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MEASUREMENTS OF THE CORONAL ACCELERATION REGION OF A SOLAR FLARE
Krucker, Sä,m,Hudson, H. S.,Glesener, L.,White, S. M.,Masuda, S.,Wuelser, J.-P.,Lin, R. P. IOP Publishing 2010 The Astrophysical journal Vol.714 No.2
<P>The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Nobeyama Radioheliograph (NoRH) are used to investigate coronal hard X-ray and microwave emissions in the partially disk-occulted solar flare of 2007 December 31. The STEREO mission provides EUV images of the flare site at different viewing angles, establishing a two-ribbon flare geometry and occultation heights of the RHESSI and NoRH observations of similar to 16 Mm and similar to 25 Mm, respectively. Despite the occultation, intense hard X-ray emission up to similar to 80 keV occurs during the impulsive phase from a coronal source that is also seen in microwaves. The hard X-ray and microwave source during the impulsive phase is located similar to 6 Mm above thermal flare loops seen later at the soft X-ray peak time, similar in location to the above-the-loop-top source in the Masuda flare. A single non-thermal electron population with a power-law distribution (with spectral index of similar to 3.7 from similar to 16 keV up to the MeV range) radiating in both bremsstrahlung and gyrosynchrotron emission can explain the observed hard X-ray and microwave spectrum, respectively. This clearly establishes the non-thermal nature of the above-the-loop-top source. The large hard X-ray intensity requires a very large number (>5 x 10(35) above 16 keV for the derived upper limit of the ambient density of similar to 8 x 10(9) cm(-3)) of suprathermal electrons to be present in this above-the-loop-top source. This is of the same order of magnitude as the number of ambient thermal electrons. We show that collisional losses of these accelerated electrons would heat all ambient electrons to superhot temperatures (tens of keV) within seconds. Hence, the standard scenario, with hard X-rays produced by a beam comprising the tail of a dominant thermal core plasma, does not work. Instead, all electrons in the above-the-loop-top source seem to be accelerated, suggesting that the above-the-loop-top source is itself the electron acceleration region.</P>
Microscopic control ofSi29nuclear spins near phosphorus donors in silicon
Jä,rvinen, J.,Zvezdov, D.,Ahokas, J.,Sheludyakov, S.,Vainio, O.,Lehtonen, L.,Vasiliev, S.,Fujii, Y.,Mitsudo, S.,Mizusaki, T.,Gwak, M.,Lee, SangGap,Lee, Soonchil,Vlasenko, L. American Physical Society 2015 Physical review. B, Condensed matter and materials Vol.92 No.12
MEGAMASER DISKS REVEAL A BROAD DISTRIBUTION OF BLACK HOLE MASS IN SPIRAL GALAXIES
Greene, J. E.,Seth, A.,Kim, M.,Lä,sker, R.,Goulding, A.,Gao, F.,Braatz, J. A.,Henkel, C.,Condon, J.,Lo, K. Y.,Zhao, W. American Astronomical Society 2016 ASTROPHYSICAL JOURNAL LETTERS - Vol.826 No.2
<P>We use new precision measurements of black hole (BH) masses from water megamaser disks to investigate scaling relations between macroscopic galaxy properties and supermassive BH mass. The megamaser-derived BH masses span 10(6)-10(8) M-circle dot, while all the galaxy properties that we examine (including total stellar mass, central mass density, and central velocity dispersion) lie within a narrower range. Thus, no galaxy property correlates tightly with M-BH in similar to L* spiral galaxies as traced by megamaser disks. Of them all, stellar velocity dispersion provides the tightest relation, but at fixed sigma* the mean megamaser M-BH are offset by -0.6 +/- 0.1 dex relative to early-type galaxies. Spiral galaxies with non-maser dynamical BH masses do not appear to show this offset. At low mass, we do not yet know the full distribution of BH mass at fixed galaxy property; the non-maser dynamical measurements may miss the low-mass end of the BH distribution due to an inability to resolve their spheres of influence and/or megamasers may preferentially occur in lower-mass BHs.</P>
Unusual A2142 supercluster with a collapsing core: distribution of light and mass
Einasto, Maret,Gramann, Mirt,Saar, Enn,Liivamä,gi, Lauri Juhan,Tempel, Elmo,Nevalainen, Jukka,Heinä,mä,ki, Pekka,Park, Changbom,Einasto, Jaan EDP Sciences 2015 Astronomy and astrophysics Vol.580 No.-
<P>Context. Superclusters of galaxies can be used to test cosmological models of the formation and evolution of the largest structures in the cosmic web, and of galaxy and cluster evolution in superclusters. Aims. We study the distribution, masses, and dynamical properties of galaxy groups in the A2142 supercluster. Methods. We analyse the global luminosity density distribution in the supercluster and divide the supercluster into the high-density core and the low-density outskirts regions. We find galaxy groups and filaments in these regions, calculate their masses and mass-to-light ratios and analyse their dynamical state with 1D and 3D statistics. We use the spherical collapse model to study the dynamical state of the supercluster. Results. In the A2142 supercluster rich groups and clusters lie along an almost straight line forming the 50h<SUP>−1</SUP> Mpc long main body of the supercluster. The A2142 supercluster has a very high density core surrounded by lower-density outskirts. The total estimated mass of the supercluster is M<SUB>est</SUB> = 6.2 × 10<SUP>15</SUP> M<SUB>⊙</SUB>. More than a half of groups with at least ten member galaxies in the supercluster lie in the high-density core of the supercluster, centred at the X-ray cluster A2142. Most of the groups in the core region are multimodal. In the outskirts of the supercluster, the number of groups is larger than in the core, and groups are poorer. The orientation of the axis of the cluster A2142 follows the orientations of its X-ray substructures and radio halo, and is aligned along the supercluster axis. The high-density core of the supercluster with the global density D8≥17 and perhaps with D8 ≥13 may have started to collapse. Conclusions. A2142 supercluster with collapsing core and straight body, is an unusual object among superclusters. In the course of the future evolution, the supercluster may split into several systems.</P>
Chatrchyan, S.,Khachatryan, V.,Sirunyan, A. M.,Tumasyan, A.,Adam, W.,Bergauer, T.,Dragicevic, M.,Erö,, J.,Fabjan, C.,Friedl, M.,Frü,hwirth, R.,Ghete, V. M.,Hammer, J.,Hä,nsel, S.,Hoch, M. Springer-Verlag 2011 Journal of high energy physics Vol.2011 No.7
<P>The t (t) over bar production cross section and top quark mass are measured in proton-proton collisions at root s = 7 TeV in a data sample corresponding to an integrated luminosity of 36 pb(-1) collected by the CMS experiment. The measurements are performed in events with two leptons (electrons or muons) in the final state. Results of the cross section measurement in events with and without b-quark identification are obtained and combined. The measured value is sigma(tt) - 168 +/- 18 (stat:) +/- 14 (syst:) +/- 7 (lumi:) pb, consistent with predictions from the standard model. The top quark mass m(top) is reconstructed with two different methods, a full kinematic analysis and a matrix weighting technique. The combination yields a measurement of m(top) = 175.5 +/- 4.6 (stat:) +/- 4: 6 (syst:) GeV/c(2).</P>
Induced versus intrinsic magnetic moments in ultrafast magnetization dynamics
Hofherr, M.,Moretti, S.,Shim, J.,Hä,user, S.,Safonova, N. Y.,Stiehl, M.,Ali, A.,Sakshath, S.,Kim, J. W.,Kim, D. H.,Kim, H. J.,Hong, J. I.,Kapteyn, H. C.,Murnane, M. M.,Cinchetti, M.,Steil, D.,Math American Physical Society 2018 Physical Review B Vol.98 No.17
Hybrid circuit cavity quantum electrodynamics with a micromechanical resonator
Pirkkalainen, J.-M.,Cho, S. U.,Li, Jian,Paraoanu, G. S.,Hakonen, P. J.,Sillanpä,ä,, M. A. Nature Publishing Group, a division of Macmillan P 2013 Nature Vol.494 No.7436
Hybrid quantum systems with inherently distinct degrees of freedom have a key role in many physical phenomena. Well-known examples include cavity quantum electrodynamics, trapped ions, and electrons and phonons in the solid state. In those systems, strong coupling makes the constituents lose their individual character and form dressed states, which represent a collective form of dynamics. As well as having fundamental importance, hybrid systems also have practical applications, notably in the emerging field of quantum information control. A promising approach is to combine long-lived atomic states with the accessible electrical degrees of freedom in superconducting cavities and quantum bits (qubits). Here we integrate circuit cavity quantum electrodynamics with phonons. Apart from coupling to a microwave cavity, our superconducting transmon qubit, consisting of tunnel junctions and a capacitor, interacts with a phonon mode in a micromechanical resonator, and thus acts like an atom coupled to two different cavities. We measure the phonon Stark shift, as well as the splitting of the qubit spectral line into motional sidebands, which feature transitions between the dressed electromechanical states. In the time domain, we observe coherent conversion of qubit excitation to phonons as sideband Rabi oscillations. This is a model system with potential for a quantum interface, which may allow for storage of quantum information in long-lived phonon states, coupling to optical photons or for investigations of strongly coupled quantum systems near the classical limit.