We present the results of a search for untriggered gamma-ray burst (GRB) afterglows with the Robotic Optical Transient Search Experiment-III (ROTSE-III) telescope array. This search covers ...observations from 2003 September to 2005 March. We have an effective coverage of 1.74 deg super(2) yr for rapidly fading transients that remain brighter than 617.5 mag for more than 30 minutes. This search is the first large-area survey to be able to detect typical untriggered GRB afterglows. Our background rate is very low and purely astrophysical. We have found four previously unknown cataclysmic variables (CVs) and one new flare star. We have not detected any candidate afterglow events or other unidentified transients. We can place an upper limit on the rate of fading optical transients with quiescent counterparts dimmer than 620th magnitude at a rate of less than 1.9 deg super(-2) yr super(-1) with 95% confidence. This places limits on the optical characteristics of off-axis (orphan) GRB afterglows. As a by-product of this search, we have an effective 652 deg super(2) yr of coverage for very slowly decaying transients, such as CVs. This implies an overall rate of outbursts from high Galactic latitude CVs of 0.1 deg super(-2) yr super(-1).
We've got you surrounded! Conjugated units that are encapsulated within the cavities of macrocycles can have unique properties often including the ability to rotate or wobble within an otherwise ...stationary crystal lattice. We introduce a strategy for forming macrocycles of this type in only a few synthetic steps using pyridine coordination to transition metals as the final, ring‐closing step. More information can be found in the Research Article by N. P. Bowling and co‐workers. (DOI: 10.1002/chem.202301745).
We present the unfiltered ROTSE-III light curve of the optical transient associated with GRB 050319 beginning 4 s after the cessation of g-ray activity. We fit a power-law function to the data using ...the revised trigger time given by Chincarini and coworkers, and a smoothly broken power-law to the data using the original trigger disseminated through the GCN notices. Including the RAPTOR data from Wo zniak and coworkers, the best-fit power-law indices are a = -0.854 c 0.014 for the single power-law and a sub(1) = -0.364 super(+) sub(-) super(0) sub(0) super(.) sub(.) super(0) sub(0) super(2) sub(1) super(0) sub(9), a sub(2) = -0.881 super(+) sub(-) super(0) sub(0) super(.) sub(.) super(0) sub(0) super(3) sub(3) super(0) sub(1), with a break at t sub(b) = 418 super(+) sub(-) super(3) sub(3) super(1) sub(0) s for the smoothly broken fit. We discuss the fit results, with emphasis placed on the importance of knowing the true start time of the optical transient for this multipeaked burst. As Swift continues to provide prompt GRB locations, it becomes more important to answer the question, "when does the afterglow begin?" in order to correctly interpret the light curves.
The Robotic Optical Transient Search Experiment I (ROTSE-I) experiment has generated CCD photometry for the entire northern sky in two epochs nightly since 1998 March. These sky patrol data are a ...powerful resource for studies of astrophysical transients. As a demonstration project, we present first results of a search for periodic variable stars derived from ROTSE-I observations. Variable identification, period determination, and type classification are conducted via automatic algorithms. In a set of nine ROTSE-I sky patrol fields covering roughly 2000 deg2, we identify 1781 periodic variable stars with mean magnitudes between m{sub v} = 10.0 and m{sub v} 15.5. About 90% of these objects are newly identified as variable. Examples of many familiar types are presented. All classifications for this study have been manually confirmed. The selection criteria for this analysis have been conservatively defined and are known to be biased against some variable classes. This preliminary study includes only 5.6% of the total ROTSE-I sky coverage, suggesting that the full ROTSE-I variable catalog will include more than 32,000 periodic variable stars. (c) (c) 2000. The American Astronomical Society.
The electronic properties of a pyrazine-containing arylene ethynylene unit are influenced by hydrogen bond and halogen bond donors that are held in proximity of the pyrazine rotor. These interactions ...are evident with iodine- and bromine-centered halogen bonds and O–H- and C–H-based hydrogen bonds. Bathochromic shifts of UV–vis and fluorescence signals are the best indicators of this intramolecular attraction. The effects can be attenuated in solvents that are less favorable for intramolecular halogen or hydrogen bonding, such as 2-propanol, and amplified in solvents that are supportive, such as toluene. Intramolecular attractions promote planarity in the pyrazine ethynylene system, likely increasing the effective conjugation of the unsaturated backbone. Additionally, computations at the B3LYP and M062X levels of theory using 6-311++G(2d,p) and aug-cc-pVTZ basis sets suggest that the Lewis acidity of the halogen and hydrogen atoms influences electronic behavior even in the absence of conformational constraints.
Despite becoming increasingly represented in academic departments, women scholars face a critical lack of support as they navigate demands pertaining to pregnancy, motherhood, and child caregiving. ...In addition, cultural norms surrounding how faculty and academic leaders discuss and talk about tenure, promotion, and career success have created pressure for women who wish to grow their family and care for their children, leading to questions about whether it is possible for these women to have a family and an academic career. This paper is a call to action for academia to build structures that support professors who are women as they navigate the complexities of pregnancy, the postpartum period, and the caregiving demands of their children. We specifically call on those of us in I-O psychology, management, and related departments to lead the way. In making this call, we first present the realistic, moral, and financial cases for why this issue needs to be at the forefront of discussions surrounding success in the academy. We then discuss how, in the U.S. and elsewhere, an absence of policies supporting women places two groups of academics—department heads (as the leaders of departments who have discretion outside of formal policies to make work better for women) and other faculty members (as potential allies both in the department and within our professional organizations)—in a critical position to enact support and change. We conclude with our boldest call—to make a cultural shift that shatters the assumption that having a family is not compatible with academic success. Combined, we seek to launch a discussion that leads directly to necessary and overdue changes in how women scholars are supported in academia.
Data quality monitoring (DQM) is an integral part of the data taking process of HEP experiments. DQM involves automated analysis of monitoring data through user-defined algorithms and relaying the ...summary of the analysis results to the shift personnel while data is being processed. In the online environment, DQM provides the shifter with current run information that can be used to overcome problems early on. During the offline reconstruction, more complex analysis of physics quantities is performed by DQM, and the results are used to assess the quality of the reconstructed data. The ATLAS data quality monitoring framework (DQMF) is a distributed software system providing DQM functionality in the online environment. The DQMF has a scalable architecture achieved by distributing the execution of the analysis algorithms over a configurable number of DQMF agents running on different nodes connected over the network. The core part of the DQMF is designed to have dependence only on software that is common between online and offline (such as ROOT) and therefore the same framework can be used in both environments. This paper describes the main requirements, the architectural design, and the implementation of the DQMF.
Abstract
We describe the spectroscopic data processing pipeline of the Dark Energy Spectroscopic Instrument (DESI), which is conducting a redshift survey of about 40 million galaxies and quasars ...using a purpose-built instrument on the 4 m Mayall Telescope at Kitt Peak National Observatory. The main goal of DESI is to measure with unprecedented precision the expansion history of the universe with the baryon acoustic oscillation technique and the growth rate of structure with redshift space distortions. Ten spectrographs with three cameras each disperse the light from 5000 fibers onto 30 CCDs, covering the near-UV to near-infrared (3600–9800 Å) with a spectral resolution ranging from 2000 to 5000. The DESI data pipeline generates wavelength- and flux-calibrated spectra of all the targets, along with spectroscopic classifications and redshift measurements. Fully processed data from each night are typically available to the DESI collaboration the following morning. We give details about the pipeline’s algorithms, and provide performance results on the stability of the optics, the quality of the sky background subtraction, and the precision and accuracy of the instrumental calibration. This pipeline has been used to process the DESI Survey Validation data set, and has exceeded the project’s requirements for redshift performance, with high efficiency and a purity greater than 99% for all target classes.
Abstract
The Dark Energy Spectroscopic Instrument (DESI) will precisely constrain cosmic expansion and the growth of structure by collecting ∼40 million extragalactic redshifts across ∼80% of cosmic ...history and one-third of the sky. The Emission Line galaxy (ELG) sample, which will comprise about one-third of all DESI tracers, will be used to probe the universe over the 0.6 <
z
< 1.6 range, including the 1.1 <
z
< 1.6 range, which is expected to provide the tightest constraints. We present the target selection for the DESI Survey Validation (SV) and Main Survey ELG samples, which relies on the imaging of the Legacy Surveys. The Main ELG selection consists of a
g
-band magnitude cut and a (
g
−
r
) versus (
r
−
z
) color box, while the SV selection explores extensions of the Main selection boundaries. The Main ELG sample is composed of two disjoint subsamples, which have target densities of about 1940 deg
−2
and 460 deg
−2
, respectively. We first characterize their photometric properties and density variations across the footprint. We then analyze the DESI spectroscopic data that have been obtained from 2020 December to 2021 December in the SV and Main Survey. We establish a preliminary criterion for selecting reliable redshifts, based on the O
ii
flux measurement, and assess its performance. Using this criterion, we are able to present the spectroscopic efficiency of the Main ELG selection, along with its redshift distribution. We thus demonstrate that the Main selection 1940 deg
−2
subsample alone should provide 400 deg
−2
and 460 deg
−2
reliable redshifts in the 0.6 <
z
< 1.1 and the 1.1 <
z
< 1.6 ranges, respectively.
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