Search Publications
Resolved Star Formation on Sub-galactic Scales in a Merger at z = 1.7
Rigby, Jane R.; Whitaker, Katherine E.; Brammer, Gabriel B. +4 more
We present a detailed analysis of Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) G141 grism spectroscopy for seven star-forming regions of the highly magnified lensed starburst galaxy RCSGA 032727-132609 at z = 1.704. We measure the spatial variations of the extinction in RCS0327 through the observed Hγ/Hβ emission line ratios, finding a …
Half-megasecond Chandra Spectral Imaging of the Hot Circumgalactic Nebula around Quasar Mrk 231
Maiolino, R.; Sturm, E.; Veilleux, S. +2 more
A deep 400 ks ACIS-S observation of the nearest quasar known, Mrk 231, is combined with archival 120 ks data to carry out the first ever spatially resolved spectral analysis of a hot X-ray-emitting circumgalactic nebula around a quasar. The 65 × 50 kpc X-ray nebula shares no resemblance with the tidal debris seen at optical wavelengths. One notabl…
An Estimate of the Coronal Magnetic Field near a Solar Coronal Mass Ejection from Low-frequency Radio Observations
Ramesh, R.; Kathiravan, C.; Hariharan, K. +2 more
We report ground-based, low-frequency (<100 MHz) radio imaging, spectral, and polarimeter observations of the type II radio burst associated with the solar coronal mass ejection (CME) that occurred on 2013 May 2. The spectral observations indicate that the burst has fundamental (F) and harmonic (H) emission components with split-band and herrin…
The Distribution of Satellites around Massive Galaxies at 1 < z < 3 in ZFOURGE/CANDELS: Dependence on Star Formation Activity
Papovich, Casey; Ferguson, Henry C.; Koekemoer, Anton M. +23 more
We study the statistical distribution of satellites around star-forming and quiescent central galaxies at 1 < z < 3 using imaging from the FourStar Galaxy Evolution Survey and the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey. The deep near-IR data select satellites down to log (M/M ⊙) > 9 at z < 3. The radial sat…
A New Detection of LYα Absorption from the Heliotail
Redfield, Seth; Wood, Brian E.; Edelman, Eric +2 more
We present new Hubble Space Telescope observations of H I Lyα absorption toward the F8 V star HD 35296. This line of sight is only a few degrees from the downwind direction of the local interstellar medium flow vector. As a consequence, Lyα absorption from the heliotail is detected in the spectrum, consistent with three previous downwind detection…
Search for the Infrared Emission Features from Deuterated Interstellar Polycyclic Aromatic Hydrocarbons
Onaka, Takashi; Sakon, Itsuki; Kaneda, Hidehiro +4 more
We report the results of a search for emission features from interstellar deuterated polycyclic aromatic hydrocarbons (PAHs) in the 4 µm region with the Infrared Camera (IRC) on board AKARI. No significant excess emission is seen in 4.3-4.7 µm in the spectra toward the Orion Bar and M17 after the subtraction of line emission from the i…
Charge State Evolution in the Solar Wind. III. Model Comparison with Observations
Lepri, S. T.; Zurbuchen, T. H.; Fisk, L. A. +3 more
We test three theoretical models of the fast solar wind with a set of remote sensing observations and in-situ measurements taken during the minimum of solar cycle 23. First, the model electron density and temperature are compared to SOHO/SUMER spectroscopic measurements. Second, the model electron density, temperature, and wind speed are used to p…
Constraining the Age of the NGC 4565 H I Disk Warp: Determining the Origin of Gas Warps
Bell, Eric F.; Holwerda, Benne W.; Monachesi, Antonela +7 more
We have mapped the distribution of young and old stars in the gaseous H I warp of NGC 4565. We find a clear correlation of young stars (<600 Myr) with the warp but no coincident old stars (>1 Gyr), which places an upper limit on the age of the structure. The formation rate of the young stars, which increased ~300 Myr ago relative to the surr…
Discovery of a Gas-rich Companion to the Extremely Metal-poor Galaxy DDO 68
Bailin, Jeremy; McQuinn, Kristen B. W.; Cannon, John M. +17 more
We present H I spectral-line imaging of the extremely metal-poor galaxy DDO 68. This system has a nebular oxygen abundance of only ~3% Z ⊙, making it one of the most metal-deficient galaxies known in the local volume. Surprisingly, DDO 68 is a relatively massive and luminous galaxy for its metal content, making it a significant outlier …
Microlensing Events by Proxima Centauri in 2014 and 2016: Opportunities for Mass Determination and Possible Planet Detection
Anderson, Jay; Bond, Howard E.; Sahu, Kailash C. +1 more
We have found that Proxima Centauri, the star closest to our Sun, will pass close to a pair of faint background stars in the next few years. Using Hubble Space Telescope (HST) images obtained in 2012 October, we determine that the passage close to a mag 20 star will occur in 2014 October (impact parameter 1.''6), and to a mag 19.5 star in 2016 Feb…