Search Publications
Cloud Structure of Galactic OB Cluster-forming Regions from Combining Ground- and Space-based Bolometric Observations
Li, Di; Qian, Lei; Rosolowsky, Erik +13 more
We have developed an iterative procedure to systematically combine the millimeter and submillimeter images of OB cluster-forming molecular clouds, which were taken by ground-based (CSO, JCMT, APEX, and IRAM-30 m) and space telescopes (Herschel and Planck). For the seven luminous (L\gt {10}6 L ⊙) Galactic OB cluster-forming mo…
Caught in the Act: Gas and Stellar Velocity Dispersions in a Fast Quenching Compact Star-Forming Galaxy at z~1.7
Finkelstein, Steven L.; Barro, Guillermo; Pérez-González, Pablo G. +20 more
We present Keck I MOSFIRE spectroscopy in the Y and H bands of GDN-8231, a massive, compact, star-forming galaxy at a redshift of z ∼ 1.7. Its spectrum reveals both Hα and [N II] emission lines and strong Balmer absorption lines. The Hα and Spitzer MIPS 24 µm fluxes are both weak, thus indicating a low star-formation rate of SFR ≲ 5{--}10 {M…
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. VII. Implications from the Nearly Universal Nature of Horizontal Branch Discontinuities
Dalessandro, E.; Salaris, M.; Anderson, J. +14 more
The UV-initiative Hubble Space Telescope Treasury survey of Galactic globular clusters provides a new window into the phenomena that shape the morphological features of the horizontal branch (HB). Using this large and homogeneous catalog of UV and blue photometry, we demonstrate that the HB exhibits discontinuities that are remarkably consistent i…
Surface Albedo and Spectral Variability of Ceres
Nathues, Andreas; Schröder, Stefan E.; Russell, Christopher T. +21 more
Previous observations suggested that Ceres has active, but possibly sporadic, water outgassing as well as possibly varying spectral characteristics over a timescale of months. We used all available data of Ceres collected in the past three decades from the ground and the Hubble Space Telescope, as well as the newly acquired images by the Dawn Fra…
Constraining the Properties of Dark Matter with Observations of the Cosmic Microwave Background
Kopp, Michael; Skordis, Constantinos; Thomas, Daniel B.
We examine how the properties of dark matter, parameterized by an equation-of-state parameter w and two perturbative generalized dark matter (GDM) parameters, c 2 s (the sound speed) and {c}{vis}2 (the viscosity), are constrained by existing cosmological data, particularly the Planck 2015 data release.…
Nature of the Soft ULX in NGC 247: Super-Eddington Outflow and Transition between the Supersoft and Soft Ultraluminous Regimes
Tao, Lian; Feng, Hua; Grisé, Fabien +1 more
We report on XMM-Newton/Chandra/Swift/Hubble Space Telescope observations of the ultraluminous X-ray source (ULX) in NGC 247, which is found to make transitions between the supersoft ultraluminous (SSUL) regime with a spectrum dominated by a cool (∼0.1 keV) blackbody component and the soft ultraluminous (SUL) regime with comparable luminosities sh…
What Is Controlling the Fragmentation in the Infrared Dark Cloud G14.225-0.506?: Different Levels of Fragmentation in Twin Hubs.
Zhang, Qizhou; Palau, Aina; Pillai, Thushara +7 more
We present observations of the 1.3 mm continuum emission toward hub-N and hub-S of the infrared dark cloud G14.225-0.506 carried out with the Submillimeter Array, together with observations of the dust emission at 870 and 350 µm obtained with APEX and CSO telescopes. The large-scale dust emission of both hubs consists of a single peaked clum…
Quasi-periodic Pulsations during the Impulsive and Decay phases of an X-class Flare
Hayes, L. A.; Gallagher, P. T.; Dennis, B. R. +3 more
Quasi-periodic pulsations (QPPs) are often observed in X-ray emission from solar flares. To date, it is unclear what their physical origins are. Here, we present a multi-instrument investigation of the nature of QPP during the impulsive and decay phases of the X1.0 flare of 2013 October 28. We focus on the character of the fine structure pulsation…
The Infrared Spectral Properties of Magellanic Carbon Stars
van Loon, J. Th.; Sahai, R.; Wood, P. R. +12 more
The Infrared Spectrograph on the Spitzer Space Telescope observed 184 carbon stars in the Magellanic Clouds. This sample reveals that the dust-production rate (DPR) from carbon stars generally increases with the pulsation period of the star. The composition of the dust grains follows two condensation sequences, with more SiC condensing before amor…
A Deep Campaign to Characterize the Synchronous Radio/X-Ray Mode Switching of PSR B0943+10
Tiengo, A.; Mereghetti, S.; Esposito, P. +14 more
Observations of PSR B0943+10 with XMM-Newton and the LOFAR, LWA, and Arecibo radio telescopes in 2014 November confirm the synchronous X-ray/radio switching between a radio-bright (B) mode and a radio-quiet (Q) mode, in which the X-ray flux is a factor ∼2.4 higher than in the B-mode. We discovered X-ray pulsations during the B-mode (0.5-2 keV puls…