Infrared Diagnostics for the Extended 12 micron Sample of Seyferts

We present an analysis of Spitzer IRS spectroscopy of 83 active galaxies from the extended 12 micron sample. We find rank correlations between several tracers of star formation which suggest that (1) the PAH feature is a reliable tracer of star formation, (2) there is a significant contribution to the heating of the cool dust by stars, (3) the H$_2$ emission is also primarily excited by star formation. The 55-90 vs. 20-30 spectral index plot is also a diagnostic of the relative contribution of Starburst to AGN. We see there is a large change in spectral index across the sample. Thus, the contribution to the IR spectrum from the AGN and starburst components can be comparable in magnitude but the relative contribution also varies widely across the sample. We find rank correlations between several AGN tracers. We search for correlations between AGN and Starburst tracers and we conclude that the AGN and Starburst tracers are not correlated. This is consistent with our conclusion that the relative strength of the AGN and Starburst components varies widely across the sample. Thus, there is no simple link between AGN fueling and Black Hole Growth and star formation in these galaxies. The distribution of Sil 10 micron and 18 micron strengths is consistent with the clumpy torus models of Sirocky et al. We find a rank correlation between the [NeV] 14 micron line and the 6.7 micron continuum which may be due to an extended component of hot dust. The Sy 2s with a Hidden Broad Line Region (HBLR) have a higher ratio of AGN to Starburst contribution to the SED than Sy 2s without an HBLR. This may contribute to the detection of the HBLR in polarized light. The Sy 2s with an HBLR are more similar to the Sy 1s than they are to the Sy 2s without an HBLR

Characterizing Large Format 10 μm Cutoff Detector Arrays for Low Background Space Applications

This thesis discusses the ongoing development of large format 2k x 2k pixel 10 μm cutoff wavelength HgCdTe detector arrays for low background space applications. This collaboration among Teledyne Imaging Sensors (TIS), University of Rochester, and NASA JPL seeks to determine the performance of the latest arrays that were produced by TIS for the NEOCam space mission, and characterize the image quality. Analysis of the dark current mechanisms of one array shows that these detector arrays are limited by thermal diffusion current down to ~ 42 K, have some contribution of thermal G-R current down to 41 K, then limited by a 0.2 e-/s light leak in our dewar. The trap-to-band tunneling current that has been the limiting mechanism for a previous generation of detectors is not significant at the applied reverse bias required by NEOCam. In order to demonstrate the ability of these detectors to operate in a space-like environment, proton testing was conducted at the University of California Davis Crocker Nuclear Laboratory. During proton irradiation, the 1k x 1k detector array whose substrate thickness is now the baseline had no measurable substrate luminescence, and the pixels that were hit by a proton recovered after reset. The total operability decreased by a few percent after a cumulative lifetime dose of irradiation, but was still above the NEOCam requirement of > 90%. We also assessed the temperature stability and found that the noise measured while the temperature is fluctuating ± 50 mK was the same as measured at a constant temperature. Finally in order to assess the probable image quality, we measured the MTF and the effect of residual images

Characterizing large format 10 um cutoff detector arrays for low background space applications

Thesis (Ph. D.)--University of Rochester. Materials Science Program, 2019.This thesis discusses the ongoing development of large format 2k x 2k pixel 10 μm cutoff wavelength HgCdTe detector arrays for low background space applications. This collaboration among Teledyne Imaging Sensors (TIS), University of Rochester, and NASA JPL seeks to determine the performance of the latest arrays that were produced by TIS for the NEOCam space mission, and characterize the image quality. Analysis of the dark current mechanisms of one array shows that these detector arrays are limited by thermal diffusion current down to ~ 42 K, have some contribution of thermal G-R current down to 41 K, then limited by a 0.2 e-/s light leak in our dewar. The trap-to-band tunneling current that has been the limiting mechanism for a previous generation of detectors is not significant at the applied reverse bias required by NEOCam. In order to demonstrate the ability of these detectors to operate in a space-like environment, proton testing was conducted at the University of California Davis Crocker Nuclear Laboratory. During proton irradiation, the 1k x 1k detector array whose substrate thickness is now the baseline had no measurable substrate luminescence, and the pixels that were hit by a proton recovered after reset. The total operability decreased by a few percent after a cumulative lifetime dose of irradiation, but was still above the NEOCam requirement of >90%. We also assessed the temperature stability and found that the noise measured while the temperature is fluctuating ±50 mK was the same as measured at a constant temperature. Finally in order to assess the probable image quality, we measured the MTF and the effect of residual images

The diversity of the Chagas parasite, <i>Trypanosoma cruzi</i>, infecting the main Central American vector, <i>Triatoma dimidiata</i>, from Mexico to Colombia

<div><p>Little is known about the strains of <i>Trypanosoma cruzi</i> circulating in Central America and specifically in the most important vector in this region, <i>Triatoma dimidiata</i>. Approximately six million people are infected with <i>T</i>. <i>cruzi</i>, the causative agent of Chagas disease, which has the greatest negative economic impact and is responsible for ~12,000 deaths annually in Latin America. By international consensus, strains of <i>T</i>. <i>cruzi</i> are divided into six monophyletic clades called discrete typing units (DTUs TcI-VI) and a seventh DTU first identified in bats called TcBat. TcI shows the greatest geographic range and diversity. Identifying strains present and diversity within these strains is important as different strains and their genotypes may cause different pathologies and may circulate in different localities and transmission cycles, thus impacting control efforts, treatment and vaccine development. To determine parasite strains present in <i>T</i>. <i>dimidiata</i> across its geographic range from Mexico to Colombia, we isolated abdominal DNA from <i>T</i>. <i>dimidiata</i> and determined which specimens were infected with <i>T</i>. <i>cruzi</i> by PCR. Strains from infected insects were determined by comparing the sequence of the 18S rDNA and the spliced-leader intergenic region to typed strains in GenBank. Two DTUs were found: 94% of infected <i>T</i>. <i>dimidiata</i> contained TcI and 6% contained TcIV. TcI exhibited high genetic diversity. Geographic structure of TcI haplotypes was evident by Principal Component and Median-Joining Network analyses as well as a significant result in the Mantel test, indicating isolation by distance. There was little evidence of association with TcI haplotypes and host/vector or ecotope. This study provides new information about the strains circulating in the most important Chagas vector in Central America and reveals considerable variability within TcI as well as geographic structuring at this large geographic scale. The lack of association with particular vectors/hosts or ecotopes suggests the parasites are moving among vectors/hosts and ecotopes therefore a comprehensive approach, such as the Ecohealth approach that makes houses refractory to the vectors will be needed to successfully halt transmission of Chagas disease.</p></div

ERRATUM: INFRARED DIAGNOSTICS FOR THE EXTENDED 12 mu m SAMPLE OF SEYFERTS (vol 710, pg 289, 2010)

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