Search Publications
Discovery and origins of giant optical nebulae surrounding quasar PKS 0454-22
Johnson, Sean D.; Chen, Hsiao-Wen; Greene, Jenny E. +1 more
We report optical integral-field spectroscopy in the field of one of the most luminous quasars in the z < 1 Universe, PKS 0454-22, with the Multi-Unit Spectroscopic Explorer. These data enable the discovery of three large ionized nebulae emitting in [O II], H β, and [O III] with projected areas of 1720, 1520, and 130 pkpc2, which we …
Modeling a Coronal Mass Ejection from an Extended Filament Channel. I. Eruption and Early Evolution
Kazachenko, Maria D.; Lynch, Benjamin J.; Palmerio, Erika +4 more
We present observations and modeling of the magnetic field configuration, morphology, and dynamics of a large-scale, high-latitude filament eruption observed by the Solar Dynamics Observatory. We analyze the 2015 July 9-10 filament eruption and the evolution of the resulting coronal mass ejection (CME) through the solar corona. The slow streamer-b…
Stellar flares from blended and neighbouring stars in Kepler short cadence observations
Loyd, R. O. Parke; Jackman, James A. G.; Shkolnik, Evgenya
We present the results of a search for stellar flares from stars neighbouring the target sources in the Kepler short cadence data. These flares have been discarded as contaminants in previous surveys and therefore provide an unexplored resource of flare events, in particular high-energy events from faint stars. We have measured M dwarf flare energ…
Massive Star Cluster Formation and Destruction in Luminous Infrared Galaxies in GOALS. II. An ACS/WFC3 Survey of Nearby LIRGs
Surace, J. A.; Inami, H.; Murphy, E. J. +14 more
We present the results of a Hubble Space Telescope WFC3 near-UV and Advanced Camera for Surveys Wide Field Channel optical study into the star cluster populations of a sample of 10 luminous infrared galaxies (LIRGs) in the Great Observatories All-Sky LIRG Survey. Through integrated broadband photometry we have derived ages, masses, and extinctions…
The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. IV. The Star Formation History of Andromeda VII Derived from Long-period Variable Stars
Javadi, Atefeh; Saremi, Elham; van Loon, Jacco Th. +10 more
We have examined the star formation history (SFH) of Andromeda VII (And VII), the brightest and most massive dwarf spheroidal (dSph) satellite of the Andromeda galaxy (M31). Although M31 is surrounded by several dSph companions with old stellar populations and low metallicity, it has a metal-rich stellar halo with an age of 6-8 Gyr. This indicates…
A Multi-Observing Technique Study of the Dynamical Evolution of the Viscous Disk around the Be Star ω CMa
Rivinius, Thomas; Baade, Dietrich; Carciofi, Alex C. +3 more
The observed emission lines of Be stars originate from a circumstellar Keplerian disk, which is generally well explained by the viscous decretion disk model. In an earlier work we performed modeling of the full light curve of the bright Be star ω CMa with the 1D time-dependent hydrodynamic code SINGLEBE and the Monte Carlo radiative transfer code …
TITANS metal-poor reference stars. I. Accurate effective temperatures and surface gravities for dwarfs and subgiants from 3D non-LTE Hα profiles and Gaia parallaxes
Smiljanic, R.; da Silva, A. R.; Giribaldi, R. E. +1 more
Context. Several large stellar spectroscopic surveys are producing enormous amounts of data that can be used to determine stellar atmospheric parameters and chemical abundances. Nonetheless, the accuracy achieved in the derived astrophysical parameters is still insufficient, mainly because of the paucity of adequate calibrators, particularly in th…
New mercury-manganese stars and candidates from LAMOST DR4
Paunzen, E.; Bernhard, K.; Hümmerich, S.
Aims: The present work presents our efforts at identifying new mercury-manganese (HgMn/CP3) stars using spectra obtained with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST).
Methods: Suitable candidates were searched for among pre-selected early-type spectra from LAMOST DR4 using a modified version of the MKCLASS …
Exploring Mutual Information between IRIS Spectral Lines. I. Correlations between Spectral Lines during Solar Flares and within the Quiet Sun.
Kleint, Lucia; Panos, Brandon; Voloshynovskiy, Sviatoslav
Spectral lines allow us to probe the thermodynamics of the solar atmosphere, but the shape of a single spectral line may be similar for different thermodynamic solutions. Multiline analyses are therefore crucial, but computationally cumbersome. We investigate correlations between several chromospheric and transition region lines to restrain the th…
Constraints on the [C II] luminosity of a proto-globular cluster at z ∼ 6 obtained with ALMA
Carniani, Stefano; Rosati, Piero; Meneghetti, Massimo +10 more
We report on ALMA observations of D1, a system at z ~ 6.15 with stellar mass $M_{*} \sim 10^7 \, \mathrm{M}_{\odot }$ containing globular cluster (GC) precursors, strongly magnified by the galaxy cluster MACS J0416.1-2403. Since the discovery of GC progenitors at high redshift, ours is the first attempt to probe directly the physical properties of…