INTRODUCTION For a long time S18 has been noted as a strange source, with the first studies taking place in the 1950s . It is a supergiant B[e] star in the Small Magellanic Cloud (SMC) that doubles as an X-ray source and a variable star. In addition, the star has in few cases exhibited an extreme and unexplained He II emission . My collaborators and I utilize the Southern Observatory for Astronomical Research (SOAR) telescope to produce high resolution spectra of S18. In the proceeding we examine spectra of this system and attempt the first period determination by measuring radial velocities from these spectra. Such a measurement would put a constraint on the nature of the companion. Currently the proposed secondary star is unclassified. A white dwarf is however favored because of observed X-ray, visual, and UV luminosity . This system is of interest to us because of the debate surrounding the classification of the system. Confirmation of a secondary object will help indicate the sources of many of the mysterious properties of the system. We are also interested in the classification of the companion object seeing as how both of these companion types have interesting implications for a B[e] system with such a range of physical parameters. Together this information will allow for better categorization of the central star and the system as a whole.

THE BASICS An example of an inline equation: a + b = αγ. To display an equation, you use the equation environment. \left({\partial t^2}\right) = -{r^2} We can also do display math without an equation number: $$ G_{\mu\nu} = 8\pi T_{\mu\nu}. $$ The equation environment allows us to cross-reference equations: equation ([e.Newton]) is Newton’s equation. Citations are handled with the cite command and its variants: “observations of the quiescent luminosity of MAXI J0556-332 suggest the presence of a strong heat source in its accreted envelope .” Notice that this style uses an author-date system. With author-date, there are fancier versions of the cite command: “with the release of the second MESA paper, ”. Here I would like to cite this result .

We present a new method for measuring the photometry of objects around galaxy clusters, employing a novel mode-filtering technique for both detection and photometry. With this, we are able to investigate the galaxy populations inside the 25 massive clusters observed by the Cluster Lensing and Supernova survey with Hubble (CLASH). We produce multi-wavelength catalogs covering 16 bandpasses from ultraviolet (∼2360 Å) to infrared ($\sim 1.54 $) including photometric redshifts. A comparison with spectroscopic values from the literature finds that ∼82% of our reported photometric redshifts lie within |zp − zs|/(1 + zs)<0.05. This improvement in redshift accuracy, in combination with a detection scheme designed to maximize purity, yields a substantial upgrade in cluster member identification over the previous CLASH galaxy catalog. We find consistency between the galaxy magnitudes, colors, and photometric redshifts obtained here and from previous studies, including a deeper observation of one of the CLASH clusters. Evaluating the luminosity functions for these clusters, we find that we are able to observe galaxies down to ${\rm M} \sim {\rm M}^* + 5$, and the values of M* we derive are consistent with that expected from published cluster galaxy luminosity functions. These clusters follow a consistent trend in mass-richness that agrees with low-mass cluster observations. We measure luminosity functions for these clusters, which we use to derive total luminosity, and, from that, stellar masses. We find stellar mass fractions of 1.8 ± 0.7% of the total halo mass, in agreement with previous studies. Not only will this catalog enable new studies of the properties of CLASH clusters, but the photometric techniques we use set the stage for future surveys of galaxy clusters.

hooray!

MULTIWAVELNGTH DIAGNOSTICS ON AGNS FROM CHILES SAMPLE. Radio Optical X-Ray

ABSTRACT This paper will primarily focus on a study by on how gravity modes could be excited by convection in massive main sequence stars. The first portion of this paper will explain the more commonly understood method of how gravity modes are driven by adiabatic expansion at the core and why gravity modes produced this way are so difficult to observe. The second part of this paper will briefly go over the methods for detecting gravity modes and the observational challenges faced. The third portion will look at models constructed using the MESA stellar evolution code that were used to estimate mode frequencies, excitation amplitudes and where in the stellar interior of various sized main sequence stars, gravity modes would propagate. The final portion of this paper will look at future advancements in detecting gravity modes and promising observations taken from the Kepler space satellite.

INTRODUCTION

In October of 2012, the first four-star planet was confirmed by the Planet Hunters program from Yale. The planet – called Planet Hunters 1 (PH1) – is a circumbinary planet meaning it is orbiting a pair of stars instead of just one. Furthermore, orbiting that pair of stars is another pair meaning this planet is in a system with four stars total. With so many large forces acting on this system, the stability is, of course, a question of concern. According to the paper announcing PH1’s discovery, though, “the system is indeed stable on gigayear timescales” . This implies there are formation possibilities never considered and is inspiring further study of PH1.

WHY REVAMP AST 208, _PLANETS AND TELESCOPES_? The undergraduate major not only imparts knowledge about a discipline; it also trains students in the practice of that field. Astrophysics—like all sciences—evolves, and the skills that a student of astrophysics is expected to acquire therefore also evolve. Numerical software has made tables of integrals gather dust; data analysis and CCD detectors have replaced visual scanning of photographic plates. Further, although the majority of astrophysics majors do not become professional astronomers, they do find employment in a variety of STEM fields. For both these reasons, the undergraduate major must impart skills that are broadly applicable. As part of a response to an institutional accreditation review, the astronomy group at Michigan State University committed to the following learning outcomes for the undergraduate astrophysics major. Students completing an Astrophysics degree will be able to: 1. Apply concepts from physics, mathematics, and scientific computing to solve quantitative problems in astrophysics; 2. Gather, analyze, and interpret astronomical data from sources including telescopes, databases, computer simulations, analytic models, and the scientific literature; and 3. Effectively communicate scientific ideas in both written and oral form. Data analysis and numerical computation are now ubiquitous in astrophysics and in STEM careers; yet undergraduate curricula have been slower to systematically train students in these skills. In addition to having a greater reliance on statistical and computational techniques, STEM fields (including astrophysics) are increasingly collaborative. Skills such as communication and project management are an essential component of a student’s education. This gap between what is taught in courses and what is needed by the discipline is readily apparent when astrophysics students begin their senior theses, which are a requirement for an astrophysics degree at Michigan State. As noted in the astronomy group’s response to the accreditation review, During the past decade, we have found that many of our students begin their senior thesis project without the statistical, computational, and/or database skills needed to make sufficiently rapid progress. Our faculty members have therefore had to spend precious one-on-one thesis-advising time teaching skills that students could have learned as part of their coursework. Our revisions to AST 208 (_Planets and Telescopes_), AST 304 (_Stars_), and AST 308 (_Galaxies_) remedy this deficiency by pacing student progress toward these modern learning goals, so that students emerge with a deeper knowledge base and readily applicable skills. In this document, we describe in detail the innovative changes made to AST 208.

ABSTRACT