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Articles 1 - 30 of 282
Full-Text Articles in Astrophysics and Astronomy
Born Dry Or Born Wet? A Palette Of Water Growth Histories In Trappist-1 Analogs And Compact Planetary Systems, Howard Chen, Matthew S. Clement, Le Chris Wang, Jesse T. Gu
Born Dry Or Born Wet? A Palette Of Water Growth Histories In Trappist-1 Analogs And Compact Planetary Systems, Howard Chen, Matthew S. Clement, Le Chris Wang, Jesse T. Gu
Aerospace, Physics, and Space Science Faculty Publications
It is still unclear whether exoplanets in compact multiplanet systems such as TRAPPIST-1 are able to accrete large quantities of volatiles, grow to sufficient mass, and maintain robust atmospheres and hydrospheres. Previous estimates of water content in M-dwarf systems have largely relied on population synthesis or atmosphere–interior evolution models, often treating impacts and atmospheric loss in isolation. In this work, we combined impact delivery, impact erosion, and mantle-atmosphere exchange within a unified framework that tracks volatile evolution through stochastic collision histories. By explicitly including both planetesimal accretion and the prolonged luminous pre-main-sequence phase of M dwarfs, we find systematically lower …
Deuterium Escape On Photoevaporating Sub-Neptunes, Pin-Gao Gu, Howard Chen
Deuterium Escape On Photoevaporating Sub-Neptunes, Pin-Gao Gu, Howard Chen
Aerospace, Physics, and Space Science Faculty Publications
We investigate the evolution of the deuterium-to-hydrogen (D/H) mass ratio driven by EUV photoevaporation of hydrogen-rich atmospheres of close-in sub-Neptunes around solar-type stars. For the first time, the diffusion-limited approach in conjunction with energy-limited photoevaporation is considered in evaluating deuterium escape from evolving exoplanet H/He envelopes. We find that the planets with smaller initial gas envelopes and thus smaller sizes can lead to weaker atmospheric escape, which facilitates hydrogen–deuterium fractionation. Specifically, in our grid of simulations with a low envelope mass fraction of less than 0.005, a low-mass sub-Neptune (4–5 M⊕) at about 0.25–0.4 au or a high-mass sub-Neptune …
Sporadic Spin-Orbit Variations In Compact Multiplanet Systems And Their Influence On Exoplanet Climate, Howard Chen, Gongjie Li, Adiv Paradise, Ravi K. Kopparapu
Sporadic Spin-Orbit Variations In Compact Multiplanet Systems And Their Influence On Exoplanet Climate, Howard Chen, Gongjie Li, Adiv Paradise, Ravi K. Kopparapu
Aerospace, Physics, and Space Science Faculty Publications
Climate modeling has shown that tidally influenced terrestrial exoplanets, particularly those orbiting M-dwarfs, have unique atmospheric dynamics and surface conditions that may enhance their likelihood to host viable habitats. However, sporadic libration and rotation induced by planetary interactions, such as those due to mean motion resonances (MMR) in compact planetary systems, may destabilize attendant exoplanets away from synchronized states (1:1 spin-orbit ratios). Here, we use a three-dimensional N-rigid-body integrator and an intermediately complex general circulation model to simulate the evolving climates of TRAPPIST-1 e and f with different orbitaland spin-evolution pathways. Planet f scenarios perturbed by MMR effects with chaotic …
The Solar Energetic Particle Event Of 2010 August 14: Connectivity With The Solar Source Inferred From Multiple Spacecraft Observations And Modeling, D. Lario, R.-Y. Kwon, I. G. Richardson, N. E. Raouafi, B. J. Thompson, T. T. Von Rosenvinge, M. L. Mays, P. A. Makela, H. Xie, H. M. Bain, M. Zhang, L. Zhao, H. V. Cane, A. Papaioannou, N. Thakur, P. Riley
The Solar Energetic Particle Event Of 2010 August 14: Connectivity With The Solar Source Inferred From Multiple Spacecraft Observations And Modeling, D. Lario, R.-Y. Kwon, I. G. Richardson, N. E. Raouafi, B. J. Thompson, T. T. Von Rosenvinge, M. L. Mays, P. A. Makela, H. Xie, H. M. Bain, M. Zhang, L. Zhao, H. V. Cane, A. Papaioannou, N. Thakur, P. Riley
Aerospace, Physics, and Space Science Faculty Publications
We analyze one of the first solar energetic particle (SEP) events of solar cycle 24 observed at widely separated spacecraft in order to assess the reliability of models currently used to determine the connectivity between the sources of SEPs at the Sun and spacecraft in the inner heliosphere. This SEP event was observed on 2010 August 14 by near-Earth spacecraft, STEREO-A (∼80° west of Earth) and STEREO-B (∼72° east of Earth). In contrast to near-Earth spacecraft, the footpoints of the nominal magnetic field lines connecting STEREO-A and STEREO-B with the Sun were separated from the region where the parent fast …
Biosignature Anisotropy Modeled On Temperate Tidally Locked M-Dwarf Planets, Howard Chen, Eric T. Wolf, Ravi Kopparapu, Shawn Domagal-Goldman, Daniel E. Horton
Biosignature Anisotropy Modeled On Temperate Tidally Locked M-Dwarf Planets, Howard Chen, Eric T. Wolf, Ravi Kopparapu, Shawn Domagal-Goldman, Daniel E. Horton
Aerospace, Physics, and Space Science Faculty Publications
A planet’s atmospheric constituents (e.g., O2, O3, H2Ov, CO2, CH4, and N2O) can provide clues to its surface habitability, and may offer biosignature targets for remote life detection efforts. The plethora of rocky exoplanets found by recent transit surveys (e.g., the Kepler mission) indicates that potentially habitable systems orbiting K- and M-dwarf stars may have very different orbital and atmospheric characteristics than Earth. To assess the physical distribution and observational prospects of various biosignatures and habitability indicators, it is important to understand how they may change under different astrophysical and geophysical configurations, and to simulate these changes with …
Orbital Characteristics Of The Subdwarf-B And F V Star Binary Ec 20117-4014 (=V4640 Sgr), Tomomi Otani, T. D. Oswalt, A. E. Lynas-Gray, D. Kilkenny, C. Koen, M. Amaral, R. Jordan
Orbital Characteristics Of The Subdwarf-B And F V Star Binary Ec 20117-4014 (=V4640 Sgr), Tomomi Otani, T. D. Oswalt, A. E. Lynas-Gray, D. Kilkenny, C. Koen, M. Amaral, R. Jordan
Aerospace, Physics, and Space Science Faculty Publications
Among the competing evolution theories for subdwarf-B (sdB) stars is the binary evolution scenario. EC 20117- 4014 (=V4640 Sgr) is a spectroscopic binary system consisting of a pulsating sdB star and a late F main-sequence companion; however, the period and the orbit semimajor axes have not been precisely determined. This paper presents orbital characteristics of the EC 20117-4014 binary system using 20 years of photometric data. Periodic observed minus calculated (O–C) variations were detected in the two highest-amplitude pulsations identified in the EC 20117-4014 power spectrum, indicating the binary system’s precise orbital period (P = 792.3 days) and the light-travel-time …
Effects Of Coronal Magnetic Field Structures On The Transport Of Solar Energetic Particles, Lulu Zhao, Ming Zhang
Effects Of Coronal Magnetic Field Structures On The Transport Of Solar Energetic Particles, Lulu Zhao, Ming Zhang
Aerospace, Physics, and Space Science Faculty Publications
This Letter presents a model calculation of solar energetic particle (SEP) transport to test the sensitivity of the distribution of escaped SEPs in interplanetary space and dependence upon the details of the magnetic field structure in the corona. It is applied to a circumsolar event on 2011 November 3, in which SEPs are observed promptly after the solar event eruption by three spacecraft (the twin Solar TErrestrial RElations Observatories (STEREO-A and STEREO-B) and ACE) separated by more than 100° in longitude from each other. The corona magnetic field reconstructed from photosphseric field measurements using the PFSS method changes substantially before …
Illuminating Low Surface Brightness Galaxies With The Hyper Suprime-Cam Survey, Johnny P. Greco, Jenny E. Greene, Michael A. Strauss, Lauren A. Macarthur, Xzavier Flowers, Andy D. Goulding, Song Huang, Ji Hoon Kim, Yutaka Komiyama, Alexie Leauthaud, Lukas Leisman, Robert H. Lupton, Cristobal Sifon, Shiang-Yu Wang
Illuminating Low Surface Brightness Galaxies With The Hyper Suprime-Cam Survey, Johnny P. Greco, Jenny E. Greene, Michael A. Strauss, Lauren A. Macarthur, Xzavier Flowers, Andy D. Goulding, Song Huang, Ji Hoon Kim, Yutaka Komiyama, Alexie Leauthaud, Lukas Leisman, Robert H. Lupton, Cristobal Sifon, Shiang-Yu Wang
Aerospace, Physics, and Space Science Faculty Publications
We present a catalog of extended low surface brightness galaxies (LSBGs) identified in the Wide layer of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). Using the first ∼200 deg2 of the survey, we have uncovered 781 LSBGs, spanning red (g − I >/0.64) and blue (g − i < 0.64) colors and a wide range of morphologies. Since we focus on extended galaxies (reff = 2 5–14″), our sample is likely dominated by low- redshift objects. We define LSBGs to have mean surface brightnesses m¯ eff (g) > 24.3 mag arcsec−2, which allows nucleated galaxies into our sample. As a result, the central surface brightness distribution spans a wide range of μ0(g) = 18–27.4 mag arcsec−2, with 50% and 95% of galaxies fainter than 24.3 and 22 mag arcsec−2, respectively. Furthermore, the surface brightness distribution is a strong function of …
An X-Ray Imaging Survey Of Quasar Jets: The Complete Survey, H. L. Marshall, J. M. Gelbord, D. M. Worrall, M. Birkinshaw, D. A. Schwartz, D. L. Jauncey, G. Griffiths, D. W. Murphy, J. E. J. Lovell, E. S. Perlman, L. Godfrey
An X-Ray Imaging Survey Of Quasar Jets: The Complete Survey, H. L. Marshall, J. M. Gelbord, D. M. Worrall, M. Birkinshaw, D. A. Schwartz, D. L. Jauncey, G. Griffiths, D. W. Murphy, J. E. J. Lovell, E. S. Perlman, L. Godfrey
Aerospace, Physics, and Space Science Faculty Publications
We present Chandra X-ray imaging of a flux-limited sample of flat spectrum radio-emitting quasars with jet-like structure. X-rays are detected from 59% of 56 jets. No counter-jets were detected. The core spectra are fitted by power-law spectra with a photon index Γx, whose distribution is consistent with a normal distribution, with a mean of 1.61+0.04 and dispersion of 0.15+0.04. We show that the distribution of α , the spectral index between the X-ray −0.05 −0.03 rx and radio band jet fluxes, fits a Gaussian with a mean of 0.974 ± 0.012 and dispersion of 0.077 ± 0.008. We test the …
Whole Earth Telescope Discovery Of A Strongly Distorted Quadrupole Pulsation In The Largest Amplitude Rapidly Oscillating Ap Star, Daniel L. Holdsworth, Donald W. Kurtz, Hideyuki Saio, Judith L. Provençal, Bruno Letarte, Ramotholo R. Sefako, Véronique Petit, Barry Smalley, H. Thomsen, C. L. Fletcher
Whole Earth Telescope Discovery Of A Strongly Distorted Quadrupole Pulsation In The Largest Amplitude Rapidly Oscillating Ap Star, Daniel L. Holdsworth, Donald W. Kurtz, Hideyuki Saio, Judith L. Provençal, Bruno Letarte, Ramotholo R. Sefako, Véronique Petit, Barry Smalley, H. Thomsen, C. L. Fletcher
Aerospace, Physics, and Space Science Faculty Publications
We present a new analysis of the rapidly oscillating Ap (roAp) star, 2MASS J19400781 - 4420093 (J1940; V = 13.1). The star was discovered using SuperWASP broad-band photometry to have a frequency of 176.39 d-1 (2041.55 μHz; P = 8.2min; Holdsworth et al. 2014a) and is shown here to have a peak-to-peak amplitude of 34 mmag. J1940 has been observed during three seasons at the South African Astronomical Observatory, and has been the target of a Whole Earth Telescope campaign. The observations reveal that J1940 pulsates in a distorted quadrupole mode with unusual pulsational phase variations. A higher signal-to-noise ratio …
The Complex, Dusty Narrow-Line Region Of Ngc 4388: Gas–Jet Interactions, Outflows And Extinction Revealed By Near-Ir Spectroscopy, A. Rodriguez-Ardila,, R. E. Mason, L. Martins, C. Ramos Almeida, R. A. Riffel, R. Riffel, P. Lira, O. Gonzalez Martin, N. Z. Dametto, H. Flohic, L. C. Ho, D. Ruschel-Dutra, K. Thanjavur, L. Colina, R. M. Mcdermid, E. Perlman, C. Winge
The Complex, Dusty Narrow-Line Region Of Ngc 4388: Gas–Jet Interactions, Outflows And Extinction Revealed By Near-Ir Spectroscopy, A. Rodriguez-Ardila,, R. E. Mason, L. Martins, C. Ramos Almeida, R. A. Riffel, R. Riffel, P. Lira, O. Gonzalez Martin, N. Z. Dametto, H. Flohic, L. C. Ho, D. Ruschel-Dutra, K. Thanjavur, L. Colina, R. M. Mcdermid, E. Perlman, C. Winge
Aerospace, Physics, and Space Science Faculty Publications
We present Gemini/GNIRS (Gemini Near-Infrared Spectrograph) spectroscopy of the Seyfert 2 galaxy NGC 4388, with simultaneous coverage from 0.85 to 2.5 µm. Several spatially extended emission lines are detected for the first time, both in the obscured and unobscured portion of the optical narrow-line region (NLR), allowing us to assess the combined effects of the central continuum source, outflowing gas and shocks generated by the radio jet on the central 280 pc gas. The H I and [Fe II] lines allow us to map the extinction affecting the NLR. We found that the nuclear region is heavily obscured, with E(B …
Precipitation And Release Of Solar Energetic Particles From The Solar Coronal Magnetic Field, Ming Zhang, Lulu Zhao
Precipitation And Release Of Solar Energetic Particles From The Solar Coronal Magnetic Field, Ming Zhang, Lulu Zhao
Aerospace, Physics, and Space Science Faculty Publications
Most solar energetic particles (SEPs) are produced in the corona. They propagate through complex coronal magnetic fields subject to scattering and diffusion across the averaged field lines by turbulence. We examine the behaviors of particle transport using a stochastic 3D focused transport simulation in a potential field source surface model of coronal magnetic field. The model is applied to an SEP event on 2010 February 7. We study three scenarios of particle injection at (i) the compact solar flare site, (ii) the coronal mass ejection (CME) shock, and (iii) the EUV wave near the surface. The majority of particles injected …
The Effects Of Interplanetary Transport In The Event-Intergrated Solar Energetic Particle Spectra, Lulu Zhao, Ming Zhang, Hamid K. Rassoul
The Effects Of Interplanetary Transport In The Event-Intergrated Solar Energetic Particle Spectra, Lulu Zhao, Ming Zhang, Hamid K. Rassoul
Aerospace, Physics, and Space Science Faculty Publications
Previous investigations on the energy spectra of solar energetic particle (SEP) events revealed that the energy spectra observed at 1 au often show double power laws with break energies from one to tens of MeV/nuc. In order to determine whether the double power-law features result from the SEP source or the interplanetary transport process from the Sun to 1 au, we separately analyze the SEP spectra in the decay phase, during which the transport effect is minimum. In this paper, we reported three events observed by the Interplanetary Monitory Platform 8 spacecraft, which occurred on 1977 September 19, November 22, …
Characterizing The Source Properties Of Terrestrial Gamma Ray Flashes, Joseph R. Dwyer, Ningyu Liu, J. Eric Grove, Hamid K. Rassoul, David M. Smith
Characterizing The Source Properties Of Terrestrial Gamma Ray Flashes, Joseph R. Dwyer, Ningyu Liu, J. Eric Grove, Hamid K. Rassoul, David M. Smith
Aerospace, Physics, and Space Science Faculty Publications
Monte Carlo simulations are used to determine source properties of terrestrial gamma ray flashes (TGFs) as a function of atmospheric column depth and beaming geometry. The total mass per unit area traversed by all the runaway electrons (i.e., the total grammage) during a TGF, Ξ, is introduced, defined to be the total distance traveled by all the runaway electrons along the electric field lines multiplied by the local air mass density along their paths. It is shown that key properties of TGFs may be directly calculated from Ξ and its time derivative, including the gamma ray emission rate, the current …
A Test Of The Interstellar Boundary Explorer Ribbon Formation In The Outer Heliosheath, Konstantin V. Gamayunov, Jacob Heerikhuisen, Hamid K. Rassoul
A Test Of The Interstellar Boundary Explorer Ribbon Formation In The Outer Heliosheath, Konstantin V. Gamayunov, Jacob Heerikhuisen, Hamid K. Rassoul
Aerospace, Physics, and Space Science Faculty Publications
NASA's Interstellar Boundary EXplorer (IBEX) mission is imaging energetic neutral atoms (ENAs) propagating to Earth from the outer heliosphere and local interstellar medium (LISM). A dominant feature in all ENA maps is a ribbon of enhanced fluxes that was not predicted before IBEX. While more than a dozen models of the ribbon formation have been proposed, consensus has gathered around the so-called secondary ENA model. Two classes of secondary ENA models have been proposed; the first class assumes weak scattering of the energetic pickup protons in the LISM, and the second class assumes strong but spatially localized scattering. Here we …
Possible Pair-Instability Supernovae At Solar Motallicity From Magnetic Stellar Progenitors, Cyril Georgy, Georges Meynet, Sylvia Ekström, Gregg A. Wade, Véronique Petit, Zsolt Keszthelyi, Raphael Hirschi
Possible Pair-Instability Supernovae At Solar Motallicity From Magnetic Stellar Progenitors, Cyril Georgy, Georges Meynet, Sylvia Ekström, Gregg A. Wade, Véronique Petit, Zsolt Keszthelyi, Raphael Hirschi
Aerospace, Physics, and Space Science Faculty Publications
Near-solar metallicity (and low-redshift) pair-instability supernova (PISN) candidates challenge stellar evolution models. Indeed, at such a metallicity, even an initially very massive star generally loses so much mass by stellar winds that it will avoid the electron-positron pair-creation instability. We use recent results showing that a magnetic field at the surface of a massive star can significantly reduce its effective mass-loss rate to compute magnetic models of very massive stars (VMSs) at solar metallicity and explore the possibility that such stars end as PISNe. We implement the quenching of the mass loss produced by a surface dipolar magnetic field into …
The Puzzling Case Of The Radio-Loud Qso 3c 186: A Gravitational Wave Recoiling Black Hole In A Young Radio Source?, Marco Chiaberge, Eric S. Perlman
The Puzzling Case Of The Radio-Loud Qso 3c 186: A Gravitational Wave Recoiling Black Hole In A Young Radio Source?, Marco Chiaberge, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
Context. Radio-loud active galactic nuclei with powerful relativistic jets are thought to be associated with rapidly spinning black holes (BHs). BH spin-up may result from a number of processes, including accretion of matter onto the BH itself, and catastrophic events such as BH-BH mergers. Aims. We study the intriguing properties of the powerful (Lbol ∼ 1047 erg s-1) radio-loud quasar 3C 186. This object shows peculiar features both in the images and in the spectra. Methods. We utilize near-IR Hubble Space Telescope (HST) images to study the properties of the host galaxy, and HST UV and Sloan Digital Sky Survey …
Studying The Photometric And Spectroscopic Variability Of The Magnetic Hot Supergiant Ζ Orionis Aa, Bram Buysschaert, Alexandre David-Uraz
Studying The Photometric And Spectroscopic Variability Of The Magnetic Hot Supergiant Ζ Orionis Aa, Bram Buysschaert, Alexandre David-Uraz
Aerospace, Physics, and Space Science Faculty Publications
Massive stars play a significant role in the chemical and dynamical evolution of galaxies. However, much of their variability, particularly during their evolved supergiant stage, is poorly understood. To understand the variability of evolved massive stars in more detail, we present a study of the O9.2Ib supergiant ζ Ori Aa, the only currently confirmed supergiant to host a magnetic field. We have obtained two-color space-based BRIght Target Explorer photometry (BRITE) for ζ Ori Aa during two observing campaigns, as well as simultaneous ground-based, high-resolution optical CHIRON spectroscopy. We perform a detailed frequency analysis to detect and characterize the star's periodic …
A Multi-Band Study Of The Remarkable Jet In Quasar 4c+19.44, Daniel E. Harris, Eric S. Perlman
A Multi-Band Study Of The Remarkable Jet In Quasar 4c+19.44, Daniel E. Harris, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present arcsecond-resolution data in the radio, IR, optical, and X-ray for 4C+19.44 (=PKS 1354+195), the longest and straightest quasar jet with deep X-ray observations. We report results from radio images with half to one arcsecond angular resolution at three frequencies, plus Hubble Space Telescope and Spitzer data. The Chandra data allow us to measure the X-ray spectral index in 10 distinct regions along the 18″ jet and compare with the radio index. The radio and X-ray spectral indices of the jet regions are consistent with a value of throughout the jet, to within uncertainties. The X-ray jet structure to …
Magnetic Massive Stars As Progenitors Of ‘Heavy’ Stellar-Mass Black Holes, V. Petit, Z. Keszthelyi, R. Macinnis, D. H. Cohen, R. H. D. Townsend, G. A. Wade, S. L. Thomas, S. P. Owocki, J. Puls, A. Ud-Doula
Magnetic Massive Stars As Progenitors Of ‘Heavy’ Stellar-Mass Black Holes, V. Petit, Z. Keszthelyi, R. Macinnis, D. H. Cohen, R. H. D. Townsend, G. A. Wade, S. L. Thomas, S. P. Owocki, J. Puls, A. Ud-Doula
Aerospace, Physics, and Space Science Faculty Publications
The groundbreaking detection of gravitational waves produced by the inspiralling and coales- cence of the black hole (BH) binary GW150914 confirms the existence of ‘heavy’ stellar-mass BHs with masses >25 M . Initial characterization of the system by Abbott et al. supposes that the formation of BHs with such large masses from the evolution of single massive stars is only feasible if the wind mass-loss rates of the progenitors were greatly reduced relative to the mass-loss rates of massive stars in the Galaxy, concluding that heavy BHs must form in low-metallicity (Z ,:S 0.25 0.5 Z ) environments. However, strong …
Hd 164492c: A Rapidly Rotating, Hα-Bright, Magnetic Early B Star Associated With A 12.5 D Spectroscopic Binary, G. A. Wade, M. Shultz, J. Sikora, M.-E. Bernier, Th. Rivinius, E. Alecian, V. Petit, J. H. Grunhut, Binamics Collaboration
Hd 164492c: A Rapidly Rotating, Hα-Bright, Magnetic Early B Star Associated With A 12.5 D Spectroscopic Binary, G. A. Wade, M. Shultz, J. Sikora, M.-E. Bernier, Th. Rivinius, E. Alecian, V. Petit, J. H. Grunhut, Binamics Collaboration
Aerospace, Physics, and Space Science Faculty Publications
We employ high-resolution spectroscopy and spectropolarimetry to derive the physical proper- ties and magnetic characteristics of the multiple system HD 164492C, located in the young open cluster M20. The spectrum reveals evidence of three components: a broad-lined early B star (HD 164492C1), a narrow-lined early B star (HD 164492C2) and a late B star (HD 164492C3). Components C2 and C3 exhibit significant (>100 km s−1) bulk radial velocity variations with a period of 12.5351(7) d that we attribute to eccentric binary motion around a common centre- of-mass. Component C1 exhibits no detectable radial velocity variations. Using constraints derived from …
A Dynamical Analysis Of The Kepler-80 System Of Five Transiting Planets, Mariah G. Macdonald, Darin A. Ragozzine
A Dynamical Analysis Of The Kepler-80 System Of Five Transiting Planets, Mariah G. Macdonald, Darin A. Ragozzine
Aerospace, Physics, and Space Science Faculty Publications
Kepler has discovered hundreds of systems with multiple transiting exoplanets which hold tremendous potential both individually and collectively for understanding the formation and evolution of planetary systems. Many of these systems consist of multiple small planets with periods less than ~50 days known as Systems with Tightly spaced Inner Planets, or STIPs. One especially intriguing STIP, Kepler-80 (KOI-500), contains five transiting planets: f, d, e, b, and c with periods of 1.0, 3.1, 4.6, 7.1, and 9.5 days, respectively. We provide measurements of transit times and a transit timing variation (TTV) dynamical analysis. We find that TTVs cannot reliably detect …
Infrared Polarimetry Of Mrk 231: Scattering Off Hot Dust Grains In The Central Core, E. Lopez-Rodriguez, C. Packham, T. J. Jones, R. Siebenmorgen, P. F. Roche, N. A. Levenson, A. Alonso-Herrero, E. Perlman, K. Ichikawa, C. Ramos Almeida, O. Gonzalez-Martin, R. Nikutta, M. Martinez-Paredez, D. Shenoy, M. S. Gordon, C. M. Telesco
Infrared Polarimetry Of Mrk 231: Scattering Off Hot Dust Grains In The Central Core, E. Lopez-Rodriguez, C. Packham, T. J. Jones, R. Siebenmorgen, P. F. Roche, N. A. Levenson, A. Alonso-Herrero, E. Perlman, K. Ichikawa, C. Ramos Almeida, O. Gonzalez-Martin, R. Nikutta, M. Martinez-Paredez, D. Shenoy, M. S. Gordon, C. M. Telesco
Aerospace, Physics, and Space Science Faculty Publications
We present high-angular (0.17–0.35 arcsec) resolution imaging polarimetric observations of Mrk 231 in the 3.1 μm filter using MMT-Pol on the 6.5-m MMT, and in the 8.7, 10.3, and 11.6 μm filters using CanariCam on the 10.4-m Gran Telescopio CANARIAS. In combination with already published observations, we compile the 1–12 μm total and polarized nuclear spectral energy distribution (SED). The total flux SED in the central 400 pc is explained as the combination of (1) a hot (731 4 K) dusty structure, directly irradiated by the central engine, which is at 1.6 0.1 pc away and attributed to be in …
A Deep Search For Additional Satellites Around The Dwarf Planet Haumea, Luke D. Burkhart, Darin Ragozzine, Michael E. Brown
A Deep Search For Additional Satellites Around The Dwarf Planet Haumea, Luke D. Burkhart, Darin Ragozzine, Michael E. Brown
Aerospace, Physics, and Space Science Faculty Publications
Haumea is a dwarf planet with two known satellites, an unusually high spin rate, and a large collisional family, making it one of the most interesting objects in the outer solar system. A fully self-consistent formation scenario responsible for the satellite and family formation is still elusive, but some processes predict the initial formation of many small moons, similar to the small moons recently discovered around Pluto. Deep searches for regular satellites around Kuiper belt objects are difficult due to observational limitations, but Haumea is one of the few for which sufficient data exist. We analyze Hubble Space Telescope (HST) …
Dynamic Flaring Non-Potential Fields On Quiet Sun Networks Scales, David L. Chesney, Hakeem M. Oluseyi, Norton B. Orange
Dynamic Flaring Non-Potential Fields On Quiet Sun Networks Scales, David L. Chesney, Hakeem M. Oluseyi, Norton B. Orange
Aerospace, Physics, and Space Science Faculty Publications
We report on the identification of dynamic flaring non-potential structures on quiet Sun (QS) supergranular network scales. Data from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory allow for the high spatial and temporal resolution of this diverse class of compact structures. The rapidly evolving nonpotential events presented here, with lifetimes <10 minutes, are on the order of 10″ in length. Thus, they contrast significantly with well-known active region (AR) non-potential structures such as high-temperature X-ray and EUV sigmoids (>100″) and micro-sigmoids (>10″) with lifetimes on the order of hours to days. The photospheric magnetic field environment derived from the Helioseismic and Magnetic Imager shows a lack of evidence for these flaring non-potential fields being associated with significant concentrations of bipolar magnetic elements. Of much …
Double Power Laws In The Event-Integrated Solar Energetic Particle Spectrum, Lulu Zhao, Ming Zhang, Hamid K. Rassoul
Double Power Laws In The Event-Integrated Solar Energetic Particle Spectrum, Lulu Zhao, Ming Zhang, Hamid K. Rassoul
Aerospace, Physics, and Space Science Faculty Publications
A double power law or a power law with exponential rollover at a few to tens of MeV nucleon−1 of the eventintegrated differential spectra has been reported in many solar energetic particle (SEP) events. The rollover energies per nucleon of different elements correlate with a particleʼs charge-to-mass ratio (Q/A). The probable causes are suggested as residing in shock finite lifetimes, shock finite sizes, shock geometry, and an adiabatic cooling effect. In this work, we conduct a numerical simulation to investigate a particleʼs transport process in the inner heliosphere. We solve the focused transport equation using a time-backward Markov stochastic approach. …
Efficient Geometric Probabilities Of Multi-Transiting Exoplanetary Systems From Corbits, Joshua Brakensiek, Darin Ragozzine
Efficient Geometric Probabilities Of Multi-Transiting Exoplanetary Systems From Corbits, Joshua Brakensiek, Darin Ragozzine
Aerospace, Physics, and Space Science Faculty Publications
NASA’s Kepler Space Telescope has successfully discovered thousands of exoplanet candidates using the transit method, including hundreds of stars with multiple transiting planets. In order to estimate the frequency of these valuable systems, it is essential to account for the unique geometric probabilities of detecting multiple transiting extrasolar planets around the same parent star. In order to improve on previous studies that used numerical methods, we have constructed an efficient, semi-analytical algorithm called the Computed Occurrence of Revolving Bodies for the Investigation of Transiting Systems (CORBITS), which, given a collection of conjectured exoplanets orbiting a star, computes the probability that …
Kepler Eclipsing Binary Stars. Vii. The Catalog Of Eclipsing Binaries Found In The Entire Kepler Data Set, Brian Kirk, Darin Ragozzine
Kepler Eclipsing Binary Stars. Vii. The Catalog Of Eclipsing Binaries Found In The Entire Kepler Data Set, Brian Kirk, Darin Ragozzine
Aerospace, Physics, and Space Science Faculty Publications
The primary Kepler Mission provided nearly continuous monitoring of ∼200,000 objects with unprecedented photometric precision. We present the final catalog of eclipsing binary systems within the 105 deg2 Kepler field of view. This release incorporates the full extent of the data from the primary mission (Q0-Q17 Data Release). As a result, new systems have been added, additional false positives have been removed, ephemerides and principal parameters have been recomputed, classifications have been revised to rely on analytical models, and eclipse timing variations have been computed for each system. We identify several classes of systems including those that exhibit tertiary eclipse …
A Normal Supermassive Black Hole In Ngc 1277, Alister W. Graham, Mark Durré, Giulia A.D. Savorgnan, Anne M. Medling, Dan Batcheldor, Nicholas Scott, Beverly Watson, Alessandro Marconi
A Normal Supermassive Black Hole In Ngc 1277, Alister W. Graham, Mark Durré, Giulia A.D. Savorgnan, Anne M. Medling, Dan Batcheldor, Nicholas Scott, Beverly Watson, Alessandro Marconi
Aerospace, Physics, and Space Science Faculty Publications
The identification of galaxies with “overly massive” black holes requires two measurements: a black hole mass (Mbh) and a host spheroid mass (Msph,*). Here we provide our measurements for NGC 1277. Our structural decomposition reveals that NGC 1277 is dominated by a “classical” spheroid with a Sérsic index n = 5.3, a half-light radius Rₑmajor: You have a new taskSpace: You have a new task,major = 2.1 kpc, and a stellar mass of 2.7 10^11 11 M⊙ (using M*/ LV = 11.65, Martín-Navarro et al.). This mass is an order of magnitude greater than originally reported. Using the latest Mbh–n, …
An Hst Proper-Motion Study Of The Large Scale Jet Of 3c273, Eileen T. Meyer, William B. Sparks, Markos Georganopoulos, Jay Anderson, Roeland Van Der Marel, John Biretta, Sangmo Tony Sohn, Marco Chiaberge, Eric S. Perlman, Colin Norman
An Hst Proper-Motion Study Of The Large Scale Jet Of 3c273, Eileen T. Meyer, William B. Sparks, Markos Georganopoulos, Jay Anderson, Roeland Van Der Marel, John Biretta, Sangmo Tony Sohn, Marco Chiaberge, Eric S. Perlman, Colin Norman
Aerospace, Physics, and Space Science Faculty Publications
The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly relativistic on sub-parsec scales, with apparent proper motions up to 15c observed by very long baseline interferometry. In contrast, we find that the kiloparsec-scale knots are compatible with being stationary, with a mean speed of -0.2 ±0.5c over the whole jet. Assuming …