Astrophysics and Astronomy Commons^™

Astrometric Mass Ratios For Three Spectroscopic Binaries, Johannes Sahlmann, Francis C. Fekel

Information Systems and Engineering Management Research Publications

The orbits of five single-lined spectroscopic binaries have recently been determined. We now use astrometric measurements that were collected with the HIPPARCOS satellite to constrain the systems’ mass ratios and secondary masses. The barycentric astrometric orbits of three binary systems, HD 140667, HD 158222, and HD 217924, are fully determined and precise estimates of their mass ratios are obtained. Follow-up of these systems with infrared spectroscopy could yield model-independent dynamical masses for all components.

2013 Annual Meeting Program

Journal of the South Carolina Academy of Science

No abstract provided.

Validation Of Data Reduction Interactive Pipeline For Forcast On Sofia, Brent C. Nicklas, William T. Reach, Sachindev S. Shenoy

STAR Program Research Presentations

The Stratospheric Observatory For Infrared Astronomy (SOFIA) is a heavily modified Boeing 747SP aircraft equipped with 2.5 meter reflecting telescope. Among the suite of instruments onboard is the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST). FORCAST features two cameras for short (5-25 microns) and long (25-40 microns) wavelength detection. Making infrared observations in these wavelengths presents a challenge because the telescope and sky emit background radiation magnitudes brighter than the object of interest. Because of this, the raw FORCAST data must be corrected and reduced. The Data Reduction Interactive Pipeline (DRIP) was developed to process all FORCAST data …

Characterization Of Samples For Optimization Of Infrared Stray Light Coatings, Carey L. Baxter, Rebecca Salvemini, Zaheer A. Ali, Patrick Waddell, Greg Perryman, Bob Thompson

STAR Program Research Presentations

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) is a converted 747SP that houses a 2.5 m telescope that observes the sky through an opening in the side of the aircraft. Because it flies at altitudes up to 45,000 feet, SOFIA gets 99.99% transmission in the infrared. Multiple science instruments mount one at a time on the telescope to interpret infrared and visible light from target sources. Ball Infrared Black (BIRB) currently coats everything that the optics sees inside the telescope assembly (TA) cavity in order to eliminate noise from the glow of background sky, aircraft exhaust, and other sources. A …

Analyzing The Performance Of The Sofia Infrared Telescope, Sarah M. Bass, Jeffrey Van Cleve, Zaheer Ali

STAR Program Research Presentations

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is an airborne near-space observatory onboard a modified Boeing 747-SP aircraft, which flies at altitudes of 45,000 ft., above 99% of the Earth’s water vapor. SOFIA contains an effective 2.5 m infrared (IR) telescope that has a dichroic tertiary mirror, reflecting IR and visible wavelengths to the science instrument (SI) and focal plane imager (FPI), respectively. To date, seven different SIs have been designed to cover a wide range of wavelengths and spectral resolutions. Since the telescope operates in the infrared, different techniques, including chopping, nodding, and dithering, are used to reduce the …

Tools And Methods To Optimize The Analysis Of Telescopic Performance Metrics On Sofia, Steven R. Wilson, Holger Jakob, Stefan Teufel, Zaheer Ali, Jeffrey Van Cleve, Brian Eney, Greg Perryman

STAR Program Research Presentations

SOFIA is an infrared observatory mounted on a modified 747 engineered to do infrared astronomy at 45000 feet. The telescope equipment contains a number of sensors and stabilizers that allow the telescope to capture images while mounted in a moving plane. We have developed methods to analyze the performance of the telescope assembly that will help improve the stabilization and image capturing performance of the observatory. Here we present reusable methods to analyze telescope performance data that will enable improvements in the quality of the scientific data that is produced by the SOFIA. This poster focuses on the multi-flight performance …

Flitecam Data Process Validation, Jesse K. Tsai, Sachindev S. Shenoy, Brent Cedric Nicklas, Zaheer Ali, William T. Reach

STAR Program Research Presentations

FLITECAM Data Processing Validation

Many of the challenges that come from working with astronomical imaging arise from the reduction of raw data into scientifically meaningful data. First Light Infrared Test CAMera (FLITECAM) is an infrared camera operating in the 1.0–5.5 μm waveband on board SOFIA (Stratospheric Observatory For Infrared Astronomy). Due to the significant noise from the atmosphere and the camera itself, astronomers have developed many methods to reduce the effects of atmospheric and instrumental emission. The FLITECAM Data Reduction Program (FDRP) is a program, developed at SOFIA Science Center, subtracts darks, removes flats, and dithers images.

This project contains …

Accretion Variability Of Herbig Ae/Be Stars Observed By X-Shooter Hd 31648 And Hd 163296, I Mendigutia, Sean D. Brittain, C Eiroa, G Meeus, B Montesinos, A Mora, J Muzerolle, R D. Oudmaijer, E Rigliaco

Publications

This work presents X-Shooter/Very Large Telescope spectra of the prototypical, isolated Herbig Ae stars HD 31648 (MWC 480) and HD 163296 over five epochs separated by timescales ranging from days to months. Each spectrum spans over a wide wavelength range covering from 310 to 2475 nm. We have monitored the continuum excess in the Balmer region of the spectra and the luminosity of 12 ultraviolet, optical, and near-infrared spectral lines that are commonly used as accretion tracers for T Tauri stars. The observed strengths of the Balmer excesses have been reproduced from a magnetospheric accretion shock model, providing a mean …

Suppressed Carrier Scattering In Cds-Encapsulated Pbs Nanocrystal Films, Pavel Moroz, Natalia Kholmicheva, Bryan Mellott, Geethika Liyanage, Upendra Rijal, Ebin Bastola, Kyla Huband, Elena Khon, Keith Mcbride, Mikhail Zamkov

Physics and Astronomy Faculty Publications

One of the key challenges facing the realization of functional nanocrystal devices concerns the development of techniques for depositing colloidal nanocrystals into electrically coupled nanoparticle solids. This work compares several alternative strategies for the assembly of such films using an all-optical approach to the characterization of electron transport phenomena. By measuring excited carrier lifetimes in either ligand-linked or matrix-encapsulated PbS nanocrystal films containing a tunable fraction of insulating ZnS domains, we uniquely distinguish the dynamics of charge scattering on defects from other processes of exciton dissociation. The measured times are subsequently used to estimate the diffusion length and the carrier …

Gr 20 Workshop, Warsaw, July 2013, Ian M. Anderson, Charles G. Torre

Presentations

These are the Maple worksheets used at the Differential Geometry in Maple Workshop, which was held at the 20th International Conference on General Relativity and Gravitation, in Warsaw, July 2013.

There are 6 worksheets which can be downloaded from the list of files below.

Type Ii Cepheid Candidates. Iv. Objects From The Northern Sky Variability Survey, Edward G. Schmidt

Edward Schmidt Publications

We have obtained VR photometry of 447 Cepheid variable star candidates with declinations north of −14°30’, most of which were identified using the Northern Sky Variability Survey (NSVS) data archive. Periods and other photometric properties were derived from the combination of our data with the NSVS data. Atmospheric parameters were determined for 81 of these stars from low-resolution spectra. The identification of type II Cepheids based on the data presented in all four papers in this series is discussed. On the basis of spectra, 30 type II Cepheids were identified while 53 variables were identified as cool, main sequence stars …

The Stellar Content Of The Young Open Cluster Trumpler 37, R. Errmann, R. Neuhäuser, L. Marschall, G. Torres, M. Mugrauer, W. P. Chen, S. C.-L. Hu, C. Briceño, R. Chini, L. Bukowiecki, D. P. Dimitrov, D. P. Kjurkchieva, Eric L.N. Jensen, David H. Cohen, Z.-Y. Wu, T. Pribulla, M. Vaňko, V. Krushevska, J. Budaj, Y. Oasa, A. K. Pandey, M. Fernández, A. Kellerer, C. Marka

Physics & Astronomy Faculty Works

With an apparent cluster diameter of 1.5 degrees and an age of 4 Myr, Trumpler 37 is an ideal target for photometric monitoring of young stars as well as for the search of planetary transits, eclipsing binaries and other sources of variability. The YETI consortium has monitored Trumpler 37 throughout 2010 and 2011 to obtain a comprehensive view of variable phenomena in this region. In this first paper we present the cluster properties and membership determination as derived from an extensive investigation of the literature. We also compared the coordinate list to some YETI images. For 1872 stars we found …

Wind Channeling, Magnetospheres, And Spindown Of Magnetic Massive Stars, S. P. Owocki, A. Ud-Doula, R. H. D. Townsend, V. Petit, J. O. Sundqvist, David H. Cohen

Physics & Astronomy Faculty Works

A subpopulation (~10%) of hot, luminous, massive stars have been revealed through spectropolarimetry to harbor strong (hundreds to tens of thousand Gauss), steady, large-scale (often significantly dipolar) magnetic fields. This review focuses on the role of such fields in channeling and trapping the radiatively driven wind of massive stars, including both in the strongly perturbed outflow from open field regions, and the wind-fed “magnetospheres” that develop from closed magnetic loops. For B-type stars with weak winds and moderately fast rotation, one finds “centrifugal magnetospheres”, in which rotational support allows magnetically trapped wind to accumulate to a large density, with quite …

An X-Ray-Uv Correlation In Cen X-4 During Quiescence, E. M. Cackett, E. F. Brown, N. Degenaar, J. M. Miller, M. Reynolds, R. Wijnands

Physics and Astronomy Faculty Research Publications

Quiescent emission from the neutron star low-mass X-ray binary Cen X-4 is seen to be variable on time-scales from hundreds of seconds to years, suggesting that at least in this object, low-level accretion is important during quiescence. Here, we present results from recent XMM-Newton and Swift observations of Cen X-4, where the X-ray flux (0.5-10 keV) varies by a factor of 6.5 between the brightest and faintest states. We find a positive correlation between the X-ray flux and the simultaneous near-ultraviolet (UV) flux, where as there is no significant correlation between the X-ray and simultaneous optical (V, B) fluxes. This …

The Redshift And Mass Dependence On The Formation Of The Hubble Sequence At Z > 1 From Candels/Uds, Alice Mortlock, Christopher J. Conselice, William G. Hartley, Jamie R. Ownsworth, Caterina Lani, Asa F. L. Bluck, Omar Almaini, Kenneth Duncan, Arjen Van Der Wel, Anton M. Koekemoer, Avishai Dekel, Romeel Davé, Harry C. Ferguson, Duilia F. De Mello, Jeffrey A. Newman, Sandra M. Faber, Norman A. Grogin, Dalibor D. Kocevski, Kamson Lai

Physics and Astronomy Faculty Publications

In this paper we present a detailed study of the structures and morphologies of a sample of 1188 massive galaxies with M_* ≥ 10¹⁰ M_⊙between redshifts z = 1 and 3 within the Ultra Deep Survey (UDS) region of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) field. Using this sample we determine how galaxy structure and morphology evolve with time, and investigate the nature of galaxy structure at high redshift. We visually classify our sample into discs, ellipticals and peculiar systems and correct for redshift effects on these classifications through simulations. We find significant …

Exploring The Variable Sky With Linear. Ii. Halo Structure And Substructure Traced By Rr Lyrae Stars To 30 Kpc, Branimir Sesar, Hakeem Oluseyi

Aerospace, Physics, and Space Science Faculty Publications

We present a sample of ∼5000 RR Lyrae stars selected from the recalibrated LINEAR data set and detected at heliocentric distances between 5 kpc and 30 kpc over ∼8000 deg2 of sky. The coordinates and light curve properties, such as period and Oosterhoff type, are made publicly available. We analyze in detail the light curve properties and Galactic distribution of the subset of ∼4000 type ab RR Lyrae (RRab) stars, including a search for new halo substructures and the number density distribution as a function of Oosterhoff type. We find evidence for the Oosterhoff dichotomy among field RR Lyrae stars, …

The Magnesium Isotopologues Of Mgh In The A2Π-X 2Σ+ System, Kenneth H. Hinkle, Lloyd Wallace, Ram S. Ram, Peter F. Bernath, Christopher Sneden, Sara Lucatello

Chemistry & Biochemistry Faculty Publications

Using laboratory hollow cathode spectra we have identified lines of the less common magnesium isotopologues of MgH, ²⁵MgH and ²⁶MgH, in the A²Π-X²Σ⁺ system. Based on the previous analysis of ²⁴MgH, molecular lines have been measured and molecular constants derived for ²⁵MgH and ²⁶MgH. Term values and linelists, in both wavenumber and wavelength units, are presented. The A²Π-X²Σ⁺ system of MgH is important for measuring the magnesium isotope ratios in stars. Examples of analysis using the new linelists to derive the Mg isotope ratio in …

Field Localization And Mass Generation In An Alternative 5-Dimensional Brane Model, Preston Jones, Doug Singleton, Gerardo Muñoz, Triyanta

Publications

This proceedings is from a talk given at the APS DPF 2013 on a 5- dimensional brane world model. This alternative brane world model is formally related but physically distinct from the Randall-Sundrum brane world model. The spin dependent localization of 5D fields for the alternative model are different and in some ways superior to the RandallSundrum. The alternative model also exhibits a cutoff in the localization of massive scalar fields not seen in the Randall-Sundrum model. This revision includes a correction to the integrand for the scalar field action appearing in the principle reference [1].

Designing A Cold Source To Be Integrated With The Existing Telescope Assembly Alignment Simulator, Rebecca L. Salvemini, Carey Baxter, Zaheer Ali, Greg Perryman, Robert Thompson, Daniel Nolan

STAR Program Research Presentations

The stratospheric observatory for infrared astronomy (SOFIA), is a modified Boeing 747-SP with a 2.5m telescope mounted inside. SOFIA flies at an altitude of 45,000 feet, above 99% of the water vapor in the atmosphere, allowing transmission of most infrared radiation. SOFIA has seven different science instruments (SI) that can be used to collect astronomical data, enabling scientists to look at many different wavelengths of infrared and visible radiation.

The Occulting Galaxy Pair Ugc 3995 : Dust Properties From Hst And Califa Data., Benne W. Holwerda, W. C. Keel

Faculty and Staff Scholarship

UGC 3995 is an interacting and occulting galaxy pair. UGC 3995B is a foreground face-on spiral and UGC 3995A a bright background spiral with an AGN. We present analysis of the dust in the disc of UGC 3995B based on archival Hubble Space Telescope (HST) WFPC2 and PPAK IFU data from the CALIFA survey’s first data release. From the HST F606W image, we construct an extinction map by modeling the isophotes of the background galaxy UGC 3995A and the resulting transmission through UGC 3995B. This extinction map of UGC 3995B shows several distinct spiral extinction features. The radial distribution of …