This paper describes the rapidly evolving and unusual supernova LSQ13ddu, discovered by the La Silla-QUEST survey. LSQ13ddu displayed a rapid rise of just 4.8\(\pm\)0.9 d to reach a peak brightness ...of \(-\)19.70\(\pm\)0.02 mag in the \(\mathit{LSQgr}\) band. Early spectra of LSQ13ddu showed the presence of weak and narrow He I features arising from interaction with circumstellar material (CSM). These interaction signatures weakened quickly, with broad features consistent with those seen in stripped-envelope SNe becoming dominant around two weeks after maximum. The narrow He I velocities are consistent with the wind velocities of luminous blue variables but its spectra lack the typically seen hydrogen features. The fast and bright early light curve is inconsistent with radioactive \(^{56}\)Ni powering but can be explained through a combination of CSM interaction and an underlying \(^{56}\)Ni decay component that dominates the later time behaviour of LSQ13ddu. Based on the strength of the underlying broad features, LSQ13ddu appears deficient in He compared to standard SNe Ib.
A wide-field space-based imaging telescope is necessary to fully exploit the technique of observing dark matter via weak gravitational lensing. This first paper in a three part series outlines the ...survey strategies and relevant instrumental parameters for such a mission. As a concrete example of hardware design, we consider the proposed Supernova/Acceleration Probe (SNAP). Using SNAP engineering models, we quantify the major contributions to this telescope's point spread function (PSF). These PSF contributions are relevant to any similar wide-field space telescope. We further show that the PSF of SNAP or a similar telescope will be smaller than current ground-based PSFs, and more isotropic and stable over time than the PSF of the Hubble Space Telescope. We outline survey strategies for two different regimes--a ``wide'' 300 square degree survey and a ``deep'' 15 square degree survey that will accomplish various weak lensing goals including statistical studies and dark matter mapping.
A key tracer of the elusive progenitor systems of Type Ia supernovae (SNe Ia) is the detection of narrow blueshifted time-varying Na I D absorption lines, interpreted as evidence of circumstellar ...material (CSM) surrounding the progenitor system. The origin of this material is controversial, but the simplest explanation is that it results from previous mass loss in a system containing a white dwarf and a non-degenerate companion star. We present new single-epoch intermediate-resolution spectra of 17 low-redshift SNe Ia taken with XShooter on the ESO Very Large Telescope. Combining this sample with events from the literature, we confirm an excess (~20 per cent) of SNe Ia displaying blueshifted narrow Na I D absorption features compared to non-blueshifted Na I D features. The host galaxies of SNe Ia displaying blueshifted absorption profiles are skewed towards later-type galaxies, compared to SNe Ia that show no Na I D absorption, and SNe Ia displaying blueshifted narrow Na I D absorption features have broader light curves. The strength of the Na I D absorption is stronger in SNe Ia displaying blueshifted Na I D absorption features than those without blueshifted features, and the strength of the blueshifted Na I D is correlated with the B-V colour of the SN at maximum light. This strongly suggests the absorbing material is local to the SN. In the context of the progenitor systems of SNe Ia, we discuss the significance of these findings and other recent observational evidence on the nature of SN Ia progenitors. We present a summary that suggests there are at least two distinct populations of normal, cosmologically useful SNe Ia.
Studied changes in departmental and job characteristics with 153 Ss over a 10-mo period in a government ministry undergoing top-down reorganization. Three waves of data were collected, 5 mo apart. ...Using a ^h 3 × 3 ^H multivariate ANOVA, the effects of positive change, no change, and negative changes in jobs and in departmental characteristics were examined. Contrary to the findings of a sizable number of correlational studies, but in agreement with 4 other longitudinal studies, changes in job characteristics were not related to changes in perceived effort, performance, and satisfaction (Job Descriptive Index). Job changes were, however, positively related to changes in job involvement. No changes were found in the strength of Ss' growth needs following changes in job characteristics. Analysis of departmental changes revealed more favorable work attitudes where no change occurred than in departments in which change was occurring (either supposedly "positive" or "negative" change.) A general decline over time was found in the favorableness of work attitudes. The latter 2 findings are interpreted as the consequences of top-down imposed change. (33 ref)
Exploration of the time variability on the sky over a broad range of flux
levels and wavelengths is rapidly becoming a new frontier of astronomical
research. We describe here briefly the ...Palomar-QUEST survey being carried out
from the Samuel Oschin 48-inch Schmidt telescope at Palomar. The following
features make the survey an attractive candidate for studying time variability:
anticipated survey area of 12,000 - 15,000 sq. degrees in the drift scan mode,
point source depth of 21st mag. in I under good conditions, near simultaneous
observations in four filters, and at least four passes per year at each
location covered. The survey will yield a large number of transients and highly
variable sources in the near future and in that sense is a prototype of LSST
and Pan-STARRS. We briefly outline our strategy for searching such objects and
the proposed pipeline for detecting transients in real-time.
The advent of wide-area multicolour synoptic sky surveys is leading to data
sets unprecedented in size, complexity and data throughput. VO technology
offers a way to exploit these to the full but ...requires changes in design
philosophy. The Palomar-QUEST survey is a major new survey being undertaken by
Caltech, Yale, JPL and Indiana University to repeatedly observe 1/3 of the sky
(~15000 sq. deg. between -27 < Dec <27 in seven passbands. Utilising the
48-inch Oschin Schmidt Telescope at the Palomar Observatory with the 112-CCD
QUEST camera covering the full 4 x 4 sq. deg. field of view, it will generate
\~1TB of data per month. In this paper, we review the design of QUEST as a VO
resource, a federated data set and an exemplar of VO standards.
Exploration of the time variability on the sky over a broad range of flux levels and wavelengths is rapidly becoming a new frontier of astronomical research. We describe here briefly the ...Palomar-QUEST survey being carried out from the Samuel Oschin 48-inch Schmidt telescope at Palomar. The following features make the survey an attractive candidate for studying time variability: anticipated survey area of 12,000 - 15,000 sq. degrees in the drift scan mode, point source depth of 21st mag. in I under good conditions, near simultaneous observations in four filters, and at least four passes per year at each location covered. The survey will yield a large number of transients and highly variable sources in the near future and in that sense is a prototype of LSST and Pan-STARRS. We briefly outline our strategy for searching such objects and the proposed pipeline for detecting transients in real-time.
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