A 3D model for the stellar populations in the nuclei of NGC 1433,NGC 1566, and NGC 1808

Aims. We aim to characterize the properties of the stellar populations in the central few hundred parsecs of nearby galactic nuclei; specifically their age, mass, and 3D geometry. Methods. We use spatially resolved spectroscopic observations of NGC 1433, NGC 1566, and NGC 1808 obtained with SINFONI to constrain a 3D model composed of a spherically symmetric nuclear star cluster (NSC) and an extended thick stellar disk. We computed UV to mid-infrared single stellar population (UMISSP) spectra to determine the age of the stellar populations and construct synthetic observations for our model. To overcome degeneracies between key parameters, we simultaneously fit the spatially resolved line-of-sight velocity, line-of-sight-velocity-dispersion, low-spectral-resolution NIR continuum, and high-spectral-resolution CO absorption features for each pixel. Results. For the three objects, we derive the age and mass of the young and old stellar populations in the NSC and surrounding disk, as well as their 3D geometry: radius for the NSC; thickness, inclination, and position angle for the disk. These results are consistent with published independent measurements when available. Conclusions. The proposed method allows us to derive a consistent 3D model of the stellar populations in nearby galactic centers solely based on a near-infrared IFU observation

Ionized regions in the central arcsecond of NGC 1068. YJHK spatially resolved spectroscopy

Context. Several bright emission line regions have been observed in the central 100 parsecs of the active galaxy NGC 1068. Aims. We aim to determine the properties and ionization mechanism of three regions of NGC 1068: the nucleus (B) and two clouds located at 0.3" and 0.7" north of it (C and D). Methods. We combined SPHERE (0.95 - 1.65 um) and SINFONI (1.5 - 2.45 um) spectra for the three regions B, C, and D. We compared these spectra to several CLOUDY photoionization models and to the MAPPINGS III Library of Fast Radiative Shock Models. Results. The emission line spectra of the three regions are almost identical to each other and contribute to most of the emission line flux in the nuclear region. The emitting media contain multiple phases, the most luminous of which have temperatures ranging from 104.8 K to 106 K. Central photoionization models can reproduce some features of the spectra, but the fast radiative shock model provides the best fit to the data. Conclusions. The similarity between the three regions indicates that they belong to the same class of objects. Based on our comparisons, we conclude that they are shock regions located where the jet of the active galactic nucleus impacts massive molecular clouds.Comment: A&A, Forthcoming article, accepted for publicatio

A globális éghajlatváltozás várható hatásai a növényvédelemben

A légköri CO2 koncentráció és az egyéb üvegházhatásért felelős gázok koncentrációjának növekedése miatt a Föld éghajlata melegszik és a klíma változik. Összeállításban a legfontosabb üvegházhatást kiváltó tényezők általános hatásait vizsgáljuk a növénypatogén mikroorganizmusokra, kártevő rovarokra és a gyomnövényekre, bemutatják a növény természetes ellenálló képességének útjait az abiotikus stressz-hatásokkal szemben. A megemelkedett CO2 koncentráció és a globális hőmérséklet-növekedés megváltoztatja a károsítók viselkedését, egyrészt, mert a megváltozott légköri CO2 tartalom miatt megváltozik fejlődési sebességük és a kiváltott tünetek ill. károk mértéke. Másrészt a megváltozott körülmények miatt megváltoznak maguk a növények is, amelyek ugyancsak változtatják a kórokozók fertőzési jellemzőit, a rovarok fejlődését is. Az előbb említett két fő tényező károsítókra gyakorolt hatása szerteágazó, egyes esetekben stimuláló, más esetekben gátló hatásokra kell számítanunk. Emiatt a hatások eredőjét nehéz tudományosan is megalapozott módon megjósolni. Mindehhez hozzá kell tenni azt is, hogy az éghajlatváltozás a mezőgazdasági régiók eltolódását is maga után vonhatja, és ez kiváltja a termesztett növények és azok károsítóinak változását is. Ennek következménye lehet az is, hogy az új területen megjelenő növénybetegségek és állati kártevők azokat a természetes növényi társulásokat is megváltoztathatják, amelyek azelőtt nem voltak kitéve a kultúrnövényeket károsító – számos esetben sokkal agresszívebb – fajoknak vagy változatoknak

How to create Sgr A East: Where did the supernova explode?

Sgr A East is the supernova remnant closest to the centre of the Milky Way. Its age has been estimated to be either very young, around 1-2 kyr, or about 10 kyr, and its exact origin remains unclear. We aspire to create a simple model of a supernova explosion that reproduces the shape, size, and location of Sgr A East. Using a simplified hydrodynamical code, we simulated the evolution of a supernova remnant in the medium around the Galactic centre. The latter consists of a nearby massive molecular cloud with which Sgr A East is known to be interacting and a wind from the nuclear star cluster. Our preferred models of the Sgr A East remnant are compatible with an age of around 10 kyr. We also find suitable solutions for older ages, but not for ages younger than 5 kyr. Our simulations predict that the supernova exploded at a distance of about 3.5 pc from the Galactic centre, below the Galactic plane, slightly eastwards from the centre and 3 pc behind it.Comment: 13 pages, 15 figures, accepted by A&

Pre-Excitation Studies for Rubidium-Plasma Generation

The key element in the Proton-Driven-Plasma-Wake-Field-Accelerator (AWAKE) project is the generation of highly uniform plasma from Rubidium vapor. The standard way to achieve full ionization is to use high power laser which can assure the over-barrier-ionization (OBI) along the 10 meters long active region. The Wigner-team in Budapest is investigating an alternative way of uniform plasma generation. The proposed Resonance Enhanced Multi Photon Ionization (REMPI) scheme probably can be realized by much less laser power. In the following the resonant pre-excitations of the Rb atoms are investigated, theoretically and the status report about the preparatory work on the experiment are presented.Comment: 8 pages, 6 figures, submitted to Nucl. Inst. and Meth. in Phys. Res.

Crossover of texture and morphology in (Ti1 − xAlx)1 − yYyN alloy films and the pathway of structure evolution

In our earlier published work, we have shown that there is a composition range of the (Ti 1 − x Al x ) 1 − y Y y N alloy films (0.72 b Ti/Al b 0.88) deposited at oblique vapour beam incidence and 500 °C (corresponding to zone T) in which mixed cubic TiN (c-TiN) and wurtzite AlN (w-AlN) structures were formed together with an unusual complex texture. The texture of c-TiN phase changed from 〈001〉 to b111N at a certain thickness forming a definite crossover. Moreover the c-TiNb111N and the w-AlN〈0001〉 crystals were epitaxially related with axes tilted to the direction of the vapour beam. Based on a comprehensive transmission electron microscopy (TEM) and diffraction (XRD and selected area electron diffraction (SAED)) structure and morphology analysis, we discovered the details of this exotic structure making it possible to construct the complex pathway of structure evolution including the formation of the w-AlN phase and the change of the dominating texture of c-TiN phase with thickness in dependence of the Ti/Al ratio and the deposition parameters. This pathway could be deduced from the fundamental phenomena of structure formation and may be generalised for multi-component thin film systems. A composition structure zone model has been also proposed for the (Ti 1 − x Al x ) 1 − y Y y N thin film system in the 0 b x b 1 composition range

Crossover of texture and morphology in (Ti 1 − x Al x ) 1 − y Y y N alloy films and the pathway of structure evolution

In our earlier published work, we have shown that there is a composition range of the (Ti 1 − x Al x ) 1 − y Y y N alloy films (0.72 b Ti/Al b 0.88) deposited at oblique vapour beam incidence and 500 °C (corresponding to zone T) in which mixed cubic TiN (c-TiN) and wurtzite AlN (w-AlN) structures were formed together with an unusual complex texture. The texture of c-TiN phase changed from 〈001〉 to b111N at a certain thickness forming a definite crossover. Moreover the c-TiNb111N and the w-AlN〈0001〉 crystals were epitaxially related with axes tilted to the direction of the vapour beam. Based on a comprehensive transmission electron microscopy (TEM) and diffraction (XRD and selected area electron diffraction (SAED)) structure and morphology analysis, we discovered the details of this exotic structure making it possible to construct the complex pathway of structure evolution including the formation of the w-AlN phase and the change of the dominating texture of c-TiN phase with thickness in dependence of the Ti/Al ratio and the deposition parameters. This pathway could be deduced from the fundamental phenomena of structure formation and may be generalised for multi-component thin film systems. A composition structure zone model has been also proposed for the (Ti 1 − x Al x ) 1 − y Y y N thin film system in the 0 b x b 1 composition range

Search for the QCD critical point in nuclear collisions at the CERN SPS

Pion production in nuclear collisions at the SPS is investigated with the aim to search, in a restricted domain of the phase diagram, for power-laws in the behavior of correlations which are compatible with critical QCD. We have analyzed interactions of nuclei of different size (p+p, C+C, Si+Si, Pb+Pb) at 158$A$ GeV adopting, as appropriate observables, scaled factorial moments in a search for intermittent fluctuations in transverse dimensions. The analysis is performed for $\pi^+\pi^-$ pairs with invariant mass very close to the two-pion threshold. In this sector one may capture critical fluctuations of the sigma component in a hadronic medium, even if the $\sigma$-meson has no well defined vacuum state. It turns out that for the Pb+Pb system the proposed analysis technique cannot be applied without entering the invariant mass region with strong Coulomb correlations. As a result the treatment becomes inconclusive in this case. Our results for the other systems indicate the presence of power-law fluctuations in the freeze-out state of Si+Si approaching in size the prediction of critical QCD.Comment: 31 pages, 11 figure

Rapidity and energy dependence of the electric charge correlations in A+A collisions at the SPS energies

Results from electric charge correlations studied with the Balance Function method in A+A collisions from 20\emph{A} to 158\emph{A} GeV are presented in two different rapidity intervals: In the mid-rapidity region we observe a decrease of the width of the Balance Function distribution with increasing centrality of the collision, whereas this effect vanishes in the forward rapidity region. Results from the energy dependence study in central Pb+Pb collisions show that the narrowing of the Balance Function expressed by the normalised width parameter \textit{W} increases with energy towards the highest SPS and RHIC energies. Finally we compare our experimental data points with predictions of several models. The hadronic string models UrQMD and HIJING do not reproduce the observed narrowing of the Balance Function. However, AMPT which contains a quark-parton transport phase before hadronization can reproduce the narrowing of the BF's width with centrality. This confirms the proposed sensitivity of the Balance Function analysis to the time of hadronization.Comment: Submitted in Phys. Rev.

High p_T Spectra of Identified Particles Produced in Pb+Pb Collisions at 158GeV/nucleon Beam Energy

Transverse momentum spectra of pi^{+/-}, p, pbar, K^{+/-}, K^0_s and Lambda at midrapidity were measured at high p_T in Pb+Pb collisions at 158GeV/nucleon beam energy by the NA49 experiment. Particle yield ratios (p/pi, K/pi and Lambda/K^0_s) show an enhancement of the baryon/meson ratio for p_T>2GeV/c. The nuclear modification factor R_{CP} is extracted and compared to RHIC measurements and pQCD calculations.Comment: Quark Matter 2005 parallel section proceeding