A comprehensive X-ray view of the active nucleus in NGC 4258

(Abridged) We present a detailed broadband X-ray spectrum of NGC 4258, with the goal of precisely measuring the coronal luminosity and accretion flow properties of the AGN, and track any possible variation across two decades of observations. We collect archival XMM-Newton, Chandra, Swift/BAT and NuSTAR spectroscopic observations spanning 15 years, and fit them with a suite of state of the art models, including a warped disk model which is suspected to provide the well known obscuration observed in the X-rays. We complement this information with archival results from the literature. Clear spectral variability is observed among the different epochs. The obscuring column density shows possibly periodic fluctuations on a timescale of 10 years, while the intrinsic luminosity displays a long term decrease of a factor of three in a time span of 15 years (from $L_{2-10~\text{keV}} \sim 10^{41}$ erg s$^{-1}$ in the early 2000s, to $L_{2-10~\text{keV}} \sim 3 \times 10^{40}$ erg s$^{-1}$ in 2016). The average absorption-corrected X-ray luminosity $L_{2-10~\text{keV}}$, combined with archival determinations of the bolometric luminosity, implies a bolometric correction $k_{\rm bol} \sim 20$, intriguingly typical for Seyferts powered by accretion through geometrically thin, radiatively efficient disks. Moreover, the X-ray photon index $\Gamma$ is consistent with the typical value of the broader AGN population. However, the accretion rate in Eddington units is very low, well within the expected RIAF regime. Our results suggest that NGC 4258 is a genuinely low-luminosity Seyfert II, with no strong indications in its X-ray emission for a hot, RIAF-like accretion flow.Comment: Accepted for publication in A&A. 14 pages, 6 figures, 3 table

Comments on “Ochratoxin A: In utero Exposure in Mice Induces Adducts in Testicular DNA. Toxins 2010, 2, 1428–1444”—Mis-Citation of Rat Literature to Justify a Hypothetical Role for Ochratoxin A in Testicular Cancer

A manuscript in the journal recently cited experimental rat data from two manuscripts to support plausibility of a thesis that ochratoxin A might be a cause of human testicular cancer. I believe that there is no experimental evidence that ochratoxin A produces testicular cancer in rats or mice

Coherent Diffraction Radiation experiment at CTF3—Simulation studies

A two-target model was developed for the simulations of Coherent Diffraction Radiation (CDR) phenomenon for the experiment at the CLIC Test Facility 3 (CTF3 at CERN). The model is based on a classical DR theory. The radiation distribution from the targets, as a function of the angle and the frequency, was calculated for the first and the second target separately in order to understand how the final radiation distribution from the two targets, working as a system, is formed. The final radiation distribution of destructive interference between the two targets was obtained as well. The distributions were calculated for the working parameters of both the CTF3 and the experimental setup and were used for a single-electron spectrum calculation, required for the bunch profile reconstruction