Search Publications
Asteroseismology of the Pre-main-sequence δ Scuti Pulsator IP Persei
Li, Yan; Chen, Xinghao
A grid of theoretical models are computed to fit the nine oscillation modes of IP Per detected earlier from a multi-site ground-based campaign. Fitting results show that there are two sets of theoretical models that could reproduce the observed frequencies more or less equally as well. In view of other available spectroscopic and photometric measu…
A Carbon-rich Hot Bubble in the Planetary Nebula NGC 5189
Karovska, Margarita; Toalá, Jesús A.; Montez, Rodolfo, Jr.
We present the discovery of extended X-ray emission from the planetary nebula (PN) NGC 5189 around the [WO1]-type WD 1330-657 with XMM-Newton. The X-ray-emitting gas fills the cavities detected in the Hubble Space Telescope [O III] narrowband image and presents a limb-brightened morphology toward the outer edges of the east and west lobes. The bul…
Testing Seismic Models of Hot B Subdwarfs with Gaia Data
Latour, M.; Green, E. M.; Fontaine, G. +5 more
We report the results of a study designed to test further the basic validity of the seismic models of hot pulsating B subdwarfs that have been developed over the last two decades. Given estimates of the effective temperature, surface gravity, and mass as obtained from a seismic analysis, and given an estimate of the He/H ratio as available from in…
The Central Star of NGC 2346 as a Clue to Binary Evolution through the Common Envelope Phase
Bianchi, L.; Manteiga, M.; Gómez-Muñoz, M. A. +2 more
We present an analysis of the binary central star of the planetary nebula NGC 2346 based on archival data from the International Ultraviolet Explorer, and new low- and high-resolution optical spectra (3700-7300 Å). By including in the spectral analysis the contribution of both stellar and nebular continuum, we reconciled long-time discrepant UV an…
Propagation of Solar Energetic Particles in the Outer Heliosphere: Interplay between Scattering and Adiabatic Focusing
Wan, W.; He, H. -Q.
The turbulence and spatial nonuniformity of the guide magnetic field cause two competitive effects, namely, the scattering effect and the adiabatic focusing effect, respectively. In this work, we numerically solve the five-dimensional Fokker-Planck transport equation to investigate the radial evolutions of these important effects undergone by the …
Constraining the Active Galactic Nucleus and Starburst Properties of the IR-luminous Quasar Host Galaxy APM08279+5255 at Redshift 4 with SOFIA
Casey, Caitlin M.; Staguhn, Johannes; Dowell, C. Darren +3 more
We present far-IR photometry and the infrared spectrum of the z = 3.9114 quasar/starburst composite system APM 08279+5255, obtained using the Stratospheric Observatory for Infrared Astronomy (SOFIA)/High-resolution Airborne Wideband Camera+ (HAWC+) and the Spitzer Space Telescope Infrared Spectrograph. We decompose the IR-to-radio spectral energy …
X-Ray Spectrum of RBS 315: Absorption or Intrinsic Curvature
Behar, Ehud; Mushotzky, Richard F.; Ben Haim, Sivan
X-ray absorption of high-redshift quasars is enigmatic, because it remains unclear where in the universe the absorbing gas is. If absorption occurs near the high-z host, it could help us understand early stages of galaxy formation. If it is in the intergalactic medium (IGM), it provides a unique way to probe this elusive baryon component. We repor…
Lens Model and Source Reconstruction Reveal the Morphology and Star Formation Distribution in the Cool Spiral LIRG SGAS J143845.1+145407
Rigby, Jane R.; Whitaker, Katherine E.; Sharon, Keren +8 more
We present Hubble Space Telescope (HST) imaging and grism spectroscopy of a strongly lensed LIRG at z = 0.816, SGAS 143845.1+145407, and use the magnification boost of gravitational lensing to study the distribution of star formation throughout this galaxy. Based on the HST imaging data, we create a lens model for this system; we compute the mass …
A Hubble Space Telescope Survey for Novae in the Globular Clusters of M87
Shara, Michael M.; Zurek, David; Doyle, Trisha F. +1 more
The giant elliptical galaxy M87 has been imaged over 30 consecutive days in 2001, 60 consecutive days in 2005-2006, and every 5 days over a 265-day span in 2016-2017 with the Hubble Space Telescope, leading to the detection of 137 classical novae throughout M87. We have identified 2134 globular clusters (GC) in M87 in these images and carried out …
Broadband X-Ray Constraints on the Accreting Black Hole in Quasar 4C 74.26
Yukita, M.; Ptak, A.; LaMassa, S. +2 more
X-ray data for quasar 4C 74.26 have previously been modeled with a broad Fe Kα emission line and reflection continuum originating in the inner part of the accretion disk around the central supermassive black hole (SMBH), i.e., the strong-gravity regime. We modeled broadband X-ray spectra from Suzaku and NuSTAR with MYTORUS, self-consistently accou…