Massive present-day early-type (elliptical and lenticular) galaxies probably gained the bulk of their stellar mass and heavy elements through intense, dust-enshrouded starbursts--that is, increased ...rates of star formation--in the most massive dark-matter haloes at early epochs. However, it remains unknown how soon after the Big Bang massive starburst progenitors exist. The measured redshift (z) distribution of dusty, massive starbursts has long been suspected to be biased low in z owing to selection effects, as confirmed by recent findings of systems with redshifts as high as ~5 (refs 2-4). Here we report the identification of a massive starburst galaxy at z = 6.34 through a submillimetre colour-selection technique. We unambiguously determined the redshift from a suite of molecular and atomic fine-structure cooling lines. These measurements reveal a hundred billion solar masses of highly excited, chemically evolved interstellar medium in this galaxy, which constitutes at least 40 per cent of the baryonic mass. A 'maximum starburst' converts the gas into stars at a rate more than 2,000 times that of the Milky Way, a rate among the highest observed at any epoch. Despite the overall downturn in cosmic star formation towards the highest redshifts, it seems that environments mature enough to form the most massive, intense starbursts existed at least as early as 880 million years after the Big Bang.
We present the first broadband Delta *l = 1 mm spectrum toward the z = 2.56 Cloverleaf quasar, obtained with Z-Spec, a grating spectrograph on the 10.4 m Caltech Submillimeter Observatory. The ...190-305 GHz observation band corresponds to the rest frame 272-444 Delta *mm, and we measure the dust continuum as well as all four transitions of carbon monoxide (CO) lying in this range. The power-law dust emission, F Delta *n = 14 mJy( Delta *n/240 GHz)3.9 is consistent with the published continuum measurements. The CO J = 6 -> 5, J = 8 -> 7, and J = 9 -> 8 measurements are the first, and now provide the highest-J CO information in this source. Our measured CO intensities are very close to the previously published interferometric measurements of J = 7 -> 6, and we use all available transitions and our 13CO upper limits to constrain the physical conditions in the Cloverleaf molecular gas disk. We find a large mass (2-50 X 109 M ) of highly excited gas with thermal pressure nT > 106 K cm-3. The ratio of the total CO cooling to the far-IR dust emission exceeds that in the local dusty galaxies, and we investigate the potential heating sources for this bulk of warm molecular gas. We conclude that both UV photons and X-rays likely contribute, and discuss implications for a top-heavy stellar initial mass function arising in the X-ray-irradiated starburst. Finally, we present tentative identifications of other species in the spectrum, including a possible detection of the H2O \20,2 -> 11,1 transition at Delta *lrest = 303 Delta *mm.
Scholarship about ethics in higher education often focuses on wrongdoing: cheating, incivility, and a host of other misdeeds. We focus, instead, on ethicality as the enactment of integrity across ...everyday work life. This approach is particularly true in student affairs where administrators, faculty members, staff members, and students intersect multiple social and professional arenas. Continuing the analysis of data from a previous study, we examined what it means “to be ethical,” especially in relationship to institutional and professional standards. We use theatrical metaphor techniques to explore scripting, staging, performing, and interpreting. Discussion centers on the spectacle of ethics in student affairs.
Participant selection is one of the most invisible and least critiqued methods in qualitative circles. Researchers do not just collect and analyze neutral data; they decide who matters as data. Each ...choice repositions inquiry, closing down some opportunities while creating others. After reviewing the selection literature, we present critical vignettes of our selection choices in three separate studies, examining how those choices directed meaning making within and beyond the studies. Our analysis across these vignettes uncovered a constant interface—and often a struggle—between our personal situations and social agendas as qualitative researchers. Four aspects of this Reporting In/Reporting Out tension are discussed: trusting qualitative research, building the story, dealing with powerful others, and accepting unintended consequences. We encourage qualitative researchers to critically think forward their selection choices before and during the research process, to be mindful that selection is a constitutive method of the data collection and analysis process.
We present a 190-307 GHz broadband spectrum obtained with Z-Spec of NGC 1068 with new measurements of molecular rotational transitions. After combining our measurements with those previously ...published and considering the specific geometry of this Seyfert 2 galaxy, we conduct a multi-species Bayesian likelihood analysis of the density, temperature, and relative molecular abundances of HCN, HNC, CS, and HCO+. We find that these molecules trace warm (T>100 K) gas of H2 number densities 104.2-104.9 cm--3. Our models also place strong constraints on the column densities and relative abundances of these molecules, as well as on the total mass in the circumnuclear disk. Using the uniform calibration afforded by the broad Z-Spec bandpass, we compare our line ratios to X-ray-dominated region (XDR) and photon-dominated region models. The majority of our line ratios are consistent with the XDR models at the densities indicated by the likelihood analysis, lending substantial support to the emerging interpretation that the energetics in the circumnuclear disk of NGC 1068 are dominated by accretion onto an active galactic nucleus.
This article discusses theoretical assumptions underlying physiological stress reactivity research. It examines early conceptualizations of activation and recovery and contrasts these with current ...practices in designing, analyzing, and reporting stress reactivity studies. Study protocols from four major journals covering the last 2 years of publication were examined for current practices. Of the 105 studies which tested physiological reactivity, 63% collected recovery data but only 23% reported the recovery data. We concluded that stress recovery issues are neglected and a renewed case is made for their conceptual and ecological importance. The case for studying recovery is further supported by a selective review of studies using recovery protocols that revealed positive findings not apparent in reactivity comparisons only. Finally, options for sound design of recovery protocols, statistical processing of resulting data, and interpretation of findings are presented.
To explore the differential effects of harassment on cardiovascular and neuroendocrine stress reactivity and recovery, 28 men and 32 women were randomized to a harassment or no-harassment control ...condition (four groups in total). The harassment consisted of three scripted statements delivered during performance of a mental arithmetic stress task. The harassing statements were delivered on a fixed schedule during the task by a same-gender experimenter. Cardiovascular, salivary cortisol, and state affect measures were taken at baseline, immediately posttask, and throughout an extended recovery period. In comparison to the control condition, harassment accentuated the stress reactivity responses on all measures, physiological and self-report of subjective affect. In addition, several gender differences in response to the stressor and during the recovery period were observed. Harassed men had the largest reactivity on cortisol and diastolic blood pressure, whereas the harassed women showed a more pronounced response on heart rate and self-reported hostility. The harassed groups were the only ones to show significant cortisol responses. Within the harassed condition, comparison of effect sizes revealed that cortisol reactivity in men was twice that of women. Control groups did not exhibit significant cortisol changes. During the recovery period, harassed men exhibited attenuated return to baseline on cardiovascular indices and cortisol, whereas women, overall, tended to exhibit an overcompensation response on cardiovascular measures. These results contribute to showing a pathway that may link negative affect (i.e., hostile or angry feelings) with the development of cardiovascular disease.
ABSTRACT We report on the detection of an extremely bright (37mJy at 1100μm and 91mJy at 880μm) submillimetre galaxy (SMG), AzTEC-ASTE-SXDF1100.001 (hereafter referred to as SXDF1100.001 or Orochi), ...discovered in the 1100μm observations of the Subaru/XMM-NewtonDeep Fieldusing AzTEC on ASTE. Subsequent CARMA 1300-μm and SMA 880-μm observations successfully pinpoint the location of Orochi and suggest that it has two components, one extended full width at half-maximum (FWHM) of 4arcsec and one compact (unresolved). Z-Spec on CSO has also been used to obtain a wide-band spectrum from 190 to 308GHz, although no significant emission/absorption lines were found. The derived upper limit to the line-to-continuum flux ratio is 0.1-0.3 (2σ) across the Z-Spec band. Based on the analysis of the derived spectral energy distribution from optical to radio wavelengths of possible counterparts near the SMA/CARMA peak position, we suggest that Orochi is a lensed, optically dark SMG lying atz 3.4 behind a foreground, optically visible (but red) galaxy atz 1.4. The deduced apparent (i.e., no correction for magnification) infrared luminosity (LIR) and star formation rate (SFR) are 6 × 1013L and 11000 Myr-1, respectively, assuming that theLIR is dominated by star formation. These values suggest that Orochi will consume its gas reservoir within a short time-scale (3 × 107yr), which is indeed comparable to those in extreme starbursts like the centres of local ultraluminous infrared galaxies (ULIRGs). PUBLICATION ABSTRACT