Search Publications
Stellar Populations in the Outer Disk and Halo of the Spiral Galaxy M101
Mihos, J. Christopher; Harding, Paul; Durrell, Patrick R. +2 more
We use deep Hubble Space Telescope imaging in the outskirts of the nearby spiral M101 to study stellar populations in the galaxy’s outer disk and halo. Our Advanced Camera for Surveys (ACS) field lies 17.‧6 (36 kpc) from the center of M101 and targets the blue “NE Plume” of M101's outer disk, while the parallel Wide Field Camera 3 (WFC3) field lie…
The gaseous environments of quasars: associate absorption lines with density and distance constraints
Hamann, Fred; Chen, Chen; Simon, Leah +1 more
Associated absorption lines (AALs) in quasar spectra are valuable probes of the gas kinematics and physical conditions in quasar environments. The host galaxies are by definition in an active evolution stage that might involve large-scale blowouts and/or cold-mode accretion (infall) from the intergalactic medium (IGM). We discuss rest-frame UV spe…
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…
Exposed bright features on the comet 67P/Churyumov-Gerasimenko: distribution and evolution
Jorda, L.; Lamy, P. L.; Bertaux, J. -L. +46 more
Context. Since its arrival at the comet 67P/Churyumov-Gerasimenko in August 2014, the Rosetta spacecraft followed the comet as it went past the perihelion and beyond until September 2016. During this time there were many scientific instruments operating on board Rosetta to study the comet and its evolution in unprecedented detail. In this context,…
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 …
Small Bodies Near and Far (SBNAF): A benchmark study on physical and thermal properties of small bodies in the Solar System
Marton, G.; Müller, T. G.; Alí-Lagoa, V. +15 more
The combination of visible and thermal data from the ground and astrophysics space missions is key to improving the scientific understanding of near-Earth, main-belt, trojans, centaurs, and trans-Neptunian objects. To get full information on a small sample of selected bodies we combine different methods and techniques: lightcurve inversion, stella…
VLT/SPHERE astrometric confirmation and orbital analysis of the brown dwarf companion HR 2562 B
Rouan, D.; Augereau, J. -C.; Henning, T. +46 more
Context. A low-mass brown dwarf has recently been imaged around HR 2562 (HD 50571), a star hosting a debris disk resolved in the far infrared. Interestingly, the companion location is compatible with an orbit coplanar with the disk and interior to the debris belt. This feature makes the system a valuable laboratory to analyze the formation of subs…
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…