2018 MASC Presentation List

The following provides you with a summary of the presentations that will be given at the Meeting of Astronomers of South Carolina. Order in the table does not reflect order of presentations.

Last Name First Name Institution Title of Presentation Abstract
2018 Presentation List
Myers Jeannette Francis Marion University    
Hartmann Dieter Clemson University Binary Neutron Star Mergers: Catching the electromagnetic afterglows of gravitational wave events The LIGO/VIRGO /Fermi discovery of nearby GW170817/GRB170817A and its global follow-up pushed the Multimessenger window wide open. I will discuss the new area of kilonova astrophysics revealed by this groundbreaking event and plans for the next round of ground- and space-based follow-up of gravitational wave events. The improved sensitivity of the coming installment of laser interferometers will push the diastase limit to which we can see such mergers and thus produce these opportunities at an increased rate, so the community is gearing up for exciting times.
Kirby Alexander University of South Carolina Constraining Extinction due to Dust in Distant Galaxies Extinction due to interstellar dust is a ubiquitous phenomenon that dims and reddens the light of background objects. As such, it is essential to apply extinction corrections to observations of distant objects in order to deduce their properties. Since the discovery of interstellar extinction in 1930, astronomers have developed a fairly detailed understanding of the interstellar dust in the Milky Way and other Local Group galaxies, especially the Magellanic Clouds. However, studies of extinction by dust in galaxies beyond the Local Group have been limited. In this work, we seek to generate better constraints on dust extinction in other galaxies in order to improve corrections for observations of objects that lie beyond them. As such, we are constructing spectral energy distributions (SEDs) for quasars/active galactic nuclei whose lines of sight go through foreground galaxies at lower redshifts. We will describe our compilation of archival optical, UV, and IR spectroscopic and photometric data from various observatories. Using the SEDs compiled from these data, and fitting the underlying continuum of the background quasar/AGN, we will estimate dust extinction curves for each foreground galaxy, and compare those with extinction curves in the Milky Way and the Magellanic Clouds.
Desai Abhishek Clemson University EBL with Pass 8 The extragalactic background light (EBL), from ultra-violet to infrared, that encodes the emission from all stars, galaxies and actively accreting black holes in the observable Universe is critically important to probe models of star formation and galaxy evolution, but remains at present poorly constrained. The Large Area Telescope (LAT), on board Fermi, produced an unprecedented measurement (relying on 750 blazars and the first 9 years of Pass 8 data) of the EBL optical depth at 12 different epochs from redshift 0 up to a redshift of 3. In this talk, I will present the measurement and how it constrains the EBL energy density and its evolution with cosmic time. I will also discuss how this paves the road to the first point-source-independent determinations of the star-formation history of the Universe.
Paliya Vaidehi Sharan Clemson University Gamma-ray Emitting Narrow Line Seyfert 1 Galaxies: Past, Present, and Future The detection of the significant γ-ray emission from about half-a-dozen radio-loud (RL) narrow line Seyfert 1 galaxies (NLSy1s) enables to study the properties of relativistic jets at different jet launching environment than that generally claimed for blazars. However, due to their small sample size, a conclusive remark cannot be made. Here we report the first detection of the significant γ-ray emission from AGNs which are recently classified as NLSy1 from their SDSS optical spectrum. Comparing their broadband properties with blazars reveals their resemblance with flat spectrum radio quasars, though at low black hole mass end. We will summarize our current understanding about γ-ray emitting NLSy1 galaxies with a focus on using them as a tool to disentangle the disk-jet connection in jetted active galaxies.
Marchesi Stefano Clemson University A multi-observatory X-ray approach to characterize heavily obscured AGN According to the different models of Cosmic X-ray Background (CXB), the diffuse X-ray emission observed in the 1 to ~200-300 keV band, is mainly caused by accreting supermassive black holes, the so-called active Galactic Nuclei (AGN). Particularly, at the peak of the CXB (~30 keV) a significant fraction of emission (10-25%) is expected to be produced by a numerous population of heavily obscured, Compton thick (CT-) AGN, having intrinsic column density NH>=1E24 cm{-2}. Nonetheless, in the nearby Universe (z<=0.1) the observed fraction of CT-AGN with respect to the total population appears to be lower than the one expected on the basis of the majority of CXB model predictions (~20-30%), being between 5 and 10%. This discrepancy between data and models is one of the open challenges for X-ray astronomers, and needs to be solved to get a complete understanding of the AGN population. In this presentation, I will discuss a multi-observatory X-ray approach to find and characterize heavily obscured AGN. Candidate sources are first selected in the 100-month Swift-BAT catalog, the result of a ~7 years all-sky survey in the 15-150 keV band. These objects are then targeted with snapshot (5-10 ks) observations with Chandra and Swift-XRT, which allow us to constrain the intrinsic absorption value within a 20-30% uncertainty. Finally, deep (25-50 ks) observations with XMM-Newton and NuSTAR allow us to study the physics of these complex and elusive sources.