Extensions of the space trajectories error analysis programs

A generalized covariance analysis technique which permits the study of the sensitivity of linear estimation algorithms to errors in a priori statistics has been developed and programed. Several sample cases are presented to illustrate the use of this technique. Modifications to the Simulated Trajectories Error Analysis Program (STEAP) to enable targeting a multiprobe mission of the Planetary Explorer type are discussed. The logic for the mini-probe targeting is presented. Finally, the initial phases of the conversion of the Viking mission Lander Trajectory Reconstruction (LTR) program for use on Venus missions is discussed. An integrator instability problem is discussed and a solution proposed

Lander Trajectory Reconstruction computer program

The Lander Trajectory Reconstruction (LTR) computer program is a tool for analysis of the planetary entry trajectory and atmosphere reconstruction process for a lander or probe. The program can be divided into two parts: (1) the data generator and (2) the reconstructor. The data generator provides the real environment in which the lander or probe is presumed to find itself. The reconstructor reconstructs the entry trajectory and atmosphere using sensor data generated by the data generator and a Kalman-Schmidt consider filter. A wide variety of vehicle and environmental parameters may be either solved-for or considered in the filter process

X-ray Shots of Cyg X-1

X-ray shots of Cyg X-1 in different energy bands and spectral states have been studied with PCA/RXTE observations. The detailed shot structure is obtained by superposing many shots with one millisecond time bin through aligning their peaks with an improved algorithm. In general, the shots are composed of a slow rise and fast decay. The shot structures in the different states are different. The duration of shot in the high state is shorter than that in the low and transition states. The shot profile in the high energy band is more asymmetric and narrower than that in the low energy band. The average hardness of shot is lower than that of steady emission in the transition and low states but higher than that in the high state. The time lags between the shots in higher and lower energy bands have been found in the different states. In transition states, the time lag is the largest among the different states of Cyg X-1, and it is the smallest in the low state. The implications of the observed shot features for shot models are discussed.Comment: Latex, 20 pages, 12 figures(included), to be published in Ap

Mosquitoes of Urban Oklahoma and Their Potential as Disease Vectors

The mosquito diversity of Oklahoma was last evaluated in a series of surveys conducted between 2003 and 2006 and before that, the previous survey was in 1965. Prior surveys targeted specific questions including the evaluation of West Nile virus. However, a systematic survey of the cities in Oklahoma was not conducted. In this study, mosquito populations were surveyed approximately bi-weekly at six different cities, including four with military bases, in central and southeastern Oklahoma between May and September 2016. Three different traps were used: CDC Mini Light traps with lights removed and baited with dry ice, CDC Gravid traps baited with Bermuda grass-conditioned water, and BG-Sentinel� traps baited with BG lure. A total of 11,980 adult female mosquitoes representing 34 species were collected over 834 trapping events. Mosquito communities differed significantly among trap type, with CDC Mini Light traps collecting the most individuals. Mosquito communities also differed significantly among cities sampled. These results show that urban areas in Oklahoma do not possess a homogenous mosquito community, and each city should be evaluated individually (at least within the same climate region). Aedes aegypti, an important disease vector was recorded in Oklahoma for the first time since 1940. Eighty-eight specimens of Ae. aegypti were collected in the cities of Altus, Ardmore, Frederick, and Lawton. CDC Mini Light traps were more attractive to Ae. aegypti than other two trap types. The most abundant mosquito species: Ae. albopictus, Ae. sollicitans, Ae. triseriatus, Cx. pipiens, and Cx. tarsalis were tested for presence of Dirolfilaria immitis, the causative agent for dog heartworm, and other parasitic nematodes. One mosquito pool tested was PCR positive for D. immitis, from a Cx. pipiens pool. Six other nematodes were collected in pools from Ae. albopictus. The D. immitis positive pool was collected from Idabel, OK, while four other positive pools were collected from Ardmore, OK, and one from Midwest City, OK. The information generated from this study provides insight into mosquito populations and potential for nematode transmission in Oklahoma. With increases in human populations living in cities, movement of people and global climate change, the results of this study serves as a baseline and informs mosquito management strategies for southern Oklahoma.Entomology & Plant Pathology (MS

HE 0435-1223: a wide separation quadruple QSO and gravitational lens

We report the discovery of a new gravitationally lensed QSO, at a redshift z = 1.689, with four QSO components in a cross-shaped arrangement around a bright galaxy. The maximum separation between images is 2.6 arcsec, enabling a reliable decomposition of the system. Three of the QSO components have g = 19.6, while component A is about 0.6 mag brighter. The four components have nearly identical colours, suggesting little if any dust extinction in the foreground galaxy. The lensing galaxy is prominent in the i band, weaker in r and not detected in g. Its spatial profile is that of an elliptical galaxy with a scale length of $\sim$ 12 kpc. Combining the measured colours and a mass model for the lens, we estimate a most likely redshift range of 0.3 < z < 0.4. Predicted time delays between the components are \la 10 days. The QSO shows evidence for variability, with total g band magnitudes of 17.89 and 17.71 for two epochs separated by $\sim 2$ months. However, the relative fluxes of the components did not change, indicating that the variations are intrinsic to the QSO rather than induced by microlensing.Comment: 7 pages, submitted to Astronomy and Astrophysic

X-Ray Light Curves of Gamma-ray Bursts Detected with the All-Sky Monitor on RXTE

We present X-ray light curves (1.5-12 keV) for fifteen gamma-ray bursts (GRBs) detected by the All-Sky Monitor on the Rossi X-ray Timing Explorer. We compare these soft X-ray light curves with count rate histories obtained by the high-energy (>12 keV) experiments BATSE, Konus-Wind, the BeppoSAX Gamma-Ray Burst Monitor, and the burst monitor on Ulysses. We discuss these light curves within the context of a simple relativistic fireball and synchrotron shock paradigm, and we address the possibility of having observed the transition between a GRB and its afterglow. The light curves show diverse morphologies, with striking differences between energy bands. In several bursts, intervals of significant emission are evident in the ASM energy range with little or no corresponding emission apparent in the high-energy light curves. For example, the final peak of GRB 970815 as recorded by the ASM is only detected in the softest BATSE energy bands. We also study the duration of bursts as a function of energy. Simple, singly-peaked bursts seem consistent with the E^{-0.5} power law expected from an origin in synchrotron radiation, but durations of bursts that exhibit complex temporal structure are not consistent with this prediction. Bursts such as GRB 970828 that show many short spikes of emission at high energies last significantly longer at low energies than the synchrotron cooling law would predict.Comment: 15 pages with 20 figures and 2 tables. In emulateapj format. Accepted by ApJ

A Giant Glitch in the Energetic 69 ms X-ray Pulsar AXS J161730-505505

We present new results on the recently discovered 69 ms X-ray pulsar AXS J161730-505505, the sixth youngest sample of all known pulsars. We have undertaken a comprehensive X-ray observing campaign of AXS J161730-505505 with the ASCA, SAX, and XTE observatories and follow its long term spin-down history between 1989 and 1999, using these, archival GINGA and ASCA data sets, and the radio ephemeris. The spin-down is not simply described by a linear function as originally thought, but instead we find evidence of a giant glitch (|Delta P/P| > 10E-6) between 1993 August and 1997 September, perhaps the largest yet observed from a young pulsar. The glitch is well described by steps in the period and its first derivative accompanied by a persistent second derivative similar to those in the Vela pulsar. The pulse profile of AXS J161730-505505 presents a single asymmetric peak which is maintained over all observation epochs. The energy spectrum is also steady over time, characterized by a highly absorbed power-law with a photon index 1.4 +/- 0.2, consistent with that found for other young rotation powered pulsars.Comment: 6 pages with 2 figures, LaTex, emulateapj.sty. To appear in the Astrophysical Journal Letter

Future X-ray timing missions

Thanks to the Rossi X-ray Timing Explorer (RXTE), it is now widely recognized that fast X-ray timing can be used to probe strong gravity fields around collapsed objects and constrain the equation of state of dense matter in neutron stars. We first discuss some of the outstanding issues which could be solved with an X-ray timing mission building on the great successes of RXTE and providing an order of magnitude better sensitivity. Then we briefly describe the 'Experiment for X-ray timing and Relativistic Astrophysics' (EXTRA) recently proposed to the European Space Agency as a follow-up to RXTE and the related US mission 'Relativistic Astrophysics Explorer' (RAE).Comment: To be published in `Proceedings of the Third Microquasar Workshop: Granada Workshop on galactic relativistic jet sources', Eds A. J. Castro-Tirado, J. Greiner and J. M. Paredes, Astrophysics and Space Science, in press. More about EXTRA can be found at: http://www.cesr.fr/~barret/extra.htm

Guide to the twelve most-important Oklahoma mosquitoes of concern for pest control specialists

The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311