Search Publications
Two Distinct-absorption X-Ray Components from Type IIn Supernovae: Evidence for Asphericity in the Circumstellar Medium
Sugawara, Yasuharu; Katsuda, Satoru; Kawabata, Koji +7 more
We present multi-epoch X-ray spectral observations of three Type IIn supernovae (SNe), SN 2005kd, SN 2006jd, and SN 2010jl, acquired with Chandra, XMM-Newton, Suzaku, and Swift. Previous extensive X-ray studies of SN 2010jl have revealed that X-ray spectra are dominated by thermal emission, which likely arises from a hot plasma heated by a forward…
Star Formation around Mid-Infrared Bubble N37: Evidence of Cloud-Cloud Collision
Dewangan, L. K.; Ojha, D. K.; Baug, T. +1 more
We have performed a multi-wavelength analysis of a mid-infrared (MIR) bubble N37 and its surrounding environment. The selected 15‧ × 15‧ area around the bubble contains two molecular clouds (N37 cloud; {V}{lsr} ∼ 37-43 km s-1, and C25.29+0.31; {V}{lsr} ∼ 43-48 km s-1) along the line of sight. A total of …
A Giant Lyα Nebula in the Core of an X-Ray Cluster at Z = 1.99: Implications for Early Energy Injection
Dickinson, Mark; Daddi, Emanuele; Vignali, Cristian +17 more
We present the discovery of a giant ≳100 kpc Lyα nebula detected in the core of the X-ray emitting cluster CL J1449+0856 at z = 1.99 through Keck/LRIS narrow-band imaging. This detection extends the known relation between Lyα nebulae and overdense regions of the universe to the dense core of a 5-7 × 1013 M ⊙ cluster. The most…
SHIELD: Comparing Gas and Star Formation in Low-mass Galaxies
McQuinn, Kristen B. W.; Cannon, John M.; Skillman, Evan D. +22 more
We analyze the relationships between atomic, neutral hydrogen (H I) and star formation (SF) in the 12 low-mass SHIELD galaxies. We compare high spectral (∼0.82 km s-1 ch-1) and spatial resolution (physical resolutions of 160-640 pc) H I imaging from the VLA with Hα and far-ultraviolet imaging. We quantify the degree of co-spa…
A Comprehensive Investigation on the Slowing Down of Cosmic Acceleration
Li, Nan; Li, Miao; Wang, Shuang +1 more
Shafieloo et al. first proposed the possibility that the current cosmic acceleration (CA) is slowing down. However, this is rather counterintuitive because a slowing down CA cannot be accommodated in most mainstream cosmological models. In this work, by exploring the evolutionary trajectories of the dark energy equation of state w(z) and decelerat…
Empirically Constrained Predictions for Metal-line Emission from the Circumgalactic Medium
Schiminovich, David; Corlies, Lauren
The circumgalactic medium (CGM) is one of the remaining least constrained components of galaxies and as such has significant potential for advancing galaxy formation theories. In this work, we vary the extragalactic ultraviolet background for a high-resolution cosmological simulation of a Milky-Way-like galaxy and examine the effect on the absorpt…
An HST Proper-motion Study of the Large-scale Jet of 3C273
Anderson, Jay; Sparks, William B.; Georganopoulos, Markos +7 more
The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly rela…
Ion Acceleration at the Quasi-parallel Bow Shock: Decoding the Signature of Injection
Burgess, D.; Sundberg, Torbjörn; Haynes, Christopher T. +1 more
Collisionless shocks are efficient particle accelerators. At Earth, ions with energies exceeding 100 keV are seen upstream of the bow shock when the magnetic geometry is quasi-parallel, and large-scale supernova remnant shocks can accelerate ions into cosmic-ray energies. This energization is attributed to diffusive shock acceleration however, for…
Young, Star-forming Galaxies and Their Local Counterparts: The Evolving Relationship of Mass-SFR-Metallicity Since z ∼ 2.1
Trump, Jonathan R.; Schneider, Donald P.; Gronwall, Caryl +5 more
We explore the evolution of the Stellar Mass-Star Formation Rate (SFR)-Metallicity relation using a set of 256 COSMOS and GOODS galaxies in the redshift range 1.90 < z < 2.35. We present the galaxies’ rest-frame optical emission-line fluxes derived from IR-grism spectroscopy with the Hubble Space Telescope and combine these data with SFRs an…
Angular Momentum Loss in the Envelope-Disk Transition Region of the HH 111 Protostellar System: Evidence for Magnetic Braking?
Lee, Chin-Fei; Li, Zhi-Yun; Hwang, Hsiang-Chih
HH 111 is a Class I protostellar system at a distance of ∼400 pc, with the central source VLA 1 associated with a rotating disk deeply embedded in a flattened envelope. Here we present the observations of this system at ∼0.″6 (240 au) resolution in C18O (J = 2 — 1) and a 230 GHz continuum obtained with the Atacama Large Millimeter/Submi…