Search Publications
A Close-up View of the Young Circumbinary Disk HD 142527
Ricci, L.; Boehler, Y.; Grady, C. +4 more
We present ALMA observations of the 0.88 millimeter dust continuum and the 13CO and C18O J = 3-2 line emission of the circumbinary disk HD 142527 at a spatial resolution of ∼0.″25. This system is characterized by a large central cavity of roughly 120 au in radius, and asymmetric dust and gas emission. By comparing the observa…
MOSFIRE Spectroscopy of Quiescent Galaxies at 1.5 < z < 2.5. I. Evolution of Structural and Dynamical Properties
Ellis, Richard S.; Belli, Sirio; Newman, Andrew B.
We present deep near-infrared spectra for a sample of 24 quiescent galaxies in the redshift range 1.5< z< 2.5 obtained with the MOSFIRE spectrograph at the W. M. Keck Observatory. In conjunction with a similar data set we obtained in the range 1< z< 1.5 with the LRIS spectrograph, we analyze the kinematic and structural properties for …
Planet Formation in AB Aurigae: Imaging of the Inner Gaseous Spirals Observed inside the Dust Cavity
Inutsuka, Shu-ichiro; Ohashi, Nagayoshi; Tang, Ya-Wen +13 more
We report the results of ALMA observations of a protoplanetary disk surrounding the Herbig Ae star AB Aurigae. We obtained high-resolution (0.″1 14 au) images in 12CO J = 2 - 1 emission and in the dust continuum at the wavelength of 1.3 mm. The continuum emission is detected at the center and at the ring with a radius (r) of ∼120 au. Th…
Revealing Black Holes with Gaia
Larson, Shane L.; Breivik, Katelyn; Chatterjee, Sourav
We estimate the population of black holes with luminous stellar companions (BH-LCs) in the Milky Way (MW) observable by Gaia. We evolve a realistic distribution of BH-LC progenitors from zero-age to the current epoch taking into account relevant physics, including binary stellar evolution, BH-formation physics, and star formation rate, in order to…
Multi-viewpoint Coronal Mass Ejection Catalog Based on STEREO COR2 Observations
Vourlidas, Angelos; Stenborg, Guillermo; Balmaceda, Laura A. +1 more
We present the first multi-viewpoint coronal mass ejection (CME) catalog. The events are identified visually in simultaneous total brightness observations from the twin SECCHI/COR2 coronagraphs on board the Solar Terrestrial Relations Observatory mission. The Multi-View CME Catalog differs from past catalogs in three key aspects: (1) all events be…
The Atmospheric Response to High Nonthermal Electron Beam Fluxes in Solar Flares. I. Modeling the Brightest NUV Footpoints in the X1 Solar Flare of 2014 March 29
Kowalski, Adam F.; Daw, Adrian; Carlsson, Mats +2 more
The 2014 March 29 X1 solar flare (SOL20140329T17:48) produced bright continuum emission in the far- and near-ultraviolet (NUV) and highly asymmetric chromospheric emission lines, providing long-sought constraints on the heating mechanisms of the lower atmosphere in solar flares. We analyze the continuum and emission line data from the Interface Re…
Chasing Shadows: Rotation of the Azimuthal Asymmetry in the TW Hya Disk
Weinberger, Alycia J.; Debes, John H.; Roberge, Aki +8 more
We have obtained new images of the protoplanetary disk orbiting TW Hya in visible, total intensity light with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST), using the newly commissioned BAR5 occulter. These HST/STIS observations achieved an inner working angle of ∼0.″2, or 11.7 au, probing the system at angula…
PHAT. XIX. The Ancient Star Formation History of the M31 Disk
Bell, Eric F.; Monachesi, Antonela; Dolphin, Andrew E. +7 more
We map the star formation history across M31 by fitting stellar evolution models to color-magnitude diagrams of each 83″ × 83″ (0.3 × 1.4 kpc, deprojected) region of the Panchromatic Hubble Andromeda Treasury (PHAT) survey outside of the innermost 6\prime × 12\prime portion. We find that most of the star formation occurred pr…
Using Long-term Millisecond Pulsar Timing to Obtain Physical Characteristics of the Bulge Globular Cluster Terzan 5
Cadelano, Mario; Freire, Paulo C. C.; Ransom, Scott M. +4 more
Over the past decade, the discovery of three unique stellar populations and a large number of confirmed pulsars within the globular cluster Terzan 5 has raised questions over its classification. Using the long-term radio pulsar timing of 36 ms pulsars in the cluster core, we provide new measurements of key physical properties of the system. As Ter…
The Chandra COSMOS Legacy Survey: Energy Spectrum of the Cosmic X-Ray Background and Constraints on Undetected Populations
Treister, E.; Comastri, Andrea; Elvis, Martin +15 more
Using Chandra observations in the 2.15 deg2 COSMOS-legacy field, we present one of the most accurate measurements of the Cosmic X-ray Background (CXB) spectrum to date in the [0.3-7] keV energy band. The CXB has three distinct components: contributions from two Galactic collisional thermal plasmas at kT ∼ 0.27 and 0.07 keV and an extrag…