The cooling flow cluster Hydra A was observed during the orbital activation and calibration phase of Chandra Observatory. While X-ray image exhibits complex structure in central region as reported McNamara et al., large-scale morphology is fairly smooth. spectroscopic analysis ACIS data shows that gas temperature increases outward, reaches a maximum 4 keV at 200 kpc, then decreases slightly larger radii. distribution heavy elements nonuniform, with factor 2 increase Fe Si abundances within...

view Abstract Citations (245) References (55) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Cosmological Implications of ROSAT Observations Groups and Clusters Galaxies David, Laurence P. ; Jones, Christine Forman, William We have combined PSPC optical observations a sample groups clusters galaxies to determine the fundamental parameters these systems (e.g., dark matter distribution, gas mass fraction, baryon mass-to-light ratio, ratio total-to- luminous...

New Chandra X-ray data and extensive optical spectroscopy, obtained with AAOmega on the 3.9 m Anglo-Australian Telescope, are used to study complex merger taking place in galaxy cluster Abell 2744. Combining our spectra from literature provides a catalog of 1237 redshifts for extragalactic objects lying within 15' center. From these, we confirm 343 members projected 3 Mpc positions velocities, identify two major substructures, corresponding remnants subclusters. The new consistent post core...

The radio source Hercules A resides at the center of a cooling flow cluster galaxies redshift z = 0.154. Chandra X-ray image reveals shock front in intracluster medium (ICM) surrounding source, about 160 kpc from active galactic nucleus (AGN) that hosts it. has Mach number 1.65, making it strongest cluster-scale shocks driven by an AGN outburst found so far. age is ≃5.9 × 107 yr, its energy ~3 1061 ergs, and mean power ~1.6 1046 ergs s-1. As for other large outbursts clusters, this...

Luminous X-ray gas coronae in the dark matter halos of massive spiral galaxies are a fundamental prediction structure formation models, yet only few such have been detected so far. In this paper, we study hot beyond optical disks two "normal" spirals, NGC 1961 and 6753. Based on XMM-Newton observations, gaseous emission is to ∼60 kpc—well their radii. The has best-fit temperature kT ∼ 0.6 keV an abundance ∼0.1 Solar, exhibits fairly uniform distribution, suggesting that quasi-static resides...

We present the Complete Local-Volume Groups Sample (CLoGS), a statistically complete optically-selected sample of 53 groups within 80 Mpc. Our goal is to combine X-ray, radio and optical data investigate relationship between member galaxies, their active nuclei, hot intra-group medium (IGM). describe selection, define 26-group high-richness subsample containing at least 4 optically bright (log L_B>=10.2 LBsol) report results XMM-Newton Chandra observations these systems. find that 14 26 are...

We present ALMA Band 6 observations of the CO(2-1), HCN(3-2), and HCO$^{+}$(3-2) lines in nearby radio galaxy / brightest cluster (BCG) NGC 1275 with spatial resolution $\sim20$ pc. In previous observations, CO(2-1) emission was detected as radial filaments lying east-west direction. resolved inner filament found that cannot be represented by a simple infalling stream both morphologically kinematically. The observed complex nature resembles cold gas structure predicted recent numerical...

Abstract Recent observations of galaxy clusters and groups with misalignments between their central active galactic nucleus jets X-ray cavities, or multiple misaligned have raised concerns about the jet–bubble connection in cooling cores, processes responsible for jet realignment. To investigate frequency causes such misalignments, we construct a sample 16 cool core groups. Using Very Long Baseline Array radio data, measure parsec-scale position angle jets, compare it cavities detected...

(abridged) A Chandra observation of the X-ray bright group NGC 5044 shows that emitting gas has been strongly perturbed by recent outbursts from central AGN and also motion dominant galaxy relative to gas. The hosts many small radio quiet cavities with a nearly isotropic distribution, cool filaments, semi-circular cold front two-armed spiral shaped feature GMRT at 610 MHz presence extended emission "torus-shaped" morphology. largest filament appears thread torus, suggesting lower entropy...

We report on the results of an analysis Chandra, XMM-Newton, and new Giant Metrewave Radio Telescope (GMRT) data X-ray bright compact group galaxies HCG 62, which is one few groups known to possess clear, small cavities in inner regions. This part ongoing X-ray/low-frequency radio study 18 groups, initially chosen for availability good-quality evidence active galactic nucleus/hot gas interaction. At higher frequency (1.4 GHz), 62 cavity system shows minimal if any emission, but GMRT...

We present new Giant Metrewave Radio Telescope observations at 235 MHz and 610 of 18 X-ray bright galaxy groups. These are part an extended project, presented here in future papers, which combines low-frequency radio data to investigate the interaction between central active galactic nuclei (AGNs) intra-group medium (IGM). The images show a very diverse population group-central sources, varying widely size, power, morphology, spectral index. Comparison with Chandra XMM-Newton shows that...

view Abstract Citations (124) References (63) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Mapping the Dark Matter in NGC 5044 Group with ROSAT: Evidence for a Nearly Homogeneous Cooling Flow Wake David, Laurence P. ; Jones, Christine Forman, William Daines, Stuart The group of galaxies was observed by ROSAT PSPC 30 ks during its reduced pointed phase (1991 July). Due to relatively cool gas temperature (kT = 0.98+/-0.02 keV) and excellent photon statistics...

We have analyzed Chandra observations of 18 low-luminosity early-type galaxies with LB ≲ 3 × 1010 L☉B. Thermal emission from hot gas temperatures between 0.2 and 0.8 keV comprises 5%-70% the total 0.5-2.0 these galaxies. find that X-ray luminosity LMXBs (resolved plus power-law component unresolved emission) scales roughly linearly K-band a normalization comparable to found in more luminous All our sample are gas-poor, masses much less than expected accumulation stellar mass loss over...

A deep Chandra observation of the X-ray bright group, NGC 5044, shows that central region this group has been strongly perturbed by repeated AGN outbursts. These recent outbursts have produced many small cavities, cool filaments and cold fronts. We find a correlation between coolest emitting gas morphology Ha filaments. The are oriented in direction suggesting warm responsible for Halpha emission originated near center 5044 was dredged up behind buoyant, AGN-inflated cavities. detailed...

We present new ALMA CO(2--1) observations of two well studied group-centered elliptical galaxies: NGC~4636 and NGC~5846. In addition, we include a revised analysis Cycle 0 the central galaxy in NGC~5044 group that has been previously published. find evidence molecular gas, form off-center orbiting clouds, is common presence bright galaxies (BGG). CO line widths are $\gtrsim 10$ times broader than Galactic using reference Milky Way $X_{CO}$, total mass ranges from as low $2.6\times 10^5...

Abstract We present Chandra and XMM-Newton X-ray observations of the compact group HCG 57, optical integral field spectroscopy interacting galaxy pair 57A/D. These two spiral galaxies recently suffered an off-axis collision with 57D passing through disk A. find evidence a gas bridge linking galaxies, containing ∼10 8 M ⊙ hot, ∼1 keV thermal plasma warm ionized radiating in H α , β [O iii ] [N ii lines. The emission lines central regions show excitation properties consistent -regions, while...

We propose that the outer portions of cooling flows (CFs) in clusters galaxies are frequently disrupted by radio jets, and their effective ages much shorter than cluster ages. The inner regions, where gas density is higher, more difficult to disrupt, may continue harbor CFs even after disruption events. main assumption proposed scenario that, on a time scale about 2-4 times 10^9 years cD CF undergo powerful bursts AGN activity produce strong jets. jets excite shock waves moving at several...

We present the results of ROSAT PSPC observations three cool (kT ⩽ 3 keV) Abell clusters galaxies (A262, A539, and A2589). Spatially resolved X-ray spectroscopy shows that gas in these is essentially isothermal beyond central cooling flow region. The spectra A262 also show excess soft absorption above expected from galactic hydrogen column density. not confined to region but distributed across entire field view with a slight increase at large radii. this coincides cirrus observed by IRAS....

We present the results of a Chandra study Hydra A galaxy cluster, where powerful active galactic nucleus (AGN) outburst created large-scale cocoon shock. investigated possible azimuthal variations in shock strength and shape, finding indications for weak with Mach number range ∼1.2–1.3. measured temperature change across front. However, detection rise regions immediately inside front is complicated by underlying profile cluster atmosphere. global up to 700 kpc, which represents farthest...

Abstract Mergers between galaxy clusters often drive shocks into the intracluster medium, effects of which are sometimes visible via temperature and density jumps in X-ray radio emission from relativistic particles energized by shock’s passage. A2108 was selected as a likely merger system through comparing luminosity to Planck Sunyaev–Zeldovich signal, where this cluster appeared highly underluminous. Follow-up observations confirmed it be merging low-mass featuring two distinct subclusters,...

In many clusters of galaxies, radiative cooling in the central regions appears to drive an accretion flow. Many these "cooling-flow clusters" possess strong radio sources regions, which suggests a causal relation between flow and source. We consider general model produces interacts with relativistic electrons core cluster. These heat inflowing gas, generating negative feedback that reduces rate. For sufficiently feedback, shows oscillatory behavior on timescale several hundred million years.

We present a Chandra observation of the merging cluster galaxies Abell 2744. The shows strong evidence for an ongoing major merger which we believe to be responsible radio halo. X-ray emission and temperature maps cluster, combined with spatial redshift distribution galaxies, indicate roughly north–south axis merger, significant velocity component along line sight. is occurring at very large velocity, –3. estimate mass ratio subclusters order unity. They are nearing their closest approach...

A1758 was classified by Abell as a single rich cluster of galaxies, but ROSAT observation showed that this system consists two distinct clusters (A1758N and A1758S) separated approximately 8' (a projected separation 2 Mpc in the rest frame clusters). Only few galaxy redshifts have been published for these clusters, redshift Fe lines Chandra XMM-Newton spectra shows recessional velocities A1758N A1758S are within 2100 km s-1. Thus, most likely form gravitationally bound system, our imaging...

We use a Chandra observation of the poor cluster AWM 4 to map temperature and abundance intracluster medium, so as examine influence central radio galaxy on its environment. While core is generally enriched near-solar abundances, we find evidence supersolar abundances correlated with jets, extending ∼35 kpc from dominant NGC 6051 along minor-axis. conclude that gas has been transported out through action source. estimate excess mass iron in entrained be ∼1.4 × 106 M⊙ this can produced within...