Search results for "STELLA"

Post-flare Ultraviolet Light Curves Explained with Thermal Instability of Loop Plasma

2012

In the present work, we study the C8 flare that occurred on 2000 September 26 at 19:49 UT and observed by the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation spectrometer from the beginning of the impulsive phase to well beyond the disappearance in the X-rays. The emission first decayed progressively through equilibrium states until the plasma reached 2-3 MK. Then, a series of cooler lines, i.e., Ca X, Ca VII, Ne VI, O IV, and Si III (formed in the temperature range log T = 4.3-6.3 under equilibrium conditions), are emitted at the same time and all evolve in a similar way. Here, we show that the simultaneous emission of lines with such a different forma…

Chromospheric evaporation and phase mixing of Alfvén waves in coronal loops

2020

Phase mixing of Alfv\'en waves has been studied extensively as a possible coronal heating mechanism but without the full thermodynamic consequences considered self-consistently. It has been argued that in some cases, the thermodynamic feedback of the heating could substantially affect the transverse density gradient and even inhibit the phase mixing process. In this paper, we use MHD simulations with the appropriate thermodynamical terms included to quantify the evaporation following heating by phase mixing of Alfv\'en waves in a coronal loop and the effect of this evaporation on the transverse density profile. The numerical simulations were performed using the Lare2D code. We set up a 2D l…

Author Correction: Induced unconventional superconductivity on the surface states of Bi2Te3 topological insulator

2018

Topological superconductivity is central to a variety of novel phenomena involving the interplay between topologically ordered phases and broken-symmetry states. The key ingredient is an unconventional order parameter, with an orbital component containing a chiral p x + ip y wave term. Here we present phase-sensitive measurements, based on the quantum interference in nanoscale Josephson junctions, realized by using Bi2Te3 topological insulator. We demonstrate that the induced superconductivity is unconventional and consistent with a sign-changing order parameter, such as a chiral p x + ip y component. The magnetic field pattern of the junctions shows a dip at zero externally applied magneti…

Continuity and Change in Cosmological Ideas in Spain Between the Sixteenth and Seventeenth Centuries: The Impact of Celestial Novelties

2010

The star which became visible in 1572 in the constellation of Cassiopeia (identified by twentieth-century astronomers as a Type I supernova), and the works and polemics to which it gave rise, marked an important stage in the abandonment of Aristotelian and medieval cosmology and their replacement by the idea of the infinite—or indefinite—universe of modern physics and astronomy.

Optical and X-ray Observations of M31N 2007-12b: An Extragalactic Recurrent Nova with a Detected

2009

The REFLEX galaxy cluster survey VIII. Spectroscopic observations and optical atlas

2009

We present the final data from the spectroscopic survey of the ROSAT-ESO Flux-Limited X-ray (REFLEX) catalog of galaxy clusters. The REFLEX survey covers 4.24 steradians (34% of the entire sky) below a declination of 2.5 deg and at high Galactic latitude (|b| > 20 deg). The REFLEX catalog includes 447 entries with a median redshift of 0.08 and is better than 90% complete to a limiting flux fx = 3x10^{-12} erg s^{-1} cm^{-2} (0.1 to 2.4 keV), representing the largest statistically homogeneous sample of clusters drawn from the ROSAT All-Sky Survey (RASS) to date. Here we describe the details of the spectroscopic observations carried out at the ESO 1.5 m, 2.2 m, and 3.6 m telescopes, as wel…

Optical counterpart to Swift J0243.6+6124

2020

Context. Swift J0243.6+6124 is a unique system. It is the first and only ultra-luminous X-ray source in our Galaxy. It is the first and only high-mass Be X-ray pulsar showing radio jet emission. It was discovered during a giant X-ray outburst in October 2017. While there are numerous studies in the X-ray band, very little is known about the optical counterpart. Aims. Our aim is to characterize the variability timescales in the optical and infrared bands in order to understand the nature of this intriguing system. Methods. We performed optical spectroscopic observations to determine the spectral type. Long-term photometric light curves together with the equivalent width of the Hα line were u…

Reframing the systemic approach to complex organizations as intangible portfolios

2012

The aim of this paper is to pave the way towards the inclusion of mainstream sociological approaches (based on Luhmann’s approach) for the studies of firms-organizations. In social sciences we can observe that the theoretic consequences of a paradigm shift is signiicantly represented by the evolution of systemic thinking from Parsons to Luhmann. This shift implies the change from the vision of systemic organizations as “structures” to that of systemic organizations as “communication flows”. The milestone of systemic approach in management maybe found in the research and applied works of Anthony Staford Beer with his Viable System Model (VSM) that today faced a relevant reconiguration by Gol…

Apología de los palos dados al Excmo. Sr. D. Lorenzo Calvo por el Teniente-Coronel D. Joaquin de Osma

Segons Rogers i Lapuente el Licenciado Palomeque i Dr. Encina són pseudònims de Bartolomé José Gallardo Vinyeta a port Text a 1 col

Papel serijocoso para el presente precio : arancel economico para manterner una casa en Madrid : compuesta de marido, que no sea desperdiciador, muge…

Filets Les p. 17-22 amb orla tip Text a 1 col Sign.: A12