We present the first results of a narrow-band photometric study of the massive galaxy cluster XMMU J2235.3-2557 at z= 1.39. We obtained deep H narrow-band imaging with the Near InfraRed Imager and Spectrometer on Gemini North, corresponding to Hα emission at the cluster's redshift. Our sample consists of 82 galaxies within a radius of ˜500 kpc, 10

We chose all galaxies with radial velocity Vradio 1.0' at Galactic latitude |b|>30 ° using HyperLEDA (Paturel et al. 2003, Cat. VII/237, VII/238). (1 data file).

The very high energy (VHE; E > 100 GeV) blazar Markarian 501 (Mrk 501) has a well-studied history of extreme spectral variability and is an excellent laboratory for studying the physical processes within the jets of active galactic nuclei. However, there are few detailed multiwavelength studies of Mrk 501 during its quiescent state, due to its low

There are ubiquitous flows observed in the solar atmosphere of sub-Alfvénic speeds; however, after flaring and coronal mass ejection events flows can become Alfvénic. In this Letter, we derive an expression for the standing kink mode frequency due to siphon flow in coronal loops, valid for both low and high speed regimes. It is found that siphon

We report the detection of a type I X-ray burst in a 9ksec-long RXTE-PCA observation of the neutron star transient SAX J1747.0-2853. The burst bolometric flux was [1.7+/-0.1]x10{-8} erg/s/cm2 at the peak, on 2011-03-10 16:29:13 UTC, and the burst lasted for about 15 seconds. The blackbody temperature reached 2.4+/-0.1 keV at the peak and decayed to

Aims: We propose and explore a new diagnostic technique based upon the linear polarization emitted in Hanle-sensitive lines in disk-integrated stars where a dipolar magnetic field breaks the rotational symmetry of the resonance scattering polarization Methods: A star with a simple dipolar field and a 1-0 spectral line were used to compute