Astrophysics and Astronomy Commons^™

Analytic Exoplanet Transit Analysis, And Investigation Into Wasp, Kepler, And Qatar Systems, Colan Gulla

College Honors Program

In this paper we analyze exoplanet transit data. First, we discuss an analytical method of assessing the data similar to the one derived in Agol & Mandel, 2002¹. The time series photometric data for transits used in this paper was downloaded from the NASA Exoplanet Archive. Similar data was also extracted from the Exoplanet Transit Database for analysis. We use a formula for relative flux from Agol & Mandel, 2002¹ to study the specific transit systems of WASP 1b, WASP 12b, Kepler 1, Qatar 1b and TRES-1b. The formula for relative flux is fit to a set …

Near-Infrared Variability In Dusty White Dwarfs: Tracing The Accretion Of Planetary Material, Laura K. Rogers, Siyi Xu, Amy Bonsor, Simon Hodgkin, Kate Y.L. Su, Ted Von Hippel, Michael Jura

Publications

The inwards scattering of planetesimals towards white dwarfs is expected to be a stochastic process with variability on human time-scales. The planetesimals tidally disrupt at the Roche radius, producing dusty debris detectable as excess infrared emission. When sufficiently close to the white dwarf, this debris sublimates and accretes on to the white dwarf and pollutes its atmosphere. Studying this infrared emission around polluted white dwarfs can reveal how this planetary material arrives in their atmospheres. We report a near-infrared monitoring campaign of 34 white dwarfs with infrared excesses with the aim to search for variability in the dust emission. Time …

Tracing The Anemic Stellar Halo Of M 101, In Sung Jang, Roelof S. De Jong, Benne W. Holwerda, Antonela Monachesi, Eric F. Bell, Jeremy Bailin

Faculty and Staff Scholarship

Models of galaxy formation in a cosmological context predict that massive disk galaxies should have structured extended stellar halos. Recent studies in integrated light, however, report that a few galaxies, including the nearby disk galaxy M 101, have no measurable stellar halos to the detection limit. We aim to quantify the stellar content and structure of M 101's outskirts by resolving its stars. We present the photometry of its stars based on deep F606W and F814W images taken with Hubble Space Telescope (HST) as part of the GHOSTS survey. The HST fields are placed along the east and west sides …

Mergers Trigger Active Galactic Nuclei Out To Z ∼0.6, F. Gao, L. Wang, W. J. Pearson, Y. A. Gordon, Benne W. Holwerda, A. M. Hopkins, M. J.I. Brown, J. Bland-Hawthorn, M. S. Owers

Faculty and Staff Scholarship

Aims. The fueling and feedback of active galactic nuclei (AGNs) are important for understanding the co-evolution between black holes and host galaxies. Mergers are thought to have the capability to bring gas inward and ignite nuclear activity, especially for more powerful AGNs. However, there is still significant ongoing debate on whether mergers can trigger AGNs and, if they do, whether mergers are a significant triggering mechanism. Methods. We selected a low-redshift (0.005  <   z  <   0.1) sample from the Sloan Digital Sky Survey and a high-redshift (0  <   z  <   0.6) sample from the Galaxy And Mass Assembly survey. We took advantage of the convolutional neural network technique to identify mergers. We used mid-infrared (MIR) color cut and optical emission line diagnostics to classify AGNs. We also included low excitation radio galaxies (LERGs) to investigate the connection between mergers and low accretion rate AGNs. Results. We find that AGNs are more likely to be found in mergers than non-mergers, with an AGN excess up to 1.81 ± 0.16, suggesting that mergers can trigger AGNs. We also find that the fraction of mergers in AGNs is higher than that in non-AGN controls, for both MIR and optically selected AGNs, as well as LERGs, with values between 16.40 ± 0.5% and 39.23 ± 2.10%, implying a non-negligible to potentially significant role of mergers in triggering AGNs. This merger fraction in AGNs increases as stellar mass increases, which supports the idea that mergers are more important for triggering AGNs in more massive galaxies. In terms of merger fraction as a function of AGN power we find a positive trend for MIR selected AGNs and a complex trend for optically selected AGNs, which we interpret under an evolutionary scenario proposed by previous studies. In addition, obscured MIR selected AGNs are more likely to be hosted in mergers than unobscured MIR selected AGNs.

Fingerprints Of Binary Black Hole Formation Channels Encoded In The Mass And Spin Of Merger Remnants, Manuel Arca Sedda, Michaela Mapelli, Mario Spera, Matthew Benacquista, Nicola Giacobbo

Physics & Astronomy Faculty Publications

Binary black holes (BBHs) are thought to form in different environments, including the galactic field and (globular, nuclear, young, and open) star clusters. Here, we propose a method to estimate the fingerprints of the main BBH formation channels associated with these different environments. We show that the metallicity distribution of galaxies in the local universe along with the relative amount of mergers forming in the field or in star clusters determine the main properties of the BBH population. Our fiducial model predicts that the heaviest merger to date, GW170729, originated from a progenitor that underwent 2–3 merger events in a …

Updated Parameters And A New Transmission Spectrum Of Hd 97658b, Xueying Guo, Ian J. M. Crossfield, Diana Dragomir, Molly Kosiarek, Joshua Lothringer, Thomas Mikal-Evans, Lee J. Rosenthal, Björn Benneke, Heather Knutson, Paul A. Dalba, Eliza M. R. Kempton, Gregory W. Henry, Peter R. Mccullough, Travis Barman, Sarah C. Blunt, Ashley Chontos, Jonathan J. Fortney, Benjamin Fulton, Lea A. Hirsch, Andrew W. Howard, Howard Isaacson, Jaymie Matthews, Teo Mocnik, Caroline Morley, Erik A. Petigura, Lauren M. Weiss

Information Systems and Engineering Management Research Publications

Recent years have seen increasing interest in the characterization of sub-Neptune-sized planets because of their prevalence in the Galaxy, contrasted with their absence in our solar system. HD 97658 is one of the brightest stars hosting a planet of this kind, and we present the transmission spectrum of this planet by combining four Hubble Space Telescope transits, 12 Spitzer/IRAC transits, and eight MOST transits of this system. Our transmission spectrum has a higher signal-to-noise ratio than those from previous works, and the result suggests that the slight increase in transit depth from wavelength 1.1–1.7 μm reported in previous works on …

Swift Spectroscopy Of The Accretion Disk Wind In The Black Hole Gro J1655-40, M. Balakrishnan, J. M. Miller, N. Trueba, M. Reynolds, J. Raymond, Daniel Proga, A. C. Fabian, T. Kallman, J. Kaastra

Physics & Astronomy Faculty Research

Chandra obtained two High Energy Transmission Grating spectra of the stellar-mass black hole GRO J1655−40 during its 2005 outburst, revealing a rich and complex disk wind. Soon after its launch, the Neil Gehrels Swift Observatory began monitoring the same outburst. Some X-ray Telescope (XRT) observations were obtained in a mode that makes it impossible to remove strong Mn calibration lines, so the Fe Kα line region in the spectra was previously neglected. However, these lines enable a precise calibration of the energy scale, facilitating studies of the absorption-dominated disk wind and its velocity shifts. Here we present fits to 15 …

Sensory-Friendly Show Set To Return At Staerkel Planetarium, Erik Johnson

Natural Science Faculty

When most people come to the William M. Staerkel Planetarium at Parkland College for a show, they are greeted by a 50-foot dome and the impressive – but imposing – Zeiss star projector. As the programs begin, the lights get dimmer than they would in a movie theater, which may briefly create an environment that can be distressing for some guests, particularly if they are sensitive to significant sensory changes.

However, on February 29, the Staerkel Planetarium took a different approach and hosted its first ever sensory-friendly shows with the goal of providing a more welcoming experience for members of …

Predictions And Outcomes For The Dynamics Of Rotating Galaxies, Stacy S. Mcgaugh

Faculty Scholarship

A review is given of a priori predictions made for the dynamics of rotating galaxies. One theory-MOND-has had many predictions corroborated by subsequent observations. While it is sometimes possible to offer post hoc explanations for these observations in terms of dark matter, it is seldom possible to use dark matter to predict the same phenomena.

Optical To Near-Infrared Transmission Spectrum Of The Warm Sub-Saturn Hat-P-12b, Ian Wong, Björn Benneke, Peter Gao, Heather Knutson, Yayaati Chachan, Gregory W. Henry, Drake Deming, Tiffany Kataria, Elspeth K. H. Lee, Nikolay Nikolov, David K. Sing, Gilda E. Ballester, Nathaniel J. Baskin, Hannah R. Wakeford, Michael H. Williamson

Information Systems and Engineering Management Research Publications

We present the transmission spectrum of HAT-P-12b through a joint analysis of data obtained from the Hubble Space Telescope Space Telescope Imaging Spectrograph and Wide Field Camera 3 and Spitzer, covering the wavelength range 0.3–5.0 μm. We detect a muted water vapor absorption feature at 1.4 μm attenuated by clouds, as well as a Rayleigh scattering slope in the optical indicative of small particles. We interpret the transmission spectrum using both the state-of-the-art atmospheric retrieval code SCARLET and the aerosol microphysics model CARMA. These models indicate that the atmosphere of HAT-P-12b is consistent with a broad range of metallicities between …

Observations Of Binary Stars With The Differential Speckle Survey Instrument. Ix. Observations Of Known And Suspected Binaries, And A Partial Survey Of Be Stars, Elliott P. Horch, Gerard T. Van Belle, James W. Davidson Jr., Daryl W. Willmarth, Francis C. Fekel, Matthew W. Muterspaugh, Dana I. Casetti-Dinescu, Frederick W. Hahne, Nicole M. Granucci, Catherine A. Clark, Jennifer G. Winters, Justin D. Rupert, Samuel A. Weiss, Nicole M. Colton, Daniel A. Nusdeo, Todd J. Henry

Information Systems and Engineering Management Research Publications

We report 370 measures of 170 components of binary and multiple-star systems, obtained from speckle imaging observations made with the Differential Speckle Survey Instrument at Lowell Observatory's Discovery Channel Telescope in 2015 through 2017. Of the systems studied, 147 are binary stars, 10 are seen as triple systems, and 1 quadruple system is measured. Seventy-six high-quality nondetections and 15 newly resolved components are presented in our observations. The uncertainty in relative astrometry appears to be similar to our previous work at Lowell, namely, linear measurement uncertainties of approximately 2 mas, and the relative photometry appears to be uncertain at the …

Alma 0.88 Mm Survey Of Disks Around Planetary-Mass Companions, Ya-Lin Wu, Brendan P. Bowler, Patrick D. Sheehan, Sean M. Andrews, Gregory J. Herczeg, Adam L. Kraus, Luca Ricci, David J. Wilner, Zhaohuan Zhu

Physics & Astronomy Faculty Research

Characterizing the physical properties and compositions of circumplanetary disks can provide important insights into the formation of giant planets and satellites. We report Atacama Large Millimeter/submillimeter Array 0.88 mm (Band 7) continuum observations of six planetary-mass (10–20 M Jup) companions: CT Cha b, 1RXS 1609 b, ROXs 12 b, ROXs 42B b, DH Tau b, and FU Tau b. No continuum sources are detected at the locations of the companions down to 3σ limits of 120–210 μJy. Given these nondetections, it is not clear whether disks around planetary-mass companions indeed follow the disk-flux–host-mass trend in the stellar regime. The faint …

Automated Spectroscopic Detection And Mapping Using Alma And Machine Learningtechniques, Steven Cocke, Andrew Wilkins, Josephine Mcdaniel, John Santerre, Conor Nixon

SMU Data Science Review

In this paper we present a methodology for automating theclassification of spectrally resolved observations of multiple emissionlines with the Atacama Large Millimeter/submillimeter Array (ALMA).Molecules in planetary atmospheres emit or absorb different wavelengthsof light thereby providing a unique signature for each species. ALMAdata were taken from interferometric observations of Titan made be-tween UT 2012 July 03 23:22:14 and 2012 July 04 01:06:18 as part ofALMA project 2011.0.00319.S. We first employed a greedy set cover algorithm to identify the most probable molecules that would reproducethe set of frequencies with respective flux greater than 3σaway from themean. We then selected a subset of …

Detection Of Na, K, And H2o In The Hazy Atmosphere Of Wasp-6b, Aarynn L. Carter, Nikolay Nikolov, David K. Sing, Munazza K. Alam, Jayesh M. Goyal, Thomas Mikal-Evans, Hannah R. Wakeford, Gregory W. Henry, Sam Morrell, Mercedes López-Morales, Barry Smalley, Panayotis Lavvas, Joanna K. Barstow, Antonio García Muñoz, Neale P. Gibson, Paul A. Wilson

Information Systems and Engineering Management Research Publications

We present new observations of the transmission spectrum of the hot Jupiter WASP-6b both from the ground with the Very Large Telescope FOcal Reducer and Spectrograph (FORS2) from 0.45 to 0.83 μm, and space with the Transiting Exoplanet Survey Satellite from 0.6 to 1.0 μm and the Hubble Space Telescope (HST) Wide Field Camera 3 from 1.12 to 1.65 μm. Archival data from the HST Space Telescope Imaging Spectrograph (STIS) and Spitzer are also re-analysed on a common Gaussian process framework, of which the STIS data show a good overall agreement with the overlapping FORS2 data. We also explore the …

Collective Neutrino Flavor Oscillations In Multiple Dimensions And Scales, Joshua D. Martin

Physics & Astronomy ETDs

Hot and dense astrophysical environments such as the early universe, core collapse novae and binary neutron star mergers generate dense neutrino gases which can sub- sequently have an important effect on processes which occur in these environments. In this thesis we will present the results from several numerical simulations of these gases particularly in cases which are relevant to core collapse supernovae. These simulations employ fewer imposed spatial symmetries than those used in earlier works, and provide insight into behavior which may be expected to occur in three key regions of the explosion. We observe that when the neutrino gas …

Optics Observatory Conversion From Solar To Stellar, Nicholas Schragal, Logan Curtis, Astronomy Club

Research Horizons Day Posters

No abstract provided.

Perfect Circles: A Study Of The Scattering Regions Of Wolf Rayet Binary Stars, Stella Yoos, Jennifer Hoffman, Andrew Fullard

DU Undergraduate Research Journal Archive

Although we have been able to develop an understanding of many aspects of stellar evolution and formation, a few key gaps remain. One is the fate of massive binary star systems composed of Wolf-Rayet (WR) and O-type stars. In these WR + O binaries, the stellar winds surrounding these stars collide, creating a complex interaction region in which light from the stars scatters and becomes polarized. To study these scattering regions, I employ a technique that allows me to map the polarization of the light emitted from these stars and track its variation over the binary orbit. I found that …

Polarization Measurements Of The Polluted White Dwarf G29-38, Ted Von Hippel, Daniel V. Cotton, Jeremy Bailey, J.E. Pringle, William B. Sparks, Jonathan P. Marshall

Publications

We have made high-precision polarimetric observations of the polluted white dwarf G29-38 with the HIgh Precision Polarimetric Instrument 2. The observations were made at two different observatories – using the 8.1-m Gemini North Telescope and the 3.9-m Anglo-Australian Telescope – and are consistent with each other. After allowing for a small amount of interstellar polarization, the intrinsic linear polarization of the system is found to be 275.3 ± 31.9 parts per million at a position angle of 90.8 ± 3.8◦ in the SDSS g

band. We compare the observed polarization with the predictions of circumstellar disc models. The measured polarization …

Supercritical Carbon Dioxide Based Heat Exchanger On The Martian, Sarah Guinn

Discovery Day - Prescott

The use of supercritical carbon dioxide (sCO2) in power cycles has been fairly new in the last decade. Due to this, there is a lack in research for both terrestrial and extraterrestrial applications. The purpose of this project is to utilize sCO2 as a working fluid and design and optimize a Brayton Cycle based heat exchanger on the Martian surface. Due to the lack of water on Mars, this research will provide a stronger analysis of planetary based drycooling processes in low atmospheric pressure and colder temperatures. We have been conducting an in-depth analysis of the heat exchanger by modeling …

The Sophie Search For Northern Extrasolar Planets Xvi. Hd 158259: A Compact Planetary System In A Near-3:2 Mean Motion Resonance Chain, Nathan Hara, François Bouchy, Manu Stalport, Isabelle Boisse, J. Rodrigues, Jean-Baptiste Delisle, Alexandre Santerne, Gregory W. Henry, Luc Arnold, Nicola Astudillo-Defru, Simon Borgniet, Xavier Bonfils, Vincent Bourrier, Bastien Brugger, B. Courcol, Shweta Dalal, Magali Deleuil, Xavier Delfosse, Olivier Demangeon, Rodrigo F. Díaz, Xavier Dumusque, Thierry Forveille, Guillaume Hébrard, Melissa J. Hobson, ‪Flavien Kiefer, Théodore Lopez, ‪Lucile Mignon, Olivier Mousis, Claire Moutou, Francesco Pepe, Javiera Rey, Nuno C. Santos, Damien Ségransan, Stéphane Udry, Paul Anthony Wilson

Information Systems and Engineering Management Research Publications

Aims. Since 2011, the SOPHIE spectrograph has been used to search for Neptunes and super-Earths in the northern hemisphere. As part of this observational program, 290 radial velocity measurements of the 6.4 V magnitude star HD 158259 were obtained. Additionally, TESS photometric measurements of this target are available. We present an analysis of the SOPHIE data and compare our results with the output of the TESS pipeline.

Methods. The radial velocity data, ancillary spectroscopic indices, and ground-based photometric measurements were analyzed with classical and ℓ₁ periodograms. The stellar activity was modeled as a correlated Gaussian noise and its impact …