Very peculiar wind from BD+53 2790, the optical counterpart to 4U 2206+54

BD+53 2790, an O9.5Vp star, is the optical counterpart to the HMXRB
 4U 2206+54. This system was classified initially as a BeX, but
 observational evidence soon stressed the need to revise this classification.
 The permanent asymmetry in the H-alpha line profiles (in contrast with
 the cyclic variations shown by Be stars), the variations in the profile
 of this line in time scales of hours (while time scales from weeks to
 months are expected in Be stars), and the lack of correlation between

Sunday, 1 Jun 2008

Discovery of slow X-ray pulsations in the high-mass X-ray binary 4U 2206+54

The source 4U 2206+54 is one of the most enigmatic high-mass X-ray binaries.
In spite of intensive searches, X-ray pulsations have not been detected in
the time range 0.001-1000 s. A cyclotron line at ~30 keV has been suggested
by various authors but never detected with significance. The stellar wind
of the optical companion is abnormally slow. The orbital period, initially
reported to be 9.6 days, disappeared and a new periodicity of 19.25 days
emerged. Our new long and uninterrupted RXTE observations allow us to search

Thursday, 1 Jan 2009

Correlated optical/X-ray variability in the high-mass X-ray binary SAX J2103.5+4545

SAX J2103.5+4545 is the Be/X-ray binary with the shortest orbital period.
It shows extended bright and faint X-ray states that last for a few hundred
days. The main objective of this work is to investigate the relationship
between the X-ray and optical variability and to characterise the spectral
and timing properties of the bright and faint states. We have found a
correlation between the spectral and temporal parameters that fit the
energy and power spectra. Softer energy spectra correspond to softer power

Thursday, 1 Jan 2009


MXGS stands for Monitor X-ray and Gamma-ray Sensor and it is the high energy sensor in the Atmospheric-Space Interaction Monitor (ASIM). ASIM was proposed for the International Space Station external facilities on the Columbus module,  with the scientific goal of studying high-altitude optical emissions from the stratosphere and mesosphere, the so-called red sprites, blue jets, and elves  (or Transient Luminous Events, TLEs) and to provide evidence on the possible link between these optical emissions and Terrestial Gamma Ray Flashes (TGFs)
See ASIM page at the Danish Space Research Institute (DSRI).

ASIM logo 2


SUNRISE is a mission to study the structure and dynamics of the solar magnetic field. A 1 metre telescope will be flown in December 2006 in the Antartica on a NASA long duration stratospheric balloon. IMaX (Imaging Magnetograph eXperiment), focal plane instrument on SUNRISE, will produce very high resolution vector magnetograms. See IMAX page Instituto de Astrofísica de Canarias(IAC). See SUNRISE page.


INTEGRAL (INTErnational Gamma-Ray Astrophysics Lab)

The Coded Masks of SPI, IBIS and JEM-X instruments on board ESA Gamma Ray Mission were designed and developed at Valencia. INTEGRAL was launched in October 2002 and is still under operation phase.


Image Processing Laboratory

Grupo dependiente de la Universitat de Valencia cuya misión tecnológica es: "imaging" (creación de imágenes reales o de paramétros geo-biofísicos) a partir de datos de satélite y teledeteccción.

Universitat de Valencia

Entidad responsable de la enseñanza universitaria.

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