A Captured Runaway Black Hole in NGC 1277?

Recent results indicate that the compact lenticular galaxy NGC 1277 in the Perseus Cluster contains a black hole of approximately 10 billion solar masses. This far exceeds the expected mass of the central black hole in a galaxy of the modest dimensions of NGC 1277. We suggest that this giant black hole was ejected from the nearby giant galaxy NGC 1275 and subsequently captured by NGC 1277. The ejection was the result of gravitational radiation recoil when two large black holes merged following the merger of two giant ellipticals that helped to form NGC 1275. The black hole wandered in the cluster core until it was captured in a close encounter with NGC 1277. The migration of black holes in clusters may be a common occurrence.Comment: Four pages, accepted by The Astrophysical Journal Letters. Major revisions, especially Section

The Black Hole Mass - Galaxy Luminosity Relationship for Sloan Digital Sky Survey Quasars

We investigate the relationship between the mass of the central supermassive black hole, M_bh, and the host galaxy luminosity, L_gal, in a sample of quasars from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7). We use composite quasar spectra binned by black hole mass and redshift to assess galaxy features that would otherwise be overwhelmed by noise in individual spectra. The black hole mass is calculated using the photoionization method, and the host galaxy luminosity is inferred from the depth of the Ca II H + K features in the composite spectra. We evaluate the evolution in the M_bh - L_gal relationship by examining the redshift dependence of Delta log M_bh, the offset in black hole mass from the local black hole - bulge relationship. There is little systematic trend in Delta log M_bh out to z = 0.8. Using the width of the [O III] emission line as a proxy for the stellar velocity dispersion, sigma_*, we find agreement of our derived host luminosities with the locally-observed Faber-Jackson relation. This supports the utility of the width of the [O III] line as a proxy for sigma_* in statistical studies.Comment: 10 pages, 5 figures; final version; major revision

Accretion Disk Temperatures of QSOs: Constraints from the Emission Lines

QSO emission-line spectra are compared to predictions based on theoretical ionizing continua of accretion disks. Observed line intensities do not show the expected trend of higher ionization with higher accretion disk temperature as derived from the black hole mass and accretion rate. This suggests that, at least for accretion rates close to the Eddington limit, the inner disk does not reach temperatures as high as expected from standard disk theory. Modified radial temperature profiles, taking account of winds or advection in the inner disk, achieve better agreement with observation. This conclusion agrees with an earlier study of QSO continuum colors as a function of disk temperature. The emission lines of radio-detected and radio-undetected sources show different trends as a function of disk temperature.Comment: 9 pages, 8 figures, submitted to Ap

Income and happiness: Evidence, explanations and economic implications

There is now a great deal of micro-econometric evidence, both cross-section and panel, showing that income is positively correlated with well-being. Yet the famous Easterlin paradox shows essentially no change in average happiness at the country level, despite spectacular rises in per capita GDP. We argue that survey well-being questions are indeed good proxy measures of utility, and resolve the Easterlin paradox by appealing to income comparisons: these can be to others (social comparisons) or to oneself in the past (habituation). We review a substantial amount of econometric, experimental and neurological literature consistent with comparisons, and then spell out the implications for a wide range of economic issues.income ; happiness ; social comparisons ; habituation ; economic policy

High chemical abundances in stripped Virgo spiral galaxies

Based on a comparison of the oxygen abundances in H 2 regions in field and Virgo cluster late type spiral galaxies, Shields, Skillman, & Kennicutt (1991) suggested that the highly stripped spiral galaxies in the Virgo cluster have systematically higher abundances than comparable field galaxies. In April 1991 and May 1992 we used the blue channel spectrograph on the MMT to obtain new observations of 30 H 2 regions in Virgo spiral galaxies. These spectra cover the wavelength range from (O II) lambda 3727 to (S II) lambda 6731. We now have observed at least 4 H II regions in 9 spiral galaxies in the Virgo cluster. Combining (O II) and (O III) line strengths, we calculate the H II region oxygen abundances based on the empirical calibration of Edmunds & Pagel (1984). These observations show: (1) The stripped, low luminosity Virgo spirals (N4689, N4571) truly have abundances characteristic of much more luminous field spirals; (2) Virgo spirals which show no evidence of stripping (N4651, N4713) have abundances comparable to field galaxies; and (3) Evidence for transition galaxies (e.g., N4254, N4321), with marginally stripped disks and marginal abundance enhancements. The new observations presented here confirm the validity of the oxygen over-abundances in the stripped Virgo spirals. Shields et al. (1991) discussed two different mechanisms for producing the higher abundances in the disks of stripped galaxies in Virgo. The first is the supression of infall of near-primordial material, the second is the suppression of radial inflow of metal-poor gas. Distinguishing between the two cases will require more observations of the Virgo cluster spirals and a better understanding of which parameters determine the variation of abundance with radius in field spirals (cf., Garnett & Shields 1987)

The Black Hole Mass - Galaxy Bulge Relationship for QSOs in the SDSS DR3

We investigate the relationship between black hole mass and host galaxy velocity dispersion for QSOs in Data Release 3 of the Sloan Digital Sky Survey. We derive black hole mass from the broad Hbeta line width and continuum luminosity, and the bulge stellar velocity dispersion from the [OIII] narrow line width. At higher redshifts, we use MgII and [OII] in place of Hbeta and [OIII]. For redshifts z < 0.5, our results agree with the black hole mass - bulge velocity dispersion relationship for nearby galaxies. For 0.5 < z < 1.2, this relationship appears to show evolution with redshift in the sense that the bulges are too small for their black holes. However, we find that part of this apparent trend can be attributed to observational biases, including a Malmquist bias involving the QSO luminosity. Accounting for these biases, we find ~0.2 dex evolution in the black hole mass-bulge velocity dispersion relationship between now and redshift z ~ 1.Comment: Accepted by ApJ, 15 pages, 9 figure

Is there an Income Gradient in Child Health? It depends whom you ask

A large literature uses parental evaluations of child health status to provide evidence on the socioeconomic determinants of health. If how parents perceive health questions differs by income or education level, then estimates of the socioeconomic gradient are likely to be biased and potentially misleading. In this paper we examine this issue. We directly compare child mental health evaluations from parents, teachers, children and psychiatrists for mental health problems, test whether these differences are systematically related to observable child and parent characteristics, and examine the implications of the different reports for the estimated income gradient. We find that respondents frequently evaluate children differently and while the sign of the income gradient is in the same direction across respondents, systematic differences in evaluations mean that the estimated magnitude and significance of the health-income gradient is highly dependent upon the choice of respondent and the measure of child health.Child Health, Income, Reporting Bias