91 research outputs found
Altmetrics, Legacy Scholarship, and Scholarly Legacy
When using alternative metrics (altmetrics) to investigate the impact of a scholar’s work, researchers and librarians are typically cautioned that altmetrics will be less useful for older works of scholarship. This is because it is difficult to collect social media and other attention retroactively, and the numbers will be lower if the work was published before social media marketing and promotion were widely accepted in a field. In this article, we argue that altmetrics can provide useful information about older works in the form of documenting renewed attention to past scholarship as part of a scholar’s legacy. Using the altmetrics profile of the late Dr. Thomas E. Starzl, often referred to as “the father of modern transplantation”, we describe two cases where altmetrics provided information about renewed interest in his works: a controversy about race and genetics that shows the ongoing impact of a particular work, and posthumous remembrances by colleagues which reveal his scholarly legacy.</jats:p
Informing the Digital Archive with Altmetrics
Altmetrics can be used to understand impact beyond citations, particularly for digitized collections. As cultural institutions look to pursue more active engagement with communities of practice, altmetrics help archivists understand the conversations happening in real time that will allow them to provide access to the most relevant materials. Through the use of case studies, we aim to demonstrate how applying altmetrics while considering the curation of digital collections can allow archivists to stay engaged with target communities outside traditional channels, demonstrating both the applicability of altmetrics to legacy scholarly work and the value of digitization as an access method.</jats:p
Cosmic shear requirements on the wavelength-dependence of telescope point spread functions
Cosmic shear requires high precision measurement of galaxy shapes in the
presence of the observational Point Spread Function (PSF) that smears out the
image. The PSF must therefore be known for each galaxy to a high accuracy.
However, for several reasons, the PSF is usually wavelength dependent,
therefore the differences between the spectral energy distribution of the
observed objects introduces further complexity. In this paper we investigate
the effect of the wavelength-dependence of the PSF, focusing on instruments in
which the PSF size is dominated by the diffraction-limit of the telescope and
which use broad-band filters for shape measurement.
We first calculate biases on cosmological parameter estimation from cosmic
shear when the stellar PSF is used uncorrected. Using realistic galaxy and star
spectral energy distributions and populations and a simple three-component
circular PSF we find that the colour-dependence must be taken into account for
the next generation of telescopes. We then consider two different methods for
removing the effect (i) the use of stars of the same colour as the galaxies and
(ii) estimation of the galaxy spectral energy distribution using multiple
colours and using a telescope model for the PSF. We find that both of these
methods correct the effect to levels below the tolerances required for per-cent
level measurements of dark energy parameters. Comparison of the two methods
favours the template-fitting method because its efficiency is less dependent on
galaxy redshift than the broad-band colour method and takes full advantage of
deeper photometry.Comment: 10 pages, 8 figures, version accepted for publication in MNRA
Predicting spectral features in galaxy spectra from broad-band photometry
We explore the prospects of predicting emission line features present in
galaxy spectra given broad-band photometry alone. There is a general consent
that colours, and spectral features, most notably the 4000 A break, can predict
many properties of galaxies, including star formation rates and hence they
could infer some of the line properties. We argue that these techniques have
great prospects in helping us understand line emission in extragalactic objects
and might speed up future galaxy redshift surveys if they are to target
emission line objects only. We use two independent methods, Artifical Neural
Neworks (based on the ANNz code) and Locally Weighted Regression (LWR), to
retrieve correlations present in the colour N-dimensional space and to predict
the equivalent widths present in the corresponding spectra. We also investigate
how well it is possible to separate galaxies with and without lines from broad
band photometry only. We find, unsurprisingly, that recombination lines can be
well predicted by galaxy colours. However, among collisional lines some can and
some cannot be predicted well from galaxy colours alone, without any further
redshift information. We also use our techniques to estimate how much
information contained in spectral diagnostic diagrams can be recovered from
broad-band photometry alone. We find that it is possible to classify AGN and
star formation objects relatively well using colours only. We suggest that this
technique could be used to considerably improve redshift surveys such as the
upcoming FMOS survey and the planned WFMOS survey.Comment: 10 pages 7 figures summitted to MNRA
Automated reliability assessment for spectroscopic redshift measurements
We present a new approach to automate the spectroscopic redshift reliability
assessment based on machine learning (ML) and characteristics of the redshift
probability density function (PDF).
We propose to rephrase the spectroscopic redshift estimation into a Bayesian
framework, in order to incorporate all sources of information and uncertainties
related to the redshift estimation process, and produce a redshift posterior
PDF that will be the starting-point for ML algorithms to provide an automated
assessment of a redshift reliability.
As a use case, public data from the VIMOS VLT Deep Survey is exploited to
present and test this new methodology. We first tried to reproduce the existing
reliability flags using supervised classification to describe different types
of redshift PDFs, but due to the subjective definition of these flags, soon
opted for a new homogeneous partitioning of the data into distinct clusters via
unsupervised classification. After assessing the accuracy of the new clusters
via resubstitution and test predictions, unlabelled data from preliminary mock
simulations for the Euclid space mission are projected into this mapping to
predict their redshift reliability labels.Comment: Submitted on 02 June 2017 (v1). Revised on 08 September 2017 (v2).
Latest version 28 September 2017 (this version v3
A social scientific framework for social systems in online video games: Building a better looking for raid loot system in World of Warcraft
This paper examines social behavior in the online video game World of Warcraft. Specifically focusing on one element of social design: the behavior of players in the first release of Looking-for-Raid (LFR) loot system of World of Warcraft. It uses lens of economic game theory, combined with Williams (2010) mapping principle and a modern theoretical account of human decision-making, to explore how theory about individual interactions in well-defined contexts (games) can explain collective behavior. It provides some support for this theoretical approach with an examination of data collected as part of an ethnographic study, through focus groups, and a survey distributed to 333 World of Warcraft players. It concludes with a discussion of the results and some guidelines for predicting collective outcomes in certain types of online games using the introduced framework. © 2014 Elsevier Ltd. All rights reserved
A multi-disciplinary perspective on emergent and future innovations in peer review [version 1; peer review: 2 approved with reservations]
Peer review of research articles is a core part of our scholarly communication system. In spite of its importance, the status and purpose of peer review is often contested. What is its role in our modern digital research and communications infrastructure? Does it perform to the high standards with which it is generally regarded? Studies of peer review have shown that it is prone to bias and abuse in numerous dimensions, frequently unreliable, and can fail to detect even fraudulent research. With the advent of Web technologies, we are now witnessing a phase of innovation and experimentation in our approaches to peer review. These developments prompted us to examine emerging models of peer review from a range of disciplines and venues, and to ask how they might address some of the issues with our current systems of peer review. We examine the functionality of a range of social Web platforms, and compare these with the traits underlying a viable peer review system: quality control, quantified performance metrics as engagement incentives, and certification and reputation. Ideally, any new systems will demonstrate that they out-perform current models while avoiding as many of the biases of existing systems as possible. We conclude that there is considerable scope for new peer review initiatives to be developed, each with their own potential issues and advantages. We also propose a novel hybrid platform model that, at least partially, resolves many of the technical and social issues associated with peer review, and can potentially disrupt the entire scholarly communication system. Success for any such development relies on reaching a critical threshold of research community engagement with both the process and the platform, and therefore cannot be achieved without a significant change of incentives in research environments
Herschel-ATLAS: Multi-wavelength SEDs and physical properties of 250 micron-selected galaxies at z < 0.5
We present a pan-chromatic analysis of an unprecedented sample of 1402 250
micron-selected galaxies at z < 0.5 (mean z = 0.24) from the Herschel-ATLAS
survey. We complement our Herschel 100-500 micron data with UV-K-band
photometry from the Galaxy And Mass Assembly (GAMA) survey and apply the
MAGPHYS energy-balance technique to produce pan-chromatic SEDs for a
representative sample of 250 micron selected galaxies spanning the most recent
5 Gyr of cosmic history. We derive estimates of physical parameters, including
star formation rates, stellar masses, dust masses and infrared luminosities.
The typical H-ATLAS galaxy at z < 0.5 has a far-infrared luminosity in the
range 10^10 - 10^12 Lsolar (SFR: 1-50 Msolar/yr) thus is broadly representative
of normal star forming galaxies over this redshift range. We show that 250
micron-selected galaxies contain a larger mass of dust at a given infra-red
luminosity or star formation rate than previous samples selected at 60 micron
from IRAS. We derive typical SEDs for H-ATLAS galaxies, and show that the
emergent SED shape is most sensitive to specific star formation rate. The
optical-UV SEDs also become more reddened due to dust at higher redshifts. Our
template SEDs are significantly cooler than existing infra-red templates. They
may therefore be most appropriate for inferring total IR luminosities from
moderate redshift submillimetre selected samples and for inclusion in models of
the lower redshift submillimetre galaxy populations.Comment: 26 pages, 24 figures, Accepted by MNRA
Herschel-ATLAS: VISTA VIKING near-IR counterparts in the Phase 1 GAMA 9h data
We identify near-infrared Ks band counterparts to Herschel-ATLAS sub-mm
sources, using a preliminary object catalogue from the VISTA VIKING survey. The
sub-mm sources are selected from the H-ATLAS Phase 1 catalogue of the GAMA 9h
field, which includes all objects detected at 250, 350 or 500 um with the SPIRE
instrument. We apply and discuss a likelihood ratio (LR) method for VIKING
candidates within a search radius of 10" of the 22,000 SPIRE sources with a 5
sigma detection at 250 um. We find that 11,294(51%) of the SPIRE sources have a
best VIKING counterpart with a reliability , and the false
identification rate of these is estimated to be 4.2%. We expect to miss ~5% of
true VIKING counterparts. There is evidence from Z-J and J-Ks colours that the
reliable counterparts to SPIRE galaxies are marginally redder than the field
population. We obtain photometric redshifts for ~68% of all (non-stellar)
VIKING candidates with a median redshift of 0.405. Comparing to the results of
the optical identifications supplied with the Phase I catalogue, we find that
the use of medium-deep near-infrared data improves the identification rate of
reliable counterparts from 36% to 51%.Comment: 20 pages, 20 figures, 3 tables, accepted by MNRA
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