Search Publications
The Geometry of the Sagittarius Stream from Pan-STARRS1 3π RR Lyrae
Chambers, Kenneth C.; Rix, Hans-Walter; Belokurov, Vasily +11 more
We present a comprehensive and precise description of the Sagittarius (Sgr) stellar stream’s 3D geometry as traced by its old stellar population. This analysis draws on the sample of ∼44,000 RR Lyrae (RRab) stars from the Pan-STARRS1 (PS1) 3π survey, which is ∼ 80 % complete and ∼ 90 % pure within 80 kpc, and extends to ≳ 120 {kpc} with a distance…
Microflare Heating of a Solar Active Region Observed with NuSTAR, Hinode/XRT, and SDO/AIA
Krucker, Säm; White, Stephen M.; Grefenstette, Brian W. +7 more
NuSTAR is a highly sensitive focusing hard X-ray (HXR) telescope and has observed several small microflares in its initial solar pointings. In this paper, we present the first joint observation of a microflare with NuSTAR and Hinode/XRT on 2015 April 29 at ∼11:29 UT. This microflare shows the heating of material to several million Kelvin, observed…
Solar Active Region Coronal Jets. II. Triggering and Evolution of Violent Jets
Panesar, Navdeep K.; Moore, Ronald L.; Sterling, Alphonse C. +2 more
We study a series of X-ray-bright, rapidly evolving active region coronal jets outside the leading sunspot of AR 12259, using Hinode/X-ray telescope, Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI), and Interface Region Imaging Spectrograph (IRIS) data. The detailed evolution of such r…
Chemistry and Kinematics of the Late-forming Dwarf Irregular Galaxies Leo A, Aquarius, and Sagittarius DIG
Skillman, Evan D.; Cole, Andrew A.; Held, Enrico V. +5 more
We present Keck/DEIMOS spectroscopy of individual stars in the relatively isolated Local Group dwarf galaxies Leo A, Aquarius, and the Sagittarius dwarf irregular galaxy. The three galaxies—but especially Leo A and Aquarius—share in common delayed star formation histories (SFHs) relative to many other isolated dwarf galaxies. The stars in all thre…
On the Connection between Turbulent Motions and Particle Acceleration in Galaxy Clusters
Paltani, S.; Gastaldello, F.; Tramacere, A. +5 more
Giant radio halos are megaparsec-scale diffuse radio sources associated with the central regions of galaxy clusters. The most promising scenario to explain the origin of these sources is that of turbulent re-acceleration, in which MeV electrons injected throughout the formation history of galaxy clusters are accelerated to higher energies by turbu…
The Sizes and Depletions of the Dust and Gas Cavities in the Transitional Disk J160421.7-213028
Dong, Ruobing; Ohashi, Nagayoshi; Tamura, Motohide +18 more
We report ALMA Cycle 2 observations of 230 GHz (1.3 mm) dust continuum emission, and 12CO, 13CO, and C18O J = 2-1 line emission, from the Upper Scorpius transitional disk [PZ99] J160421.7-213028, with an angular resolution of ∼0\buildrel{\prime\prime}\over{.} 25 (35 au). Armed with these data and existing H-band sc…
Kinematics and Optical Depth in the Green Peas: Suppressed Superwinds in Candidate LyC Emitters
Scarlata, Claudia; Jaskot, Anne E.; Dowd, Tara +1 more
By clearing neutral gas away from a young starburst, superwinds may regulate the escape of Lyman continuum (LyC) photons from star-forming galaxies. However, models predict that superwinds may not launch in the most extreme, compact starbursts. We explore the role of outflows in generating low optical depths in the Green Peas (GPs), the only known…
Interstellar Gas-phase Element Depletions in the Small Magellanic Cloud: A Guide to Correcting for Dust in QSO Absorption Line Systems
Jenkins, Edward B.; Wallerstein, George
We present data on the gas-phase abundances for 9 different elements in the interstellar medium of the Small Magellanic Cloud (SMC), based on the strengths of ultraviolet absorption features over relevant velocities in the spectra of 18 stars within the SMC. From this information and the total abundances defined by the element fractions in young s…
A 2500 deg2 CMB Lensing Map from Combined South Pole Telescope and Planck Data
Bleem, L. E.; Stark, A. A.; George, E. M. +44 more
We present a cosmic microwave background (CMB) lensing map produced from a linear combination of South Pole Telescope (SPT) and Planck temperature data. The 150 GHz temperature data from the 2500 deg2 SPT-SZ survey is combined with the Planck 143 GHz data in harmonic space to obtain a temperature map that has a broader ℓ coverage and le…
Neutral Carbon Emission in Luminous Infrared Galaxies: The [C I] Lines as Total Molecular Gas Tracers
Gao, Yu; Zhang, Zhi-Yu; Zhu, Ming +3 more
We present a statistical study of the [C I] (3P1 \to 3P0), [C I] (3P2 \to 3P1) lines (hereafter [C I] (1-0) and [C I] (2-1), respectively) and the CO(1-0) line for a sample of (ultra-)luminous infrared galaxies ((U)LIRGs). We explore the correlations between th…