Nuclear hard X-ray luminosities (L{sub X,nuc}) for a sample of 112 early-type galaxies within a distance of 67 Mpc are used to investigate their relationship with the central galactic black hole mass ...M{sub BH} (coming from direct dynamical studies or the M{sub BH}-{sigma} relation), the inner galactic structure (using the parameters describing its cuspiness), the hot gas content, and the core radio luminosity. For this sample, L {sub X,nuc} ranges from 10{sup 38} to 10{sup 42} erg s{sup -1}, and the Eddington ratio L{sub X,nuc}/L {sub Edd} from 10{sup -9} to 10{sup -4}, with the largest values belonging to four Seyfert galaxies. Together with a trend for L{sub X,nuc} to increase on average with the galactic luminosity L{sub B} and M{sub BH}, there is a wide variation of L{sub X,nuc} (and L{sub X,nuc}/L {sub Edd}), by up to 4 orders of magnitude, at any fixed L{sub B} > 6 x 10{sup 9} L{sub B,sun} or M{sub BH} > 10{sup 7} M{sub sun}. This large observed range should reflect a large variation of the mass accretion rate M-dot{sub BH}, and possible reasons for this difference are searched for. On the circumnuclear scale, in a scenario where accretion is (quasi) steady, M-dot{sub BH} at fixed L{sub B} (or M{sub BH}) could vary due to differences in the fuel production rate from stellar mass return linked to the inner galactic structure; a trend of L {sub X,nuc} with cuspiness is not observed, though, while a tendency for L{sub X,nuc}/L {sub Edd} to be larger in cuspier galaxies is present. In fact, M-dot {sub BH} is predicted to vary with cuspiness by a factor exceeding a few only in hot gas-poor galaxies and for large differences in the core radius; for a subsample with these characteristics the expected effect seems to be present in the observed L{sub X,nuc} values. L{sub X,nuc} does not show a dependence on the age of the stellar population in the central galactic region, for ages >3 Gyr; less luminous nuclei, though, are found among the youngest galaxies or galaxies with a younger stellar component. On the global galactic scale, L{sub X,nuc} shows a trend with the total galactic hot gas cooling rate (L{sub X,ISM}): it is detected both in gas-poor and gas-rich galaxies, and on average increases with L{sub X,ISM}, but again with a large scatter. The observed lack of a tight relationship between L{sub X,nuc} and the circumnuclear and total gas content can be explained if accretion is regulated by factors overcoming the importance of fuel availability, as (1) the gas is heated by black hole feedback and M-dot {sub BH} varies due to an activity cycle, and (2) the mass effectively accreted by the black hole can be largely reduced with respect to that entering the circumnuclear region, as in radiatively inefficient accretion with winds/outflows. Finally, differently from L{sub X,nuc}, the central 5 GHz VLA luminosity shows a clear trend with the inner galactic structure that is similar to that shown by the total soft X-ray emission; therefore, it is suggested that they could both be produced by the hot gas.
In order to find an explanation for the radiative quiescence of supermassive black holes in the local universe, the most accurate estimates for a sample of nearby galaxies are collected for the mass ...of a central black hole (M sub(BH)), the nuclear X-ray luminosity L sub(X,nuc), and the circumnuclear hot gas density and temperature, by using Chandra data. The nuclear X-ray luminosity L sub(X,nuc) varies by 63 orders of magnitude and does not show a relationship with M sub(BH) or with the Bondi mass accretion rate M sub(B); L sub(X,nuc) is always much lower than expected if M sub(B) ends in a standard accretion disk with high radiative efficiency (this instead can be the case of the active nucleus of Cen A). Radiatively inefficient accretion as in the standard advection-dominated accretion flow (ADAF) modeling may explain the low luminosities of a few cases; for others, the predicted luminosity is still too high, and, in terms of Eddington-scaled quantities, it is increasingly higher than that observed for increasing M sub(B). Variants of the simple radiatively inefficient scenario including outflow and convection may reproduce the low emission levels observed, since the amount of matter actually accreted is reduced considerably. However, the most promising scenario includes feedback from accretion on the surrounding gas; this has the important advantages of naturally explaining the observed lack of relationship among L sub(X,nuc), M sub(BH), and M sub(B), and evading the problem of the fate of the material accumulating in the central galactic regions over cosmological times.
Recently, the temperature T and the luminosity LX of the hot gas halos of early-type galaxies have been derived, with unprecedented accuracy, from Chandra data for a sample of 30 galaxies, covering a ...wider range of galactic luminosity (and central velocity dispersion Delta *s c ) than before. This work investigates the origin of the observed temperatures by examining the relationship between them and the galaxy structure, the gas heating due to Type Ia supernovae (SNe Ia) and the gravitational potential, and the dynamical status of the gas flow. In galaxies with Delta *s c 200 km s--1, the T's are close to a fiducial average temperature of gas in outflow; at 200 < Delta *s c (km s--1) < 250, the T's are generally lower than this and unrelated to Delta *s c , which requires a more complex gas flow status; at larger Delta *s c , the T's may increase as Delta *s2 c , as expected for infall heating, though heating from SNe Ia, that is independent of Delta *s c , should be dominant. All observed T's are larger than the virial temperature, by up to ~0.5 keV. The additional heating can be provided in the X-ray brightest galaxies by SNe Ia and infall heating, with an SN Ia energy input even lower than in standard assumptions; in the X-ray fainter ones it can be provided by SNe Ia, whose energy input would be required to be close to the full standard value at the largest Delta *s c . This same energy input, though, would produce temperatures larger than observed at low Delta *s c if entirely thermalized. The values of the observed T's increase from outflows to inflows; the gas is relatively hotter in outflows, however, if the T's are rescaled by the virial temperature. For 200 < Delta *s c (km s--1) < 250, lower LX values tend to correspond to lower T's, a result that deserves further investigation.
Aims.
The collimation of relativistic jets in galaxies is a poorly understood process. Detailed radio studies of the jet collimation region have been performed so far in a few individual objects, ...providing important constraints for jet formation models. However, the extent of the collimation zone as well as the nature of the external medium possibly confining the jet are still debated.
Methods.
In this article, we present a multifrequency and multiscale analysis of the radio galaxy NGC 315, including the use of mm-VLBI data up to 86 GHz, aimed at revealing the evolution of the jet collimation profile. We then consider results from the literature to compare the jet expansion profile in a sample of 27 low-redshift sources, mainly comprising radio galaxies and BL Lacs, which were classified based on the accretion properties as low-excitation (LEG) and high-excitation (HEG) galaxies.
Results.
We propose that the jet collimation in NGC 315 is completed on sub-parsec scales. A transition from a parabolic to conical jet shape is detected at
z
t
= 0.58 ± 0.28 parsecs or ∼5 × 10
3
Schwarzschild radii (
R
S
) from the central engine, a distance which is much smaller than the Bondi radius,
r
B
∼ 92 pc, estimated based on X-ray data. The jet in this and in a few other LEG in our sample may be initially confined by a thick disk extending out to ∼10
3
− 10
4
R
S
. A comparison between the mass-scaled jet expansion profiles of all sources indicates that jets in HEG are surrounded by thicker disk-launched sheaths and collimate on larger scales with respect to jets in LEG. These results suggest that disk winds play an important role in the jet collimation mechanism, particularly in high-luminosity sources. The impact of winds on the origin of the FRI and FRII dichotomy in radio galaxies is also discussed.
•The addition of pelletized biochar suddenly increases soil water retention.•The use of pelletized biochar is effective as conditioner in a fine-textured soil.•The incorporation of pelletized biochar ...creates functional accommodation pores.•The amount of biochar directly influences AWC of amended soil.•The pyrolysis process influences biochar AWC.
The field application of pelletized biochar is seldom employed and its effect on soil hydrological behavior scarcely investigated. Biochar is usually added in powdered or granular form to improve the homogeneity of distribution, meanwhile favoring its interaction with soil matrix. In this paper we evaluated the possibility of applying pelletized biochar as soil conditioner during a single cropping season of a tomato cultivation. For that purpose, the water retention curves (WRCs) were determined three months after the addition of two differently pyrolysed biochars (B1 and B2), at the rate of 14Mgha−1, to a silty clay loam soil prone to compaction. Starting from the WRCs the pore size distribution was determined. The gravimetric water content at both field capacity (FC) and wilting point (WP) was also measured on biochar samples to assess their available water capacity (AWC).
In both the treatments, soil bulk density (BD) was significantly lower compared to control (Co), apparently as direct consequence of the addition of low density pellets. Actually, excluding the intrinsic biochar porosity from soil bulk density calculation, BD values of the treated soils remain lower of around 10% over Co. Such findings suggest that a modification of soil structural characteristics might have been induced by pellet addition. Data of the SWRCs indicate a significant increase in transmission (500–50μm), storage (50–0.5μm) and AWC pores (30–0.2μm) for the amended soils. The pyrolysis process seemed to differentiate the extent of direct biochar contribution expressed by AWC values The addition of pelletized biochar was able to enhance the soil water retention properties even in the short term, and such improvement might be correlated to both the inherent biochar retention capacity and to a more functional rearrangement of soil aggregates/particles with pellets.
Japanese quails in wild life live in small groups with females being even solitary during the laying period. Although it is a poultry species widely used for egg production, information regarding ...laying behavior motivations or influencing variables is scarce. Our study focuses on evaluating along 7 d the quail laying behavior in a novel environmental set up. This set up allows the female to choose between remaining separated from a conspecific in one side of the apparatus or to voluntarily enter their space (box-mate side) and interact with it. We evaluated whether the female insemination status prior to enter the environmental set up, and the presence of a female or a male partner in the box-mate side can influence their laying and social behavior. Thus, 4 experimental groups were established. Females spent a higher (P < 0.05) percentage of time in the box-mate side than in their separated sector in all groups. In 3 of the 4 experimental groups (non-inseminated females interacting with a female or a male box-mate, and inseminated females interacting with a male box-mate) females also laid a greater percentage (≥65%, P < 0.05, in all cases) of eggs in the box-mate sector than in their separated sector. However, the group of inseminated females that interacted with a female box-mate shifted their egg distribution and laid equally between both sides of the apparatus. Aggressive social interactions were reduced (P < 0.05) throughout the testing days but this was depending upon the female insemination status and the sex of their box-mate. Findings suggest that females can change their laying side choice when they are inseminated but depending on the sex identity of their box-mate partners. Thus, providing quail female breeders with the option of laying their eggs in separated enclosures from conspecifics could be key to favor their well-being.
To evaluate the impact of management practices on the soil environment, it is necessary to quantify the modifications to the soil structure. Soil structure conditions were evaluated by characterizing ...porosity using a combination of mercury intrusion porosimetry, image analysis and micromorphological observations. Saturated hydraulic conductivity and aggregate stability were also analysed.
In soils tilled by alternative tillage systems, like ripper subsoiling, the macroporosity was generally higher and homogeneously distributed through the profile while the conventional tillage systems, like the mouldboard ploughing, showed a significant reduction of porosity both in the surface layer (0–100
mm) and at the lower cultivation depth (400–500
mm). The higher macroporosity in soils under alternative tillage systems was due to a larger number of elongated transmission pores. Also, the microporosity within the aggregates, measured by mercury intrusion porosimetry, increased in the soil tilled by ripper subsoiling and disc harrow (minimum tillage). The resulting soil structure was more open and more homogeneous, thus allowing better water movement, as confirmed by the higher hydraulic conductivity in the soil tilled by ripper subsoiling. Aggregates were less stable in ploughed soils and this resulted in a more pronounced tendency to form surface crust compared with soils under minimum tillage and ripper subsoiling.
The application of compost and manure improved the soil porosity and the soil aggregation. A better aggregation indicated that the addition of organic materials plays an important role in preventing soil crust formation.
These results confirm that it is possible to adopt alternative tillage systems to prevent soil physical degradation and that the application of organic materials is essential to improve the soil structure quality.
•severely ill-posed nonlinear problem solved with adaptive Kalman filter.•information from measurements, evolution model and regularization is integrated.•regularization weighing provides estimates ...in better agreement with actual flow.•convergence properties improved through incorporation of flow evolution models.•three-dimensional analysis of experimental data validates the approach.
Electrical impedance tomography (EIT) is a severely ill-posed nonlinear inverse problem. In order to obtain solutions with physical meaning, the inverse of the model of measurements requires the combination of information from various sources. This paper proposes a new approach through Kalman filtering for adaptive integration of EIT measurements, Tikhonov regularization and evolution models for the characterization of a two-phase air–water fluid flow. The Tikhonov regularization factor is embedded into the observation error covariance matrix, thus allowing for individual adjustment for each of the regularization equations. The filter outputs for different evolution models—random walk, advective and advective–diffusive—are compared in terms of estimate convergence and physical meaning. With the random walk evolution model the analysis of experimental data shows that the proposed information fusion strategy provides fewer artifacts, enabling a more effective identification of the phase interfaces. When the other two evolution models are incorporated into the Kalman filter and compared with the random walk model, faster and more accurate estimates of the flow are obtained even away from the electrodes, as well as sharper phase interfaces are identified. The results suggest that the reason for this improved performance is the fused information from the upstream–downstream dynamics of the advective and advective–diffusive models with the outer-inner structure influence of measurements.
In this prospective study, we evaluated the steroid levels in 111 follicular fluids (FF) collected from 13 women stimulated with FSH monotherapy and 205 FF collected from 28 women stimulated with FSH ...+ LH because of a previous history of hypo-responsiveness to FSH. Steroid levels were measured by HPLC/MS-MS and related to ovarian stimulation protocol, oocyte maturity, fertilization and quality of blastocysts, after individually tracking the fate of all retrieved oocytes. 17-Hydroxy-Progesterone, Androstenedione, Estradiol and Estrone were significantly higher in the FSH + LH protocol. Progesterone, 17-Hydroxy-Progesterone and Estradiol were more expressed in FF yielding a mature oocyte (p < 0.01) in the FSH + LH protocol. FF Progesterone concentration was correlated with the rate of normal fertilization in the FSH protocol. None of the FF steroids measured were associated with blastocyst quality and achievement of pregnancy. Our results indicate that LH supplementation in hypo-responsive women modifies ovarian steroid production, mimicking physiological production better and likely contributing to an improved ovarian response. Employing a correct methodological procedure to evaluate the relationship between FF steroid hormones and assisted reproduction outcomes, our study reveals that some steroids in single follicles may be helpful in predicting oocyte maturity and fertilization.
The Hubble Space Telescope has revealed a dichotomy in the central surface brightness profiles of early-type galaxies, which have subsequently been grouped into two families: core, boxy, anisotropic ...systems; and cuspy (‘power-law’), discy, rotating ones. Here we investigate whether a dichotomy is also present in the X-ray properties of the two families. We consider both their total soft emission (LSX,tot), which is a measure of the galactic hot gas content, and their nuclear hard emission (LHX,nuc), mostly coming from Chandra observations, which is a measure of the nuclear activity. At any optical luminosity, the highest LSX,tot values are reached by core galaxies; this is explained by their being the central dominant galaxies of groups, subclusters or clusters, in many of the log LSX,tot (erg s−1) ≳ 41.5 cases. The highest LHX,nuc values, similar to those of classical active galactic nuclei (AGNs), in this sample are hosted only by core or intermediate galaxies; at low luminosity AGN levels, LHX,nuc is independent of the central stellar profile shape. The presence of optical nuclei (also found by HST) is unrelated to the level of LHX,nuc, even though the highest LHX,nuc are all associated with optical nuclei. The implications of these findings for galaxy evolution and accretion modalities at the present epoch are discussed.
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