Utilizando modelos semiempíricos de los espectros de fotoabsorción de varios fullerenos individuales (C_80, C_240, C_320 y C_540) predecimos transiciones en la región de la banda difusa más intensa del medio interestelar a 4430 A que podrían explicar su origen, hasta ahora desconocido. Estos modelos también presentan una alta densidad de transiciones en el ultravioleta que reproducen el denominado "bump" a 2175 A en la curva de extinción del medio interestelar (Iglesias-Groth 2004). Parece que los fullerenos podrían ser responsables de dos de los mayores rasgos de la absorción interestelar. Haciendo uso de las secciones eficaces teóricas y de los datos empíricos estimamos que la abundancia de fullerenos es de 0.05 moléculas por millón de átomos de hidrógeno en regiones del medio interestelar con índice de exceso de color E(B-V)~ 1.0.
Advertised on
It may interest you
-
The Necklace nebula is a bipolar, post-common-envelope planetary nebula, the central star of which has been shown to have a dwarf carbon star companion. We aim to understand the origins of the Necklace and its dwarf carbon central star. We study the carbon abundance of the nebula through far-ultraviolet spectroscopy obtained with the Hubble Space Telescope. Furthermore, through simultaneous modelling of multi-band light and velocity curves, we attempt to constrain the parameters of the central star system. Puzzlingly, we find that the region of the inner nebula observed with the Hubble SpaceAdvertised on -
The Near-Infrared Spectrometer and Photometer (NISP) on board the Euclid space mission has obtained near-infrared (NIR) spectra of millions of objects, including hundreds of ultracool dwarfs (UCDs). Euclid observations retrieve images and slitless spectra simultaneously. This observing mode marks a new era in the discovery of new objects, such as L- and T-type dwarfs, which can be found from direct identification through the H2O and CH4 absorption bands. NISP spectral resolution (R ∼ 450) is enough to classify the objects by the spectral type using known standard templates. Q1 provided moreAdvertised on -
An international team of researchers led by the Instituto de Astrofísica de Canarias (IAC) and the Universidad de La Laguna (ULL), has unveiled a breakthrough explanation for the origin of tiny, jet-like plasma ejections in the solar atmosphere, known as “nanojets.” These elusive events which are recently discovered by the NASA’s solar telescopes are thought to play an important role in heating and sustaining the solar corona at temperatures above one million Kelvin. Why Study Nanojets? For decades, solar physicists have been puzzled by the so-called “coronal heating problem.” While the SunAdvertised on