Search Publications
Connecting optical and X-ray tracers of galaxy cluster relaxation
Parker, Laura C.; Roberts, Ian D.; Hlavacek-Larrondo, Julie
Substantial effort has been devoted in determining the ideal proxy for quantifying the morphology of the hot intracluster medium in clusters of galaxies. These proxies, based on X-ray emission, typically require expensive, high-quality X-ray observations making them difficult to apply to large surveys of groups and clusters. Here, we compare optic…
ALICE Data Release: A Revaluation of HST-NICMOS Coronagraphic Images
Vigan, Arthur; Choquet, Élodie; Soummer, Rémi +1 more
The Hubble Space Telescope NICMOS instrument was used from 1997 to 2008 to perform coronagraphic observations of about 400 targets. Most of them were part of surveys looking for substellar companions or resolved circumstellar disks to young nearby stars, making the NICMOS coronagraphic archive a valuable database for exoplanets and disks studies. …
Multi-spacecraft Observations of the Rotation and Nonradial Motion of a CME Flux Rope Causing an Intense Geomagnetic Storm
Wang, Rui; Liu, Ying D.; Hu, Huidong +2 more
We present an investigation of the rotation and nonradial motion of a coronal mass ejection (CME) from AR 12468 on 2015 December 16 using observations from SDO, SOHO, STEREO A, and Wind. The EUV and HMI observations of the source region show that the associated magnetic flux rope (MFR) axis pointed to the east before the eruption. We use a nonline…
Metal Deficiency in Two Massive Dead Galaxies at z ∼ 2
Vulcani, B.; Treu, T.; Jones, T. +8 more
Local massive early-type galaxies are believed to have completed most of their star formation ∼10 Gyr ago and evolved without having substantial star formation since that time. If so, their progenitors should have roughly solar stellar metallicities (Z *), comparable to their values today. We report the discovery of two lensed massive (…
Modelling interstellar structures around Vela X-1
Gvaramadze, V. V.; Kniazev, A. Y.; Katushkina, O. A. +1 more
We report the discovery of filamentary structures stretched behind the bow-shock-producing high-mass X-ray binary Vela X-1 using the SuperCOSMOS H-alpha Survey and present the results of optical spectroscopy of the bow shock carried out with the Southern African Large Telescope. The geometry of the detected structures suggests that Vela X-1 has en…
Extended X-ray emission in PKS 1718-649
Callingham, J. R.; Wilms, J.; Kadler, M. +15 more
PKS 1718-649 is one of the closest and most comprehensively studied candidates of a young active galactic nucleus (AGN) that is still embedded in its optical host galaxy. The compact radio structure, with a maximal extent of a few parsecs, makes it a member of the group of compact symmetric objects (CSO). Its environment imposes a turnover of the …
Dark energy constraints in light of Pantheon SNe Ia, BAO, cosmic chronometers and CMB polarization and lensing data
Wang, Deng
To explore whether there is new physics going beyond the standard cosmological model or not, we constrain seven cosmological models by combining the latest and largest Pantheon Type Ia supernovae sample with the data combination of baryonic acoustic oscillations, cosmic microwave background radiation, Planck lensing and cosmic chronometers. We fin…
Obscured Star Formation in the Host Galaxies of Superluminous Supernovae
Morokuma, T.; Matsuda, Y.; Konishi, M. +7 more
We present the results of 3 GHz radio continuum observations of the eight host galaxies of superluminous supernovae (SLSNe) at 0.1 < z < 0.3 by using the Karl G. Jansky Very Large Array. Four host galaxies are detected significantly, and two of them are found to have high star formation rates (SFRs > 20 M ⊙ yr-1) der…
Betatron Cooling of Suprathermal Electrons in the Terrestrial Magnetotail
Xu, Y.; Liu, Y. Y.; Liu, C. M. +1 more
The cigar distribution of suprathermal electrons (40-200 keV), showing electron pitch angles primarily in the parallel and anti-parallel directions, has been frequently observed in the terrestrial magnetotail. The formation of such a distribution is typically attributed to Fermi acceleration, betatron cooling, or a combination of these. To date, F…
The TRENDS High-contrast Imaging Survey. VII. Discovery of a Nearby Sirius-like White Dwarf System (HD 169889)
Stone, Jordan; Ertel, Steve; Spalding, Eckhart +8 more
Monitoring the long-term radial velocity (RV) and acceleration of nearby stars has been proven as an effective method for directly detecting binary and substellar companions. Some fraction of nearby RV trend systems are expected to be comprised of compact objects that likewise induce a systemic Doppler signal. In this paper, we report the discover…