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We present far-ultraviolet (UV) observations at 150 nm of the jet of the quasar 3C 273 obtained with the Advanced Camera for Surveys Solar Blind Channel (ACS/SBC) on board the Hubble Space Telescope. While the jet morphology is very similar to that in the optical and near-ultraviolet, the spectral energy distributions (SEDs) of the jets sub-regions show an upturn in nu f_nu at 150 nm compared to 300 nm everywhere in the jet. Moreover, the 150 nm flux is compatible with extrapolating the X-ray power-law down to the ultra-violet region. This constitutes strong support for a common origin of the jets far-UV and X-ray emission. It implies that even a substantial fraction of the *visible light* in the X-ray brightest parts of the jet arises from the same spectral component as the X-rays, as had been suggested earlier based on Spitzer Space Telescope observations. We argue that the identification of this UV/X-ray component opens up the possibility to establish the synchrotron origin of the X-ray emission by optical polarimetry.
With six recorded nova outbursts, the prototypical recurrent nova T Pyxidis is the ideal cataclysmic variable system to assess the net change of the white dwarf mass within a nova cycle. Recent estimates of the mass ejected in the 2011 outburst range
We present an analysis of the blank sky spectra observed with the Faint Object Spectrograph on board the Hubble Space Telescope. We study the diffuse sky emission from ultraviolet to optical wavelengths, which is composed of the zodiacal light (ZL),
We report on detection of the double pulsar system J0737-3039 in the far-UV with the ACS/SBC detector aboard HST. We measured the energy flux F = 4.5+/-1.0e-17 erg cm-2s-1 in the 1250-1550 AA band, which corresponds to the extinction-corrected lumino
We report new results from an HST archival program to study proper motions in the optical jet of the nearby radio galaxy M87. Using over 13 years of archival imaging, we reach accuracies below 0.1c in measuring the apparent velocities of individual k
As one of the most luminous radio-loud quasars showing intrinsic ultraviolet (UV) and X-ray absorption, 3C 351 provides a laboratory for studying the kinematics and physical conditions of such ionized absorbers. We present an analysis of the intrinsi