Theory and Simulations of Refractive Substructure in Resolved Scatter-Broadened Images

At radio wavelengths, scattering in the interstellar medium distorts the appearance of astronomical sources. Averaged over a scattering ensemble, the result is a blurred image of the source. However, Narayan & Goodman (1989) and Goodman & Narayan (1989) showed that for an incomplete average, scattering introduces refractive substructure in the image of a point source that is both persistent and wideband. We show that this substructure is quenched but not smoothed by an extended source. As a result, when the scatter-broadening is comparable to or exceeds the unscattered source size, the scattering can introduce spurious compact features into images. In addition, we derive efficient strategies to numerically compute realistic scattered images, and we present characteristic examples from simulations. Our results show that refractive substructure is an important consideration for ongoing missions at the highest angular resolutions, and we discuss specific implications for RadioAstron and the Event Horizon Telescope.Comment: Equation numbering in appendix now matches published version. Two minor typos correcte

Ronin Nights

Below is a reflection paper based on my time at UNO earning my M.F.A. in Film Production. It also covers the experience in creating my thesis film Ronin Nights. After the reflection will be the shooting script and all the forms that were filled out for the productio

Optimal Correlation Estimators for Quantized Signals

Using a maximum-likelihood criterion, we derive optimal correlation strategies for signals with and without digitization. We assume that the signals are drawn from zero-mean Gaussian distributions, as is expected in radio-astronomical applications, and we present correlation estimators both with and without a priori knowledge of the signal variances. We demonstrate that traditional estimators of correlation, which rely on averaging products, exhibit large and paradoxical noise when the correlation is strong. However, we also show that these estimators are fully optimal in the limit of vanishing correlation. We calculate the bias and noise in each of these estimators and discuss their suitability for implementation in modern digital correlators.Comment: 8 Pages, 3 Figures, Submitted to Ap

Postcard: Hall of Marquette Lodge No. 353 A.F. & A.M.

This black and white printed postcard is an invitation to attend the Marquette Lodge meeting. There is an image of a ruler and compass with a capital G in the center. Printed text and handwriting are on the front of the card. Handwriting is on the back of the card.https://scholars.fhsu.edu/tj_postcards/2178/thumbnail.jp

The Role of Military Chaplains and Effective Spiritual Care for Strengthening Military Marriages During Deployments

Military chaplains provide spiritual support and counseling to the military populations alongside conducting religious services. As a military process, chaplaincy operates as a liaison between military personnel, mental health professionals, and clinical marriage counselors. In this context, the military population is extensive and consists of military personnel, military chaplains, and their civilian families. It must be acknowledged that various service-motivated challenges confront these individuals. For instance, military marriages are threatened by lengthy deployment and family separations. Therefore, it is significant to contextualize military marriages’ coping, survival, and strengthening as most contemporary researchers have focused on this subject. Most studies have investigated several in-house mechanisms like spiritual care and outsourced coping agents like professional psychiatrists and marriage counselors among military populations (Bliese et al., 2008; Seddon et al., 2011). However, this study focused on interventions available at military facilities—chaplaincy and spiritual care. It is important to understand the role of spirituality as advanced by military chaplains as a coping mechanism among military personnel and a marriage-strengthening technique to verify its ability to improve marriage sustainability. Therefore, the study investigated the association between spirituality and marriage strengthening among military personnel. This phenomenological study aimed to examine the effectiveness of military chaplains and the spiritual care and support they provide to strengthen military marriages among military populations. As such, the study qualitatively examined the role of chaplains and spirituality among two military population participants—military personnel and chaplains at the Ellsworth Air Force Base. The theories guiding this study were the family stress theory advanced by Bowen (1971) and Selye’s (1956) stress theory, which helped explain the stressors in military marriages. Data were collected from semistructured, in-depth interviews with a study sample of 15 participants. The data were then transcribed, analyzed, and interpreted. The findings indicated that spiritual care provided by chaplains was critical in building trust and strengthening bonds among married couples. At the same time, spirituality equipped military couples with essential virtues for marriage stability. The study also found that psychological well-being was a critical factor in promoting healthy relationships and chaplains played a role in promoting the mental well-being of the military couples, which furthered the stability of the unions. Finally, the study acknowledged that other interventions and resources were critical in supporting strong marriages besides the spiritual care provided by chaplains. As such, couples were advised to join personal and family-oriented programs (e.g., marital counseling, the strong bonds program, and reintegration counseling) and use other resources to maintain their marriages