Search Publications
A Late-type L Dwarf at 11 pc Hiding in the Galactic Plane Characterized Using Gaia DR2
Gonzales, Eileen C.; Burgasser, Adam J.; Marocco, Federico +4 more
We report on the characterization of a nearby (d={11.20}-0.08+0.09 pc) ultracool L dwarf (WISE J192512.78+070038.8; hereafter W1925) identified as a faint (G = 20.038 ± 0.009) object with high proper motion (219.834 ± 1.843 mas yr-1)in the Gaia Data Releases 1 and 2. A Palomar/TripleSpec near-infrared spectrum of W…
Late Bloomer Galaxies: Growing Up in Cosmic Autumn
Kelson, Daniel D.; Dressler, Alan; Abramson, Louis E.
Late bloomers (LBs) are massive ({M}* > {10}10 {\text{}}{M}⊙ ) galaxies at z < 1 that formed the majority of their stars within ∼2 Gyr of the epoch of observation. Our improved methodology for deriving star formation histories (SFHs) of galaxies at redshifts 0.45 < z < 0.75 from the Carnegie-Spitzer-IMA…
Density Fluctuations in a Polar Coronal Hole
Hahn, Michael; D'Huys, Elke; Savin, Daniel Wolf
We have measured the root-mean-square (rms) amplitude of intensity fluctuations, ΔI, in plume and interplume regions of a polar coronal hole. These intensity fluctuations correspond to density fluctuations. Using data from the Sun Watcher using the Active Pixel System detector and Image Processing on the Project for Onboard Autonomy (Proba2), our …
High Spectral Resolution SOFIA/EXES Observations of C2H2 toward Orion IRc2
Le Gal, Romane; Herbst, Eric; Acharyya, Kinsuk +8 more
We present high spectral resolution observations from 12.96 to 13.33 microns toward Orion IRc2 using the mid-infrared spectrograph, Echelon-Cross-Echelle Spectrograph (EXES), at Stratospheric Observatory for Infrared Astronomy (SOFIA). These observations probe the physical and chemical conditions of the Orion hot core, which is sampled by a bright…
Resolving the Inner Arcsecond of the RY Tau Jet with HST
Skinner, Stephen L.; Güdel, Manuel; Audard, Marc +1 more
Faint X-ray emission from hot plasma (T x > 106 K) has been detected extending outward a few arcseconds along the optically delineated jets of some classical T Tauri stars including RY Tau. The mechanism and location where the jets are heated to X-ray temperatures are unknown. We present high spatial resolution Hubble Sp…
A UV-to-NIR Study of Molecular Gas in the Dust Cavity around RY Lupi
France, K.; Alcalá, J. M.; Williams, J. P. +10 more
We present a study of molecular gas in the inner disk (r< 20 {au}) around RY Lupi, with spectra from HST-COS, HST-STIS, and VLT-CRIRES. We model the radial distribution of flux from hot gas in a surface layer between r = 0.1-10 au, as traced by Lyα-pumped H2. The result shows H2 emission originating in a ring centered at ∼…
An Unexpected Detection of Bifurcated Blue Straggler Sequences in the Young Globular Cluster NGC 2173
Deng, Licai; de Grijs, Richard; Li, Chengyuan +2 more
The bifurcated patterns in the color-magnitude diagrams of blue straggler stars (BSSs) have attracted significant attention. This type of special (but rare) pattern of two distinct blue straggler sequences is commonly interpreted as evidence that cluster core-collapse-driven stellar collisions are an efficient formation mechanism. Here, we report …
Mapping Lyman Continuum Escape in Tololo 1247-232
Jaskot, Anne E.; James, Bethan L.; Oey, M. S. +2 more
Low-redshift, spatially resolved Lyman continuum (LyC) emitters allow us to clarify the processes for LyC escape from these starburst galaxies. We use Hubble Space Telescope (HST) WFC3 and ACS imaging of the confirmed low-redshift LyC emitter Tol 1247-232 to study the ionization structure of the gas and its relation to the ionizing star clusters. …
Herschel PACS Observations of 4-10 Myr Old Classical T Tauri Stars in Orion OB1
Qi, Chunhua; Calvet, Nuria; Espaillat, Catherine C. +12 more
We present Herschel PACS observations of eight classical T Tauri Stars in the ∼7-10 Myr old OB1a and the ∼4-5 Myr old OB1b Orion subassociations. Detailed modeling of the broadband spectral energy distributions, particularly the strong silicate emission at 10 µm, shows that these objects are (pre-)transitional disks with some amount of small…
Asteroseismology of the Double-mode High-amplitude δ Scuti Star VX Hydrae
Fu, Jian-Ning; Su, Jie; Castro, A. +11 more
Bi-site time-series photometric and high-resolution spectroscopic observations were made for the double-mode high-amplitude δ Scuti star VX Hya. The fundamental frequency f 0 = 4.4763 c days-1, the first overtone f 1 = 5.7897 c days-1, and 23 harmonics and linear combinations of f 0 and f