Constraints on jet formation mechanisms with the most energetic giant outbursts in MS 0735+7421

Giant X-ray cavities lie in some active galactic nuclei (AGNs) locating in central galaxies of clusters, most of these cavities are thought to be inflated by jets of AGNs. The jets can be either powered by rotating black holes or the accretion disks surrounding black holes, or both. In this work, we choose the most energetic cavity, MS 0735+7421, with stored energy ~ 10^62 erg, to constrain the jet formation mechanisms and the evolution of the central massive black hole in this source. The bolometric luminosity of the AGN in this cavity is ~ 10^(-5) L_Edd, however, the mean power of the jet required to inflate the cavity is estimated as ~ 0.02 L_Edd, which implies that the source has experienced strong outbursts previously. During outbursts, the jet power and the mass accretion rate should be significantly higher than its present values. We construct an accretion disk model, in which the angular momentum and energy carried away by jets is properly included, to calculate the spin and mass evolution of the massive black hole. In our calculations, different jet formation mechanisms are employed, and we find that the jets generated with the Blandford-Znajek (BZ) mechanism are unable to produce the giant cavity with ~ 10^62 erg in this source. Only the jets accelerated with the combination of the Blandford-Payne (BP) and BZ mechanisms can successfully inflate such a giant cavity, if the magnetic pressure is close to equipartition with the total (radiation+gas) pressure of the accretion disk. For dynamo generated magnetic field in the disk, such an energetic giant cavity can be inflated by the magnetically driven jets only if the initial black hole spin parameter a_0 > 0.95. Our calculations show that the final spin parameter a of the black hole is always ~ 0:9 - 0.998 for all the computational examples which can provide sufficient energy for the cavity of MS 0735+7421.Comment: 25 pages, 8 figures, accepted by Ap

Thermodynamics of static dyonic AdS black holes in the ω\omega-deformed Kaluza-Klein gauged supergravity theory

We study thermodynamical properties of static dyonic AdS black holes in four-dimensional $\omega$-deformed Kaluza-Klein gauged supergravity theory, and find that the differential first law requires a modification via introducing a new pair of thermodynamical conjugate variables (X, Y). To ensure such a modification, we then apply the quasi-local ADT formalism developed in Ref. [20] to calculate the quasi-local conserved charge and identify that the new pair is precisely the one previously introduced to modify the differential form of first law.Comment: 13 pages, no figure, elsarticle.cls, updated version to match with the published pape

Measurements of the heavy-flavour nuclear modification factor in p--Pb collisions at sNN\sqrt{s_{\rm NN}} = 5.02 TeV with ALICE at the LHC

The heavy-flavour nuclear modification factor $R_{\rm pPb}$ has been measured with the ALICE detector in p--Pb collisions at the nucleon--nucleon center of mass energy $\sqrt{s_{\rm NN}}$ = 5.02 TeV at the CERN LHC in a wide rapidity and transverse momentum range, as well as in several decay channels. $R_{\rm pPb}$ is consistent with unity within uncertainties at mid-rapidity and forward rapidity. In the backward region a slight enhancement of the yield of heavy-flavour decay muons is found in the region $2<p_{\rm T}<4$ GeV/$c$. The results are described within uncertainties by theoretical calculations that include initial-state effects. The measurements add experimental evidence that the suppression of heavy-flavour production observed at high $p_{\rm T}$ in central Pb--Pb collisions with respect to pp collisions is due to a medium effect induced by the interaction of heavy quarks with the partonic matter.Comment: 4 pages, 6 figures, submitted to NP

The Differentiation and Analysis of Relationship between “Ethics” and “Morality” in the Chinese Context

In both Western and Chinese contexts, “ethics” and “morality” have always been confused by semantics and blurred boundaries, and “ethics and morality” or “morality and ethics” are often confused with each other. This situation has brought a lot of inconvenience to academic research. Although there have been many research results on the relationship between their, there is no general consensus, and it is necessary to re-analyze and summarize them. In summary, there are three types of research on the relationship between ethics and morality in recent years in Chinese academia: synonymous, heterogeneous, species and genera. Clarifying the relationship between ethics and morality can effectively prevent the tendency of ethical moralism and moral ethicism, help clarify the issue of attribution of ethics and moral disciplines, and at the same time help rebuild the moral beliefs of contemporary people

Ethnicity and Migration ─ The Concentration and Dispersion of Foreign-Born Asians and Hispanics in the United States

Immigration from Asia and Latin America has rapidly changed the race and ethnic composition of the non-White population in the United States. This dissertation examines the question of race/ethnicity, nativity, and how acculturation and socioeconomic characteristics impact residential outcomes for Asian and Hispanic immigrants, a process often termed as residential assimilation. It also tests the effectiveness of spatial assimilation, segmented assimilation, and resurgent ethnicity theories for understanding residential segregation across metropolitan neighborhoods. Three sets of analyses are presented in this dissertation. The first set of analyses studies the nativity difference in residential segregation levels between Asians and Hispanics from non-Hispanic Whites in metropolitan areas. In general, the findings from residential segregation patterns demonstrate that the classic spatial assimilation is not solely outdated but is only applicable to Hispanics. Looking closely into the nativity groups, Hispanic immigrants are more residentially segregated from Whites than are the native-born counterparts in all immigrant destinations (traditional gateways, new destinations, and other destinations). On the contrary, Asian nativity groups show a completely reverse pattern. By comparing the segregation levels of the aforementioned destination types, the native-born Asians are highly segregated from Whites than are the immigrant groups in other destinations, which portends that as Asians disperse to the newly emerging destinations, they are not spatially assimilated with Whites. The second part of analyses examines differences in residential propinquity of living in ethnic areas (defined by PUMAs) by race, nativity, and considers the role of individual socioeconomic and demographic characteristics for understanding disparities in residential preferences of living in ethnic areas. Results show that controlling for individual differences in acculturation and socioeconomic characteristics explains away the nativity difference, as the native-born Asians and Hispanics show a higher tendency of living in the ethnic areas compared to their respective foreign-born counterparts. Build on past research findings and framework, this result lends less support to the classic spatial assimilation model, but more to the segmented assimilation and resurgent ethnicity frameworks. Hispanics are generally low in acculturation and socioeconomic attainment measures, which in turn generate a “downward” social context for the nativeborn groups. However, the relatively advantaged Asian native-born are more likely to live in ethnic areas, which is suggestive of a voluntary process that is related to preference and taste, rather than economic constraints. The results from the last set of analyses show that Hispanic nativity groups are more responsive to the effects of human capital factors (demographics, English ability, and education) compared to Asians in the internal migration patterns. This nativity difference is the strongest at the relative risk of segregation. Consistent with spatial assimilation theory, I found that greater English proficiency and education help Hispanic immigrants disperse from established immigrant metropolitan areas. Whereas for Asians, advanced degrees are strongly related to the segregation migration. Moreover, other human capital characteristics, homeownership, family income, and self-employment, impact the internal migration differently on Asians and Hispanics, providing some evidence for the segmented assimilation and resurgent ethnicity theories