Search Publications
Hubble Space Telescope Reveals Spectacular Light Echoes Associated with the Stripped-envelope Supernova 2016adj in the Iconic Dust Lane of Centaurus A
Patat, F.; Fraser, Morgan; Taddia, Francesco +6 more
We present a multiband sequence of Hubble Space Telescope images documenting the emergence and evolution of multiple light echoes (LEs) linked to the stripped-envelope supernova (SN) 2016adj located in the central dust lane of Centaurus A. Following point-spread function subtraction, we identify the earliest LE emission associated with an SN at on…
X-Ray Imaging Observations of the High-mass γ-Ray Binary HESS J0632+057
Kargaltsev, O.; Klingler, N. J.; Hare, J. +1 more
The Chandra X-Ray Observatory (CXO) imaged the high-mass γ-ray binary HESS J0632+057 with the Advanced CCD Imaging Spectrometer (ACIS). We analyzed the CXO data together with 967 ks of archival Swift-XRT observations. On arcsecond scales we find a hint of asymmetric extended emission. On arcminute scales, a region of extended emission ("the blob")…
K-band Imaging of the Nearby Clumpy, Turbulent Disk Galaxy DYNAMO G04-1
Glazebrook, Karl; Fisher, Deanne B.; Obreschkow, Danail +2 more
We present a case study of the stellar clumps in G04-1-a clumpy, turbulent disk galaxy located at z = 0.13-from the DYnamics of Newly-Assembled Massive Objects sample, using adaptive optics-enabled K-band imaging (~2.25 kpc arcsec-1) with Keck-NIRC2. We identify 15 stellar clumps in G04-1 with a range of masses from 3.6 × 106…
A Tale of Three Dust Populations: Variable R V and Extreme Polarization along Sight Lines toward ζ Ophiuchi
Piccone, Ashley N.; Kobulnicky, Henry A.
Dust permeates the interstellar medium, reddening and polarizing background starlight, but dust properties vary with local environment. In order to characterize dust in a highly irradiated diffuse cloud, we measure the reddening and optical polarization toward 27 stars surrounding the midlatitude b = +24° O9.2IV star ζ Ophiuchi, using new optical …
Characteristics of Nanoflare Heating in a Coronal Bright Point
Hahn, Michael; Savin, Daniel Wolf; Ho, Brandon
We have obtained constraints on the nanoflare energy distribution and timing for the heating of a coronal bright point. Observations of the bright point were made using the Extreme Ultraviolet Imaging Spectrometer on Hinode in slot mode, which collects a time series of monochromatic images of the region leading to unambiguous temperature diagnosti…
A Low-speed Intruder Star in Hyades: A Temporary Residence
Hu, Qingshun; Zhang, Yu; Esamdin, Ali +4 more
We hereby report a low-speed (about 21 km s-1 with respect to the Sun) intruder member in the Hyades cluster based on the data in the literature. The results show that the star is a nonnative member star for Hyades, with its radial velocity being smaller than the radial velocity of the Hyades cluster, even exceeding the standard deviati…
Deriving Thermonuclear Supernova Properties from Gamma-Ray Line Measurements
Leising, M. D.
We illustrate methods for deriving properties of thermonuclear, or Type Ia, supernovae, including synthesized 56Ni mass, total ejecta mass, ejecta kinetic energy, and 56Ni distribution in velocity, from gamma-ray line observations. We simulate data from a small number of published SNe Ia models for a simple gamma-ray instrume…
Potential Habitability as a Stellar Property: Effects of Model Uncertainties and Measurement Precision
Tuchow, Noah W.; Wright, Jason T.
Knowledge of a star's evolutionary history combined with estimates of planet occurrence rates allows one to infer whether a star would be a good target in a search for biosignatures, and to quantify this intuition using long-term habitability metrics. In this study, we analyze the sensitivity of the biosignature yield metrics formulated by Tuchow …
The Variability Behavior of NGC 925 ULX-3
Middleton, Matthew J.; Roberts, Timothy P.; Walton, Dominic J. +5 more
We report the results of a 2019-2021 monitoring campaign with Swift and associated target-of-opportunity observations with XMM-Newton and NuSTAR, examining the spectral and timing behavior of the highly variable ultraluminous X-ray source (ULX) NGC 925 ULX-3. We find that the source exhibits a 127-128-day periodicity, with fluxes typically ranging…
Compact and Variable Radio Emission from an Active Galaxy with Supersoft X-Ray Emission
Li, Di; Liu, Daizhong; Yang, Lei +15 more
RX J1301.9+2747 is a unique active galaxy with a supersoft X-ray spectrum that lacks significant emission at energies above 2 keV. In addition, it is one of few galaxies displaying quasiperiodic X-ray eruptions that recur on a timescale of 13-20 ks. We present multiepoch radio observations of RX J1301.9+2747 using GMRT, Very Large Array (VLA), and…