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

A Tale of Two Narrow-Line Regions: Ionization, Kinematics, and Spectral Energy Distributions for a Local Pair of Merging Obscured Active Galaxies

We explore the gas ionization and kinematics, as well as the optical--IR spectral energy distributions for UGC 11185, a nearby pair of merging galaxies hosting obscured active galactic nuclei (AGNs), also known as SDSS J181611.72+423941.6 and J181609.37+423923.0 (J1816NE and J1816SW, $z \approx 0.04$). Due to the wide separation between these interacting galaxies ($\sim 23$ kpc), observations of these objects provide a rare glimpse of the concurrent growth of supermassive black holes at an early merger stage. We use BPT line diagnostics to show that the full extent of the narrow line emission in both galaxies is photoionized by an AGN and confirm the existence of a 10-kpc-scale ionization cone in J1816NE, while in J1816SW the AGN narrow-line region is much more compact (1--2 kpc) and relatively undisturbed. Our observations also reveal the presence of ionized gas that nearly spans the entire distance between the galaxies which is likely in a merger-induced tidal stream. In addition, we carry out a spectral analysis of the X-ray emission using data from {\em XMM-Newton}. These galaxies represent a useful pair to explore how the [\ion{O}{3}] luminosity of an AGN is dependent on the size of the region used to explore the extended emission. Given the growing evidence for AGN "flickering" over short timescales, we speculate that the appearances and impact of these AGNs may change multiple times over the course of the galaxy merger, which is especially important given that these objects are likely the progenitors of the types of systems commonly classified as "dual AGNs."Comment: 15 pages, 10 figures, accepted by the Astrophysical Journa

A Study of CO Emission in High Redshift QSOs Using the Owens Valley Millimeter Array

Searches for CO emission in high-redshift objects have traditionally suffered from the accuracy of optically-derived redshifts due to lack of bandwidth in correlators at radio observatories. This problem has motivated the creation of the new COBRA continuum correlator, with 4 GHz available bandwidth, at the Owens Valley Radio Observatory Millimeter Array. Presented here are the first scientific results from COBRA. We report detections of redshifted CO(J=3-2) emission in the QSOs SMM J04135+10277 and VCV J140955.5+562827, as well as a probable detection in RX J0911.4+0551. At redshifts of z=2.846, z=2.585, and z=2.796, we find integrated CO flux densities of 5.4 Jy km/s, 2.4 Jy km/s, and 2.9 Jy km/s for SMM J04135+10277, VCV J140955.5+562827, and RX J0911.4+0551, respectively, over linewidths of Delta(V_{FWHM}) ~ 350 km/s. These measurements, when corrected for gravitational lensing, correspond to molecular gas masses of order M(H_2) ~ 10^{9.6-11.1} solar masses, and are consistent with previous CO observations of high-redshift QSOs. We also report 3-sigma upper limits on CO(3-2) emission in the QSO LBQS 0018-0220 of 1.3 Jy km/s. We do not detect significant 3mm continuum emission from any of the QSOs, with the exception of a tentative (3-sigma) detection in RX J0911.4+0551 of S_{3mm}=0.92 mJy/beam.Comment: 18 pages, 5 figures, 2 tables, accepted to ApJ. Changes made for version 2: citations added, 2 objects added to Table 2 and Figure

Pre-Service Teachers Self-Perceived Training Needs Associated with Program Design and Management and Leadership and SAE Development

Teacher educators face the perpetual challenge of providing pre-service teachers with the most pertinent pedagogical and content-related knowledge and skills to ensure their success in the field of education. Using a modified version of a Borich needs assessment instrument, we assessed the agricultural education training needs of agricultural education pre-service teachers (n = 69) at Iowa State University related to program design and management and leadership and Supervised Agricultural Experiences (SAE) development. The General Program Standards for Agricultural Education, developed by the Iowa Council on Agricultural Education, served as a guide for assessing the areas of pre-service teachers’ training needs. Mean weighted discrepancy scores (MWDS) were calculated for needs assessment items which served as a means to rank the areas of needs expressed by the Iowa State University agricultural education pre-service teachers. The areas of training needs were assessed as a whole and by grade classification. Overall, all 25 items included in the instrument were indicated as an area of need and the calculated MWDS ranged from 2.29 – 9.05, and variance of training needs was discovered between pre-service teachers of various grade classifications. Implications for agricultural education teacher educators and recommendations were discussed

School-based Agricultural Education Teachers’ Perceived Professional Development Needs Associated with Teaching, Classroom Management, and Technical Agriculture

Across the nation, there is a large shortage of teachers in several subject areas (Daniel, 2015; Milliard, 2015; Sutcher, Darling-Hammond, & Carver-Thomas, 2016). In agricultural education, many teachers are leaving the profession within the first five years of beginning their teaching careers (Tippens, Ricketts, Morgan, Navaro, & Flanders, 2013). Professional development opportunities for teachers can be utilized to retain teachers in the profession (Touchstone, 2015). The purpose of this study was to evaluate the professional development needs of Iowa school-based agricultural education teachers in the areas of teaching, classroom management, and technical agriculture. Motivating students to learn, teaching in a land laboratory, proper implementation of Individualized Education Program (IEP) for students with disabilities, teaching students decision-making skills, and developing performance-based assessment instruments were the teaching and classroom management items that SBAE teachers expressed the highest perceived levels of professional development needs. The items with the highest perceived training needs were teaching knowledge and skills in biotechnology, integrating current advances in agriculture technology into the curriculum, teaching knowledge and skills in agribusiness, teaching about public issues regarding agriculture, and teaching knowledge and skills in agricultural mechanic. Future research should be conducted to determine what agriculture technology and biotechnology professional development is needed by in-service teachers

A Change in Perspective: Agriculturally -Based Study Abroad Experience for Nicaraguan Students

Study abroad experiences serve to enrich students’ educational experiences, granted these programs must be evaluated to assess educational effectiveness. The purpose of this qualitative study was toexamine Nicaraguan students’ perceptions of agriculture and future aspirations, before and after engaging in a four-day agricultural-based program. Graphic elicitation and arts-based projective techniques served as metrics to assess students’ perceptions.Four major themes, with six sub-themes emerged from the data: a) perceptions of agriculture (i.e., previous agriculture); b) strength through unity (i.e., unity; and ripple effect); c) aspirations (i.e., importance of education); d) value of experience (i.e., learning new things; and thankfulness). Overall, the Nicaraguan students indicated the study abroad experience broadened their perspective of agriculture, having a direct impact on their career aspirations

The Intrinsic Eddington Ratio Distribution of Active Galactic Nuclei in Star-Forming Galaxies from the Sloan Digital Sky Survey

An important question in extragalactic astronomy concerns the distribution of black hole accretion rates of active galactic nuclei (AGNs). Based on observations at X-ray wavelengths, the observed Eddington ratio distribution appears as a power law, while optical studies have often yielded a lognormal distribution. There is increasing evidence that these observed discrepancies may be due to contamination by star formation and other selection effects. Using a sample of galaxies from the Sloan Digital Sky Survey Data Release 7, we test whether or not an intrinsic Eddington ratio distribution that takes the form of a Schechter function is consistent with previous work suggesting that young galaxies in optical surveys have an observed lognormal Eddington ratio distribution. We simulate the optical emission line properties of a population of galaxies and AGNs using a broad, instantaneous luminosity distribution described by a Schechter function near the Eddington limit. This simulated AGN population is then compared to observed galaxies via their positions on an emission line excitation diagram and Eddington ratio distributions. We present an improved method for extracting the AGN distribution using BPT diagnostics that allows us to probe over one order of magnitude lower in Eddington ratio, counteracting the effects of dilution by star formation. We conclude that for optically selected AGNs in young galaxies, the intrinsic Eddington ratio distribution is consistent with a possibly universal, broad power law with an exponential cutoff, as this distribution is observed in old, optically selected galaxies and X-rays

A Robust Determination of the size of quasar accretion disks using gravitational microlensing

Using microlensing measurements from a sample of 27 image-pairs of 19 lensed quasars we determine a maximum likelihood estimate for the accretion disk size of an {{\em}average} quasar of $r_s=4.0^{+2.4}_{-3.1}$ light days at rest frame $=1736$\AA\ for microlenses with a mean mass of $=0.3M_\odot$. This value, in good agreement with previous results from smaller samples, is roughly a factor of 5 greater than the predictions of the standard thin disk model. The individual size estimates for the 19 quasars in our sample are also in excellent agreement with the results of the joint maximum likelihood analysis.Comment: 6 pages, 3 figures, submitted to Ap

Weighing Obscured and Unobscured Quasar Hosts with the Cosmic Microwave Background

We cross-correlate a cosmic microwave background (CMB) lensing map with the projected space densities of quasars to measure the bias and halo masses of a quasar sample split into obscured and unobscured populations, the first application of this method to distinct quasar subclasses. Several recent studies of the angular clustering of obscured quasars have shown that these objects likely reside in higher-mass halos compared to their unobscured counterparts. This has important implications for models of the structure and geometry of quasars, their role in growing supermassive black holes, and mutual quasar/host galaxy evolution. However, the magnitude and significance of this difference has varied from study to study. Using data from \planck, \wise, and SDSS, we follow up on these results using the independent method of CMB lensing cross-correlations. The region and sample are identical to that used for recent angular clustering measurements, allowing for a direct comparison of the CMB-lensing and angular clustering methods. At z∼1, we find that the bias of obscured quasars is bq=2.57±0.24, while that of unobscured quasars is bq=1.89±0.19. This corresponds to halo masses of log(Mh/M⊙h−1)=13.24+0.14−0.15 (obscured) and log(Mh/M⊙h−1)=12.71+0.15−0.13 (unobscured). These results agree well with with those from angular clustering (well within 1σ), and confirm that obscured quasars reside in host halos ∼3 times as massive as halos hosting unobscured quasars. This implies that quasars spend a significant portion of their lifetime in an obscured state, possibly more than one half of the entire active phase