A5066230158- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Photocathodes and Microchannel Plates
- Astronomy and Astrophysical Research
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- History and Developments in Astronomy
- Molecular Spectroscopy and Structure
- Galaxies: Formation, Evolution, Phenomena
- Planetary Science and Exploration
- Ionosphere and magnetosphere dynamics
- Spacecraft and Cryogenic Technologies
- CCD and CMOS Imaging Sensors
- Space Exploration and Technology
- Atomic and Molecular Physics
- solar cell performance optimization
- High-pressure geophysics and materials
- Adaptive optics and wavefront sensing
- Spacecraft Design and Technology
- Astrophysics and Cosmic Phenomena
Universidad Complutense de Madrid
2015-2024
Escola Bahiana de Medicina e Saúde Pública
2022
Spanish National Observatory
1988-2007
University of Milano-Bicocca
2006
Consejo Superior de Investigaciones Científicas
2003-2005
Observatori de l'Ebre
1993
McMaster University
1991
Abstract During the last three decades, astronomers have had practically continuous access to 100–300 nm spectral range that is unreachable with ground‐based instruments but where astro‐physical processes can be efficiently studied unprecedented capability since resonance lines of most abundant atoms and ions at temperatures between 3000 300000 K are in UV. The successful International Ultraviolet Explorer (IUE) observatory, Russian ASTRON mission successor such as COS STIS spectrographs...
The analysis of high-resolution profiles the semiforbidden UV lines C III]1908 and Si III]1892 in spectra T Tauri stars (TTSs) shows following: (1) There is emission at velocities that are similar to those observed optical forbidden formed TTSs jets. luminosity comparable lines. (2) comparison between light curves indicates RY Tau not associated with accretion shocks, but it produced farther than 2 R* from star. (3) significantly broader These cannot be a narrow collimated beam, they most...
AK~Sco stands out among pre-main sequence binaries because of its prominent ultraviolet excess, the high eccentricity orbit and strong tides driven by it. AK Sco consists two F5 type stars that get as close 11R$_*$ at periastron passage. The presence a dense ($n_e \sim 10^{11}$~cm$^{-3}$) extended envelope has been unveiled recently. In this article, we report results from XMM-Newton based monitoring system. We show periastron, X-ray UV fluxes are enhanced factor $\sim 3$ with respect to...
Dedicated to spectroscopic and imaging observations of the ultraviolet sky, World Space Observatory - Ultraviolet mission is a Russian-Spanish collaboration. The project consists 1.7m telescope with instrumentation able perform: a) high resolution (R ≥50 000) spectroscopy by means two echellé spectrographs covering 115–310 nm spectral range; b) long slit (1x75 arcsec) low ∼ 1000) near-UV channel far-UV cover 115–305 c) channels 115-320 wavelength d) slitless about 500 in full 115–320 range....
RY Tau is a rapidly rotating classical T Tauri star observed close to edge-on. The combination of new HST/STIS observations obtained in 2001 with HST/GHRS archive data from 1993 has allowed us get, for the first time, information on thermal structure and velocity wind. repeated Si III] C lines show lack changes time blue side profile (dominated by wind contribution). Very high temperature plasma (log Te = 4.8) detected at densities 9.5 ≤ log ne(cm-3) 10.2 associated emitting volumes are...
Low-mass pre-main-sequence stars, i.e., T Tauri stars (TTSs), strongly radiate at high energies, from X-rays to the ultraviolet (UV). This excess radiation with respect main-sequence cool (MSCSs) is associated accretion process, it produced in extended magnetospheres, shocks on stellar surface, and outflows. Although evidence of outflow contribution high-energy have been recently addressed, there not an updated revision magnetospheric contribution. article addresses this issue. The UV...
Numerical calculations of the structure accretion shocks in T Tauri stars (TTSs) indicate that C iii]1909, O iii]1661+1666 and Si iii]1892 ultraviolet lines should have comparable intensities. We show how density velocity accreted gas can be derived from these line ratios. also parameters used, together with other less reliable such as distance extinction, to derive rate luminosity. It is shown ratios well their absolute fluxes [as measured International Ultraviolet Explorer(IUE)] are...
view Abstract Citations (44) References (42) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Origin of Forbidden Line Emission from Young Stellar Objects Gomez de Castro, Ana I. ; Pudritz, Ralph E. We present a model for the origin blueshifted, optical forbidden line emission and jets in young stellar objects based on generic properties hydromagnetic disk winds. Magnetic stresses recollimate winds to magnetic focal regions under very general conditions....
T Tauri stars (TTS) are low-mass pre-main-sequence that accreting mass from the surrounding disc. The hotspots detected in some of them probably heated by release gravitational energy accretion disc material on to star. In this work we study UV spectrum hotspot DI Cep constrain physical mechanisms heating spot and possible role magnetic field channelling flow. is a classical TTS, classified as G8 IV, with (T∼ 8500 K) covering 1–3 per cent visible hemisphere. We have carried out monitoring...
Profiles of the UV semiforbidden lines C III]1908 and Si III]1892 RW Aur have been obtained with Hubble Space Telescope (HST) STIS. The profile shows two high-velocity components at v = ±170 km s-1 a central one. is very broad (FWHM 293 s-1), are unresolved. most probably produced in rotating belt similar to that detected other sources bipolar outflows. A radius between 2.7 R* corotation (6.1 R*) derived, log Te(K) ≃ 4.7 ne(cm-3) 11.6 estimated. clumpy, likely source heating local X-ray...
Cool magnetohydrodynamics (MHD) disc wind physics is reviewed by means of a self-similar analytical model, putting special emphasis on the mathematical aspects solution. It found that key parameter theory (μ) measures relation between magnetic and tidal forces. The generation MHD winds from accretion discs requires subtle tuning both stresses because only narrow range μ values allowed; this is, indeed, close to cut-off turbulence induced development Balbus-Hawley instability. space solutions...
Ultraviolet observations of classical T Tauri Stars (cTTSs) have shown that there is a hot (Te≃ 80 000 K) and dense (ne≃ 1010 cm−3) component associated with the large-scale jet. This formed very close to base jet providing fundamental information on formation mechanism. In this series, we investigated whether can be in disc winds, either cool or warm. To conclude launching from interface between magnetic rotor (the star) studied. Synthetic profiles are calculated numerical simulations...