Search Publications
The HETDEX Survey: The Lyα Escape Fraction from 3D-HST Emission-Line Galaxies at z ∼ 2
Finkelstein, Steven L.; Schneider, Donald P.; Janowiecki, Steven +13 more
In this work, we measure the Lyα escape fraction of 935 [O III]-emitting galaxies between 1.9 < z < 2.35 by comparing stacked spectra from the Hubble Space Telescope/WFC3's near-IR grism to corresponding stacks from the Hobby-Eberly Telescope Dark Energy Experiment's Internal Data Release 2. By measuring the stacks' Hβ to Lyα ratios, we dete…
SOFIA Observations of 30 Doradus. I. Far-infrared Dust Polarization and Implications for Grain Alignment and Disruption by Radiative Torques
Lee, Min-Young; Coudé, Simon; Soam, Archana +7 more
Located in the Large Magellanic Cloud and mostly irradiated by the massive star cluster R136, 30 Doradus is an ideal target to test the leading theory of grain alignment and rotational disruption by RAdiative Torques (RATs). Here, we use publicly available polarized thermal dust emission observations of 30 Doradus at 89, 154, and 214 µm usin…
Detecting the Figure Rotation of Dark Matter Halos with Tidal Streams
Price-Whelan, Adrian M.; Valluri, Monica; Snyder, Sarah J.
The dark matter halos that surround Milky Way-like galaxies in cosmological simulations are, to first order, triaxial. Nearly 30 yr ago it was predicted that such triaxial dark matter halos should exhibit steady figure rotation or tumbling motions for durations of several gigayears. The angular frequency of figure rotation predicted by cosmologica…
STARCNET: Machine Learning for Star Cluster Identification
Calzetti, Daniela; Adamo, Angela; Messa, Matteo +4 more
We present a machine learning (ML) pipeline to identify star clusters in the multicolor images of nearby galaxies, from observations obtained with the Hubble Space Telescope as part of the Treasury Project LEGUS (Legacy ExtraGalactic Ultraviolet Survey). STARCNET (STAR Cluster classification NETwork) is a multiscale convolutional neural network (C…
Deciphering Star Cluster Evolution by Shape Morphology
Hu, Qingshun; Zhang, Yu; Esamdin, Ali +2 more
We analyze the morphological evolution of open clusters and provide shape parameters for 265 open clusters. The results show that the overall shape of sample clusters becomes more elliptical as they grow older, while their core remains circular or slightly trending to circular. There is a negative correlation of the ellipticities with the number o…
S5: The Destruction of a Bright Dwarf Galaxy as Revealed by the Chemistry of the Indus Stellar Stream
Lewis, Geraint F.; Casey, Andrew R.; Erkal, Denis +14 more
The recently discovered Indus stellar stream exhibits a diverse chemical signature compared to what is found for most other streams due to the abundances of two outlier stars, Indus_0 and Indus_13. Indus_13 exhibits an extreme enhancement in rapid neutron-capture (r-)process elements with [Eu/Fe] = + 1.81. It thus provides direct evidence of the a…
Probing Jets from Young Embedded Sources: Clues from HST Near-IR [Fe II] Images
Hartigan, Patrick; Giannini, Teresa; Nisini, Brunella +6 more
We present near-infrared [Fe II] images of four Class 0/I jets (HH 1/2, HH 34, HH 111, HH 46/47) observed with the Hubble Space Telescope (HST) Wide Field Camera 3. The unprecedented angular resolution allows us to measure proper motions, jet widths and trajectories, and extinction along the jets. In all cases, we detect the counterjet, which was …
Simulating the Solar Minimum Corona in UV Wavelengths with Forward Modeling II. Doppler Dimming and Microscopic Anisotropy Effect
Susino, Roberto; Fineschi, Silvano; Cranmer, Steven R. +5 more
In ultraviolet (UV) spectropolarimetric observations of the solar corona, the existence of a magnetic field, solar wind velocity, and temperature anisotropies modify the linear polarization associated with resonant scattering. Unlike previous empirical models or global models, which present blended results of the above physical effects, in this wo…
Modeling Solar Wind Variations over an 11 Year Cycle with Alfvén Wave Dissipation: A Parameter Study
Réville, Victor; Hazra, Soumitra; Strugarek, Antoine +3 more
We study the behavior and properties of the solar wind using a 2.5D Alfvén wave (AW)-driven wind model. We first systematically compare the results of an AW-driven wind model with a polytropic approach. Polytropic magnetohydrodynamic wind models are thermally driven, while AWs act as additional acceleration and heating mechanisms in the AW-driven …
A Long Stream of Metal-poor Cool Gas around a Massive Starburst Galaxy at z = 2.67
Cooray, A.; Fu, Hai; Prochaska, J. X. +5 more
We present the first detailed dissection of the circumgalactic medium (CGM) of massive starburst galaxies at z > 2. Our target is a submillimeter galaxy (SMG) at z = 2.674 that has a star formation rate of 1200 M⊙ yr-1 and a molecular gas reservoir of 1.3 × 1011 M⊙. We characterize its CGM with two ba…