ISOPHOT Observations of Narrow-Line Seyfert 1 Galaxies

Broad infrared spectra (7-200 micrometer) of four NLS1 galaxies, obtained with the imaging photo-polarimeter (ISOPHOT) on board the Infrared Space Observatory (ISO), are presented. The infrared luminosities and temperatures, opacities and sizes of the emitting dust components are derived. A comparison between the observed infrared spectra and the optical emission line fluxes of a sample of 16 NLS1 galaxies suggests that these objects suffer different degrees of dust absorption according to the inclination of the line of sight with respect to the dust distribution.Comment: Contributed talk presented at the Joint MPE,AIP,ESO workshop on NLS1s, Bad Honnef, Dec. 1999, to appear in New Astronomy Reviews; also available at http://wave.xray.mpe.mpg.de/conferences/nls1-worksho

A Historiographical and Pedagogical Pursuit of the United States in the Atomic Era

I. Synthesis Essay………………………………...3 II. Primary Documents and Headnotes………...29 III. Textbook Critique……………………………..41 IV. New Textbook Entry…………………………..43 V. Bibliography…………………………………....46https://digitalcommons.bard.edu/history_mat/1019/thumbnail.jp

Regulating Self-Image on Social Media: Associations Between Social Anxiety and Instagram Control Behaviors

Individuals with social anxiety try to avoid or disengage when there is a perceived lack of control in a social situation. This study examined individual differences in social anxiety to better understand how levels of social anxiety are related to differences in self-preservation and image protection behaviors on Instagram, an image-based social media application. The purpose of this empirical study was to explore Instagram control behaviors by applying Schlenker and Leary’s (1982) Social Anxiety and Self-Presentation (SASP) conceptualization model. Instagram has features and settings that allow individuals to exert varying degrees of control over the content they share on their profile and posts. I explored two aspects of self-preservation and image management as predicted by the SASP model, affiliation and preferred impression, in a non-clinical sample of college students (N = 45). Results indicated that individuals who generally experienced higher levels of social anxiety were more likely to engage in greater control behaviors on Instagram than individuals with low levels of social anxiety. While there was no relationship between control behaviors and affect, socially anxious individuals were more likely to report increases in self-esteem from Instagram even though they reported spending less time on Instagram than less socially anxious individuals. These findings suggest that there are key differences in people’s Instagram behaviors as a function of social anxiety and feared negative evaluations. The present findings can inform future work that further elucidates relations between social anxiety, self-presentation, and various ways people engage with social media platforms

Black hole growth and stellar assembly at high-z

Context. Observations indicate a strong link between star formation and black hole (BH) growth, but some questions remain unanswered: whether both activities are coeval or whether one precedes the other, what their characteristic timescales are, and what kinds of physical processes are responsible for this interplay. Aims. We examine stellar and BH masses (M_star and M_BH) in z~2 active systems at the peak of their AGN or star formation activity to investigate how they are linked and whether AGN radiative or else radio power provides a feedback mechanism that regulates the stellar growth in these systems. Methods. We analyze the infrared (IR) spectral energy distributions of radio, sub-millimeter and mid-IR selected AGNs at z~1-3 and constrain their stellar and AGN luminosities using AGN and host-galaxy templates. Results. We find evidence of increasing stellar light, thereby decreasing the AGN mid-IR power going from mid-IR selected AGNs, to radio galaxies, and to sub-millimeter AGNs. This trend can be explained by either decreasing Eddington ratios or increasing offsets from the local M_BH-M_star relation. All systems are characterized by high star formation rates regardless of their different AGN powers, thus neither AGN radiative power nor AGN-driven radio activity seems to influence the star formation rate in the selected AGNs. We discuss two possible evolutionary scenarios that might link these three AGN classes.Comment: A&A Letters accepte

3D Printing of Piezoelectric Materials and Devices

The design goal of the project is to use a stock 3D printer to 3D print materials with piezoelectric properties by adding Barium Titanate nanoparticles to the UV resin. The result of the printed material will be a device that will produce a charge when subjected to vibrations or stress. These printed devices can be used as microphones and other vibration sensors in a variety of applications. This process will be achieved by modifying the 3D printer by changing the film in the resin vat of the printer with a conductive film. This will allow for applied voltage to create an electric field to align the nanoparticles, producing a manufactured piezoelectric structure. The current progress of the project has been developing a 3D model of the devices, modification of the off the shelf parts, and researching the most effective material ratios

The far-infrared energy distributions of Seyfert and starburst galaxies in the Local Universe: ISO photometry of the 12 micron active galaxy sample

New far-infrared photometry with ISOPHOT, onboard the Infrared Space Observatory, is presented for 58 galaxies with homogeneous published data for another 32 galaxies all belonging to the 12 micron galaxy sample. In total 29 Seyfert 1's, 35 Seyfert 2's and 12 starburst galaxies, about half of the 12 micron active galaxy sample, plus 14 normal galaxies for comparison. The ISO and the IRAS data are used to define color-color diagrams and spectral energy distributions (SED). Thermal dust emission at two temperatures (one cold at 15-30K and one warm at 50-70K) can fit the 60-200 micron SED, with a dust emissivity law proportional to the inverse square of the wavelength. Seyfert 1's and Seyfert 2's are indistinguishable longward of 100 micron, while, as already seen by IRAS, the former have flatter SEDs shortward of 60 micron. A mild anti-correlation is found between the [200 - 100] color and the "60 micron excess". We infer that this is due to the fact that galaxies with a strong starburst component, and thus a strong 60 micron flux, have a steeper far-infrared turnover. In non-Seyfert galaxies, increasing the luminosity corresponds to increasing the star formation rate, that enhances the 25 and 60 micron emission. This shifts the peak emission from around 150 micron in the most quiescent spirals to shorter than 60 micron in the strongest starburst galaxies.Comment: Accepted for publication in The Astrophysical Journal AASTeX preprint with 49 pages and 20 figures Also available at http://orion.ifsi.rm.cnr.it/publ.htm

The World Social Forum and the challenges of global democracy

Protests against economic globalization helped give birth to the World Social Forum (WSF) as a space for civil society groups to coordinate actions and articulate shared visions for global change. Since 2001 the WSF has brought together hundreds of thousands of activists from all parts of the world. But creating an inclusive political space that is also effective at generating unified action has proved challenging. In this article I explore the central tensions in the 2004 WSF and explore the possibilities for the Forum to overcome these obstacles and expand global democracy