Ships Passing In The Night?

In this Cousins Research Group Report, David Mathews describes two different civic engagement movements. One is underway in higher education. On campuses across the country, leadership and service learning programs are growing, and students are taught civic skills, including civil dialogue. In addition, university partnerships with nearby communities offer technical assistance, professional advice, and access to institutional resources. The other is occurring off campus, in communities that are trying to cope with natural disasters, economic change, and other problems that threaten everyone's well-being. In these places, citizens say they want to come together as communities to maintain their communities. Unfortunately, they often have difficulty finding institutions that understand their agenda.Why are these two civic movements in danger of passing like the proverbial ships in the night? Mathews explores this disconnect, noting, "It would seem that two civic engagement movements, occurring at the same time and often in the same locations, would be closely allied -- perhaps mutually reinforcing. That doesn't seem to be happening very often." He goes on to suggest how these efforts might become mutually supportive

The Public and Public Education

This Cousins Research Group report includes two articles by Kettering Foundation president David Mathews that were published previously. "The Public for Public Schools Is Slipping" was first published in Education Week in 1995. The second piece, "Putting the Public Back into Public Education: An Old-Fashioned Remedy for a Troubled Relationship," appeared in the Summer 2015 issue of the National Civic Review. Both pieces look at the growing disconnect between the schools and the public they serve. They suggest that the usual institutional responses to repair the troubled relationship (e.g., standardized tests or better public relations) have failed to remedy the problem. The key to bridging the divide between the schools and the public may actually be found on the citizens' side. Mathews observes, "Citizens themselves and their organizations have to be actors who bring educational resources in the community to complement what the schools do.

X-ray Isophotes in a Rapidly Rotating Elliptical Galaxy: Evidence of Inflowing Gas

We describe two-dimensional gasdynamical computations of the X-ray emitting gas in the rotating elliptical galaxy NGC 4649 that indicate an inflow of about one solar mass per year at every radius. Such a large instantaneous inflow cannot have persisted over a Hubble time. The central constant-entropy temperature peak recently observed in the innermost 150 parsecs is explained by compressive heating as gas flows toward the central massive black hole. Since the cooling time of this gas is only a few million years, NGC 4649 provides the most acutely concentrated known example of the cooling flow problem in which the time-integrated apparent mass that has flowed into the galactic core exceeds the total mass observed there. This paradox can be resolved by intermittent outflows of energy or mass driven by accretion energy released near the black hole. Inflowing gas is also required at intermediate kpc radii to explain the ellipticity of X-ray isophotes due to spin-up by mass ejected by stars that rotate with the galaxy and to explain local density and temperature profiles. We provide evidence that many luminous elliptical galaxies undergo similar inflow spin-up. A small turbulent viscosity is required in NGC 4649 to avoid forming large X-ray luminous disks that are not observed, but the turbulent pressure is small and does not interfere with mass determinations that assume hydrostatic equilibrium.Comment: 21 pages, 9 figures, accepted for publication by Ap

Higher Education Exchange: 2007

This annual publication serves as a forum for new ideas and dialogue between scholars and the larger public. Essays explore ways that students, administrators, and faculty can initiate and sustain an ongoing conversation about the public life they share.The Higher Education Exchange is founded on a thought articulated by Thomas Jefferson in 1820: "I know no safe depository of the ultimate powers of the society but the people themselves; and if we think them not enlightened enough to exercise their control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education."In the tradition of Jefferson, the Higher Education Exchange agrees that a central goal of higher education is to help make democracy possible by preparing citizens for public life. The Higher Education Exchange is part of a movement to strengthen higher education's democratic mission and foster a more democratic culture throughout American society.Working in this tradition, the Higher Education Exchange publishes interviews, case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies

Hydrostatic Gas Constraints On Supermassive Black Hole Masses: Implications For Hydrostatic Equilibrium And Dynamical Modeling In A Sample Of Early-Type Galaxies

We present new mass measurements for the supermassive black holes (SMBHs) in the centers of three early-type galaxies. The gas pressure in the surrounding, hot interstellar medium (ISM) is measured through spatially resolved spectroscopy with the Chandra X-ray Observatory, allowing the SMBH mass (M(BH)) to be inferred directly under the hydrostatic approximation. This technique does not require calibration against other SMBH measurement methods and its accuracy depends only on the ISM being close to hydrostatic, which is supported by the smooth X-ray isophotes of the galaxies. Combined with results from our recent study of the elliptical galaxy NGC4649, this brings the number of galaxies with SMBHs measured in this way to four. Of these, three already have mass determinations from the kinematics of either the stars or a central gas disk, and hence join only a handful of galaxies with MBH measured by more than one technique. We find good agreement between the different methods, providing support for the assumptions implicit in both the hydrostatic and the dynamical models. The stellar mass-to-light ratios for each galaxy inferred by our technique are in agreement with the predictions of stellar population synthesis models assuming a Kroupa initial mass function (IMF). This concurrence implies that no more than similar to 10%-20% of the ISM pressure is nonthermal, unless there is a conspiracy between the shape of the IMF and nonthermal pressure. Finally, we compute Bondi accretion rates (M(bondi)), finding that the two galaxies with the highest M(bondi) exhibit little evidence of X-ray cavities, suggesting that the correlation with the active galactic nuclei jet power takes time to be established.NASA NAS5-26555, NNG04GE76G, G07-8083XAstronom

ALMA observations of molecular clouds in three group centered elliptical galaxies: NGC 5846, NGC 4636, and NGC 5044

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 of Cycle 0 ALMA observations of the central galaxy in the NGC~5044 group that has been previously published. We find evidence that molecular gas, in the form of off-center orbiting clouds, is a common presence in bright group-centered galaxies (BGG). CO line widths are $\gtrsim 10$ times broader than Galactic molecular clouds, and using the reference Milky Way $X_{CO}$, the total molecular mass ranges from as low as $2.6\times 10^5 M_\odot$ in NGC~4636 to $6.1\times 10^7 M_\odot$ in NGC~5044. With these parameters the virial parameters of the molecular structures is $\gg 1$. Complementary observations of NGC~5846 and NGC~4636 using the ALMA Compact Array (ACA) do not exhibit any detection of a CO diffuse component at the sensitivity level achieved by current exposures. The origin of the detected molecular features is still uncertain, but these ALMA observations suggest that they are the end product of the hot gas cooling process and not the result of merger events. Some of the molecular clouds are associated with dust features as revealed by HST dust extinction maps suggesting that these clouds formed from dust-enhanced cooling. The global nonlinear condensation may be triggered via the chaotic turbulent field or buoyant uplift. The large virial parameter of the molecular structures and correlation with the warm ($10^3 - 10^5 K$)/hot ($\ge10^6$) phase velocity dispersion provide evidence that they are unbound giant molecular associations drifting in the turbulent field, consistently with numerical predictions of the chaotic cold accretion process. Alternatively, the observed large CO line widths may be generated by molecular gas flowing out from cloud surfaces due to heating by the local hot gas atmosphere.Comment: Revised version to be published in ApJ, 16 pages, 10 figures, 4 table

Time-dependent Circulation Flows: Iron Enrichment in Cooling Flows with Heated Return Flows

We describe a new type of dynamical model for hot gas in galaxy groups and clusters in which gas moves simultaneously in both radial directions. Circulation flows are consistent with (1) the failure to observe cooling gas in X-ray spectra, (2) multiphase gas observed near the centers of these flows and (3) the accumulation of iron in the hot gas from Type Ia supernovae in the central galaxy. Dense inflowing gas cools, producing a positive central temperature gradient, as in normal cooling flows. Bubbles of hot, buoyant gas flow outward. Circulation flows eventually cool catastrophically if the outward flowing gas transports mass but no heat; to maintain the circulation both mass and energy must be supplied to the inflowing gas over a large volume, extending to the cooling radius. The rapid radial recirculation of gas produces a flat central core in the gas iron abundance, similar to many observations. We believe the circulation flows described here are the first gasdynamic, long-term evolutionary models that are in good agreement with all essential features observed in the hot gas: little or no gas cools as required by XMM spectra, the gas temperature increases outward near the center, and the gaseous iron abundance is about solar near the center and decreases outward.Comment: 17 pages (emulateapj5) with 6 figures; accepted by The Astrophysical Journa

Higher Education Exchange: 2009

This annual publication serves as a forum for new ideas and dialogue between scholars and the larger public. Essays explore ways that students, administrators, and faculty can initiate and sustain an ongoing conversation about the public life they share.The Higher Education Exchange is founded on a thought articulated by Thomas Jefferson in 1820: "I know no safe depository of the ultimate powers of the society but the people themselves; and if we think them not enlightened enough to exercise their control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education."In the tradition of Jefferson, the Higher Education Exchange agrees that a central goal of higher education is to help make democracy possible by preparing citizens for public life. The Higher Education Exchange is part of a movement to strengthen higher education's democratic mission and foster a more democratic culture throughout American society.Working in this tradition, the Higher Education Exchange publishes interviews, case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies