منابع مشابه
A dual emission mechanism in Sgr A * / L ′ ? ⋆
We have collected in 2004 adaptive optics corrected L ′ images of the Galactic Center region with NAOS-CONICA at VLT. A strong variability was observed as well as a correlation between the photocenter positions and fluxes of the L ′-band counterpart of Sgr A*. It is interpreted as the combined emission of a point-like flaring source at the position of Sgr A*/IR itself and an extended dust struc...
متن کاملPolarization of X–ray emission from the Sgr B2 cloud
The Sgr B2 giant molecular cloud is claimed to be an ”X–ray reflection nebula” – the reprocessing site of a powerful flare of the Sgr A* source, occurred few hundred years ago. The shape of the X–ray spectrum and the strength of the iron fluorescent line support this hypothesis. We argue that the most clean test of the origin of X–rays from Sgr B2 would be a detection of polarized emission from...
متن کاملOn the enhanced X-ray emission from SGR
Soft gamma ray repeaters (SGRs) are neutron stars that emit short (< ∼ 1 s) and luminous (< ∼10 erg s−1) soft gamma ray bursts in their active phases. The burst repetition time scales extend from a second to years (see [7] for a review). In their quiescent states, they emit persistent X-rays at luminosities similar to those of anomalous Xray pulsars (AXPs) (Lx ∼ 10 − 10 erg s−1). The spin perio...
متن کامل0 Discovery of a 6 . 4 keV Emission Line in a Burst from SGR 1900 + 14
We present evidence of a 6.4 keV emission line during a burst from the soft gamma-ray repeater SGR 1900+14. The Rossi X-ray Timing Explorer (RXTE) monitored this source extensively during its outburst in the summer of 1998. A strong burst observed on August 29, 1998 revealed a number of unique properties. The burst exhibits a precursor and is followed by a long (∼ 10 s) tail modulated at the 5....
متن کاملCharacteristics of Dual Amplified Spontaneous Emission from MEH-PPV Solutions
We report the observations of dual wavelength amplified spontaneous emission from the solutions of a conjugated polymer poly [2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV) in Tetrahydrofuran and 1, 2 Dichlorobenzene. We have prepared MEH-PPV using a modified procedure and purified several times in each step, the material offers low molecular weight, low polydispersity index an...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2005
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:200500146