2,748 research outputs found
The differing magnitude distributions of the two Jupiter Trojan color populations
The Jupiter Trojans are a significant population of minor bodies in the
middle Solar System that have garnered substantial interest in recent years.
Several spectroscopic studies of these objects have revealed notable
bimodalities with respect to near-infrared spectra, infrared albedo, and color,
which suggest the existence of two distinct groups among the Trojan population.
In this paper, we analyze the magnitude distributions of these two groups,
which we refer to as the red and less red color populations. By compiling
spectral and photometric data from several previous works, we show that the
observed bimodalities are self-consistent and categorize 221 of the 842 Trojans
with absolute magnitudes in the range H<12.3 into the two color populations. We
demonstrate that the magnitude distributions of the two color populations are
distinct to a high confidence level (>95%) and fit them individually to a
broken power law, with special attention given to evaluating and correcting for
incompleteness in the Trojan catalog as well as incompleteness in our
categorization of objects. A comparison of the best-fit curves shows that the
faint-end power-law slopes are markedly different for the two color
populations, which indicates that the red and less red Trojans likely formed in
different locations. We propose a few hypotheses for the origin and evolution
of the Trojan population based on the analyzed data.Comment: Published in AJ; 26 pages, 7 figure
Your modern career : a corporate survival guide for the greeenhorn MBA
http://deepblue.lib.umich.edu/bitstream/2027.42/96894/1/MBA_Emery_Michael_OB750_Winter_1997Final.pd
Detection of Water and/or Hydroxyl on Asteroid (16) Psyche
In order to search for evidence of hydration on M-type asteroid (16) Psyche,
we observed this object in the 3 micron spectral region using the
long-wavelength cross-dispersed (LXD: 1.9-4.2 micron) mode of the SpeX
spectrograph/imager at the NASA Infrared Telescope Facility (IRTF). Our
observations show that Psyche exhibits a 3 micron absorption feature,
attributed to water or hydroxyl. The 3 micron absorption feature is consistent
with the hydration features found on the surfaces of water-rich asteroids,
attributed to OH- and/or H2O-bearing phases (phyllosilicates). The detection of
a 3 micron hydration absorption band on Psyche suggests that this asteroid may
not be metallic core, or it could be a metallic core that has been impacted by
carbonaceous material over the past 4.5 Gyr. Our results also indicate
rotational spectral variations, which we suggest reflect heterogeneity in the
metal/silicate ratio on the surface of Psyche.Comment: 13 pages, 9 figures in Astronomical Journal, 201
Feria de empleo en organismos internacionales
Audiovisuales disponibles en YouTube: https://www.youtube.com/playlist?list=PLhZxaHZyowwe_Y-B58gOET2aXtRtjDNPpEl campus Madrid-Puerta de Toledo de la UC3M ha sido el escenario de la Feria de empleo en organismos internacionales, donde los estudiantes se informaron sobre puestos de trabajo en organismos internacionales y los requisitos necesarios para acceder a ellos.Contiene: Feria de empleo en Organismos Internacionales (p. 2). -- Entrevista a Michael Emery, Director de Recursos Humanos del Fondo de población de Naciones Unidas (UNFPA) (pp. 3-4). -- Entrevista a Ulrike Mangold, Responsable de la oficina de selección de personal europea (EPSO) (p. 5). -- Opiniones de asistentes (p.6
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