Exzellenzcluster Universe

Garching bei München, Germany

Exzellenzcluster Universe

Garching bei München, Germany

Time filter

Source Type

Wong K.C.,Japan National Astronomical Observatory | Wong K.C.,Academia Sinica, Taiwan | Suyu S.H.,Academia Sinica, Taiwan | Suyu S.H.,Max Planck Institute for Astrophysics | And 16 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2017

Strong gravitational lenses with measured time delays between the multiple images allow a direct measurement of the time-delay distance to the lens, and thus a measure of cosmological parameters, particularly the Hubble constant, H0. We present a blind lens model analysis of the quadruply imaged quasar lens HE 0435-1223 using deep Hubble Space Telescope imaging, updated time-delay measurements from the COSmological MOnitoring of GRAvItational Lenses (COSMOGRAIL), a measurement of the velocity dispersion of the lens galaxy based on Keck data, and a characterization of the mass distribution along the line of sight. HE 0435-1223 is the third lens analysed as a part of the H0 Lenses in COSMOGRAIL's Wellspring (H0LiCOW) project. We account for various sources of systematic uncertainty, including the detailed treatment of nearby perturbers, the parametrization of the galaxy light and mass profile, and the regions used for lens modelling. We constrain the effective timedelay distance to be DΔt = 2612+208 -191 Mpc, a precision of 7.6 per cent. From HE 0435-1223 alone, we infer a Hubble constant of H0 = 73.1+5.7 -6.0 km s-1 Mpc-1 assuming a flat ΛCDM cosmology. The cosmographic inference based on the three lenses analysed by H0LiCOW to date is presented in a companion paper (H0LiCOW Paper V). © 2016 The Authors.


Bonvin V.,Ecole Polytechnique Federale de Lausanne | Courbin F.,Ecole Polytechnique Federale de Lausanne | Suyu S.H.,Max Planck Institute for Astrophysics | Suyu S.H.,TU Munich | And 20 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2017

We present a new measurement of the Hubble Constant H0 and other cosmological parameters based on the joint analysis of three multiply imaged quasar systems with measured gravitational time delays. First, we measure the time delay of HE 0435-1223 from 13-yr light curves obtained as part of the COSMOGRAIL project. Companion papers detail the modelling of the main deflectors and line-of-sight effects, and how these data are combined to determine the time-delay distance of HE 0435-1223. Crucially, the measurements are carried out blindly with respect to cosmological parameters in order to avoid confirmation bias. We then combine the time-delay distance of HE 0435-1223 with previous measurements from systems B1608+656 and RXJ1131-1231 to create a Time Delay Strong Lensing probe (TDSL). In flat Λ cold dark matter (ΛCDM) with free matter and energy density, we find H0 = 71.9-3.0 +2.4 km s-1 Mpc-1 and ΩΛ = 0.62-0.35 +0.24. This measurement is completely independent of, and in agreement with, the local distance ladder measurements of H0. We explore more general cosmological models combining TDSL with other probes, illustrating its power to break degeneracies inherent to other methods. The joint constraints from TDSL and Planck are H0 = 69.2-2.2 +1.4 km s-1 Mpc-1, ΩΛ = 0.70-0.01 +0.01 and Ωk = 0.003-0.006 +0.004 in open ΛCDM and H0 = 79.0-4.2 +4.4 km s-1 Mpc-1, Ωde = 0.77-0.03 +0.02 and w = -1.38-0.16 +0.14 in flat wCDM. In combination with Planck and baryon acoustic oscillation data, when relaxing the constraints on the numbers of relativistic species we find Neff = 3.34-0.21 +0.21 in NeffΛCDM and when relaxing the total mass of neutrinos we find ∑mν =0.182 eV in mνλCDM. Finally, in an open wCDM in combination with Planck and cosmic microwave background lensing, we find H0 = 77.9-4.2 +5.0 km s-1 Mpc-1, Ωde = 0.77-0.03 +0.03, Ωk = -0.003-0.004 +0.004 and w = -1.37-0.23 +0.18. © 2016 The Authors.


Steininger T.,Max Planck Institute for Astrophysics | Steininger T.,Ludwig Maximilians University of Munich | Greiner M.,Max Planck Institute for Astrophysics | Greiner M.,Ludwig Maximilians University of Munich | And 4 more authors.
Journal of Big Data | Year: 2016

We introduce d2o, a Python module for cluster-distributed multi-dimensional numerical arrays. It acts as a layer of abstraction between the algorithm code and the data-distribution logic. The main goal is to achieve usability without losing numerical performance and scalability. d2o’s global interface is similar to the one of a numpy.ndarray, whereas the cluster node’s local data is directly accessible for use in customized high-performance modules. d2o is written in pure Python which makes it portable and easy to use and modify. Expensive operations are carried out by dedicated external libraries like numpy and mpi4py. The performance of d2o is on a par with numpy for serial applications and scales well when moving to an MPI cluster. d2o is open-source software available under the GNU General Public License v3 (GPL-3) at https://gitlab.mpcdf.mpg.de/ift/D2O. © 2016, The Author(s).


Koepferl C.M.,Ludwig Maximilians University of Munich | Ercolano B.,Ludwig Maximilians University of Munich | Ercolano B.,Exzellenzcluster Universe | Dale J.,Ludwig Maximilians University of Munich | And 5 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2013

The time-scale over which and the modality by which young stellar objects (YSOs) disperse their circumstellar discs dramatically influence the eventual formation and evolution of planetary systems. By means of extensive radiative transfer modelling, we have developed a new set of diagnostic diagrams in the infrared colour-colour plane (K - [24] versus K - [8]), to aid with the classification of the evolutionary stage of YSOs from photometric observations. Our diagrams allow the differentiation of sources with unevolved (primordial) discs from those evolving according to different clearing scenarios (e.g. homologous depletion versus inside-out dispersal), as well as from sources that have already lost their disc. Classification of over 1500 sources in 15 nearby star-forming regions reveals that approximately 39 per cent of the sources lie in the primordial disc region, whereas between 31 and 32 per cent disperse from the inside-out and up to 22 per cent of the sources have already lost their disc. Less than 2 per cent of the objects in our sample lie in the homogeneous draining regime. Time-scales for the transition phase are estimated to be typically a few 105 yr independent of stellar mass. Therefore, regardless of spectral type, we conclude that currently available infrared photometric surveys point to fast (of the order of 10 per cent of the global disc lifetime) inside-out clearing as the preferred mode of disc dispersal. © 2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.


Saglia R.P.,Max Planck Institute for Extraterrestrial Physics | Saglia R.P.,Universitats Sternwarte Munich | Opitsch M.,Max Planck Institute for Extraterrestrial Physics | Opitsch M.,Universitats Sternwarte Munich | And 16 more authors.
Astrophysical Journal | Year: 2016

We investigate the correlations between the black hole (BH) mass MBH, the velocity dispersion σ, the bulge mass MBu, the bulge average spherical density , and its spherical half-mass radius rh, constructing a database of 97 galaxies (31 core ellipticals, 17 power-law ellipticals, 30 classical bulges, and 19 pseudobulges) by joining 72 galaxies from the literature to 25 galaxies observed during our recent SINFONI BH survey. For the first time we discuss the full error covariance matrix. We analyze the well-known MBH-σ and MBH-MBu relations and establish the existence of statistically significant correlations between MBu and rh and anticorrelations between MBu and . We establish five significant bivariate correlations (MBH-σ-ρh, MBH-σ-rh, MBH-MBu-σ, MBH-MBu-ρh, MBH-MBu-rh) that predict MBH of 77 core and power-law ellipticals and classical bulges with measured and intrinsic scatter as small as dex and dex, respectively, or 0.26 dex when the subsample of 45 galaxies defined by Kormendy & Ho is considered. In contrast, pseudobulges have systematically lower MBH but approach the predictions of all of the above relations at spherical densities or scale lengths . These findings fit in a scenario of coevolution of BH and classical-bulge masses, where core ellipticals are the product of dry mergers of power-law bulges and power-law ellipticals and bulges the result of (early) gas-rich mergers and of disk galaxies. In contrast, the (secular) growth of BHs is decoupled from the growth of their pseudobulge hosts, except when (gas) densities are high enough to trigger the feedback mechanism responsible for the existence of the correlations between MBH and galaxy structural parameters. © 2016. The American Astronomical Society. All rights reserved.


Hanggi P.,University of Augsburg | Hilbert S.,Exzellenzcluster Universe | Dunkel J.,Massachusetts Institute of Technology
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2016

Depending on the exact experimental conditions, the thermodynamic properties of physical systems can be related to one or more thermostatistical ensembles. Here, we survey the notion of thermodynamic temperature in different statistical ensembles, focusing in particular on subtleties that arise when ensembles become non-equivalent. The 'mother' of all ensembles, the microcanonical ensemble, uses entropy and internal energy (the most fundamental, dynamically conserved quantity) to derive temperature as a secondary thermodynamic variable. Over the past century, some confusion has been caused by the fact that several competing microcanonical entropy definitions are used in the literature, most commonly the volume and surface entropies introduced by Gibbs. It can be proved, however, that only the volume entropy satisfies exactly the traditional form of the laws of thermodynamics for a broad class of physical systems, including all standard classical Hamiltonian systems, regardless of their size. This mathematically rigorous fact implies that negative 'absolute' temperatures and Carnot efficiencies more than 1 are not achievable within a standard thermodynamical framework. As an important offspring of microcanonical thermostatistics, we shall briefly consider the canonical ensemble and comment on the validity of the Boltzmann weight factor.We conclude by addressing open mathematical problems that arise for systems with discrete energy spectra. © 2016 The Author(s).


Hilbert S.,Exzellenzcluster Universe | Hanggi P.,University of Augsburg | Dunkel J.,Massachusetts Institute of Technology
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2014

The recent experimental realization of exotic matter states in isolated quantum systems and the ensuing controversy about the existence of negative absolute temperatures demand a careful analysis of the conceptual foundations underlying microcanonical thermostatistics. Here we provide a detailed comparison of the most commonly considered microcanonical entropy definitions, focusing specifically on whether they satisfy or violate the zeroth, first, and second laws of thermodynamics. Our analysis shows that, for a broad class of systems that includes all standard classical Hamiltonian systems, only the Gibbs volume entropy fulfills all three laws simultaneously. To avoid ambiguities, the discussion is restricted to exact results and analytically tractable examples. © 2014 American Physical Society.


PubMed | University of Augsburg, Massachusetts Institute of Technology and Exzellenzcluster Universe
Type: Journal Article | Journal: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences | Year: 2016

Depending on the exact experimental conditions, the thermodynamic properties of physical systems can be related to one or more thermostatistical ensembles. Here, we survey the notion of thermodynamic temperature in different statistical ensembles, focusing in particular on subtleties that arise when ensembles become non-equivalent. The mother of all ensembles, the microcanonical ensemble, uses entropy and internal energy (the most fundamental, dynamically conserved quantity) to derive temperature as a secondary thermodynamic variable. Over the past century, some confusion has been caused by the fact that several competing microcanonical entropy definitions are used in the literature, most commonly the volume and surface entropies introduced by Gibbs. It can be proved, however, that only the volume entropy satisfies exactly the traditional form of the laws of thermodynamics for a broad class of physical systems, including all standard classical Hamiltonian systems, regardless of their size. This mathematically rigorous fact implies that negative absolute temperatures and Carnot efficiencies more than 1 are not achievable within a standard thermodynamical framework. As an important offspring of microcanonical thermostatistics, we shall briefly consider the canonical ensemble and comment on the validity of the Boltzmann weight factor. We conclude by addressing open mathematical problems that arise for systems with discrete energy spectra.


Moll A.,Max Planck Institute for Physics | Moll A.,Exzellenzcluster Universe
Journal of Physics: Conference Series | Year: 2011

The future of CP-Violation experiments is to begin in 2014 with the launch of the SuperKEKB collider in Tsukuba, Japan. As a part of this process the BELLE experiment will undergo an upgrade, giving rise to the BELLE II experiment. The BELLE II detector will include improvements and redesigns of various subdetectors, as well as the addition of an entire new subdetector for precise vertexing. In order to reflect these changes in the existing BELLE software framework, major modifications of nearly all parts of the software would have been necessary. As a result the decision was made to completely rewrite the software framework. In this article the main concepts of the new framework and the applied technologies are presented.


De Gasperin F.,Max Planck Institute for Astrophysics | De Gasperin F.,Exzellenzcluster Universe | Merloni A.,Exzellenzcluster Universe | Merloni A.,Max Planck Institute for Extraterrestrial Physics | And 4 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2011

We present the results of the analysis of a sample of 17 low-luminosity (LX≲ 1042ergs-1), radio-loud active galactic nuclei in massive galaxies. The sample is extracted from the Sloan Digital Sky Survey data base and it spans uniformly a wide range in optical [Oiii] emission line and radio luminosity, but within a narrow redshift range (0.05 < z < 0.11) and a narrow supermassive black hole mass range (∼108M⊙). For these sources we measured core X-ray emission with the Chandra X-ray Telescope and radio emission with the Very Large Array. Our main goal is to establish which emission component, if any, can be regarded as the most reliable accretion/jet-power estimator at these regimes. In order to do so, we studied the correlation between emission-line properties, radio luminosity, radio spectral slopes and X-ray luminosity, as well as more complex multivariate relations involving black hole mass, such as the Fundamental Plane of black hole activity. We find that 15 out of 17 sources of our sample can be classified as low-excitation galaxies (LEGs), and their observed properties suggest X-ray and radio emission to originate from the jet basis. We also find that X-ray emission does not appear to be affected by nuclear obscuration and can be used as a reliable jet-power estimator. More generally, X-ray, radio and optical emission appear to be related, although no tight correlation is found. In accordance with a number of recent studies of this class of objects, these findings may be explained by a lack of cold (molecular) gaseous structures in the innermost region of these massive galaxies. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.

Loading Exzellenzcluster Universe collaborators
Loading Exzellenzcluster Universe collaborators