Mass function of dormant black holes and the evolution of active galactic nuclei

Under the assumption that accretion on to massive black holes (BHs) powers active galactic nuclei (AGNs), the mass function (MF) of the BHs responsible for their past activity is estimated. For this, we take into account not only the activity related to the optically selected AGNs, but also that required to produce the hard X-ray background (HXRB). The MF of the massive dark objects (MDOs) in nearby quiescent galaxies is computed by means of the most recent results on their demography. The two mass functions match well under the assumption that the activity is concentrated in a single significant burst with λ L L _Edd being a weakly increasing function of luminosity. This behaviour may be indicative of some level of recurrence and/or of accretion rates insufficient to maintain the Eddington rates in low-luminosity/low-redshift objects. Our results support the scenario in which the early phase of intense nuclear activity occurred mainly in early-type galaxies (E/S0) during the relatively short period in which they still had an abundant interstellar medium. Only recently, with the decline of the quasi-stellar object (QSO) luminosities, did the activity in late‐type galaxies (Sa/Sab) become statistically significant.     

Individual and Synergistic Effects of Metronidazole,Amoxicillin, and Ciprofloxacin on Methane Fermentation with Sewage Sludge

Methane fermentation is widely used to dispose of sewage sludge at wastewater treatment plants (WWTPs), due to production of renewable energy in the form of biogas. Antibiotics present in wastewater may accumulate in a sewage sludge. The aim of the present study is to investigate the impact of three antibiotics from different classes in three different doses on methane production from sewage sludge. For this purpose, metronidazole (MET), amoxicillin (AMO), and ciprofloxacin (CIP) are individually added to anaerobic reactors with sewage sludge collected from municipal WWTP. The antibiotics’ highest concentration (1024 mg kg^?1 of AMO; 512 mg kg^?1 of MET and CIP) lowers methane production and methane content in biogas. MET exerts the most marked effect and lowers methane production to 36.8 ± 3.7 mL CH₄ kg^?1 volatile solids. Tested antibiotics probably inhibit methanogenic archaea, which results in volatile fatty acids (VFAs) accumulation. Addition of MET results in accumulation of many kinds of VFAs with the highest concentration of acetic acid (17.52 ± 1.85 g L^?1). The addition of of AMO results in accumulation of butyric acid only (253.00 ± 15.89 g L^?1). However, addition of CIP results in accumulation of mainly acetic acid (7.58 ± 0.82 g L^?1) and isovaleric acid (2.01 ± 0.41 g L^?1). Next, synergistic effect of these antibiotics in a low concentration of 16 mg kg^?1 of AMO, 8 mg kg^?1 of MET, and 2 mg kg^?1 of CIP is measured in semi‐continuous conditions and causes inbibition of methane production and accumulation of VFAs.     

Application of the Unified Stream Assessment Method to Determine the Direction of Revitalization of Heavily Transformed Urban Rivers

Water Resources - The issues related to the assessment of the hydro morphological status of urban rivers in order to identify the revitalisation actions possible to be carried out, has been...     

The significance of the Variscan orogeny in the Świętokrzyskie Mountains (Mid Polish Uplands)

The witokrzyski Horst, created during the Laramide phase, is situated in the central part of the Mid Polish Uplands. It is composed of folded Paleozoic rocks partly covered by Mesozoic sediments. In this area two tectonostratigraphic units can be distinguished: the Kielce Unit to the S and the ysogóry Unit to the N.They are separated by the WNW-ESE trending witokrzyski overthrust, along which the rocks of the ysogóry Unit have been transported towards the south over the Kielce Unit. Thrusting took place after the Early Carboniferous, and before the Permian. As it is concluded from the differences of their stratigraphic and tectonic evolution, these two juxtaposed units of the witokrzyskie Mts were originally set at a considerable distance one from another. The present area of these units developed in two blocks of crust differing in structure, thickness and evolution. It is proposed that the important fault situated north of the witokrzyski overthrust and accompanied by magmatic phenomena could be a reactivation of a Variscan suture zone.

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Zusammenfassung Im Zentrum des Polnischen Mittelgebirges entstand während der laramischen Phase der witokrzyski Horst. Er besteht aus gefalteten Gesteinen, die zum Teil mit mesozoischen Ablagerungen bedeckt sind. Es lassen sich in diesem Gebiet zwei geologische Einheiten unterscheiden, die in Bau und Entwicklung wesentliche Unterschiede aufweisen: die Kielce-Einheit im S und die ysogóry-Einheit im N. Diese Einheiten werden von der WNW-OSO vorlaufenden witokrzyski-Überschiebung voneinander getrennt, an der die Gesteine des ysogóry-Einheit nach SW auf die gefalteten Ablagerungen der Kielce-Einheit überschoben worden sind. Dieser Vorgang erfolgte während der variszischen Orogenese, und zwar nach dem Unterkarbon und vor dem Oberen Perm.Die Unterschiede in der stratigraphischen und tektonischen Entwicklung der Kielce-Einheit und der ysogóry-Einheit deuten darauf hin, daß die beiden Einheiten vor der variszischen Gebirgsbildung weit voneinander entfernt gelegen haben: zwischen beiden lag im Unterkarbon ein tiefes Becken. Darauf deuten sowohl die im nördlichen Teil der Kielce-Einheit auftretenden bathypelagischen Ablagerungen aus dem Visé, als auch Spuren vulkanischer Tätigkeit.Die nördlich der witokrzyski-Überschiebung gelegene Störung, an der zahlreiche magmatische und hydrothermale Erscheinungen auftreten, ist wahrscheinlich das Relikt einer während der variszische Orogenese entstandene Suturzone.

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Résumé Le horst de Swietokrzyski, situé dans la partie centrale des «Uplands» de la Pologne moyenne, s'est formé au cours de la phase laramide. Il est constitué de roches paléozoïques plissées partiellement recouvertes de sédiments mésozoïques. Dans cette région, on distingue deux unités tectono-stratigraphiques: l'unité de Kielce au sud et celle de Lysogory au nord. Elles sont séparées par le charriage de Swietokrzyski, d'orientation WNW-ESE, suivant lequel les roches de l'unité de Lysogory ont été transportées vers le SW sur l'unité de Kielce. Ce charriage a eu lieu après le Carbonifère inférieur et avant le Permien. Les différences d'histoires stratigraphiques et tectoniques qui existent entre ces deux unités ainsi juxtaposées indiquent qu'elles devaient se trouver à l'origine à grande distance l'une de l'autre: elles étaient séparées au Carbonifère inférieur par un bassin profond. En témoignent les dépôts bathy-pélagiques viséens, ainsi que des traces d'activité volcanique dans la partie nord de l'unité de Kielce.La faille importante située au nord du charriage, faille jalonée par de multiples manifestations magmatiques et hydrothermales, est probablement la trace d'une zone de suture engendrée au cours de l'orogenèse varisque.

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A Lateglacial–early Holocene tephrochronology for SW Sweden

Four cores from southwestern Sweden are presented together with their tephra geochemistry. Two cryptotephra horizons were confirmed geochemically in the cores, the Vedde Ash and the Hässeldalen Tephra. The Lateglacial Hässeldalen Tephra (11 360–11 300 cal. a BP) offers great potential as a regional isochrone to add a new degree of certainty to the deglaciation chronology of southern Sweden, including the extent of glacial Lake Bolmen. In addition, the geographical distribution of the Hässeldalen Tephra has recently been extended outside of Sweden, making it an important time‐marker horizon in northern Europe. There are potential difficulties, however. Proper identification of the actual isochrone is complicated by the vertical pattern of shard distribution, which could be the result of several eruptive events, as well as by the fact that shards from the 10‐ka Askja horizon (10 500–10 350 cal. a BP) were found in close stratigraphical proximity. The geochemical data presented are the result of improved EPMA methodology, which significantly reduces sodium mobilization. The results therefore have slightly altered values, which has consequences for classifying new finds when they are compared with previous data for geochemically similar tephras. Finally, potential indications of the Borrobol/Penifiler horizon are presented, although the existence of the horizon could not be confirmed geochemically. This highlights the need to retrieve cores from different locations within a basin based on an analysis of basin morphology if horizons are to be located.     

Malacological and palynological evidence of the Lower Pleistocene cold phase at the Carpathian Foothills (Southern Poland)

Early Pleistocene sediments bearing gastropod shells and pollen flora were found during coring at Jawornik (South Poland) at a depth interval of 54.30–39.00 m, beneath the oldest till of the Carpathians. Thirteen land-snail taxa identified in 55 samples of the core formed two molluscan assemblages. In the bottom part, typical cold-loving snails were found (e.g. Vallonia tenuilabris, Pupilla loessica, Vertigo genesii, Columella columella), whereas in the upper part only Semilimax kotulae was present. The succession of molluscan assemblages may suggest that at the site of deposition, after a phase of tundra, steppe-tundra or forest-steppe landscape with patches of wet habitats in cold climate, the climate became slightly milder but still cool, favourable to the spreading of boreal (coniferous) woodlands. Pollen analysis was performed only for the upper part of the profile. The pollen spectra, besides the Tertiary (Miocene) elements, contained sporomorphs common to the Tertiary and Quaternary floras. Among them, the highest percentages were noted for Pinus haploxylon t., P. diploxylon t., Picea, Quercus, Ericaceae, Betula, and Ulmus. The fact that the sediments with organic remains underlie the oldest Scandinavian till suggests that they are older than the oldest glacial unit of the South-Polish Complex (Narevian = Menapian, ~ 1.2 Ma).     

A New Species of Megarhyphus,an Interesting Discovery from the Lower Jurassic of England(Diptera,Anisopodidae)

<正>The oldest representative of the genus Megarhyphus Kovalev(Diptera:Anisopodidae)is described from the Lower Jurassic(Sinemurian)of England.A summary of our knowledge of Jurassic Anisopodidae is given.     

The structure of voids

Presented here are high spatial and spectral resolution Chandra X-ray observations of the famous interacting galaxy pair, the Mice, a system similar to, though less evolved than, the well-known Antennae galaxies. Previously unpublished ROSAT High Resolution Imager data of the system are also presented.
Starburst-driven galactic winds outflowing along the minor axis of both galaxies (but particularly the northern one) are observed, and spectral and spatial properties, and energetics are presented. That such a phenomenon can occur in such a rapidly evolving and turbulent system is surprising, and this is the first time that the very beginning – the onset, of starburst-driven hot gaseous outflow in a full-blown disc–disc merger has been seen.
Point-source emission is seen at the galaxy nuclei, and within the interaction-induced tidal tails. Further point-source emission is associated with the galactic bar in the southern system. A comparison of the source X-ray luminosity function and of the diffuse emission properties is made with the Antennae and other galaxies, and evidence of a more rapid evolution of the source population than the diffuse component is found. No evidence for variability is found between the Chandra and previous observations.