background : the main objective of this research was to study photocatalytic oxidation of phenol in aquatic solutions by using of uv, tio 2 and the combination of them. phenol compounds are widely used in industries and other daily life. highly toxicity and carcinogenicity of these compounds can causal considerable adverse effects on the aquatic ecosystems and human health. methods : the study ...

The optical-UV and X-ray instruments on-board XMM-Newton provide an excellent opportunity to perform simultaneous observations of violently variable objects over a broad wavelength range. The UV and X-ray bright BL Lac object PKS 2155–304 has been repeatedly observed with XMM-Newton about twice per year. In this paper, we present a detailed analysis of the simultaneous multi-wavelength variabil...

We present UV imaging polarimetry data of the Seyfert 2 galaxy Mrk 3 taken by the Hubble Space Telescope. The polarized flux is found to be extended to ∼ 1 kpc from the nucleus, and the position angles of polarization are centrosymmetric, confirming that the polarization is caused by scattering. We determine the location of the hidden nucleus as the center of this centrosymmetric pattern. From ...

We analyze archived Chandra and XMM-Newton X-ray observations of 536 Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) quasars (QSOs) at 1.7 ≤ z ≤ 2.7 in order to characterize the relative UV and X-ray spectral properties of QSOs that do not have broad UV absorption lines (BALs). We constrain the fraction of X-ray weak, non-BAL QSOs and find that such objects are rare; for example, sources u...

The core of the galactic globular cluster M13 (NGC 6205) has been observed with WFPC2 on the Hubble Space Telescope through visual, blue and midand far-UV filters in a programme devoted to study the UV population in a sample of Galactic globular clusters. In the UV Color Magnitude Diagrams derived from the HST images we have discovered three faint objects with a strong UV excess, which lie sign...

In a survey of the UV-brightest AGN using the Far Ultraviolet Spectroscopic Explorer (FUSE), we commonly find associated absorption in the O vi λλ1032, 1038 resonance doublet. Of 34 Type I AGN observed to date with z < 0.15, 16 show detectable O vi absorption. Most absorption systems show multiple components with intrinsic widths of ∼ 100 km s spread over a blue-shifted velocity range of < 1000...

We present the first spatially separated X-ray observation of the active UV Ceti binary with Chandra, providing important new information on the relative X-ray activity levels of its nearly identical dM5.5e components. The two components had similar X-ray luminosities during low-level periods and emission measure loci derived from Low Energy Transmission Grating spectra reveal similar coronal t...

We present Chandra X-ray observations of the radio-quiet QSO PG 2302+029. This quasar has a rare system of ultra-high velocity (−56, 000 km s) UV absorption lines that form in an outflow from the active nucleus (Jannuzi et al. 2003). The Chandra data indicate that soft X-ray absorption is also present. We perform a joint UV and X-ray analysis, using photoionization calculations, to detemine the...

We present a spectral analysis of a ∼ 30 d, near-continuous observation of the Seyfert 1 galaxy NGC 7469 with RXTE. Daily integrations show strong spectral changes during the observation. Our main result is that we find the X-ray spectral index to be correlated with the UV flux. Furthermore, the broad-band X-ray photon flux is also correlated with the UV continuum. These correlations point towa...

We show that the prompt and afterglow X-ray emission of GRB060218, as well as its early (t 1 d) optical-UV emission, can be explained by a model in which a radiation-mediated shock propagates through a compact progenitor star into a dense wind. The prompt thermal X-ray emission is produced in this model as the mildly relativistic shock, β ≈ 0.85 carrying few ×10 49 erg, reaches the wind (Thomso...