Search Publications
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…
Contribution of Field Strength Gradients to the Net Vertical Current of Active Regions
Vemareddy, P.
We examined the contribution of field strength gradients for the degree of net vertical current (NVC) neutralization in active regions (ARs). We used photospheric vector magnetic field observations of AR 11158 obtained by Helioseismic and Magnetic Imager on board SDO and Hinode. The vertical component of the electric current is decomposed into twi…
A Differential Abundance Analysis of Very Metal-poor Stars
McWilliam, Andrew; Chaboyer, Brian; O'Malley, Erin M. +1 more
We have performed a differential line-by-line chemical abundance analysis, ultimately relative to the Sun, of nine very metal-poor main-sequence (MS) halo stars, near [Fe/H] = -2 dex. Our abundances range from -2.66≤slant [{Fe}/{{H}}]≤slant -1.40 dex with conservative uncertainties of 0.07 dex. We find an average [α/Fe] = 0.34 ± 0.09 dex, typical …
Chandra Observations of the Field Containing HESS J1616-508
Pavlov, George G.; Kargaltsev, Oleg; Hare, Jeremy +2 more
We report the results of three Chandra observations covering most of the extent of the TeV γ-ray source HESS J1616-508 and a search for a lower-energy counterpart to this source. We detect 56 X-ray sources, 37 of which have counterparts at lower frequencies, including a young massive star cluster, but none of them appear to be a particularly promi…
Search for Exoplanets around Northern Circumpolar Stars. II. The Detection of Radial Velocity Variations in M Giant Stars HD 36384, HD 52030, and HD 208742
Lee, Byeong-Cheol; Park, Myeong-Gu; Han, Inwoo +8 more
We present the detection of long-period RV variations in HD 36384, HD 52030, and HD 208742 by using the high-resolution, fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) for the precise radial velocity (RV) survey of about 200 northern circumpolar stars. Analyses of RV data, chromospheric activity indicators, and bisector variations spa…
Analysis of the Amplitude of the Sunyaev-Zel’dovich Effect out to Redshift z = 0.8
López-Corredoira, M.; Génova-Santos, R. T.; Gutiérrez, C. M.
The interaction of the cosmic microwave background (CMB) with the hot gas in clusters of galaxies, the so-called Sunyaev-Zel’dovich (SZ) effect, is a very useful tool that allows us to determine the physical conditions in such clusters and fundamental parameters of the cosmological models. In this work, we determine the dependence of the SZ surfac…
Are All Flare Ribbons Simply Connected to the Corona?
Judge, Philip G.; Paraschiv, Alin; Lacatus, Daniela +2 more
We consider the observational basis for the belief that flare ribbons in the chromosphere result from energy transport from the overlying corona. We study ribbons of small flares using magnetic and intensity data from the Hinode, Solar Dynamics Observatory, and IRIS missions. While most ribbons appear connected to the corona and overlie regions of…