We apply a reflection‐dominated model to the second XMM–Newton observation of the narrow‐line Seyfert 1 galaxy 1H 0707–495. As in the first XMM–Newton observation, a sharp spectral drop is detected with energy that has shifted from 7 to 7.5 keV in two years. The drop is interpreted in terms of relativistically blurred ionized reflection from the accretion disc, while the energy shift can be accounted for by changes in the ionization state and, more importantly, emissivity profile on the disc. A flatter emissivity profile during the second higher flux observation reduces gravitational redshift effects, therefore shifting the edge to higher energy. Remarkably, ionized disc reflection and the associated power‐law continuum provide a reasonable description of the broad‐band spectrum, including the soft excess. Considering both observations, the spectral variability in 1H 0707–495 appears to be a result of the interplay between these two spectral components. The reflection component in the second observation is significantly less variable than the power law. Changes of the emissivity profile, spectral shape and variability properties (such as the rms spectrum) within the two observations are all consistent with a recently proposed model in which relativistic effects in the very inner regions of the nucleus play a major role.

This paper discusses Swift observations of the γ-ray burst GRB 050315 (z=1.949) from 80 s to 10 days after the onset of the burst. The X-ray light curve displayed a steep early decay (t −5 ) for ∼ 200 s and several breaks. However, both the prompt hard X-ray/γ-ray emission (observed by the BAT) and the first ∼ 300 s of X-ray emission (observed by the XRT) can be explained by exponential decays, with similar decay constants. Extrapolating the BAT light curve into the XRT band suggests the rapidly decaying, early X-ray emission was simply a continuation of the fading prompt emission; this strong similarity between the prompt γ-ray and early X-ray emission may be related to the simple temporal and spectral character of this X-ray rich GRB. The prompt (BAT) spectrum was a steep down to ∼ 15 keV, and appeared to continue through the XRT bandpass, implying a low peak energy, inconsistent with the Amati relation. Following the initial steep decline the X-ray afterglow did not fade for ∼ 1.2×10 4 s, after which time it decayed with a temporal index of α ≈ 0.7, followed by a second break at ∼ 2.5 × 10 5 s to a slope of α ∼ 2. The apparent 'plateau' in the X-ray light curve, after the early rapid decay, makes this one of the most extreme examples of the steep-flat-steep X-ray light curves revealed by Swift. If the second afterglow break is identified with a jet break then the jet opening angle was θ 0 ∼ 5 • , and implying E γ ∼ > 10 50 erg.

We describe the first results from a six-month long reverberation-mapping experiment in the ultraviolet based on 171 observations of the Seyfert 1 galaxy NGC 5548 with the Cosmic Origins Spectrograph on the Hubble Space Telescope. Significant correlated variability is found in the continuum and broad emission lines, with amplitudes ranging from ∼30% to a factor of two in the emission lines and a factor of three in the continuum. The variations of all the strong emission lines lag behind those of the continuum, with He II λ1640 lagging behind the continuum by ∼2.5 days and Lyα λ1215, C IV λ1550, and Si IV λ1400 lagging by ∼5-6 days. The relationship between the continuum and emission lines is complex. In particular, during the second half of the campaign, all emission-line lags increased by a factor of 1.3-2 and differences appear in the detailed structure of the continuum and emissionline light curves. Velocity-resolved cross-correlation analysis shows coherent structure in lag versus line of sight velocity for the emission lines; the high-velocity wings of C IV respond to continuum variations more rapidly than the line core, probably indicating higher velocity broad-line region clouds at smaller distances from the central

Stress exposure triggers ligand-independent EGF receptor (EGFR) endocytosis, but its post-endocytic fate and role in regulating signalling are unclear. We show that the p38 MAP kinase-dependent, EGFR tyrosine kinase (TK)-independent EGFR internalization induced by ultraviolet light C (UVC) or the cancer therapeutic cisplatin, is followed by diversion from the canonical endocytic pathway. Instead of lysosomal degradation or plasma membrane recycling, EGFR accumulates in a subset of LBPA-rich perinuclear multivesicular bodies (MVBs) distinct from those carrying EGF-stimulated EGFR. Stress-internalized EGFR co-segregates with exogenously expressed pre-melanosomal markers OA1 and fibrillar PMEL, following early endosomal sorting by the actin polymerization-promoting WASH complex. Stress-internalized EGFR is retained intracellularly by continued p38 activity in a mechanism involving ubiquitin-independent, ESCRT/ALIX-dependent incorporation onto intraluminal vesicles (ILVs) of MVBs. In contrast to the internalization-independent EGF-stimulated activation, UVC/cisplatin-triggered EGFR activation depends on EGFR internalization and intracellular retention. EGFR signalling from this MVB subpopulation delays apoptosis and might contribute to chemoresistance.