Search Publications
Chemical Abundances along the 1G Sequence of the Chromosome Maps: The Globular Cluster NGC 3201
Milone, A. P.; Cordoni, G.; Marino, A. F. +10 more
The Hubble Space Telescope (HST) UV Legacy Survey of Galactic Globular Clusters (GCs) has investigated multiple stellar populations by means of the “chromosome map” (ChM) diagnostic tool that maximizes the separation between stars with different chemical compositions. One of the most challenging features revealed by ChM analysis is the apparent in…
Neutral Gas Properties and Lyα Escape in Extreme Green Pea Galaxies
Jaskot, Anne E.; Yun, Min S.; Dowd, Tara +3 more
Mechanisms regulating the escape of Lyα photons and ionizing radiation remain poorly understood. To study these processes, we analyze Very Large Array 21 cm observations of one Green Pea (GP), J160810+352809 (hereafter J1608), and Hubble Space Telescope Cosmic Origins Spectrograph (COS) spectra of 17 GP galaxies at z< 0.2. All are highly ionize…
Tensile Strength of Porous Dust Aggregates
Kataoka, Akimasa; Tatsuuma, Misako; Tanaka, Hidekazu
Comets are thought to have information about the formation process of our solar system. Recently, detailed information about comet 67P/Churyumov-Gerasimenko was found by Rosetta. It is remarkable that its tensile strength was estimated. In this paper, we measure and formulate the tensile strength of porous dust aggregates using numerical simulatio…
Compton-thick AGNs in the NuSTAR Era. III. A Systematic Study of the Torus Covering Factor
Cusumano, G.; Vignali, C.; Comastri, A. +9 more
We present the analysis of a sample of 35 candidate Compton-thick active galactic nuclei (AGNs) selected in the nearby universe (average redshift < z> ∼ 0.03) with the Swift-BAT 100-month survey. All sources have available NuSTAR data, thus allowing us to constrain with unprecedented quality important spectral parameters such as the obscurin…
Combined Effects of Rotation and Age Spreads on Extended Main-Sequence Turn Offs
Dolphin, Andrew E.; Williams, Benjamin F.; Johnson, L. Clifton +10 more
The extended main-sequence turn offs (eMSTOs) of several young to intermediate age clusters are examined in the Magellanic Clouds and the Milky Way. We explore the effects of extended star formation (eSF) and a range of stellar rotation rates on the behavior of the color-magnitude diagram, paying particular attention to the MSTO. We create synthet…
The Carnegie-Chicago Hubble Program. VII. The Distance to M101 via the Optical Tip of the Red Giant Branch Method
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +9 more
The Carnegie-Chicago Hubble Program (CCHP) is building a direct path to the Hubble constant (H 0) using Population II stars as the calibrator of the Type Ia supernova (SN Ia)-based distance scale. This path to calibrate the SNe Ia is independent of the systematics in the traditional Cepheid-based technique. In this paper, we present the…
Hi-C 2.1 Observations of Jetlet-like Events at Edges of Solar Magnetic Network Lanes
Tiwari, Sanjiv K.; Winebarger, Amy R.; Warren, Harry P. +15 more
We present high-resolution, high-cadence observations of six, fine-scale, on-disk jet-like events observed by the High-resolution Coronal Imager 2.1 (Hi-C 2.1) during its sounding-rocket flight. We combine the Hi-C 2.1 images with images from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and the Interface Region Imaging S…
The MASSIVE Survey. XII. Connecting Stellar Populations of Early-type Galaxies to Kinematics and Environment
Ma, Chung-Pei; Greene, Jenny E.; Blakeslee, John P. +6 more
We measure the stellar populations as a function of the radius for 90 early-type galaxies (ETGs) in the MASSIVE survey, a volume-limited integral-field spectroscopic (IFS) galaxy survey targeting all northern-sky ETGs with an absolute K-band magnitude of M K < -25.3 mag or a stellar mass of {M}* ≳ 4× {10}11 {M…
An Exo-Kuiper Belt with an Extended Halo around HD 191089 in Scattered Light
Debes, John H.; Schneider, Glenn; Duchêne, Gaspard +70 more
We have obtained Hubble Space Telescope STIS and NICMOS and Gemini/GPI scattered-light images of the HD 191089 debris disk. We identify two spatial components: a ring resembling the Kuiper Belt in radial extent (FWHM ∼ 25 au, centered at ∼46 au) and a halo extending to ∼640 au. We find that the halo is significantly bluer than the ring, consistent…
PDS 70: A Transition Disk Sculpted by a Single Planet
van der Marel, Nienke; Muley, Dhruv; Fung, Jeffrey
The wide, deep cavities of transition disks are often believed to have been hollowed out by nascent planetary systems. PDS 70, a ∼5 Myr old transition disk system in which a multi-Jupiter-mass planet candidate at 22 au coexists with a ∼30 au gas and ∼60 au dust-continuum gap, provides a valuable case study for this hypothesis. Using the PEnGUIn hy…