Who, or what, holds power in business-to-business buyer–seller relationships is a debate at the heart of power theory. Power in buyer–seller relationships is variously seen as the property of ...organizations, individuals or relationships yet to be theoretically valid and useful to management, integration of these schools of thought needs to be operationalized. This paper opens up future research avenues through identifying how buyers and sellers understand the origins of power and the nature of self perceived and countervailing power. The paper presents results from 10 focus groups of both buyers and sellers revealing the underlying origins of experienced power. The results support the proposition that power in buyer–seller relationships is a pluralistic concept and that extant theories focused on organizational, individual or relational elements of power are independently too narrow in their reflections of the power construct; rather, they are all part of the same broad construct.
►We identify how buyers and sellers understand the origins of self perceived and countervailing power. ►Inductive focus groups explore buyers and sellers understanding of experienced power and its composition. ►An integrated model identifies organizational, individual and relational aspects of power from both sides of the dyad. ►An integrated perspective demonstrates multiple embedded realities of power structures.
Producing Women's Poetry is the first specialist study to consider English-language poetry by women across the seventeenth and early eighteenth centuries. Gillian Wright explores not only the forms ...and topics favoured by women, but also how their verse was enabled and shaped by their textual and biographical circumstances. She combines traditional literary and bibliographical approaches to address women's complex use of manuscript and print and their relationships with the male-generated genres of the traditional literary canon, as well as the role of agents such as scribes, publishers and editors in helping to determine how women's poetry was preserved, circulated and remembered. Wright focuses on key figures in the emerging canon of early modern women's writing, Anne Bradstreet, Katherine Philips and Anne Finch, alongside the work of lesser-known poets Anne Southwell and Mary Monck, to create a new and compelling account of early modern women's literary history.
Abstract
We present the ultraviolet luminosity function and an estimate of the cosmic star formation rate density at 8 <
z
< 13 derived from deep NIRCam observations taken in parallel with the MIRI ...Deep Survey of the Hubble Ultra Deep Field (HUDF), NIRCam covering the parallel field 2. Our deep (40 hr) NIRCam observations reach an F277W magnitude of 30.8 (5
σ
), more than 2 mag deeper than JWST public data sets already analyzed to find high-redshift galaxies. We select a sample of 44
z
> 8 galaxy candidates based on their dropout nature in the F115W and/or F150W filters, a high probability for their photometric redshifts, estimated with three different codes, being at
z
> 8, good fits based on
χ
2
calculations, and predominant solutions compared to
z
< 8 alternatives. We find mild evolution in the luminosity function from
z
∼ 13 to
z
∼ 8, i.e., only a small increase in the average number density of ∼0.2 dex, while the faint-end slope and absolute magnitude of the knee remain approximately constant, with values
α
= − 2.2 ± 0.1, and
M
*
= − 20.8 ± 0.2 mag. Comparing our results with the predictions of state-of-the-art galaxy evolution models, we find two main results: (1) a slower increase with time in the cosmic star formation rate density compared to a steeper rise predicted by models; (2) nearly a factor of 10 higher star formation activity concentrated in scales around 2 kpc in galaxies with stellar masses ∼10
8
M
⊙
during the first 350 Myr of the universe,
z
∼ 12, with models matching better the luminosity density observational estimations ∼150 Myr later, by
z
∼ 9.
Abstract We present a JWST imaging survey of I Zw 18, the archetypal extremely metal-poor, star-forming (SF), blue compact dwarf galaxy. With an oxygen abundance of only ∼3% Z ⊙ , it is among the ...lowest-metallicity systems known in the local Universe, and is, therefore, an excellent accessible analog for the galactic building blocks which existed at early epochs of ionization and star formation. These JWST data provide a comprehensive infrared (IR) view of I Zw 18 with eight filters utilizing both Near Infrared Camera (F115W, F200W, F356W, and F444W) and Mid-Infrared Instrument (F770W, F1000W, F1500W, and F1800W) photometry, which we have used to identify key stellar populations that are bright in the near- and mid-IR. These data allow for a better understanding of the origins of dust and dust-production mechanisms in metal-poor environments by characterizing the population of massive, evolved stars in the red supergiant (RSG) and asymptotic giant branch (AGB) phases. In addition, it enables the identification of the brightest dust-enshrouded young stellar objects (YSOs), which provide insight into the formation of massive stars at extremely low metallicities typical of the very early Universe. This paper provides an overview of the observational strategy and data processing, and presents first science results, including identifications of dusty AGB, RSG, and bright YSO candidates. These first results assess the scientific quality of JWST data and provide a guide for obtaining and interpreting future observations of the dusty and evolved stars inhabiting compact dwarf SF galaxies in the local Universe.
Context
. The Medium Resolution integral field Spectrometer (MRS) of the Mid-Infrared Instrument (MIRI) on board the
James Webb
Space Telescope (JWST) performs spectroscopy between 5 and 28 µm, with ...a field of view varying from ~13 to ~56 sq. arcsec. The optics of the MRS introduce substantial distortion and this needs to be rectified in order to reconstruct the observed astrophysical scenario.
Aims
. We aim to use data from the JWST/MIRI commissioning and cycle 1 calibration phase to derive the MRS geometric distortion and astrometric solution, a critical step in the calibration of MRS data. These solutions come in the form of transform matrices that map the detector pixels to spatial coordinates of a local MRS coordinate system called
α
/
β
, to the global JWST observatory coordinates
V
2 and
V
3 (
V
2+
V
3).
Methods
. For every MRS spectral band and each slice dispersed on the detector, we fit the transform of detector pixels to
α
/
β
by a two-dimensional (2D) polynomial, using a raster of point source observations. The dispersed trace of the point source on the detector was initially estimated by fitting a one-dimensional (1D) empirical function and then iterating on the first distortion solution using forward modelling of the point spread function model based on the
webbpsf python
package. A polynomial transform was used to map the coordinates from α/
β
to
V
2+
V
3.
Results
. We calibrated the distortion of all 198 discrete slices of the MIRI/MRS integral field units and derived an updated field of view (FoV) for each MRS spectral band. The precision of the distortion solution is estimated to be better than one-tenth of a spatial resolution element, with a root mean square (rms) of 10 milli-arc-second (mas) at 5 µm, to 23 mas at 27 µm. Finally, we found that the wheel positioning repeatability causes an additional astrometric rms error of 30 mas.
Conclusions
. We demonstrate the application of the MRS astrometric calibration strategy and analysis for all four integral field units and all spectral bands of the MRS that enable the calibration of MRS spectra. This is a critical step in the data pipeline of every MRS observation. The distortion calibration was folded into the JWST pipeline in the Calibration Reference Data System (CRDS) context (jwst_1094.pmap), meeting the pre-launch requirement, with an estimated total astrometric uncertainty of 50 mas.
Abstract
We present here the first ever mid-infrared spectroscopic time series observation of the transiting exoplanet L 168-9 b with the Mid-Infrared Instrument (MIRI) on the James Webb Space ...Telescope. The data were obtained as part of the MIRI commissioning activities, to characterize the performance of the Low Resolution Spectroscopy (LRS) mode for these challenging observations. To assess the MIRI LRS performance, we performed two independent analyses of the data. We find that with a single transit observation we reached a spectro-photometric precision of ∼50 ppm in the 7–8
μ
m range at
R
= 50, consistent with ∼25 ppm systematic noise. The derived band averaged transit depth is 524 ± 15 ppm and 547 ± 13 ppm for the two applied analysis methods, respectively, recovering the known transit depth to within 1
σ
. The measured noise in the planet’s transmission spectrum is approximately 15%–20% higher than random noise simulations over wavelengths 6.8 ≲
λ
≲ 11
μ
m. We observed an larger excess noise at the shortest wavelengths of up to a factor of two, for which possible causes are discussed. This performance was achieved with limited in-flight calibration data, demonstrating the future potential of MIRI for the characterization of exoplanet atmospheres.
Power, as a significant dimension of relationships, continues to be of critical interest in the inter-organizational literature. This article assesses how different relationship types and strategic ...foci are related to buyers' and sellers' power priorities. Contributing to the discussion of buyer–seller power priority areas as commercial detail, operational issues, strategic issues and attitudes, the research focuses on the influence of relationship types (new, approved, preferred, partnership) on these power priorities in B2B contexts. This is important as partnerships do not simply emerge, but evolve over time suggesting that for both parties there is a period that is transitory. Through a survey of buyers and sellers (n=355), the research highlights that as partnerships evolve, relational issues complement, but do not supersede, the focus on commercial and operational concerns. Furthermore, within partnerships, whilst sellers' focus on strategic issues increases, it is the total power that grows and the influence agenda is extended, rather than re-distributed. Additionally, it provides detail on how power priorities vary and are differentially distributed between buyers and sellers in different relationship types. This paper contributes to B2B partnership and power theories, challenging assumptions about relationships and adding weight to the increasing suggestion that relationship success is overplayed.
•Through a survey we identify the influence of relationship types on the power priorities of buyers and sellers.•As partnerships evolve, relational issues complement, but do not supersede, a focus on commercial and operational concerns.•Power priorities vary and are differentially distributed between buyers and sellers in different relationship types.•Challenges assumptions of the relational view and adds weight to the suggestion that partnerships are overplayed
The James Webb space telescope GARDNER, Jonathan P; MATHER, John C; LUNINE, Jonathan I ...
Space science reviews,
01/2006, Letnik:
123, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Issue Title: The James Webb Space Telescope The James Webb Space Telescope (JWST) is a large (6.6 m), cold (<50 K), infrared (IR)-optimized space observatory that will be launched early in the next ...decade into orbit around the second Earth-Sun Lagrange point. The observatory will have four instruments: a near-IR camera, a near-IR multiobject spectrograph, and a tunable filter imager will cover the wavelength range, 0.6 < ; < 5.0 μ m, while the mid-IR instrument will do both imaging and spectroscopy from 5.0 < ; < 29 μ m. The JWST science goals are divided into four themes. The key objective of The End of the Dark Ages: First Light and Reionization theme is to identify the first luminous sources to form and to determine the ionization history of the early universe. The key objective of The Assembly of Galaxies theme is to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and active nuclei within them evolved from the epoch of reionization to the present day. The key objective of The Birth of Stars and Protoplanetary Systems theme is to unravel the birth and early evolution of stars, from infall on to dust-enshrouded protostars to the genesis of planetary systems. The key objective of the Planetary Systems and the Origins of Life theme is to determine the physical and chemical properties of planetary systems including our own, and investigate the potential for the origins of life in those systems. Within these themes and objectives, we have derived representative astronomical observations. To enable these observations, JWST consists of a telescope, an instrument package, a spacecraft, and a sunshield. The telescope consists of 18 beryllium segments, some of which are deployed. The segments will be brought into optical alignment on-orbit through a process of periodic wavefront sensing and control. The instrument package contains the four science instruments and a fine guidance sensor. The spacecraft provides pointing, orbit maintenance, and communications. The sunshield provides passive thermal control. The JWST operations plan is based on that used for previous space observatories, and the majority of JWST observing time will be allocated to the international astronomical community through annual peer-reviewed proposal opportunities.PUBLICATION ABSTRACT
This paper contributes to the operationalisation of the power construct in inter-organisational relationships through establishing what buyers and sellers seek to influence, and the relative ...priorities of these areas for both roles. Through semi-structured interviews and a questionnaire, four constructs emerge: Commercial Detail, Operational Issues, Strategic Issues and Attitudes. These are identified as the key power priorities that buyers and sellers seek to influence within their inter-organisational relationships. The results reveal that despite some differences in rank-order by role, only the Commercial Detail construct reveals significant differences between the buyers’ and sellers’ ability to influence. Despite this difference, the results provide evidence that buyers and sellers share more commonalities than differences. The research adds an important dimension to understanding organisational buyer behaviour, specifically contextualising power and the boundaries of buyers’ and sellers’ influence.
Abstract We present deep James Webb Space Telescope (JWST)/Mid-Infrared Instrument (MIRI) F560W observations of a flux-limited, Atacama Large Millimeter/submillimeter Array (ALMA)-selected sample of ...28 galaxies at z = 0.5–3.7 in the Hubble Ultra Deep Field (HUDF). The data from the MIRI Deep Imaging Survey (MIDIS) reveal the stellar structure of the HUDF galaxies at rest-frame wavelengths of λ > 1 μ m for the first time. We revise the stellar mass estimates using new JWST photometry and find good agreement with pre-JWST analyses; the few discrepancies can be explained by blending issues in the earlier lower-resolution Spitzer data. At z ∼ 2.5, the resolved rest-frame near-infrared (1.6 μ m) structure of the galaxies is significantly more smooth and centrally concentrated than seen by the Hubble Space Telescope at rest-frame 450 nm (F160W), with effective radii of R e (F560W) = 1–5 kpc and Sérsic indices mostly close to an exponential (disk-like) profile ( n ≈ 1), up to n ≈ 5 (excluding active galactic nuclei). We find an average size ratio of R e (F560W)/ R e (F160W) ≈ 0.7 that decreases with stellar mass. The stellar structure of the ALMA-selected galaxies is indistinguishable from a HUDF reference sample of all galaxies with a MIRI flux density greater than 1 μ Jy. We supplement our analysis with custom-made, position-dependent, empirical point-spread function models for the F560W observations. The results imply that a smoother stellar structure is in place in massive gas-rich, star-forming galaxies at “Cosmic Noon,” despite a more clumpy rest-frame optical appearance, placing additional constraints on galaxy formation simulations. As a next step, matched-resolution, resolved ALMA observations will be crucial to further link the mass- and light-weighted galaxy structures to the dusty interstellar medium.
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