scholarly journals The inner gas mass–temperature profile in the core of nearby galaxy clusters

2020 ◽  
Vol 497 (1) ◽  
pp. 1256-1262
Author(s):  
Haonan Liu ◽  
Andrew C Fabian ◽  
Ciro Pinto

ABSTRACT We present a mass–temperature profile of gas within the central 10 kpc of a small sample of cool core clusters. The mass of the hottest gas phases, at 1.5 and 0.7 keV, is determined from X-ray spectra from the XMM Reflection Grating Spectrometers. The masses of the partially ionized atomic and the molecular phases are obtained from published H α and CO measurements. We find that the mass of gas at 0.7 keV in a cluster is remarkably similar to that of the molecular gas. Assuming pressure equilibrium between the phases, this means that they occupy volumes differing by 105. The molecular gas is located within the H α nebula which is often filamentary and coincides radially and in position angle with the soft X-ray emitting gas.

2019 ◽  
Vol 15 (S359) ◽  
pp. 180-181
Author(s):  
Konstantinos Kolokythas ◽  

AbstractMuch of the evolution of galaxies takes place in groups where feedback has the greatest impact on galaxy formation and evolution. We summarize results from studies of the central brightest group early-type galaxies (BGEs) of an optically selected, statistically complete sample of 53 nearby groups (<80 Mpc; CLoGS sample), observed in radio 235/610 MHz (GMRT), CO (IRAM/APEX) and X-ray (Chandra and XMM-Newton) frequencies. We characterize the radio-AGN population of the BGEs, their group X-ray environment and examine the jet energetics impact on the intra-group gas. We discuss the relation between the radio properties of the BGEs and their group X-ray environment along with the relation between the molecular gas content and the star formation that BGEs present. We conclude that AGN feedback in groups can appear as relatively gentle near-continuous thermal regulation, but also as extreme AGN activity which could potentially shut down cooling for longer periods.


2020 ◽  
Vol 638 ◽  
pp. A53
Author(s):  
Nastaran Fazeli ◽  
Gerold Busch ◽  
Andreas Eckart ◽  
Françoise Combes ◽  
Persis Misquitta ◽  
...  

Gas inflow processes in the vicinity of galactic nuclei play a crucial role in galaxy evolution and supermassive black hole growth. Exploring the central kiloparsec of galaxies is essential to shed more light on this subject. We present near-infrared H- and K-band results of the nuclear region of the nearby galaxy NGC 1326, observed with the integral-field spectrograph SINFONI mounted on the Very Large Telescope. The field of view covers 9″ × 9″ (650 × 650 pc2). Our work is concentrated on excitation conditions, morphology, and stellar content. The nucleus of NGC 1326 was classified as a LINER, however in our data we observed an absence of ionised gas emission in the central r ∼ 3″. We studied the morphology by analysing the distribution of ionised and molecular gas, and thereby detected an elliptically shaped, circum-nuclear star-forming ring at a mean radius of 300 pc. We estimate the starburst regions in the ring to be young with dominating ages of < 10 Myr. The molecular gas distribution also reveals an elongated east to west central structure about 3″ in radius, where gas is excited by slow or mild shock mechanisms. We calculate the ionised gas mass of 8 × 105 M⊙ completely concentrated in the nuclear ring and the warm molecular gas mass of 187 M⊙, from which half is concentrated in the ring and the other half in the elongated central structure. The stellar velocity fields show pure rotation in the plane of the galaxy. The gas velocity fields show similar rotation in the ring, but in the central elongated H2 structure they show much higher amplitudes and indications of further deviation from the stellar rotation in the central 1″ aperture. We suggest that the central 6″ elongated H2 structure might be a fast-rotating central disc. The CO(3–2) emission observations with the Atacama Large Millimeter/submillimeter Array reveal a central 1″ torus. In the central 1″ of the H2 velocity field and residual maps, we find indications for a further decoupled structure closer to a nuclear disc, which could be identified with the torus surrounding the supermassive black hole.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 380
Author(s):  
Martin Traintinger ◽  
Roman Christopher Kerschbaumer ◽  
Bernhard Lechner ◽  
Walter Friesenbichler ◽  
Thomas Lucyshyn

Injection molding of rubber compounds is an easily conducted yet sophisticated method for rubber processing. Simulation software is used to examine the optimal process conditions, identify failure scenarios, and save resources. Due to the complexity of the entire process, various aspects have to be considered in the numerical approach. This contribution focused on a comparison of process simulations with various definitions of the material’s inlet temperature, ranging from a stepwise increase, but constant temperature, to an exact axial mass temperature profile prior to injection. The latter was obtained with a specially designed, unique test stand consisting of a plasticizing cylinder equipped with pressure sensors, a throttle valve for pressure adjustments, and a measurement bar with thermocouples for the determination of the actual state of the mass temperature. For the verification of the theoretical calculations, practical experiments were conducted on a rubber injection molding machine equipped with the mold used in the simulation. The moldings, obtained at different vulcanization time, were characterized mechanically and the results were normalized to a relative degree of cure in order to enable comparison of the real process and the simulation. Considering the actual state of the mass temperature, the simulation showed an excellent correlation of the measured and calculated mass temperatures in the cold runner. Additionally, the relative degree of cure was closer to reality when the mass temperature profile after dosing was applied in the simulation.


1980 ◽  
Vol 35 (5) ◽  
pp. 564-567 ◽  
Author(s):  
Franz Lux ◽  
Oskar F. Beck ◽  
Heinz Krauß ◽  
David Brown ◽  
Tze C. Tso

Abstract Spectroscopically pure PaPc2 has been prepared by reaction between PaI4 · 4 CH3CN and o-phthalic acid dinitrile in 1-chloronaphthalene followed by sublimation at 5 · 10-3 Pa in a temperature profile with three clearly defined zones (520 °C/350 °C/room temperature). This procedure gives a product almost completely free of H2Pc impurity which is known to have been present in previously reported complexes of the type AnPc2. Thus, the trace of H2Pc in the substance could only be detected by derivative spectroscopy. X-ray powder diffraction shows the compound to be isostructural with ThPc2 and UPc2. The ligand spectrum is typical of AnPc2 complexes, f-f Bands observed in a solid state spectrum provide additional proof that the compound is PaIV Pc2.


2012 ◽  
Vol 08 ◽  
pp. 151-162 ◽  
Author(s):  
ALAN P. MARSCHER

Relativistic jets in blazars on parsec scales can now be explored with direct imaging at radio wavelengths as well as observations of time variability of flux and linear polarization at various wavebands. The results thus far suggest that the millimeter-wave "core" is usually a standing, conical shock and that the jet plasma is turbulent. Disturbances and turbulent plasma crossing the standing shock can explain much of the observed variability, as well as the appearance of bright knots moving down the jet at superluminal apparent speeds. The core, located parsecs downstream of the central engine, appears to be the site of many of the outbursts observed at optical, X-ray, and γ-ray energies. Rotations in the optical polarization position angle prior to the passage of a knot through the millimeter-wave core provide evidence for helical magnetic fields that accelerate and collimate the jet before turbulence tangles the fields.


Author(s):  
Neil Gehrels

Since its launch on 20 November 2004, the Swift mission has been detecting approximately 100 gamma-ray bursts (GRBs) each year, and immediately (within approx. 90 s) starting simultaneous X-ray and UV/optical observations of the afterglow. It has already collected an impressive database, including prompt emission to higher sensitivities than BATSE, uniform monitoring of afterglows and a rapid follow-up by other observatories notified through the GCN. Advances in our understanding of short GRBs have been spectacular. The detection of X-ray afterglows has led to accurate localizations and the conclusion that short GRBs can occur in non-star-forming galaxies or regions, whereas long GRBs are strongly concentrated within the star-forming regions. This is consistent with the NS merger model. Swift has greatly increased the redshift range of GRB detection. The highest redshift GRBs, at z ∼5–6, are approaching the era of reionization. Ground-based deep optical spectroscopy of high redshift bursts is giving metallicity measurements and other information on the source environment to a much greater distance than other techniques. The localization of GRB 060218 to a nearby galaxy, and the association with SN 2006aj, added a valuable member to the class of GRBs with detected supernova.


2021 ◽  
Vol 922 (2) ◽  
pp. L29
Author(s):  
Jianrui Li ◽  
Bjorn H. C. Emonts ◽  
Zheng Cai ◽  
J. Xavier Prochaska ◽  
Ilsang Yoon ◽  
...  

Abstract The link between the circumgalactic medium (CGM) and the stellar growth of massive galaxies at high-z depends on the properties of the widespread cold molecular gas. As part of the SUPERCOLD-CGM survey (Survey of Protocluster ELANe Revealing CO/[C i] in the Lyα-Detected CGM), we present the radio-loud QSO Q1228+3128 at z = 2.2218, which is embedded in an enormous Lyα nebula. ALMA+ACA observations of CO(4–3) reveal both a massive molecular outflow, and a more extended molecular gas reservoir across ∼100 kpc in the CGM, each containing a mass of M H2 ∼ 4–5 × 1010 M ⊙. The outflow and molecular CGM are aligned spatially, along the direction of an inner radio jet. After reanalysis of Lyα data of Q1228+3128 from the Keck Cosmic Web Imager, we found that the velocity of the extended CO agrees with the redshift derived from the Lyα nebula and the bulk velocity of the massive outflow. We propose a scenario where the radio source in Q1228+3128 is driving the molecular outflow and perhaps also enriching or cooling the CGM. In addition, we found that the extended CO emission is nearly perpendicular to the extended Lyα nebula spatially, indicating that the two gas phases are not well mixed, and possibly even represent different phenomena (e.g., outflow versus infall). Our results provide crucial evidence in support of predicted baryonic recycling processes that drive the early evolution of massive galaxies.


Author(s):  
Kyoko Onishi ◽  
Satoru Iguchi ◽  
Timothy Davis ◽  
Martin Bureau ◽  
Michele Cappellari ◽  
...  

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