Search Publications
An Extreme-ultraviolet Wave Generating Upward Secondary Waves in a Streamer-like Solar Structure
Chen, Yao; Feng, Shiwei; Zheng, Ruisheng +2 more
Extreme-ultraviolet (EUV) waves, spectacular horizontally propagating disturbances in the low solar corona, always trigger horizontal secondary waves (SWs) when they encounter the ambient coronal structure. We present the first example of upward SWs in a streamer-like structure after the passing of an EUV wave. This event occurred on 2017 June 1. …
Optical Observations of the Young Type Ic Supernova SN 2014L in M99
Zhang, Yu; Wang, Lifan; Wheeler, J. Craig +22 more
We present optical spectroscopic and photometric observations of the nearby type Ic supernova (SN Ic) SN 2014L. This SN was discovered by the Tsinghua-NAOC Transient Survey (TNTS) in the nearby type-Sc spiral galaxy M99 (NGC 4254). Fitting to the early-time light curve indicates that SN 2014L was detected at only a few hours after the shock breako…
Mapping the Kinematically Decoupled Core in NGC 1407 with MUSE
Coccato, Lodovico; Johnston, Evelyn J.; Hau, George K. T. +1 more
Studies of the kinematics of NGC 1407 have revealed complex kinematical structure, consisting of the outer galaxy, an embedded disc within a radius of ∼60 arcsec, and a kinematically decoupled core (KDC) with a radius of less than 30 arcsec. However, the size of the KDC and the amplitude of the kinematic misalignment it induces have not yet been d…
Observational constraint on spherical inhomogeneity with CMB and local Hubble parameter
Ichiki, Kiyotomo; Tokutake, Masato; Yoo, Chul-Moon
We derive an observational constraint on a spherical inhomogeneity of the void centered at our position from the angular power spectrum of the cosmic microwave background (CMB) and local measurements of the Hubble parameter. The late time behaviour of the void is assumed to be well described by the so-called Λ-Lemaȋtre-Tolman-Bondi (ΛLTB) solution…
Multi-scale analysis of compressible fluctuations in the solar wind
Narita, Yasuhito; Roberts, Owen W.; Escoubet, C. -Philippe
Compressible plasma turbulence is investigated in the fast solar wind at proton kinetic scales by the combined use of electron density and magnetic field measurements. Both the scale-dependent cross-correlation (CC) and the reduced magnetic helicity (σm) are used in tandem to determine the properties of the compressible fluctuations at …
An off-axis galaxy cluster merger: Abell 0141
Caglar, Turgay
We present structural analysis results of Abell 0141 (z = 0.23) based on X-ray data. The X-ray luminosity map demonstrates that Abell 0141 (A0141) is a bimodal galaxy cluster, which is separated on the sky by ∼0.65 Mpc with an elongation along the north-south direction. The optical galaxy density map also demonstrates this bimodality. We estimate …
Qatar Exoplanet Survey: Qatar-6b—A Grazing Transiting Hot Jupiter
Bieryla, Allyson; Latham, David W.; Baranec, Christoph +14 more
We report the discovery of Qatar-6b, a new transiting planet identified by the Qatar Exoplanet Survey (QES). The planet orbits a relatively bright (V = 11.44), early-K main-sequence star at an orbital period of P ∼ 3.506 days. An SED fit to available multi-band photometry, ranging from the near-UV to the mid-IR, yields a distance of d = 101 ± 6 pc…
Physical Nature and Orbital Behavior of the Eclipsing System UZ Leonis
Lee, Jae Woo; Park, Jang-Ho
New CCD photometric observations of UZ Leo were obtained between 2012 February and 2013 April, and on 2017 February. Its physical properties were derived from detailed analyses of our light curves and existing radial velocities. The results indicate that this system is a totally eclipsing A-subtype overcontact binary with both a high fill-out fact…
GLACiAR, an Open-Source Python Tool for Simulations of Source Recovery and Completeness in Galaxy Surveys
Trenti, M.; Oesch, P. A.; Carrasco, D. +1 more
The luminosity function is a fundamental observable for characterising how galaxies form and evolve throughout the cosmic history. One key ingredient to derive this measurement from the number counts in a survey is the characterisation of the completeness and redshift selection functions for the observations. In this paper, we present GLACiAR, an …
Toward the Measurement of the Mass of Isolated Neutron Stars: Prediction of Future Astrometric Microlensing Events by Pulsars
Ofek, Eran O.
The mass of single neutron stars (NSs) can be measured using astrometric microlensing events. In such events, the center-of-light motion of a star lensed by an NS will deviate from the expected nonlensed motion and this deviation can be used to measure the mass of the NS. I search for future conjunctions between pulsars, with measured proper motio…