52 research outputs found
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Detaching data from the state: biobanking and building big data in Sweden
LifeGene, a biobank and research infrastructure, is Sweden’s largest biomedical pro- ject. Designed for research on gene–environment interactions, the project aimed to collect data and biological samples from 500 000 individuals. The directors pointed to Sweden’s universal health-care system, national registries and pro-science citizenry as indicative of the nation’s unique suitability for this ambitious project. As researchers explained, in Sweden, large-scale national collection of per- sonal data has generally proceeded with little debate. In this view, the historical legacy of social engineering and close ties between science and the state has led to a popular sense of trust in the state to collect and use information in the best interest of the population. However, LifeGene is more than just a continuation of information-gathering-as-usual in a country where the government has long kept track of its population’s health and social characteristics. With LifeGene, the construction of surrounding research infrastructures, and a reworking of national data protection legislation, Swedish researchers and authorities are now purposely building a framework for moving from data- as-usual to Big Data and the Big Value it promises to deliver. Drawing on ethnographic fieldwork with Swedish researchers and data managers, this article will examine the legal, social and infra- structural challenges of Sweden’s bid for Big Data.</p
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AE Interviews Emily Martin: The 25th Anniversary of "The End of the Body"
PRIMUS: The relationship between Star formation and AGN accretion
We study the evidence for a connection between active galactic nuclei (AGN)
fueling and star formation by investigating the relationship between the X-ray
luminosities of AGN and the star formation rates (SFRs) of their host galaxies.
We identify a sample of 309 AGN with erg
s at in the PRIMUS redshift survey. We find AGN in
galaxies with a wide range of SFR at a given . We do not find a
significant correlation between SFR and the observed instantaneous for
star forming AGN host galaxies. However, there is a weak but significant
correlation between the mean and SFR of detected AGN in star
forming galaxies, which likely reflects that varies on shorter
timescales than SFR. We find no correlation between stellar mass and
within the AGN population. Within both populations of star
forming and quiescent galaxies, we find a similar power-law distribution in the
probability of hosting an AGN as a function of specific accretion rate.
Furthermore, at a given stellar mass, we find a star forming galaxy
more likely than a quiescent galaxy to host an AGN of a given specific
accretion rate. The probability of a galaxy hosting an AGN is constant across
the main sequence of star formation. These results indicate that there is an
underlying connection between star formation and the presence of AGN, but AGN
are often hosted by quiescent galaxies
PRIMUS: The Effect of Physical Scale on the Luminosity-Dependence of Galaxy Clustering via Cross-Correlations
We report small-scale clustering measurements from the PRIMUS spectroscopic
redshift survey as a function of color and luminosity. We measure the
real-space cross-correlations between 62,106 primary galaxies with PRIMUS
redshifts and a tracer population of 545,000 photometric galaxies over
redshifts from z=0.2 to z=1. We separately fit a power-law model in redshift
and luminosity to each of three independent color-selected samples of galaxies.
We report clustering amplitudes at fiducial values of z=0.5 and L=1.5 L*. The
clustering of the red galaxies is ~3 times as strong as that of the blue
galaxies and ~1.5 as strong as that of the green galaxies. We also find that
the luminosity dependence of the clustering is strongly dependent on physical
scale, with greater luminosity dependence being found between r=0.0625 Mpc/h
and r=0.25 Mpc/h, compared to the r=0.5 Mpc/h to r=2 Mpc/h range. Moreover,
over a range of two orders of magnitude in luminosity, a single power-law fit
to the luminosity dependence is not sufficient to explain the increase in
clustering at both the bright and faint ends at the smaller scales. We argue
that luminosity-dependent clustering at small scales is a necessary component
of galaxy-halo occupation models for blue, star-forming galaxies as well as for
red, quenched galaxies.Comment: 13 pages, 6 figures, 5 tables; published in ApJ (revised to match
published version
Dark Matter Halo Models of Stellar Mass-Dependent Galaxy Clustering in PRIMUS+DEEP2 at 0.2<z<1.2
We utilize CDM halo occupation models of galaxy clustering to
investigate the evolving stellar mass dependent clustering of galaxies in the
PRIsm MUlti-object Survey (PRIMUS) and DEEP2 Redshift Survey over the past
eight billion years of cosmic time, between . These clustering
measurements provide new constraints on the connections between dark matter
halo properties and galaxy properties in the context of the evolving
large-scale structure of the universe. Using both an analytic model and a set
of mock galaxy catalogs, we find a strong correlation between central galaxy
stellar mass and dark matter halo mass over the range
-, approximately consistent
with previous observations and theoretical predictions. However, the
stellar-to-halo mass relation (SHMR) and the mass scale where star formation
efficiency reaches a maximum appear to evolve more strongly than predicted by
other models, including models based primarily on abundance-matching
constraints. We find that the fraction of satellite galaxies in haloes of a
given mass decreases significantly from to , partly due to
the fact that haloes at fixed mass are rarer at higher redshift and have lower
abundances. We also find that the ratio, a model parameter
that quantifies the critical mass above which haloes host at least one
satellite, decreases from at to at .
Considering the evolution of the subhalo mass function vis-\`{a}-vis satellite
abundances, this trend has implications for relations between satellite
galaxies and halo substructures and for intracluster mass, which we argue has
grown due to stripped and disrupted satellites between and
.Comment: 17 pages, 9 figures and 4 tables; Astrophysical Journal, publishe
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