, Fleming, G. Micela, G. Peres, Grosso, Guenther, Güdel, Güdel, Hartmann, Imanishi, Imanishi, Jayawardhana, Kastner, Köhler, Landolt, Mamajek, Martin, Martín, Mazzotta, Mohanty, Neuhaeuser, Ozawa, Pallavicini, Pillitteri, Pizzolato, Pravdo, Preibisch, Preibisch, Preibisch, Preibisch, Preibisch, Reale, Reale, Rosati, S. Sciortino, Sciortino, Siess, Slawson, Slesnick, Smith, Stassun, Stelzer, Stelzer, Symington, Tsuboi, Tsujimoto, Voges, Walter, White   +72 more
core   +3 more sources

Thermal X-rays from stellar flares - Reevaluation of scaling from solar flares

The Astrophysical Journal, 1976
We suggest that, close to the time of maximum luminosity in both solar and stellar flares, the ratio of thermal X-ray luminosity, L/sub x/, to optical luminosity, L/sub v/, is given by the ratio of radiative to conductive energy loss rates from the X-ray flare plasma.
openaire   +1 more source

A radio jet from the optical and x-ray bright stellar tidal disruption flare ASASSN-14li [PDF]

Science, 2016
Transient radio jet from a black hole When a star passes too close to a supermassive black hole, it gets ripped apart by the gravitational forces. This causes a tidal disruption flare as the material falls into the black hole. van Velzen et al.
van Velzen, S., Anderson, Gemma, Stone, N., Fraser, M., Wevers, T., Metzger, B., Jonker, P., van der Horst, A., Staley, T., Mendez, A., Miller-Jones, J., Hodgkin, S., Campbell, H., Fender, R.   +13 more
openaire   +6 more sources

Sequential Reduction of Chromite Pellets Using Hydrogen and Silicon Carbide for Carbon Emission Abatement During Ferrochrome Production

steel research international, EarlyView.
H2 prereduction selectively metallizes Fe in UG2 chromite pellets at 1100°C, while silicon carbide becomes active at 1300°C to convert remaining Cr2O3 to carbides and promote Cr metallization. By separating the roles of H2 and SiC, the sequential route reaches up to 65.7% Cr metallization and suppresses in‐furnace CO generation by ≈75% versus ...
D. Coertzen, M. Tangstad, J. P. Beukes, P. G. van Zyl, D. G. Bessarabov, S. P. du Preez   +5 more
wiley   +1 more source

Origin of the Stellar Fe Kα Line Clarified with Far-ultraviolet and X-Ray Observations of a Superflare on the RS Canum Venaticorum–type Star UX Arietis

The Astrophysical Journal
Fluorescence line diagnostics of the Fe K α line at ∼6.4 keV observed in both solar and stellar flares can constrain the latitude and size of the flare loop, even in the absence of imaging observations. However, they are hampered by the unresolved origin
Shun Inoue, Wataru Buz Iwakiri, Tomoki Kimura, Teruaki Enoto, Yuta Notsu, Hiroyuki Uchida, Kenji Hamaguchi, Shin Toriumi, Atsushi Yamazaki, Fuminori Tsuchiya, Go Murakami, Kazuo Yoshioka, Zaven Arzoumanian, Keith Gendreau   +13 more
doaj   +1 more source

Abundance variations and first ionization potential trends during large stellar flares [PDF]

, 2007
The Solar First Ionization Potential (FIP) effect, where low-FIP elements are enriched in the corona relative to the photosphere, while high-FIP abundances remain unchanged, has been known for a long while. High resolution X-ray spectroscopy has revealed
Anders, Antiochos, Audard, Audard, Audard, Audard, Ball, Bar-Shalom, Behar, Berlicki, Brinkman, Budding, Caramazza, Crespo-Chacón, Drake, Drake, Drake, E. Behar, Feldman, Feldman, Fludra, Gu, Güdel, Güdel, Güdel, Güdel, Güdel, Hudson, Huenemoerder, Kashyap, Laming, Maggio, Mazzotta, Milligan, Neupert, Nordon, Nordon, Osten, Ottmann, Perryman, R. Nordon, Raassen, Raassen, Reale, Sanz-Forcada, Schmelz, Schmieder, Schmitt, Segransan, Strassmeier, Tellesci, Testa, Widing, Widing, Wood, Zarro   +55 more
core   +1 more source