Spitzer spectra of Seyfert galaxies

The Spitzer IRS high resolution spectra of about 90 Seyfert galaxies from the 12um Galaxy Sample are presented and discussed. These represent about 70% of the total complete sample of local Seyfert galaxies. The presence of starburst components in these galaxies can be quantified by powerful mid-IR diagnostics tools (i.e. 11.25um PAH feature equivalent width and the H_2 emission line intensity) as well as the AGN dominance can be measured by specific fine structure line ratios (e.g. [NeV]/[NeII], [NeV]/[SiII], etc.). The observed line ratios are compared to the results of semianalytical models, which can be used to compute the AGN and starburst contributions to the total luminosity of the galaxies. The results are also discussed in the light of unification and evolution models.Comment: to appear in the proceedings of "The Starburst-AGN Connection Conference", Shanghai, China, 27 Oct - 1 Nov 2008, ASP Conference Serie

Vehicle Design Study of a Straight Flying-Wing with Bell-Shaped Spanload

Straight flying-wing configurations, that is flying wings with zero quarter-chord sweep, are key to understanding bird flight, have potential performance improvements, and are suitable for survivable applications. Straight flying-wings are also well suited for morphing geometry, e.g. with variable twist, since changes in lift distribution do not impact longitudinal equilibrium. The straight-flying wing can adjust its lift distribution to optimize aerodynamic efficiency across a wide range of flight conditions. In this thesis, we conduct the design study of a flying-wing with bell-shaped spanload; the study vehicle is called Biom T1 . Biom T1 has a more efficient directional control scheme acheived by employing the same bell-shaped lift-distribution as used by birds which creates a downwash distribution favorable to proverse yaw in the outer portion of the wing. The flying qualities and control system robustness are demonstrated through linear analysis and it is shown that straight flying-wings are viable in terms of stability and control and are suitable for high-efficiency, low-payload-volume applications

CO(1-0) in z>2 Quasar Host Galaxies: No Evidence for Extended Molecular Gas Reservoirs

We report the detection of CO(1-0) emission in the strongly lensed high-redshift quasars IRAS F10214+4724 (z=2.286), the Cloverleaf (z=2.558), RX J0911+0551 (z=2.796), SMM J04135+10277 (z=2.846), and MG 0751+2716 (z=3.200), using the Expanded Very Large Array and the Green Bank Telescope. We report lensing-corrected CO(1-0) line luminosities of L'(CO) = 0.34-18.4 x 10^10 K km/s pc^2 and total molecular gas masses of M(H2) = 0.27-14.7 x 10^10 Msun for the sources in our sample. Based on CO line ratios relative to previously reported observations in J>=3 rotational transitions and line excitation modeling, we find that the CO(1-0) line strengths in our targets are consistent with single, highly-excited gas components with constant brightness temperature up to mid-J levels. We thus do not find any evidence for luminous extended, low excitation, low surface brightness molecular gas components. These properties are comparable to those found in z>4 quasars with existing CO(1-0) observations. These findings stand in contrast to recent CO(1-0) observations of z~2-4 submillimeter galaxies (SMGs), which have lower CO excitation and show evidence for multiple excitation components, including some low-excitation gas. These findings are consistent with the picture that gas-rich quasars and SMGs represent different stages in the early evolution of massive galaxies.Comment: 6 pages, 4 figures, 1 table, to appear in ApJL (EVLA Special Issue; accepted June 10, 2011

Validation of queries to a relational database

This thesis addresses the problem of preventing users of a data base system from interrogating it with query language expressions which are syntactically and semantically valid but which do not match the user's intentions. A method of assisting users of a relational data base to formulate query language expressions which are valid representations of the abstract query which the user wishes to put is developed. The central focus of the thesis is a method of communicating the critical aspects of the semantics of the relation which would be generated in response to a user's proposed operations on the data base. Certain classes of user error which can arise when using a relational algebra query system are identified, and a method of demonstrating their invalidity is demonstrated. This is achieved by representing via a graph the consequences of operations on relations. Also developed are techniques allowing the generation of pseudo-natural language text describing the relations which would be created as the result of the user's proposed query language operations. A method of allowing the creators of data base relations to incorporate informative semantic data about their relations is developed. A method of permitting this data to be modified by query language operations is specified. Pragmatic linguistic considerations which arise when this data is used to generate pseudo-natural language statements are addressed, and examples of the system's use are given

The Effect of Universal Design for Learning on Student Engagement and Achievement in a Southwest Missouri School District

The researcher’s primary purpose in this mixed-method study was to investigate if teachers who applied Universal Design for Learning (UDL) to a unit of study noted increased engagement in students overall and in teacher-identified students considered “disengaged” compared to students in the same unit of study without the UDL methods applied. Additionally, the researcher sought to determine if students in a UDL course had more significant achievement than students in the same unit of study without the UDL framework applied. Primarily, the researcher aimed to ascertain if UDL would benefit the participating district\u27s students, particularly those not utilizing special services. Participants were asked to complete a three-hour course over UDL before the study began. Via a qualitative survey, teachers answered open-ended questions allowing data analysis that included defined themes of what student engagement and disengagement entailed. Additionally, the researcher asked teachers to categorize their students within their UDL and non-UDL classrooms into one of two categories: engaged or disengaged. The researcher used quantitative analysis to determine if there were differences in achievement between disengaged students in the UDL environment versus the non-UDL environment and differences in achievement between engaged students in both settings. The researcher used a Likert-type question format pre- and post-study via survey to determine growth in teacher mindset regarding student and teacher efficacy. The results of this study were mixed. While the use of UDL did not show a difference in the increase in student scores from pre- to post-unit, there were positive results from training and the use of UDL in classrooms. Teachers saw increased student engagement and participation, increased enjoyment of content from students, increased mindsets regarding students, and increased confidence in their abilities to help all learners. This study demonstrated that UDL could increase engagement in students who had been previously identified as disengaged. It cannot be determined if UDL impacted student scores because the quantitative data showed similar scores between UDL and non-UDL classes. The size of this study and the fact that it was designed around a convenience sample of teachers limits its application beyond the district where the study was completed. That said, the results provide a positive implication for bigger studies with a broader scope of participants. Universal Design for Learning is a successful framework. This study only further demonstrates its success in reaching students outside the scope of special services for which research is lacking

Mid-Infrared Colors of Dwarf Galaxies: Young Starbursts Mimicking Active Galactic Nuclei

Searching for active galactic nuclei (AGN) in dwarf galaxies is important for our understanding of the seed black holes that formed in the early Universe. Here, we test infrared selection methods for AGN activity at low galaxy masses. Our parent sample consists of ~18,000 nearby dwarf galaxies (M*< 3 x 10^9 Msun, $z<0.055$) in the Sloan Digital Sky Survey with significant detections in the first three bands of the AllWISE data release from the Wide-field Infrared Survey Explorer (WISE). First, we demonstrate that the majority of optically-selected AGNs in dwarf galaxies are not selected as AGNs using WISE infrared color diagnostics and that the infrared emission is dominated by the host galaxies. We then investigate the infrared properties of optically-selected star-forming dwarf galaxies, finding that the galaxies with the reddest infrared colors are the most compact, with blue optical colors, young stellar ages and large specific star formation rates. These results indicate that great care must be taken when selecting AGNs in dwarf galaxies using infrared colors, as star-forming dwarf galaxies are capable of heating dust in such a way that mimics the infrared colors of more luminous AGNs. In particular, a simple $\mathrm{W1}-\mathrm{W2}$ color cut alone should not be used to select AGNs in dwarf galaxies. With these complications in mind, we present a sample of 41 dwarf galaxies worthy of follow-up observations that fall in WISE infrared color space typically occupied by more luminous AGNs.Comment: 17 pages, 12 figures, accepted by the Astrophysical Journa

Seyfert Galaxies in the Local Universe: Analysis of Spitzer Spectra of a Complete Sample

The Spitzer high resolution spectra of 72 Seyfert galaxies from the 12$\mu$m Galaxy Sample are presented and discussed. The presence of starburst components in these galaxies can be quantified by powerful mid-IR diagnostics tools (i.e. 11.25$\mu$m PAH feature equivalent width and the H$_2$ emission line intensity), as well as the AGN dominance can be measured by specific fine structure line ratios (e.g. [NeV]/[NeII], [NeV]/[SiII], etc.). The two types of Seyfert galaxies do not show any statistical difference in our diagnostic tools. However, the Seyfert 2's showing hidden Broad Line Regions in spectro-polarimetric observations have on average an higher AGN dominance, a weaker star formation component and a warmer [60 - 25] spectral index than those without broad emission lines.Comment: Proceedings of the Conference "The central kiloparsec. Active Galactic Nuclei and their hosts, 4-6 June 2008, Ierapetra, Crete, Greec

The Rest Frame Ultraviolet Spectra of UV-Selected Active Galactic Nuclei at z ~ 2-3

We present new results for a sample of 33 narrow-lined UV-selected active galactic nuclei (AGNs), identified in the course of a spectroscopic survey for star-forming galaxies at z ~ 2-3. The rest-frame UV composite spectrum for our AGN sample shows several emission lines characteristic of AGNs, as well as interstellar absorption features seen in star-forming Lyman Break Galaxies (LBGs). We report a detection of NIV]1486, which has been observed in high-redshift radio galaxies, as well as in rare optically-selected quasars. The UV continuum slope of the composite spectrum is significantly redder than that of a sample of non-AGN UV-selected star forming galaxies. Blueshifted SiIV absorption provides evidence for outflowing highly-ionized gas in these objects at speeds of ~ 10^(3) km/s, quantitatively different from what is seen in the outflows of non-AGN LBGs. Grouping the individual AGNs by parameters such as Ly-alpha equivalent width, redshift, and UV continuum magnitude allows for an analysis of the major spectroscopic trends within the sample. Stronger Ly-alpha emission is coupled with weaker low-ionization absorption, which is similar to what is seen in the non-AGN LBGs, and highlights the role that cool interstellar gas plays in the escape of Ly-alpha photons. However, the AGN composite does not show the same trends between Ly-alpha strength and extinction seen in the non-AGN LBGs. These results represent the first such comparison at high-redshift between star-forming galaxies and similar galaxies that host AGN activity.Comment: 13 pages, 6 figures, accepted by Ap

State of Florida Diviosn of Administrative Hearings: Notice of Taking Deposition

Legal documents related to a dispute between the Sawmill Slough Conservation Club vs. the University of North Floridahttps://digitalcommons.unf.edu/sawmill_history/1027/thumbnail.jp