Search Publications
New Light on an Old Problem of the Cores of Solar Resonance Lines
Judge, Philip G.; Leenaarts, Jorrit; Kleint, Lucia +2 more
We reexamine a 50+ yr old problem of deep central reversals predicted for strong solar spectral lines, in contrast to the smaller reversals seen in observations. We examine data and calculations for the resonance lines of H I, Mg II, and Ca II, the self-reversed cores of which form in the upper chromosphere. Based on 3D simulations, as well as dat…
Astrometric orbits of spectral binary brown dwarfs - I. Massive T dwarf companions to 2M1059-21 and 2M0805+48
Zapatero Osorio, M. R.; Martín, E. L.; Bouy, H. +7 more
Near-infrared spectroscopic surveys have uncovered a population of short-period, blended-light spectral binaries composed of low-mass stars and brown dwarfs. These systems are amenable to orbit determination and individual mass measurements via astrometric monitoring. Here, we present first results of a multiyear campaign to obtain high-precision …
Unusual Galactic H II Regions at the Intersection of the Central Molecular Zone and the Far Dust Lane
Heywood, I.; Ginsburg, Adam; Glover, Simon C. O. +7 more
Sgr E is a massive star formation complex found toward the Galactic center that consists of numerous discrete, compact H II regions. It is located at the intersection between the central molecular zone (CMZ) and the far dust lane of the Galactic bar, similar to "hot spots" seen in external galaxies. Compared with other Galactic star formation comp…
MUSE observations towards the lensing cluster A2744: Intersection between the LBG and LAE populations at z ∼ 3-7
Schaerer, D.; Laporte, N.; Bauer, F. E. +14 more
We present a study of the intersection between the populations of star forming galaxies selected as either Lyman break galaxies (LBGs) or Lyman-alpha emitters (LAEs) in the redshift range 2.9 - 6.7 and within the same volume of universe sampled by the Multi-Unit Spectroscopic Explorer (MUSE) behind the Hubble Frontier Fields lensing cluster A2744.…
Toward Early-type Eclipsing Binaries as Extragalactic Milestones. II. NLTE Spectral Analysis and Stellar Parameters of the Detached O-type System OGLE-LMC-ECL-06782 in the LMC
Kudritzki, Rolf-Peter; Urbaneja, Miguel A.; Gieren, Wolfgang +5 more
We combine the NLTE spectral analysis of the detached O-type eclipsing binary OGLE-LMC-ECL-06782 with the analysis of the radial velocity curve and light curve to measure an independent distance to the Large Magellanic Cloud (LMC). In our spectral analysis we study composite spectra of the system at quadrature and use the information from radial v…
Excitation and acceleration of molecular outflows in LIRGs: The extended ESO 320-G030 outflow on 200-pc scales
Rigopoulou, D.; Colina, L.; Arribas, S. +7 more
We used high-spatial resolution (70 pc; 0 {{\overset{\prime\prime}{.}}} 3) CO multi-transition (J = 1-0, 2-1, 4-3, and 6-5) ALMA data to study the physical conditions and kinematics of the cold molecular outflow in the local luminous infrared galaxy (LIRG) ESO 320-G030 (d = 48 Mpc, LIR/L⊙ = 1011.3). ESO 320-G030 is…
Asteroseismology of two Kepler detached eclipsing binaries
Liakos, A.
The present work contains light curve, spectroscopic, and asteroseismic analyses for KIC 04851217 and KIC 10686876. These systems are detached eclipsing binaries hosting a pulsating component of δ Scuti type and have been observed with the unprecedented accuracy of the Kepler space telescope. Using ground-based spectroscopic observations, the spec…
The Three Young Nuclear Super Star Clusters in NGC 5253
Smith, Linda J.; Sabbi, Elena; Ryon, Jenna +1 more
The blue compact dwarf galaxy NGC 5253 hosts a very young central starburst. The center contains intense radio thermal emission from a massive ultracompact H II region (or supernebula) and two massive and very young super star clusters (SSCs), which are seen at optical and infrared wavelengths. The spatial correspondence between these three object…
Fast and Wide CMEs without Observed >20 MeV Protons
Thompson, B. J.; Lario, D.; Krupar, V. +6 more
Statistical studies have found a close association between large solar energetic particle (SEP) events and fast and wide coronal mass ejections (CMEs). However, not all fast and wide CMEs have an associated SEP event. From the Coordinated Data Analysis Web catalog of CMEs observed by the Solar and Heliospheric Observatory (SOHO) between 2009 Janua…
Two-dimensional model for the martian exosphere: Applications to hydrogen and deuterium Lyman α observations
Bertaux, J. L.; Clarke, J. T.; Yelle, R. V. +8 more
The analysis of Lyman α observations in the exosphere of Mars has become limited by the assumption of spherical symmetry in the modeling process, as the models are being used to analyze increasingly detailed measurements. In order to overcome this limitation, a two-dimensional density model is presented, which better emulates the density distribut…