Zobrazeno 1 - 10
of 437
pro vyhledávání: '"A. Glassgold"'
The possible occurrence of dead zones in protoplanetary disks subject to the magneto-rotational instability highlights the importance of disk ionization. We present a closed-form theory for the deep-down ionization by X-rays at depths below the disk
Externí odkaz:
http://arxiv.org/abs/1708.08942
Protoplanetary disks are strongly irradiated by a stellar FUV spectrum that is dominated by Ly$\alpha$ photons. We investigate the impact of stellar Ly$\alpha$ irradiation on the terrestrial planet region of disks ($\lesssim 1$AU) using an updated th
Externí odkaz:
http://arxiv.org/abs/1512.04425
Autor:
Glassgold, A. E., Najita, J. R.
Photochemical heating is analyzed with emphasis on the heating generated by chemical reactions initiated by the products of photodissociation and photoionization. The immediate products are slowed down by collisions with the ambient gas and heat the
Externí odkaz:
http://arxiv.org/abs/1506.04167
We present an integrated thermal-chemical model for the atmosphere of the inner region of a protoplanetary disk that includes irradiation by both far ultraviolet (FUV) and X-ray radiation. We focus on how the photodissociation of water and OH affects
Externí odkaz:
http://arxiv.org/abs/1403.8131
Autor:
Ercolano, B., Glassgold, A.
Low-mass young stellar objects are powerful emitters of X-rays that can ionize and heat the disks and the young planets they harbour. The X-rays produce molecular ions that affect the chemistry of the disk atmospheres and their spectroscopic signatur
Externí odkaz:
http://arxiv.org/abs/1309.6537
Cosmic-ray and X-ray heating are derived from the electron energy loss calculations of Dalgarno, Yan and Liu for hydrogen-helium gas mixtures. These authors treated the heating from elastic scattering and collisional de-excitation of rotationally exc
Externí odkaz:
http://arxiv.org/abs/1208.0523
Observations from Spitzer and ground-based infrared spectroscopy reveal significant diversity in the molecular emission from the inner few AU of T Tauri disks. We explore theoretically the possible origin of this diversity by expanding on our earlier
Externí odkaz:
http://arxiv.org/abs/1109.6673
The consequences of the Auger effect on the population of heavy element ions are analyzed for the case of relatively cool gas irradiated by keV X-rays, with intended applications to the accretion disks of young stellar ob jects. Highly charged ions a
Externí odkaz:
http://arxiv.org/abs/1105.3453
Autor:
Guedel, M., Lahuis, F., Briggs, K. R., Carr, J., Glassgold, A. E., Henning, Th., Najita, J. R., van Boekel, R., van Dishoeck, E.
(Abridged) We have conducted a study of [NeII] line emission based on a sample of 92 pre-main sequence stars mostly belonging to the infrared Class II, including 13 accreting transition disk objects and 14 objects driving jets and outflows. We find s
Externí odkaz:
http://arxiv.org/abs/1006.2848
Autor:
Sturm, B., Bouwman, J., Henning, Th., Evans II, N. J., Acke, B., Mulders, G. D., Waters, L. B. F. M., van Dishoeck, E. F., Meeus, G., Green, J. D., Augereau, J. C., Olofsson, J., Salyk, C., Najita, J., Herczeg, G. J., van Kempen, T. A., Kristensen, L. E., Dominik, C., Carr, J. S., Waelkens, C., Bergin, E., Blake, G. A., Brown, J. M., Chen, J. -H., Cieza, L., Dunham, M. M., Glassgold, A., Güdel, M., Harvey, P. M., Hogerheijde, M. R., Jaffe, D., Jørgensen, J. K., Kim, H. J., Knez, C., Lacy, J. H., Lee, J. -E., Maret, S., Meijerink, R., Merín, B., Mundy, L., Pontoppidan, K. M., Visser, R., Yíldíz, U. A.
We present far-infrared spectroscopic observations, taken with the Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory, of the protoplanetary disk around the pre-main-sequence star HD 100546. These observations are th
Externí odkaz:
http://arxiv.org/abs/1005.3472