532 research outputs found
Galaxy And Mass Assembly (GAMA): curation and reanalysis of 16.6k redshifts in the G10/COSMOS region
We discuss the construction of the Galaxy And Mass Assembly (GAMA) 10h region (G10) using publicly available data in the Cosmic Evolution Survey region (COSMOS) in order to extend the GAMA survey to z ∼ 1 in a single deg2 field. In order to obtain the maximum number of high precision spectroscopic redshifts we re-reduce all archival zCOSMOS-bright data and use the GAMA automatic cross-correlation redshift fitting code autoz. We use all available redshift information (autoz, zCOSMOS-bright 10k, PRIMUS, VVDS, SDSS and photometric redshifts) to calculate robust best-fitting redshifts for all galaxies and visually inspect all 1D and 2D spectra to obtain 16 583 robust redshifts in the full COSMOS region. We then define the G10 region to be the central ∼1 deg2 of COSMOS, which has relatively high spectroscopic completeness, and encompasses the CHILES VLA region. We define a combined r < 23.0 mag and i < 22.0 mag G10 sample (selected to have the highest bijective overlap) with which to perform future analysis, containing 9861 sources with reliable high-precision VLT-VIMOS spectra. All tables, spectra and imaging are available at http://ict.icrar.org/cutout/G10
Non-Parametric Cell-Based Photometric Proxies for Galaxy Morphology: Methodology and Application to the Morphologically-Defined Star Formation -- Stellar Mass Relation of Spiral Galaxies in the Local Universe
(Abridged) We present a non-parametric cell-based method of selecting highly pure and largely complete samples of spiral galaxies using photometric and structural parameters as provided by standard photometric pipelines and simple shape fitting algorithms, demonstrably superior to commonly used proxies. Furthermore, we find structural parameters derived using passbands longwards of the band and linked to older stellar populations, especially the stellar mass surface density and the band effective radius , to perform at least equally well as parameters more traditionally linked to the identification of spirals by means of their young stellar populations. In particular the distinct bimodality in the parameter , consistent with expectations of different evolutionary paths for spirals and ellipticals, represents an often overlooked yet powerful parameter in differentiating between spiral and non-spiral/elliptical galaxies. We investigate the intrinsic specific star-formation rate - stellar mass relation () for a morphologically defined volume limited sample of local universe spiral galaxies, defined using the cell-based method with an appropriate parameter combination. The relation is found to be well described by over the range of with a mean interquartile range of dex. This is somewhat steeper than previous determinations based on colour-selected samples of star-forming galaxies, primarily due to the inclusion in the sample of red quiescent disks
The Hyper Suprime-Cam extended Point Spread Functions and applications to measuring the intra-halo light
We present extended point spread function (PSF) models for the Hyper
Suprime-Cam Subaru Strategic Program Public Data Release 3 (HSC-SSP PDR3) in
all and -bands. Due to its 8.2m primary mirror
and long exposure periods, HSC combines deep images with wide-field coverage,
making it one of the most suitable observing facilities for low surface
brightness (LSB) studies. By applying a median stacking technique of point
sources with different brightnesses, we show how to construct the HSC-SSP PDR3
PSF models to an extent of R 5.6 arcmin. These new PSFs provide the
community with a crucial tool to characterise LSB properties at large angles.
We apply our HSC PSFs and demonstrate that they behave reasonably in two cases:
first, to generate a 2-D model of a bright star, and second, to remove the
PSF-scattered light from an Ultra Deep image of the 400020 Galaxy And Mass
Assembly (GAMA) group in the SXDS field. Our main focus in this second
application is characterising the -band intra-halo light (IHL)
component of 400020. Building on advanced source extraction techniques with
careful consideration of PSF flux, we measure the IHL surface brightness (SB)
group profile up to 31 mag arcsec and R = 300 kpc. We estimate
the IHL fraction () profile, with a mean of
0.13. Our results show that not removing the PSF
light can overestimate the IHL SB by 1.7 mag arcsec and the
by 30%.Comment: 21 pages, 19 figures, submitted to MNRA
Preferences for Medical Consultations from Online Providers: Evidence from a Discrete Choice Experiment in the United Kingdom
Background:
In the UK, consultations for prescription medicines are available via private providers such as online pharmacies. However, these providers may have lower thresholds for prescribing certain drugs. This is a particular concern for antibiotics, given the increasing burden of antimicrobial resistance. Public preferences for consultations with online providers are unknown, hence the impact of increased availability of online consultations on antibiotic use and population health is unclear.
Objective:
To conduct a discrete choice experiment survey to understand UK public preferences for seeking online consultations, and the factors that influence these preferences, in the context of having symptoms for which antibiotics may be appropriate.
Methods:
In a survey conducted between July and August 2018, general population respondents completed 16 questions in which they chose a primary care consultation via either their local medical centre or an online provider. Consultations were described in terms of five attributes, including cost and similarity to traditional ‘face-to-face’ appointments. Choices were modelled using regression analysis.
Results:
Respondents (n = 734) placed a high value on having a consultation via their local medical centre rather than an online provider, and a low value on consultations by phone or video. However, respondents characterised as ‘busy young professionals’ showed a lower strength of preference for traditional consultations, with a higher concern for convenience.
Conclusion:
Before COVID-19, the UK public had limited appetite for consultations with online providers, or for consultations that were not face-to-face. Nevertheless, prescriptions from online providers should be monitored going forward, particularly for antibiotics, and in key patient groups
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