Search Publications
Gas Content and Kinematics in Clumpy, Turbulent Star-forming Disks
Glazebrook, Karl; Bolatto, Alberto D.; Obreschkow, Danail +6 more
We present molecular gas-mass estimates for a sample of 13 local galaxies whose kinematic and star-forming properties closely resemble those observed in z ≈ 1.5 main-sequence galaxies. Plateau de Bure observations of the CO[1-0] emission line and Herschel Space Observatory observations of the dust emission both suggest molecular gas-mass fractions…
Extended Gamma-Ray Emission from the G25.0+0.0 Region: A Star-forming Region Powered by the Newly Found OB Association?
Funk, S.; Uchiyama, Y.; Katsuta, J.
We report a study of extended γ-ray emission with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope, which is likely to be the second case of a γ-ray detection from a star-forming region (SFR) in our Galaxy. The LAT source is located in the G25 region, 1.°7 × 2.°1 around (l, b) = (25.°0, 0.°0). The γ-ray emission is found…
The Warm Circumgalactic Medium: 105-6 K Gas Associated with a Single Galaxy Halo or with an Entire Group of Galaxies?
Danforth, Charles W.; Stocke, John T.; Keeney, Brian A. +3 more
In preparation for a Hubble Space Telescope (HST) observing project using the Cosmic Origins Spectrograph (COS), the positions of all AGN targets having high-S/N far-UV G130M spectra were cross-correlated with a large catalog of low-redshift galaxy groups homogenously selected from the spectroscopic sample of the Sloan Digital Sky Survey (SDSS). S…
The Small-scale Structure of Photospheric Convection Retrieved by a Deconvolution Technique Applied to Hinode/SP Data
Solanki, S. K.; Shimizu, T.; Quintero Noda, C. +3 more
Solar granules are bright patterns surrounded by dark channels, called intergranular lanes, in the solar photosphere and are a manifestation of overshooting convection. Observational studies generally find stronger upflows in granules and weaker downflows in intergranular lanes. This trend is, however, inconsistent with the results of numerical si…
A Model for Dissipation of Solar Wind Magnetic Turbulence by Kinetic Alfvén Waves at Electron Scales: Comparison with Observations
Saur, Joachim; Schreiner, Anne
In hydrodynamic turbulence, it is well established that the length of the dissipation scale depends on the energy cascade rate, I.e., the larger the energy input rate per unit mass, the more the turbulent fluctuations need to be driven to increasingly smaller scales to dissipate the larger energy flux. Observations of magnetic spectral energy dens…
The Infrared and Radio Flux Densities of Galactic H II regions
Makai, Z.; Anderson, L. D.; Mascoop, J. L. +1 more
We derive infrared and radio flux densities of all ∼1000 known Galactic H II regions in the Galactic longitude range 17\buildrel{\circ}\over{.} 5< {\ell }< 65^\circ . Our sample comes from the Wide-Field Infrared Survey Explorer (WISE) catalog of Galactic H II regions. We compute flux densities at six wavelengths in the infrared (Spitzer GLI…
Observations of the Coronal Mass Ejection with a Complex Acceleration Profile
Reva, A. A.; Kirichenko, A. S.; Ulyanov, A. S. +1 more
We study the coronal mass ejection (CME) with a complex acceleration profile. The event occurred on 2009 April 23. It had an impulsive acceleration phase, an impulsive deceleration phase, and a second impulsive acceleration phase. During its evolution, the CME showed signatures of different acceleration mechanisms: kink instability, prominence dra…
An Active Galactic Nucleus Caught in the Act of Turning Off and On
Greene, Jenny E.; Stern, Daniel; Comerford, Julia M. +5 more
We present the discovery of an active galactic nucleus (AGN) that is turning off and then on again in the z = 0.06 galaxy SDSS J1354+1327. This episodic nuclear activity is the result of discrete accretion events that could have been triggered by a past interaction with the companion galaxy that is currently located 12.5 kpc away. We originally ta…
Are Internetwork Magnetic Fields in the Solar Photosphere Horizontal or Vertical?
Lites, B. W.; Borrero, J. M.; Danilovic, S. +1 more
Using many observations obtained during 2007 with the Spectro-Polarimeter of the Hinode Solar Optical Telescope, we explore the angular distribution of magnetic fields in the quiet internetwork regions of the solar photosphere. Our work follows from the insight of Stenflo, who examined only linear polarization signals in photospheric lines, thereb…
Search for Hydrogenated C60 (Fulleranes) in Circumstellar Envelopes
Zhang, Yong; Kwok, Sun; Sadjadi, SeyedAbdolreza +1 more
The recent detection of fullerene (C60) in space and the positive assignment of five diffuse interstellar bands to {{{C}}}60+ reinforce the notion that fullerene-related compounds can be efficiently formed in circumstellar envelopes and be present in significant quantities in the interstellar medium. Experimental s…