Search Publications
Starburst-driven Superwinds in Quasar Host Galaxies
Haas, Martin; Barthel, Peter; Wilkes, Belinda +1 more
During the past five decades astronomers have been puzzled by the presence of strong absorption features including metal lines, observed in the optical and ultraviolet spectra of quasars, signaling inflowing and outflowing gas winds with relative velocities up to several thousands of km s-1. In particular, the location of these winds—cl…
Observational Signatures of a Kink-unstable Coronal Flux Rope Using Hinode/EIS
Young, P. R.; Régnier, S.; Verwichte, E. +3 more
The signatures of energy release and energy transport for a kink-unstable coronal flux rope are investigated via forward modeling. Synthetic intensity and Doppler maps are generated from a 3D numerical simulation. The CHIANTI database is used to compute intensities for three Hinode/EIS emission lines that cover the thermal range of the loop. The i…
High Dense Gas Fraction in a Gas-rich Star-forming Galaxy at z = 1.2
Carilli, Chris; Daddi, Emanuele; Dannerbauer, Helmut +3 more
We report observations of dense molecular gas in the star-forming galaxy EGS 13004291 (z = 1.197) using the Plateau de Bure Interferometer. We tentatively detect HCN and HNC J=2\to 1 emission when stacked together at 4σ significance, yielding line luminosities of {L}HCN(J=2\to 1)}\prime =(9+/- 3)× {10}9 K km s…
Stability of Sulphur Dimers (S2) in Cometary Ices
Lunine, J. I.; Mousis, O.; Ronnet, T. +5 more
S2 has been observed for decades in comets, including comet 67P/Churyumov-Gerasimenko. Despite the fact that this molecule appears ubiquitous in these bodies, the nature of its source remains unknown. In this study, we assume that S2 is formed by irradiation (photolysis and/or radiolysis) of S-bearing molecules embedded in th…
The Magnetic Future of the Sun
Metcalfe, Travis S.; Judge, Philip G.; Guinan, Edward +2 more
We analyze space- and ground-based data for the old (7.0 ± 0.3 Gyr) solar analogs 16 Cyg A and B. The stars were observed with the Cosmic Origins UV Spectrographs on the Hubble Space Telescope (HST) on 2015 October 23 and 2016 February 3, respectively, and with the Chandra X-ray Observatory on 2016 February 7. Time-series data in Ca II data are us…
The Polarization Signature of Photospheric Magnetic Fields in 3D MHD Simulations and Observations at Disk Center
Rezaei, R.; Puschmann, K. G.; Beck, C. +1 more
Before using three-dimensional (3D) magnetohydrodynamical (MHD) simulations of the solar photosphere in the determination of elemental abundances, one has to ensure that the correct amount of magnetic flux is present in the simulations. The presence of magnetic flux modifies the thermal structure of the solar photosphere, which affects abundance d…
Galactic Latitude Dependence of Near-infrared Diffuse Galactic Light: Thermal Emission or Scattered Light?
Matsuura, S.; Sano, K.
Near-infrared (IR) diffuse Galactic light (DGL) consists of scattered light and thermal emission from interstellar dust grains illuminated by the interstellar radiation field (ISRF). At 1.25 and 2.2 µ {{m}}, a recent observational study shows that intensity ratios of the DGL to interstellar 100 µ {{m}} dust emission steeply decrease to…
ALMA Resolves the Molecular Gas in a Young Low-metallicity Starburst Galaxy at z = 1.7
Gladders, M. D.; Barrientos, L. Felipe; Sharon, Keren +6 more
We present Atacama Large Millimeter/submillimeter Array observations of CO lines and dust continuum emission of the source RCSGA 032727-132609, a young z = 1.7 low-metallicity starburst galaxy. The CO(3-2) and CO(6-5) lines and continuum at rest-frame 450 µm are detected and show a resolved structure in the image plane. We use the correspond…
Gemini Spectra of Star Clusters in the Spiral Galaxy M101
Whitmore, Bradley C.; Chandar, Rupali; Simanton-Coogan, Lesley A. +1 more
We present low resolution, visible light spectra of 41 star clusters in the spiral galaxy M101, taken with the Gemini/GMOS instrument. We measure Lick indices for each cluster and compare with BaSTI models to estimate their ages and metallicities. We also measure the line-of-sight velocities. We find that 25 of the clusters are fairly young massiv…
C II Radiative Cooling of the Galatic Diffuse Interstellar Medium: Insight into the Star Formation in Damped Lyα Systems
Menten, Karl M.; Mathur, Smita; Wolfe, Arthur M. +3 more
The far-infrared [C II] 158 µm fine structure transition is considered to be a dominant coolant in the interstellar medium (ISM). For this reason, under the assumption of a thermal steady state, it may be used to infer the heating rate and, in turn, the star formation rate (SFR) in local as well as in high redshift systems. In this work, rad…