Supermassive Black Hole feedback in early type galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 119-125
Author(s):  
W. Forman ◽  
C. Jones ◽  
A. Bogdan ◽  
R. Kraft ◽  
E. Churazov ◽  
...  

AbstractOptically luminous early type galaxies host X-ray luminous, hot atmospheres. These hot atmospheres, which we refer to as coronae, undergo the same cooling and feedback processes as are commonly found in their more massive cousins, the gas rich atmospheres of galaxy groups and galaxy clusters. In particular, the hot coronae around galaxies radiatively cool and show cavities in X-ray images that are filled with relativistic plasma originating from jets powered by supermassive black holes (SMBH) at the galaxy centers. We discuss the SMBH feedback using an X-ray survey of early type galaxies carried out using Chandra X-ray Observatory observations. Early type galaxies with coronae very commonly have weak X-ray active nuclei and have associated radio sources. Based on the enthalpy of observed cavities in the coronae, there is sufficient energy to “balance” the observed radiative cooling. There are a very few remarkable examples of optically faint galaxies that are 1) unusually X-ray luminous, 2) have large dark matter halo masses, and 3) have large SMBHs (e.g., NGC4342 and NGC4291). These properties suggest that, in some galaxies, star formation may have been truncated at early times, breaking the simple scaling relations.

Author(s):  
Elizabeth J Gonzalez ◽  
Facundo Rodriguez ◽  
Manuel Merchán ◽  
Diego García Lambas ◽  
Martín Makler ◽  
...  

Abstract Galaxy group masses are important to relate these systems with the dark matter halo hosts. However, deriving accurate mass estimates is particularly challenging for low-mass galaxy groups. Moreover, calibration of observational mass-proxies using weak-lensing estimates have been mainly focused on massive clusters. We present here a study of halo masses for a sample of galaxy groups identified according to a spectroscopic catalogue, spanning a wide mass range. The main motivation of our analysis is to assess mass estimates provided by the galaxy group catalogue derived through an abundance matching luminosity technique. We derive total halo mass estimates according to a stacking weak-lensing analysis. Our study allows to test the accuracy of mass estimates based on this technique as a proxy for the halo masses of large group samples. Lensing profiles are computed combining the groups in different bins of abundance matching mass, richness and redshift. Fitted lensing masses correlate with the masses obtained from abundance matching. However, when considering groups in the low- and intermediate-mass ranges, masses computed according to the characteristic group luminosity tend to predict higher values than the determined by the weak-lensing analysis. The agreement improves for the low-mass range if the groups selected have a central early-type galaxy. Presented results validate the use of mass estimates based on abundance matching techniques which provide good proxies to the halo host mass in a wide mass range.


2006 ◽  
Vol 2 (S235) ◽  
pp. 214-214
Author(s):  
Habib G. Khosroshahi ◽  
T. J. Ponman

AbstractWe study fossil galaxy groups, their hot gas and the galaxy properties. Fossils are more X-ray luminous than non-fossil groups, however, they fall comfortably on the conventional L-T relation of galaxy groups and clusters indicating that their X-ray luminosity and temperature are both boosted, arguably, as a result of their early formation. The central dominant galaxy in fossils have optical luminosity comparable to the brightest cluster galaxies (BCGs), however, the isophotal shapes of the central galaxy in fossils are non-boxy in contrast to the isophotes of majority of the BCGs.


2018 ◽  
Vol 620 ◽  
pp. A7 ◽  
Author(s):  
V. Guglielmo ◽  
B. M. Poggianti ◽  
B. Vulcani ◽  
C. Adami ◽  
F. Gastaldello ◽  
...  

Context. The fraction of galaxies bound in groups in the nearby Universe is high (50% at z ~ 0). Systematic studies of galaxy properties in groups are important in order to improve our understanding of the evolution of galaxies and of the physical phenomena occurring within this environment. Aims. We have built a complete spectrophotometric sample of galaxies within X-ray detected, optically spectroscopically confirmed groups and clusters (G&C), covering a wide range of halo masses at z ≤ 0.6. Methods. In the context of the XXL survey, we analyse a sample of 164 G&C in the XXL-North region (XXL-N), at z ≤ 0.6, with a wide range of virial masses (1.24 × 1013 ≤ M500,scal(M⊙) ≤ 6.63 × 1014) and X-ray luminosities ((2.27 × 1041 ≤ L500,scalXXL(erg s−1) ≤ 2.15 × 1044)). The G&C are X-ray selected and spectroscopically confirmed. We describe the membership assignment and the spectroscopic completeness analysis, and compute stellar masses. As a first scientific exploitation of the sample, we study the dependence of the galaxy stellar mass function (GSMF) on global environment. Results. We present a spectrophotometric characterisation of the G&C and their galaxies. The final sample contains 132 G&C, 22 111 field galaxies and 2225 G&C galaxies with r-band magnitude <20. Of the G&C, 95% have at least three spectroscopic members, and 70% at least ten. The shape of the GSMF seems not to depend on environment (field versus G&C) or X-ray luminosity (used as a proxy for the virial mass of the system). These results are confirmed by the study of the correlation between mean stellar mass of G&C members and L500,scalXXL. We release the spectrophotometric catalogue of galaxies with all the quantities computed in this work. Conclusions. As a first homogeneous census of galaxies within X-ray spectroscopically confirmed G&C at these redshifts, this sample will allow environmental studies of the evolution of galaxy properties.


2018 ◽  
Vol 483 (1) ◽  
pp. 711-733 ◽  
Author(s):  
K Anastasopoulou ◽  
A Zezas ◽  
V Gkiokas ◽  
K Kovlakas
Keyword(s):  
X Ray ◽  

1990 ◽  
Vol 140 ◽  
pp. 459-462
Author(s):  
Richard G. Strom

Faraday depolarization estimates of thermal densities within the components of double radio sources agree well with estimates from X-ray observations of hot halos around early-type galaxies, provided magnetic field strengths are close to their equipartition values. Internal Faraday dispersion is the main cause of the depolarization observed.


2009 ◽  
Vol 5 (H15) ◽  
pp. 89-90
Author(s):  
Takaya Ohashi

X-ray observations reveal extended halos around early-type galaxies which enable us to trace the dark matter distribution around the galaxies (see Mathews and Brighenti 2003 for a review). X-ray luminosities, LX of massive early-type galaxies are 1040−1042 erg s−1 in 0.3–2 keV. The correlation plot between LX and B-band luminosity LB shows a large scatter in the sense that LX varies by 2 orders of magnitudes for the same LB, in the brightest end (log LB ≳ 10.5). The amount of the X-ray hot gas in early-type galaxies is typically a few % of the stellar mass, in contrast to clusters of galaxies which hold ~5 times more massive gas than stars. Matsushita (2001) showed that X-ray luminous galaxies are characterized by extended X-ray halo with a few tens of re, similar to the scale of galaxy groups, so the presence of group-size potentials would be strongly linked with the problem of large LX scatter.


2009 ◽  
Vol 5 (H15) ◽  
pp. 283-283
Author(s):  
Philip J. Humphrey ◽  
David A. Buote

Understanding the process of metal enrichment is one of the key problems for our picture of structure formation and evolution, in which early-type galaxies are a crucial ingredient. X-ray observations provide a powerful tool for measuring the metal distributions in their hot ISM, which is shaped by their entire history of star-formation, evolution and feedback. In Fig 1 (left panel), we summarize the results of a Chandra survey of metals in early-type galaxies, supplemented with Suzaku data (Humphrey & Buote 2006, P. Humphrey et al., in prep.). Chandra is particularly suited to this study, as it enables temperature gradients and X-ray point sources to be resolved, mitigating two important sources of bias (e.g., Buote & Fabian 1998; Fabbiano et al. 1994). We found on average that the ISM is at least as metal-rich as the stars, and we did not find the problematical, highly sub-solar, abundances historically reported. The abundance ratios of O, Ne, Mg, Si and S with respect to Fe are similar to the centres of massive groups and clusters, suggesting homology in the enrichment process over a wide mass range. Finally, using high-quality Suzaku data, we were able to resolve, for the first time in a galaxy-scale (≲1013M⊙) object, a radial abundance gradient similar to those seen in some bright galaxy groups (Fig. 1, right panel).


2020 ◽  
Author(s):  
Pablo Lustemberg ◽  
Feng Zhang ◽  
Ramón A. Gutiérrez ◽  
Pedro J. Ramírez ◽  
Sanjaya D. Senanayake ◽  
...  

The clean activation of methane at low temperatures remains an eminent challenge and a field of competitive research. In particular, on late transition metal surfaces such as Pt(111) or Ni(111), elevated temperatures are necessary to activate the hydrocarbon molecule, but a massive deposition of carbon makes the metal surface useless for catalytic activity. However, on very low-loaded M/CeO2 (M= Pt, Ni, or Co) surfaces, the dissociation of methane occurs at room temperature, which is unexpected considering simple linear scaling relationships. This intriguing phenomenon has been studied using a combination of experimental techniques (ambient-pressure X-ray photoelectron spectroscopy, time-resolved X-ray diffraction and X-ray absorption spectroscopy) and density functional theory-based calculations. The experimental and theoretical studies show that the size and morphology of the supported nanoparticles together with strong metal-support interactions are behind the deviations from the scaling relations. These findings point toward a possible strategy to circumvent scaling relations, producing active and stable catalysts which can be employed for methane activation and conversion. <br>


2019 ◽  
Vol 486 (1) ◽  
pp. L80-L84 ◽  
Author(s):  
Ruta Kale ◽  
Krishna M Shende ◽  
Viral Parekh

ABSTRACT Diffuse radio sources associated with the intra-cluster medium are direct probes of the cosmic ray electrons and magnetic fields. We report the discovery of a diffuse radio source in the galaxy cluster RXCJ0232.2–4420 (SPT-CL J0232–4421, z = 0.2836) using 606 MHz observations with the Giant Metrewave Radio Telescope. The diffuse radio source surrounds the Brightest Cluster Galaxy in the cluster-like typical radio mini-haloes. However the total extent of it is 550 × 800 kpc2, which is larger than mini-haloes and similar to that of radio haloes. The BCG itself is also a radio source with a marginally resolved core at 7 arcsec (30 kpc) resolution. We measure the 606 MHz flux density of the RH to be 52 ± 5 mJy. Assuming a spectral index of 1.3, the 1.4 GHz radio power is 4.5 × 1024 W Hz−1. The dynamical state of the cluster has been inferred to be 'relaxed’ and also as 'complex’, depending on the classification methods based on the morphology of the X-ray surface brightness. This system thus seems to be in the transition phase from a mini-halo to a radio halo.


1982 ◽  
Vol 97 ◽  
pp. 45-46
Author(s):  
Jack O. Burns ◽  
Jean A. Eilek ◽  
Frazer N. Owen

It has been generally assumed that wide-angle tailed (WAT) sources like 3C465 are formed in a manner similar to that of the more strongly bent U-shaped sources such as NGC 1265, i.e., by ram pressure arising from galaxy motion through a dense intracluster medium (ICM). The WAT sources were thought to be less strongly bent because of the smaller ratio of tail plasma flow momentum flux to galaxy velocity. However, as noted recently by Burns (1981), there is a serious discrepancy between the ram pressure model requirements for bending WATs and the dynamics of the associated radio galaxy. To bend the tails, we calculate that the galaxy must typically move at velocities of 0.7–1×103 km s−1 for distances comparable to the length of the radio tails (∼200 kpc for 3C465). This implied galaxy motion is inconsistent with the nature of the massive cD galaxies generally associated with WATs. Cluster galaxy velocity data, X-ray observations, and recent models suggest that these giant galaxies are nearly at rest at the bottoms of cluster potential wells, at most moving ∼200 km s−1 in an oscillatory motion of small amplitude (<0.3 of a core radius, Malumuth, 1981, private communication). Thus it appears that some other mechanism is responsible for bending WAT sources.


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