Sind Arbeit und Produktion Mittel des Protests? Ist das Selbstherstellen eine unentdeckte politikwissenschaftliche Kategorie? Jens Thomas analysiert im Spannungsfeld eines Bedeutungsgewinns von ...Arbeit und eines Ansehensverlusts der Politik bislang unbeachtete Formen der Politikgestaltung und zeigt: Das Politische bahnt sich neue Wege fern eines institutionalisierten Politikbegriffs. Die von ihm in die Forschung eingeführte Kategorie der Politics of Self-Production politisiert Arbeit, entpolitisiert aber auch die Politik - und eröffnet einen neuen Blickwinkel auf die Zusammenhänge zwischen Selbermachen, Designproduktion und Nachhaltigkeit.
A number of topological structures for PAF-1 are compared with an amorphous structure for PAF-1, reproducing the ultrahigh surface area and pore volume observed experimentally. We compare the ...porosity properties of these structures and discuss potential structural strategies for increasing porosity and gas uptake properties. The PAF-1 network formation mechanism is simulated through use of an automated generation process, revealing the importance of the solvent in the resulting network structure and porosity properties. This opens up new rational design strategies and considerations for developing the next generation of porous framework materials.
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IJS, KILJ, NUK, PNG, UL, UM
Given its velocity dispersion, the early-type galaxy NGC 1600 has an unusually massive (M = 1.7 × 1010 M ) central supermassive black hole (SMBH) surrounded by a large core (rb = 0.7 kpc) with a ...tangentially biased stellar distribution. We present high-resolution equal-mass merger simulations including SMBHs to study the formation of such systems. The structural parameters of the progenitor ellipticals were chosen to produce merger remnants resembling NGC 1600. We test initial stellar density slopes of ∝ r−1 and ∝ r−3/2 and vary the initial SMBH masses from 8.5 × 108 to 8.5 × 109 M . With increasing SMBH mass, the merger remnants show a systematic decrease in central surface brightness, an increasing core size, and an increasingly tangentially biased central velocity anisotropy. Two-dimensional kinematic maps reveal decoupled, rotating core regions for the most massive SMBHs. The stellar cores form rapidly as the SMBHs become bound, while the velocity anisotropy develops more slowly after the SMBH binaries become hard. The simulated merger remnants follow distinct relations between the core radius and the sphere of influence, and the SMBH mass, similar to observed systems. We find a systematic change in the relations as a function of the progenitor density slope and present a simple scouring model reproducing this behavior. Finally, we find the best agreement with NGC 1600 using SMBH masses totaling the observed value of M = 1.7 × 1010 M . In general, density slopes of ∝ r−3/2 for the progenitor galaxies are strongly favored for the equal-mass merger scenario.
Holm 15A, the brightest cluster galaxy of the galaxy cluster Abell 85, has an ultradiffuse central region, ∼ 2 mag fainter than the faintest depleted core of any early-type galaxy (ETG) that has been ...dynamically modeled in detail. We use orbit-based, axisymmetric Schwarzschild models to analyze the stellar kinematics of Holm 15A from new high-resolution, wide-field spectral observations obtained with the Multi-Unit Spectroscopic Explorer at the Very Large Telescope. We find a supermassive black hole with a mass of ( 4.0 0.80 ) × 10 10 M at the center of Holm 15A. This is the most massive black hole with a direct dynamical detection in the local universe. We find that the distribution of stellar orbits is increasingly biased toward tangential motions inside the core. However, the tangential bias is less than that in other cored elliptical galaxies. We compare Holm 15A with N-body simulations of mergers between galaxies with black holes and find that the observed amount of tangential anisotropy and the shape of the light profile are consistent with a formation scenario where Holm 15A is the remnant of a merger between two ETGs with pre-existing depleted cores. We find that black hole masses in cored galaxies, including Holm 15A, scale inversely with the central stellar surface brightness and mass density. These correlations are independent of a specific parameterization of the light profile.
Abstract
We present the first systematic study of the detailed shapes of the line-of-sight velocity distributions (LOSVDs) in nine massive early-type galaxies (ETGs) using the novel nonparametric ...modeling code WINGFIT. High-signal spectral observations with the Multi-Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope allow us to measure between 40 and 400 individual LOSVDs in each galaxy at a signal-to-noise ratio level better than 100 per spectral bin and to trace the LOSVDs all the way out to the highest stellar velocities. We extensively discuss potential LOSVD distortions due to template mismatch and strategies to avoid them. Our analysis uncovers a plethora of complex, large-scale kinematic structures for the shapes of the LOSVDs. Most notably, in the centers of all ETGs in our sample, we detect faint, broad LOSVD “wings” extending the line-of-sight velocities,
v
los
, well beyond 3
σ
to
v
los
∼ ± 1000–1500 km s
−1
on both sides of the peak of the LOSVDs. These wings likely originate from point-spread function effects and contain velocity information about the very central unresolved regions of the galaxies. In several galaxies, we detect wings of similar shape also toward the outer parts of the MUSE field of view. We propose that these wings originate from faint halos of loosely bound stars around the ETGs, similar to the cluster-bound stellar envelopes found around many brightest cluster galaxies.
Crystallographers have an array of search‐model options for structure solution by molecular replacement (MR). The well established options of homologous experimental structures and regular ...secondary‐structure elements or motifs are increasingly supplemented by computational modelling. Such modelling may be carried out locally or may use pre‐calculated predictions retrieved from databases such as the EBI AlphaFold database. MrParse is a new pipeline to help to streamline the decision process in MR by consolidating bioinformatic predictions in one place. When reflection data are provided, MrParse can rank any experimental homologues found using eLLG, which indicates the likelihood that a given search model will work in MR. Inbuilt displays of predicted secondary structure, coiled‐coil and transmembrane regions further inform the choice of MR protocol. MrParse can also identify and rank homologues in the EBI AlphaFold database, a function that will also interest other structural biologists and bioinformaticians.
MrParse is a software package designed to aid decision making in molecular replacement (MR). It performs a sequence search to find search models, not only in the PDB, as would conventionally be performed, but also in the EBI AlphaFold database, and provides a series of analyses relevant to MR such as crystal pathology detection and sequence analysis.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
Evidence from different probes of the stellar initial mass function (IMF) of massive early-type galaxies (ETGs) has repeatedly converged on IMFs more bottom heavy than in the Milky Way (MW). ...This consensus has come under scrutiny due to often contradictory results from different methods on the level of individual galaxies. In particular, a number of strong lensing probes are ostensibly incompatible with a non-MW IMF. Radial gradients of the IMF—related to gradients of the stellar mass-to-light ratio ϒ—can potentially resolve this issue. We construct Schwarzschild models allowing for ϒ-gradients in seven massive ETGs with MUSE and SINFONI observations. We find dynamical evidence that ϒ increases toward the center for all ETGs. The gradients are confined to subkiloparsec scales. Our results suggest that constant-ϒ models may overestimate the stellar mass of galaxies by up to a factor of 1.5. For all except one galaxy, we find a radius where the total dynamical mass has a minimum. This minimum places the strongest constraints on the IMF outside the center and appears at roughly 1 kpc. We consider the IMF at this radius characteristic for the main body of each ETG. In terms of the IMF mass-normalization
α
relative to a Kroupa IMF, we find on average an MW-like IMF 〈
α
main
〉 = 1.03 ± 0.19. In the centers, we find concentrated regions with increased mass normalizations that are less extreme than previous studies suggested, but still point to a Salpeter-like IMF, 〈
α
cen
〉 = 1.54 ± 0.15.
Massive early-type galaxies represent the modern day remnants of the earliest major star formation episodes in the history of the universe. These galaxies are central to our understanding of the ...evolution of cosmic structure, stellar populations, and supermassive black holes, but the details of their complex formation histories remain uncertain. To address this situation, we have initiated the MASSIVE Survey, a volume-limited, multi-wavelength, integral-field spectroscopic (IFS) and photometric survey of the structure and dynamics of the ~100 most massive early-type galaxies within a distance of 108 Mpc. This survey probes a stellar mass range M* gap 10 super(11.5) M sub(middot in circle) and diverse galaxy environments that have not been systematically studied to date. Our wide-field IFS data cover about two effective radii of individual galaxies, and for a subset of them, we are acquiring additional IFS observations on sub-arcsecond scales with adaptive optics. We are also acquiring deep K-band imaging to trace the extended halos of the galaxies and measure accurate total magnitudes. Dynamical orbit modeling of the combined data will allow us to simultaneously determine the stellar, black hole, and dark matter halo masses. The primary goals of the project are to constrain the black hole scaling relations at high masses, investigate systematically the stellar initial mass function and dark matter distribution in massive galaxies, and probe the late-time assembly of ellipticals through stellar population and kinematical gradients. In this paper, we describe the MASSIVE sample selection, discuss the distinct demographics and structural and environmental properties of the selected galaxies, and provide an overview of our basic observational program, science goals and early survey results.
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