Search Publications
Dynamical Masses of Young Stars. I. Discordant Model Ages of Upper Scorpius
Rizzuto, Aaron C.; Dupuy, Trent J.; Ireland, Michael J. +1 more
We present the results of a long-term orbit monitoring program, using sparse aperture masking observations taken with NIRC2 on the Keck-II telescope, of seven G- to M-type members of the Upper Scorpius subgroup of the Sco-Cen OB association. We present astrometry and derived orbital elements of the binary systems we have monitored, and also determ…
Comparison of Damped Oscillations in Solar and Stellar X-Ray flares
Kim, S.; Cho, K. -S.; Nakariakov, V. M. +2 more
We explore the similarity and difference of the quasi-periodic pulsations (QPPs) observed in the decay phase of solar and stellar flares at X-rays. We identified 42 solar flares with pronounced QPPs, observed with RHESSI, and 36 stellar flares with QPPs, observed with XMM-Newton. The empirical mode decomposition (EMD) method and least-squares fit …
Gas Dynamics and Outflow in the Barred Starburst Galaxy NGC 1808 Revealed with ALMA
Salak, Dragan; Nakai, Naomasa; Miyamoto, Yusuke +1 more
NGC 1808 is a nearby barred starburst galaxy with an outflow from the nuclear region. To study the inflow and outflow processes related to star formation and dynamical evolution of the galaxy, we have carried out 12CO (J=1-0) mapping observations of the central r ∼ 4 kpc of NGC 1808 using the Atacama Large Millimeter/submillimeter Array…
A Dipole on the Sky: Predictions for Hypervelocity Stars from the Large Magellanic Cloud
Boubert, Douglas; Evans, N. Wyn
We predict the distribution of hypervelocity stars (HVSs) ejected from the Large Magellanic Cloud (LMC), under the assumption that the dwarf galaxy hosts a central massive black hole (MBH). For the majority of stars ejected from the LMC, the orbital velocity of the LMC has contributed a significant fraction of their galactic rest-frame velocity, l…
Spitzer UltRa Faint SUrvey Program (SURFS UP). II. IRAC-detected Lyman-Break Galaxies at 6 ≲ z ≲ 10 behind Strong-lensing Clusters
Castellano, Marco; Fontana, Adriano; Schmidt, Kasper B. +15 more
We study the stellar population properties of the IRAC-detected 6 ≲ z ≲ 10 galaxy candidates from the Spitzer UltRa Faint SUrvey Program. Using the Lyman Break selection technique, we find a total of 17 galaxy candidates at 6 ≲ z ≲ 10 from Hubble Space Telescope images (including the full-depth images from the Hubble Frontier Fields program for MA…
The Orion HII Region and the Orion Bar in the Mid-infrared
Tielens, A. G. G. M.; Berné, O.; Herter, T. L. +3 more
We present mid-infrared photometry of the Orion bar obtained with the Faint Object infraRed Camera for the SOFIA Telescope (FORCAST) on board SOFIA at 6.4, 6.6, 7.7, 19.7, 31.5, and 37.1 µm. By complementing this observation with archival FORCAST and Herschel/PACS images, we are able to construct a complete infrared spectral energy distribut…
The [NII] 205 µm Emission in Local Luminous Infrared Galaxies
Gao, Yu; Lu, Nanyao; Zhao, Yinghe +9 more
In this paper, we present the measurements of the [N II] 205 µm line for a flux-limited sample of 122 (ultra-)luminous infrared galaxies [(U)LIRGs] and 20 additional normal galaxies, obtained with the Herschel Space Observatory (Herschel). We explore the far-infrared (FIR) color dependence of the [N II] 205 µm (L[N II]205 µm…
Exploring the Overabundance of ULXs in Metal- and Dust-poor Local Lyman Break Analogs
Zezas, Andreas; Hornschemeier, Ann; Ptak, Andy +4 more
We have studied high-mass X-ray binary (HMXB) populations within two low-metallicity, starburst galaxies, Haro 11 and VV 114. These galaxies serve as analogs to high-redshift (z\gt 2) Lyman break galaxies and, within the larger sample of Lyman break analogs (LBAs), they are sufficiently nearby (<87 Mpc) to be spatially resolved by Chandra. Prev…
Surface Temperatures on Titan during Northern Winter and Spring
Flasar, F. M.; Coustenis, A.; Achterberg, R. K. +9 more
Meridional brightness temperatures were measured on the surface of Titan during the 2004-2014 portion of the Cassini mission by the Composite Infrared Spectrometer. Temperatures mapped from pole to pole during five two-year periods show a marked seasonal dependence. The surface temperature near the south pole over this time decreased by 2 K from 9…
Fe Line Diagnostics of Cataclysmic Variables and Galactic Ridge X-Ray Emission
Wang, Q. Daniel; Li, Xiang-Dong; Xu, Xiao-jie
The properties of the Galactic Ridge X-ray Emission (GRXE) observed in the 2-10 keV band place fundamental constraints on various types of X-ray sources in the Milky Way. Although the primarily discrete origin of the emission is now well established, the responsible populations of these sources remain uncertain, especially at relatively low fluxes…