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Dictionary of environmental and climate change law
This dictionary defines terms employed in international agreements, national legislation and scholarly legal studies related to comparative and international environmental law and the emerging law of climate change. Each term also includes its pinyin translation in order to facilitate accessing the Mandarin variants of each term.
Book
Building the Evryscope: Hardware Design and Performance
The Evryscope is a telescope array designed to open a new parameter space in optical astronomy, detecting short-timescale events across extremely large sky areas simultaneously. The system consists of a 780 MPix 22-camera array with an 8150 sq. deg. field of view, 13″ per pixel sampling, and the ability to detect objects down to m g ′ 16 in each 2-minute dark-sky exposure. The Evryscope, covering 18,400 sq. deg. with hours of high-cadence exposure time each night, is designed to find the rare events that require all-sky monitoring, including transiting exoplanets around exotic stars like white dwarfs and hot subdwarfs, stellar activity of all types within our galaxy, nearby supernovae, and other transient events such as gamma-ray bursts and gravitational-wave electromagnetic counterparts. The system averages 5000 images per night with ∼300,000 sources per image, and to date has taken over 3.0M images, totaling 250 TB of raw data. The resulting light curve database has light curves for 9.3M targets, averaging 32,600 epochs per target through 2018. This paper summarizes the hardware and performance of the Evryscope, including the lessons learned during telescope design, electronics design, a procedure for the precision polar alignment of mounts for Evryscope-like systems, robotic control and operations, and safety and performance-optimization systems. We measure the on-sky performance of the Evryscope, discuss its data analysis pipelines, and present some example variable star and eclipsing binary discoveries from the telescope. We also discuss new discoveries of very rare objects including two hot subdwarf eclipsing binaries with late M-dwarf secondaries (HW Vir systems), two white dwarf/hot subdwarf short-period binaries, and four hot subdwarf reflection binaries. We conclude with the status of our transit surveys, M-dwarf flare survey, and transient detection.
Journal Article
Evryscope Science: Exploring the Potential of All-Sky Gigapixel-Scale Telescopes
Low-cost mass-produced sensors and optics have recently made it feasible to build telescope arrays which observe the entire accessible sky simultaneously. In this article, we discuss the scientific motivation for these telescopes, including exoplanets, stellar variability, and extragalactic transients. To provide a concrete example we detail the goals and expectations for the Evryscope, an under-construction 780 MPix telescope which covers 8660 sq. deg. in each 2-minute exposure; each night, 18,400 sq. deg. will be continuously observed for an average of ≈6 hr. Despite its small 61 mm aperture, the system's large field of view provides an étendue which is ∼10% of LSST. The Evryscope, which places 27 separate individual telescopes into a common mount which tracks the entire accessible sky with only one moving part, will return 1%-precision, many-year-length, high-cadence light curves for every accessible star brighter than ∼16th magnitude. The camera readout times are short enough to provide near-continuous observing, with a 97% survey time efficiency. The array telescope will be capable of detecting transiting exoplanets around every solar-type star brighter than mV = 12, providing at least few-millimagnitude photometric precision in long-term light curves. It will be capable of searching for transiting giant planets around the brightest and most nearby stars, where the planets are much easier to characterize; it will also search for small planets nearby M-dwarfs, for planetary occultations of white dwarfs, and will perform comprehensive nearby microlensing and eclipse-timing searches for exoplanets inaccessible to other planet-finding methods. The Evryscope will also provide comprehensive monitoring of outbursting young stars, white dwarf activity, and stellar activity of all types, along with finding a large sample of very-long-period M-dwarf eclipsing binaries. When relatively rare transients events occur, such as gamma-ray bursts (GRBs), nearby supernovae, or even gravitational wave detections from the Advanced LIGO/Virgo network, the array will return minute-by-minute light curves without needing pointing toward the event as it occurs. By coadding images, the system will reach V ∼ 19 in 1-hr integrations, enabling the monitoring of faint objects. Finally, by recording all data, the Evryscope will be able to provide pre-event imaging at 2-minute cadence for bright transients and variable objects, enabling the first high-cadence searches for optical variability before, during and after all-sky events.
Journal Article
Low-cost Access to the Deep, High-cadence Sky: the Argus Optical Array
New mass-produced, wide-field, small-aperture telescopes have the potential to revolutionize ground-based astronomy by greatly reducing the cost of collecting area. In this paper, we introduce a new class of large telescope based on these advances: an all-sky, arcsecond-resolution, 1000 telescope array which builds a simultaneously high-cadence and deep survey by observing the entire sky all night. As a concrete example, we describe the Argus Array, a 5 m-class telescope with an all-sky field of view and the ability to reach extremely high cadences using low-noise CMOS detectors. Each 55 GPix Argus exposure covers 20% of the entire sky to m g = 19.6 each minute and m g = 21.9 each hour; a high-speed mode will allow sub-second survey cadences for short times. Deep coadds will reach m g = 23.6 every five nights over 47% of the sky; a larger-aperture array telescope, with an étendue close to the Rubin Observatory, could reach m g = 24.3 in five nights. These arrays can build two-color, million-epoch movies of the sky, enabling sensitive and rapid searches for high-speed transients, fast-radio-burst counterparts, gravitational-wave counterparts, exoplanet microlensing events, occultations by distant solar system bodies, and myriad other phenomena. An array of O(1000) telescopes, however, would be one of the most complex astronomical instruments yet built. Standard arrays with hundreds of tracking mounts entail thousands of moving parts and exposed optics, and maintenance costs would rapidly outpace the mass-produced-hardware cost savings compared to a monolithic large telescope. We discuss how to greatly reduce operations costs by placing all optics in thermally controlled, sealed domes with only a few moving parts. Coupled with careful software scope control and use of existing pipelines, we show that the Argus Array could become the deepest and fastest Northern sky survey, with total costs in the $20M range.
Journal Article
Barriers And Challenges Of Multidisciplinary Teams In Oncology Management: A Scoping Review Protocol
IntroductionMultidisciplinary teams (MDTs) are integral to oncology management, involving specialised healthcare professionals who collaborate to develop individualised treatment plans for patients. However, as cancer care grows more complex, MDTs must continually adapt to better address patient needs. This scoping review will explore barriers and challenges MDTs have encountered in the past decade; and propose strategies for optimising their utilisation to overcome these obstacles and improve patient care.Methods and analysisThe scoping review will follow Arksey and O’Malley’s framework and begin with a literature search using keywords in electronic databases such as PubMed/MEDLINE, Scopus and PsychINFO, covering the period from January 2013 to December 2022 and limited to English language publications. Four independent reviewers will screen titles and abstracts based on predefined inclusion criteria, followed by full-text review of selected titles. Relevant references cited in the publications will also be examined. A Preferred Reporting Items for Systematic reviews and Meta-Analyses flow diagram will be utilised to illustrate the methodology. Data from selected publications will be extracted, analysed, and categorised for further analysis.Ethics and disseminationThe results of the scoping review will provide a comprehensive overview of the barriers and challenges encountered by oncology MDTs over the past decade. These findings will contribute to the existing literature and provide insights into areas that require improvement in the functioning of MDTs in oncology management. The results will be disseminated through publication in a scientific journal, which will help to share the findings with the wider healthcare community and facilitate further research and discussion in this field.Trial registration detailsThe protocol for this scoping review is registered with Open Science Framework, available at DOI 10.17605/OSF.IO/R3Y8U.
Journal Article
Exploring the Optical Transient Sky with the Palomar Transient Factory
The Palomar Transient Factory (PTF) is a wide-field experiment designed to investigate the optical transient and variable sky on time scales from minutes to years. PTF uses the CFH12k mosaic camera, with a field of view of7.9 deg2
7.9
deg
2
and a plate scale of1″ pixel-1
1
″
pixel
-
1
, mounted on the Palomar Observatory 48 inch Samuel Oschin Telescope. The PTF operation strategy is devised to probe the existing gaps in the transient phase space and to search for theoretically predicted, but not yet detected, phenomena, such as fallback supernovae, macronovae, .Ia supernovae, and the orphan afterglows of gamma-ray bursts. PTF will also discover many new members of known source classes, from cataclysmic variables in their various avatars to supernovae and active galactic nuclei, and will provide important insights into understanding galactic dynamics (through RR Lyrae stars) and the solar system (asteroids and near-Earth objects). The lessons that can be learned from PTF will be essential for the preparation of future large synoptic sky surveys like the Large Synoptic Survey Telescope. In this article we present the scientific motivation for PTF and describe in detail the goals and expectations for this experiment.
Journal Article
Supernova SN 2011fe from an exploding carbon–oxygen white dwarf star
Multi-instrument detection of a nearby type 1a supernova shows that the exploding star was probably a carbon–oxygen white dwarf star in a binary system with a main-sequence companion.
Identification of a supernova companion
Supernova 2011fe in the Pinwheel galaxy, discovered by the Palomar Transient Factory on 24 August 2011, is the brightest type Ia supernova that's been seen from Earth for many years. Type Ia supernovae are thought to result from a thermonuclear explosion of an accreting white dwarf in a binary system, but little is known of the precise nature of the companion star and the physical properties of the progenitor system. Two new reports of observations of SN 2011fe narrow down the range of possibilities for the mystery companion. Nugent
et al
. present some of the earliest data ever obtained from a type Ia supernova. They find that the exploding star was probably a carbon–oxygen white dwarf, and conclude from the lack of an early shock that the companion may have been a main sequence star. Li
et al
. analysed pre-discovery images in the Hubble Space Telescope archives and find that no object was visible before the explosion. That rules out luminous red giants and the vast majority of helium stars as the mass-donating companion to an exploding white dwarf.
Type Ia supernovae have been used empirically as ‘standard candles’ to demonstrate the acceleration of the expansion of the Universe
1
,
2
,
3
even though fundamental details, such as the nature of their progenitor systems and how the stars explode, remain a mystery
4
,
5
,
6
. There is consensus that a white dwarf star explodes after accreting matter in a binary system, but the secondary body could be anything from a main-sequence star to a red giant, or even another white dwarf. This uncertainty stems from the fact that no recent type Ia supernova has been discovered close enough to Earth to detect the stars before explosion. Here we report early observations of supernova SN 2011fe in the galaxy M101 at a distance
7
from Earth of 6.4 megaparsecs. We find that the exploding star was probably a carbon–oxygen white dwarf, and from the lack of an early shock we conclude that the companion was probably a main-sequence star. Early spectroscopy shows high-velocity oxygen that slows rapidly, on a timescale of hours, and extensive mixing of newly synthesized intermediate-mass elements in the outermost layers of the supernova. A companion paper
8
uses pre-explosion images to rule out luminous red giants and most helium stars as companions to the progenitor.
Journal Article
The Palomar Transient Factory: System Overview, Performance, and First Results
The Palomar Transient Factory (PTF) is a fully-automated, wide-field survey aimed at a systematic exploration of the optical transient sky. The transient survey is performed using a new 8.1 square degree camera installed on the 48 inch Samuel Oschin telescope at Palomar Observatory; colors and light curves for detected transients are obtained with the automated Palomar 60 inch telescope. PTF uses 80% of the 1.2 m and 50% of the 1.5 m telescope time. With an exposure of 60 s the survey reaches a depth of
m
g
′
≈ 21.3
m
g
′
≈
21.3
and
m
R
≈ 20.6
m
R
≈
20.6
(5σ, median seeing). Four major experiments are planned for the five-year project: (1) a 5 day cadence supernova search; (2) a rapid transient search with cadences between 90 s and 1 day; (3) a search for eclipsing binaries and transiting planets in Orion; and (4) a 3π sr deep H-alpha survey. PTF provides automatic, real-time transient classification and follow-up, as well as a database including every source detected in each frame. This paper summarizes the PTF project, including several months of on-sky performance tests of the new survey camera, the observing plans, and the data reduction strategy. We conclude by detailing the first 51 PTF optical transient detections, found in commissioning data.
Journal Article
IPAC Image Processing and Data Archiving for the Palomar Transient Factory
The Palomar Transient Factory (PTF) is a multiepochal robotic survey of the northern sky that acquires data for the scientific study of transient and variable astrophysical phenomena. The camera and telescope provide for wide-field imaging in optical bands. In the five years of operation since first light on 2008 December 13, images taken with Mould-R and SDSS-g′ camera filters have been routinely acquired on a nightly basis (weather permitting), and two different Hα filters were installed in 2011 May (656 and 663 nm). The PTF image-processing and data-archival program at the Infrared Processing and Analysis Center (IPAC) is tailored to receive and reduce the data, and, from it, generate and preserve astrometrically and photometrically calibrated images, extracted source catalogs, and co-added reference images. Relational databases have been deployed to track these products in operations and the data archive. The fully automated system has benefited by lessons learned from past IPAC projects and comprises advantageous features that are potentially incorporable into other ground-based observatories. Both off-the-shelf and in-house software have been utilized for economy and rapid development. The PTF data archive is curated by the NASA/IPAC Infrared Science Archive (IRSA). A state-of-the-art custom Web interface has been deployed for downloading the raw images, processed images, and source catalogs from IRSA. Access to PTF data products is currently limited to an initial public data release (M81, M44, M42, SDSS Stripe 82, and the Kepler Survey Field). It is the intent of the PTF collaboration to release the full PTF data archive when sufficient funding becomes available.
Journal Article
Exclusion of a luminous red giant as a companion star to the progenitor of supernova SN 2011fe
Archival images of the progenitor system of supernova SN 2011fe are so sensitive that the presence of luminous red giants or most helium stars is directly ruled out.
Identification of a supernova companion
Supernova 2011fe in the Pinwheel galaxy, discovered by the Palomar Transient Factory on 24 August 2011, is the brightest type Ia supernova that's been seen from Earth for many years. Type Ia supernovae are thought to result from a thermonuclear explosion of an accreting white dwarf in a binary system, but little is known of the precise nature of the companion star and the physical properties of the progenitor system. Two new reports of observations of SN 2011fe narrow down the range of possibilities for the mystery companion. Nugent
et al
. present some of the earliest data ever obtained from a type Ia supernova. They find that the exploding star was probably a carbon–oxygen white dwarf, and conclude from the lack of an early shock that the companion may have been a main sequence star. Li
et al
. analysed pre-discovery images in the Hubble Space Telescope archives and find that no object was visible before the explosion. That rules out luminous red giants and the vast majority of helium stars as the mass-donating companion to an exploding white dwarf.
Type Ia supernovae are thought to result from a thermonuclear explosion of an accreting white dwarf in a binary system
1
,
2
, but little is known of the precise nature of the companion star and the physical properties of the progenitor system. There are two classes of models
1
,
3
: double-degenerate (involving two white dwarfs in a close binary system
2
,
4
) and single-degenerate models
5
,
6
. In the latter, the primary white dwarf accretes material from a secondary companion until conditions are such that carbon ignites, at a mass of 1.38 times the mass of the Sun. The type Ia supernova SN 2011fe was recently detected in a nearby galaxy
7
. Here we report an analysis of archival images of the location of SN 2011fe. The luminosity of the progenitor system (especially the companion star) is 10–100 times fainter than previous limits on other type Ia supernova progenitor systems
8
,
9
,
10
, allowing us to rule out luminous red giants and almost all helium stars as the mass-donating companion to the exploding white dwarf.
Journal Article