The Phoenix galaxy as seen by NuSTAR

Aims. We study the long-term variability of the well-known Seyfert 2 galaxy Mrk 1210 (a.k.a. UGC 4203, or the Phoenix galaxy). Methods. The source was observed by many X-ray facilities in the last 20 years. Here we present a NuSTAR observation and put the results in context of previously published observations. Results. NuSTAR observed Mrk 1210 in 2012 for 15.4 ks. The source showed Compton-thin obscuration similar to that observed by Chandra, Suzaku, BeppoSAX and XMM-Newton over the past two decades, but different from the first observation by ASCA in 1995, in which the active nucleus was caught in a low flux state - or obscured by Compton-thick matter, with a reflection-dominated spectrum. Thanks to the high-quality hard X-ray spectrum obtained with NuSTAR and exploiting the long-term spectral coverage spanning 16.9 years, we can precisely disentangle the transmission and reflection components and put constraints on both the intrinsic long-term variability and hidden nucleus scenarios. In the former case, the distance between the reflector and the source must be at least ~ 2 pc, while in the latter one the eclipsing cloud may be identified with a water maser-emitting clump.<br/

NuSTAR unveils a Compton-thick type 2 quasar in MrK 34

We present Nuclear Spectroscopic Telescope Array (NuSTAR) 3-40 keV observations of the optically selected Type 2 quasar (QSO2) SDSS J1034+6001 or Mrk 34. The high-quality hard X-ray spectrum and archival XMM-Newton data can be fitted self-consistently with a reflection-dominated continuum and a strong Fe K? fluorescence line with equivalent width &gt;1 keV. Prior X-ray spectral fitting below 10 keV showed the source to be consistent with being obscured by Compton-thin column densities of gas along the line of sight, despite evidence for much higher columns from multiwavelength data. NuSTAR now enables a direct measurement of this column and shows that N H lies in the Compton-thick (CT) regime. The new data also show a high intrinsic 2-10 keV luminosity of L 2-10 ~ 1044 erg s–1, in contrast to previous low-energy X-ray measurements where L 2-10 lesssim 1043 erg s–1 (i.e., X-ray selection below 10 keV does not pick up this source as an intrinsically luminous obscured quasar). Both the obscuring column and the intrinsic power are about an order of magnitude (or more) larger than inferred from pre-NuSTAR X-ray spectral fitting. Mrk 34 is thus a "gold standard" CT QSO2 and is the nearest non-merging system in this class, in contrast to the other local CT quasar NGC 6240, which is currently undergoing a major merger coupled with strong star formation. For typical X-ray bolometric correction factors, the accretion luminosity of Mrk 34 is high enough to potentially power the total infrared luminosity. X-ray spectral fitting also shows that thermal emission related to star formation is unlikely to drive the observed bright soft component below ~3 keV, favoring photoionization instead

Determination of nicarbazin as dinitrocarbanilide residues in chicken feed, breast and litter.

Abstract: To control coccidiosis, a common disease in commercial broiler production, anticoccidials are added to feed. However, concerns about the deposition of anticoccidial residues in chicken breast do exist. Brazilian law allows 200 &#956;g kg-1 of nicarbazin (main chicken anticoccidial) residue in chicken breast, but demands its withdrawal from feed 10 days before slaughter, to avoid its presence in chicken breast. The present research aimed at raising chickens for 42 days and subject them to three treatments with anticoccidials by analyzing nicarbazin residues as dinitrocarbanilide (DNC) in feed, breast and poultry litter. The results showed that feed and breast had DNC levels within the legislation, therefore chicken breast is safe for human consumption. Also, shortly after nicarbazin removal from feed, DNC concentration dropped in poultry litter by about 50% in all treatments. Resumo ? Para controlar a coccidiose, doença comum na produção comercial de frangos de corte, são adicionados anticoccidianos à ração. No entanto, preocupações sobre a deposição de resíduos de anticoccidianos no peito de frango existem. A legislação brasileira permite 200 &#956;g kg-1 de resíduo de nicarbazina (principal anticoccidiano) no peito de frango, porém exige que seja retirado da ração 10 dias antes do abate, para evitar sua presença no peito de frango. A presente pesquisa objetivou criar frangos por 42 dias e submete-los a três tratamentos com anticoccidianos, analisando resíduos de nicarbazina na forma de dinitrocarbanilida (DNC) na ração, peito e cama de aviário. Os resultados mostraram que na ração e no peito, todos níveis de DNC se mantiveram dentro da legislação, sendo o peito de frango seguro para consumo humano. Ainda, logo após a retirada da nicarbazina da ração, a concentração de DNC na cama de aviário caiu cerca de 50% em todos tratamentos.bitstream/item/219013/1/final9387.pd

The NuSTAR view of reflection and absorption in NGC 7582

NGC 7582 is a well-studied X-ray bright Seyfert 2 with moderately heavy (NH ~ 1023 - 1024 cm-2), highly variable absorption and strong reflection spectral features. The spectral shape changed around the year 2000, dropping in observed flux and becoming much more highly absorbed. Two scenarios have been put forth to explain this spectral change: (1) the central X-ray source partially "shut off" around this time, decreasing in intrinsic luminosity, with a delayed decrease in reflection features due to the light-crossing time of the Compton-thick material or (2) the source became more heavily obscured, with only a portion of the power law continuum leaking through. NuSTAR observed NGC 7582 twice in 2012, two weeks apart, in order to quantify the reflection using high-quality data above 10 keV. We find that the most plausible scenario is that NGC 7582 has recently become more heavily absorbed by a patchy torus with a covering fraction of ~80%–90% and an equatorial column density of ~ 3 ×1024 cm-2. We find the need for an additional highly variable full-covering absorber with NH = (4–6) × 1023 cm-2 in the line of sight, possibly associated with a hidden broad line region

Der Einfluss der sozialistischen Gemeinschaftsarbeit auf die Weiterentwicklung sozialistischer Gemeinschaftsbeziehungen, auf die Entwicklung des sozialistischen Bewusstseins und die Herausbildung sozialistischer Persoenlichkeiten erste Auswertung der Ergebnisse einer schriftlichen Befragung von Mitgliedern und Leitern von Arbeits- und Forschungsgemeinschaften

SIGLEISDA, Berlin / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

IC 3639 - A new bona fide Compton-thick AGN unveiled by NuSTAR

We analyze high-quality NuSTAR observations of the local (z = 0.011) Seyfert 2 active galactic nucleus (AGN) IC 3639, in conjunction with archival Suzaku and Chandra data. This provides the first broadband X-ray spectral analysis of the source, spanning nearly two decades in energy (0.5–30 keV). Previous X-ray observations of the source below 10 keV indicated strong reflection/obscuration on the basis of a pronounced iron fluorescence line at 6.4 keV. The hard X-ray energy coverage of NuSTAR, together with self-consistent toroidal reprocessing models, enables direct broadband constraints on the obscuring column density of the source. We find the source to be heavily Compton-thick (CTK) with an obscuring column in excess of 3.6 10 ´ 24 cm−2 , unconstrained at the upper end. We further find an intrinsic 2–10 keV luminosity of - = - + log erg s 43.4 L 10 2 10 keV 1 1.1 0.6 ( [ ]) – to 90% confidence, almost 400 times the observed flux, and consistent with various multiwavelength diagnostics. Such a high ratio of intrinsic to observed flux, in addition to an Fe-Kα fluorescence line equivalent width exceeding 2 keV, is extreme among known bona fide CTK AGNs, which we suggest are both due to the high level of obscuration present around IC 3639. Our study demonstrates that broadband spectroscopic modeling with NuSTAR enables large corrections for obscuration to be carried out robustly and emphasizes the need for improved modeling of AGN tori showing intense iron fluorescence

NuSTAR Observations of the Compton-thick Active Galactic Nucleus and Ultraluminous X-Ray Source Candidate in NGC 5643

We present two Nuclear Spectroscopic Telescope Array (NuSTAR) observations of the local Seyfert 2 active galactic nucleus (AGN) and an ultraluminous X-ray source (ULX) candidate in NGC 5643. Together with archival data from Chandra, XMM-Newton, and Swift-BAT, we perform a high-quality broadband spectral analysis of the AGN over two decades in energy (~0.5–100 keV). Previous X-ray observations suggested that the AGN is obscured by a Compton-thick (CT) column of obscuring gas along our line of sight. However, the lack of high-quality gsim10 keV observations, together with the presence of a nearby X-ray luminous source, NGC 5643 X–1, have left significant uncertainties in the characterization of the nuclear spectrum. NuSTAR now enables the AGN and NGC 5643 X–1 to be separately resolved above 10 keV for the first time and allows a direct measurement of the absorbing column density toward the nucleus. The new data show that the nucleus is indeed obscured by a CT column of NH gsim 5 × 1024 cm−2. The range of 2–10 keV absorption-corrected luminosity inferred from the best-fitting models is L2–10,int = (0.8–1.7) × 1042 erg s−1, consistent with that predicted from multiwavelength intrinsic luminosity indicators. In addition, we also study the NuSTAR data for NGC 5643 X–1 and show that it exhibits evidence of a spectral cutoff at energy E ~ 10 keV, similar to that seen in other ULXs observed by NuSTAR. Along with the evidence for significant X-ray luminosity variations in the 3–8 keV band from 2003 to 2014, our results further strengthen the ULX classification of NGC 5643 X–1

A New Compton-thick AGN in our Cosmic Backyard: Unveiling the Buried Nucleus in NGC 1448 with NuSTAR

NGC 1448 is one of the nearest luminous galaxies (L8−1000μm> 109L⊙) to ours (z = 0.00390), and yet the active galactic nucleus (AGN) it hosts was only recently discovered, in 2009. In this paper, we present an analysis of the nuclear source across three wavebands: mid-infrared (MIR) continuum, optical, and X-rays. We observed the source with the Nuclear Spectroscopic Telescope Array (NuSTAR), and combined this data with archival Chandra data to perform broadband X-ray spectral fitting (≈0.5-40 keV) of the AGN for the first time. Our X-ray spectral analysis reveals that the AGN is buried under a Compton-thick (CT) column of obscuring gas along our line-of-sight, with a column density of NH(los) ≳ 2.5 × 1024 cm−2. The best-fitting torus models measured an intrinsic 2-10 keV luminosity of L2−10,int = (3.5-7.6) × 1040 erg s−1, making NGC 1448 one of the lowest luminosity CTAGNs known. In addition to the NuSTAR observation, we also performed optical spectroscopy for the nucleus in this edge-on galaxy using the European Southern Observatory New Technology Telescope. We re-classify the optical nuclear spectrum as a Seyfert on the basis of the Baldwin-Philips-Terlevich diagnostic diagrams, thus identifying the AGN at optical wavelengths for the first time. We also present high spatial resolution MIR observations of NGC 1448 with Gemini/T-ReCS, in which a compact nucleus is clearly detected. The absorption-corrected 2-10 keV luminosity measured from our X-ray spectral analysis agrees with that predicted from the optical [OIII]λ5007\AA\ emission line and the MIR 12μm continuum, further supporting the CT nature of the AGN

Hard X-ray emission of the luminous infrared galaxy NGC 6240 as observed by NuSTAR

We present a broadband (~0.3−70 keV) spectral and temporal analysis of NuSTAR observations of the luminous infrared galaxy NGC 6240 combined with archival Chandra, XMM-Newton, and BeppoSAX data. NGC 6240 is a galaxy in a relatively early merger state with two distinct nuclei separated by ~1.̋5. Previous Chandra observations resolved the two nuclei and showed that they are both active and obscured by Compton-thick material. Although they cannot be resolved by NuSTAR, we were able to clearly detect, for the first time, both the primary and the reflection continuum components thanks to the unprecedented quality of the NuSTAR data at energies >10 keV. The NuSTAR hard X-ray spectrum is dominated by the primary continuum piercing through an absorbing column density which is mildly optically thick to Compton scattering (τ ≃ 1.2, NH ~ 1.5 × 1024 cm-2). We detect moderately hard X-ray (>10 keV) flux variability up to 20% on short (15−20 ks) timescales. The amplitude of the variability is largest at ~30 keV and is likely to originate from the primary continuum of the southern nucleus. Nevertheless, the mean hard X-ray flux on longer timescales (years) is relatively constant. Moreover, the two nuclei remain Compton-thick, although we find evidence of variability in the material along the line of sight with column densities NH ≤ 2 × 1023 cm-2 over long (~3−15 yr) timescales. The observed X-ray emission in the NuSTAR energy range is fully consistent with the sum of the best-fit models of the spatially resolved Chandra spectra of the two nuclei