PDS 456 is the most luminous ( L bol ∼ 10 47 erg s −1 ) radio-quiet quasar at z < 0.3 and can be regarded as a local counterpart of the powerful quasars shining at Cosmic Noon. It hosts a strong ...nuclear X-ray ultra-fast (∼0.3 c ) outflow, and a massive and clumpy CO (3–2) molecular outflow extending up to ∼5 kpc from the nucleus. We analyzed the first MUSE Wide Field Mode (WFM) and Adaptive-Optics Narrow Field Mode (AO-NFM) optical integral field spectroscopic observations of PDS456. The AO-NFM observations provide an unprecedented spatial resolution, reaching up to ∼280 pc. Our findings reveal a complex circumgalactic medium around PDS 456, extending to a maximum projected size of ≈46 kpc. This includes a reservoir of gas with a mass of ∼10 7 − 10 8 M ⊙ , along with eight companion galaxies and a multi-phase outflow. WFM and NFM MUSE data reveal an outflow on a large scale (≈12 kpc from the quasar) in O III , and on smaller scales (within 3 kpc) with higher resolution (about 280 pc) in H α , respectively. The O III outflow mass rate is 2.3 ± 0.2 M ⊙ yr −1 which is significantly lower than those typically found in other luminous quasars. Remarkably, the H α outflow shows a similar scale, morphology, and kinematics to the CO (3–2) molecular outflow, with the latter dominating in terms of kinetic energy and mass outflow rate by two and one orders of magnitude, respectively. Our results therefore indicate that mergers, powerful active galactic nucleus (AGN) activity, and feedback through AGN-driven winds collectively contribute to shaping the host galaxy evolution of PDS 456, and likely that of similar objects at the brightest end of the AGN luminosity function across all redshifts. Moreover, the finding that the momentum boost of the total outflow deviates from the expected energy-conserving expansion for large-scale outflows highlights the need of novel AGN-driven outflow models to comprehensively interpret these phenomena.
An increasing number of observations and simulations suggests that low-power (< 10 44 erg s −1 ) jets may be a significant channel of feedback produced by active galactic nuclei (AGN), but little is ...known about their actual effect on their host galaxies from the observational point of view. We targeted four luminous type 2 AGN hosting moderately powerful radio emission (∼10 44 erg s −1 ), two of which and possibly a third are associated with jets, with optical integral field spectroscopy observations from the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT) to analyze the properties of their ionized gas as well as the properties and effects of ionized outflows. We combined these observations with Very Large Array (VLA) and e-MERLIN data to investigate the relations and interactions between the radio jets and host galaxies. We detected ionized outflows as traced by the fast bulk motion of the gas. The outflows extended over kiloparsec scales in the direction of the jet, when present. In the two sources with resolved radio jets, we detected a strong enhancement in the emission-line velocity dispersion (up to 1000 km s −1 ) perpendicular to the direction of the radio jets. We also found a correlation between the mass and the energetics of this high-velocity dispersion gas and the radio power, which supports the idea that the radio emission may cause the enhanced turbulence. This phenomenon, which is now being observed in an increasing number of objects, might represent an important channel for AGN feedback on galaxies
The MURALES survey Balmaverde, B.; Capetti, A.; Marconi, A. ...
Astronomy and astrophysics (Berlin),
12/2019, Letnik:
632
Journal Article
Recenzirano
Odprti dostop
We present observations of a complete sub-sample of 20 radio galaxies from the Third Cambridge Catalog (3C) with redshift < 0.3 obtained from VLT/MUSE optical integral field spectrograph. These data ...have been obtained as part of the survey MURALES (a MUse RAdio Loud Emission line Snapshot survey) with the main goal of exploring the active galactic nuclei (AGN) feedback process in a sizeable sample of the most powerful radio sources at low redshift. We present the data analysis and, for each source, the resulting emission line images and the 2D gas velocity field. Thanks to their unprecedented depth (the median 3σ surface brightness limit in the emission line maps is 6 × 10−18 erg s−1 cm−2 arcsec−2), these observations reveal emission line structures extending to several tens of kiloparsec in most objects. In nine sources the gas velocity shows ordered rotation, but in the other cases it is highly complex. 3C sources show a connection between radio morphology and emission line properties. Whereas, in three of the four Fanaroff and Riley Class I radio galaxies (FR Is), the line emission regions are compact, ∼1 kpc in size; in all but one of the Class II radiogalaxies FR IIs, we detected large scale structures of ionized gas with a median extent of 17 kpc. Among the FR IIs, those of high and low excitation show extended gas structures with similar morphological properties, suggesting that they both inhabit regions characterized by a rich gaseous environment on kpc scale.
Proton pump inhibitors (PPI) target tumour acidic pH and have an antineoplastic effect in melanoma. The PPI esomeprazole (ESOM) kills melanoma cells through a caspase-dependent pathway involving ...cytosolic acidification and alkalinization of tumour pH. In this paper, we further investigated the mechanisms of ESOM-induced cell death in melanoma. ESOM rapidly induced accumulation of reactive oxygen species (ROS) through mitochondrial dysfunctions and involvement of NADPH oxidase. The ROS scavenger N-acetyl-L-cysteine (NAC) and inhibition of NADPH oxidase significantly reduced ESOM-induced cell death, consistent with inhibition of cytosolic acidification. Autophagy, a cellular catabolic pathway leading to lysosomal degradation and recycling of proteins and organelles, represents a defence mechanism in cancer cells under metabolic stress. ESOM induced the early accumulation of autophagosomes, at the same time reducing the autophagic flux, as observed by WB analysis of LC3-II accumulation and by fluorescence microscopy. Moreover, ESOM treatment decreased mammalian target of rapamycin signalling, as reduced phosphorylation of p70-S6K and 4-EBP1 was observed. Inhibition of autophagy by knockdown of Atg5 and Beclin-1 expression significantly increased ESOM cytotoxicity, suggesting a protective role for autophagy in ESOM-treated cells. The data presented suggest that autophagy represents an adaptive survival mechanism to overcome drug-induced cellular stress and cytotoxicity, including alteration of pH homeostasis mediated by proton pump inhibition.
ABSTRACT
We present a study of molecular gas, traced via CO (3–2) from Atacama Large Millimeter/submillimeter Array data, of four z < 0.2, ‘radio quiet’, type 2 quasars (Lbol ∼ 1045.3–1046.2 erg s−1; ...L$_{\mathrm{1.4\, GHz}}\sim 10^{23.7}\!-\!10^{24.3}$ W Hz−1). Targets were selected to have extended radio lobes (≥ 10 kpc), and compact, moderate-power jets (1–10 kpc; Pjet ∼ 1043.2–1043.7 erg s−1). All targets show evidence of central molecular outflows, or injected turbulence, within the gas discs (traced via high-velocity wing components in CO emission-line profiles). The inferred velocities (Vout = 250–440 km s−1) and spatial scales (0.6–1.6 kpc), are consistent with those of other samples of luminous low-redshift active galactic nuclei. In two targets, we observe extended molecular gas structures beyond the central discs, containing 9–53 per cent of the total molecular gas mass. These structures tend to be elongated, extending from the core, and wrap-around (or along) the radio lobes. Their properties are similar to the molecular gas filaments observed around radio lobes of, mostly ‘radio loud’, brightest cluster galaxies. They have the following: projected distances of 5–13 kpc; bulk velocities of 100–340 km s−1; velocity dispersion of 30–130 km s−1; inferred mass outflow rates of 4–20 M⊙ yr−1; and estimated kinetic powers of 1040.3–1041.7 erg s−1. Our observations are consistent with simulations that suggest moderate-power jets can have a direct (but modest) impact on molecular gas on small scales, through direct jet–cloud interactions. Then, on larger scales, jet-cocoons can push gas aside. Both processes could contribute to the long-term regulation of star formation.
We investigated the susceptibility of an Italian population of Culex pipiens mosquitoes to Zika virus (ZIKV) infection, tested in parallel with Aedes aegypti, as a positive control. We analysed ...mosquitoes at 0, 3, 7, 10, 14, 20 and 24 days after an infectious blood meal. Viral RNA was detected in the body of Cx. pipiens up to three days post-infection, but not at later time points. Our results indicate that Cx. pipiens is not susceptible to ZIKV infection.
Personnel involved in interventional practices are likely to be exposed to higher radiation doses than other workers in the medical field. Personnel monitoring and radiation protection measures play ...a crucial role in keeping these doses below the limits. EURADOS (European Radiation Dosimetry Group) Working Group 12 performed a series of investigations showing how the complexity of the scattered field reaching the operators can influence the doses to the operators. The present work was aimed at determining the possible effects on the registered doses of the scattered field and the actual position of a dosemeter on apron. This study has been performed through Monte Carlo simulations and it was validated through measurements. It does not claim to identify the 'best' position for the dosemeter, but to assess the variability of its response, showing how a variability of the order of +/- 30% to 40 should be taken into account.
Abstract
We present a multifrequency analysis of the radio galaxy 3CR 196.1 (
z
=0.198), associated with the brightest galaxy of the cool-core cluster CIZAJ0815.4-0303. This nearby radio galaxy shows ...a hybrid radio morphology and an X-ray cavity, all signatures of a turbulent past activity, potentially due to merger events and active galactic nuclei (AGN) outbursts. We present results of the comparison between Chandra and Very Large Telescope Multi-Unit Spectroscopic Explorer data for the inner region of the galaxy cluster, on a scale of tens of kpc. We discovered H
α
+ N
ii
λ
6584 emission spatially associated with the X-ray cavity (at ∼10 kpc from the galaxy nucleus) instead of with its rim. This result differs from previous discoveries of ionized gas surrounding X-ray cavities in other radio galaxies harbored in galaxy clusters and could represent the first reported case of ionized gas filling an X-ray cavity, either due to different AGN outbursts or to the cooling of warm (10
4
<
T
≤ 10
7
K) AGN outflows. We also found that the H
α
, N
ii
λ
λ
6548, 6584, and S
ii
λ
λ
6718, 6733 emission lines show an additional redward component, at ∼1000 km s
−1
from rest frame, with no detection in H
β
or O
iii
λ
λ
4960, 5008. We believe the most likely explanation for this redward component is the presence of a background gas cloud as there appears to be a discrete difference of velocities between this component and the rest frame.
The
Gaia
Multipeak (GMP) technique can be used to identify large numbers of dual or lensed active galactic nucleus (AGN) candidates at subarcsec separation, allowing us to study both multiple ...supermassive black holes (SMBHs) in the same galaxy and rare, compact lensed systems. The observed samples can be used to test the predictions of the models of SMBH merging when (1) the selection function of the GMP technique is known, and (2) each system has been classified as a dual AGN, a lensed AGN, or an AGN/star alignment. Here we show that the GMP selection is very efficient for separations above 0.15″ when the secondary (fainter) object has a magnitude
G
≲ 20.5. We present the spectroscopic classification of five GMP candidates using VLT/ERIS and Keck/OSIRIS and compare them with the classifications obtained from (a) the near-IR colors of seven systems obtained with LBT/LUCI, and (b) the analysis of the total spatially unresolved spectra. We conclude that colors and integrated spectra can already provide reliable classifications of many systems. Finally, we summarize the confirmed dual AGNs at
z
> 0.5 selected by the GMP technique, and compare this sample with other such systems from the literature, concluding that GMP can provide a large number of confirmed dual AGNs at separations below 7 kpc.
Three separate experiments were planned with the aim of assessing storage losses and discrepancies in biomass yield between plot and field, the latter being poorly studied in spite of the relevant ...management scale. The results show that storability of switchgrass is remarkable, irrespective of harvest time (summer or post-frost harvest) and bale type (rectangular, soft- or hard-core round bales). Bale weight significantly decreased over time, yet it was almost entirely attributed to a decline in moisture content. Microbial processes appeared trivial and this was corroborated by temperature inset and pH trends. In contrast, significant biomass losses were ascertained during the harvest, which accounted from 35% to 45% of potential harvestable biomass. Biomass not picked-up by the baler machine was up to 17%, while the uncut biomass due to the mower swinging averaged 29%, and it was also significantly affected by the field slope. Because of the lower ash content of basal stems, the uncut biomass penalized biofuel quality and quantity, at the same time. Potential harvestable biomass was similar to that achieved with hand-harvested plots thus revealing that the two considered sources of biomass loss (not recovered and uncut biomass) are mostly responsible of the discrepancy between plot and field yields.
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