Search Publications
Properties of jet and surrounding material of GW/GRB 170817A
Ziaeepour, Houri
We use published data in radio, optical, and X-ray bands to analyse and model afterglows of GW/GRB 170817A. Our analysis is based on a phenomenological gamma-ray burst generator model, which we previously used to study the prompt gamma-ray emission of this important transient. We find a multicomponent model and a few of its variants that are consi…
XRB continuum fitting with sensitive high-energy X-ray detectors
Fabian, A. C.; Tomsick, J. A.; Buisson, D. J. K. +4 more
The launch of the Nuclear Spectroscopic Telescope Array (NuSTAR) heralded a new era of sensitive high-energy X-ray spectroscopy for X-ray binaries (XRBs). In this paper we show how multiple physical parameters can be measured from the accretion disc spectrum when the high-energy side of the disc spectrum can be measured precisely using NuSTAR. Thi…
GK Car and GZ Nor: two low-luminous, depleted RV Tauri stars
Gezer, I.; Van Winckel, H.; Kamath, D. +1 more
We performed a photometric and spectroscopic analysis of two RV Tauri stars: GK Car and GZ Nor. Both objects are surrounded by hot circumstellar dust. Their pulsation periods, derived from ASAS (All Sky Automated Survey) photometric time-series, have been used to derive their luminosities and distances via the period-luminosity-distance (PLC) rela…
Candidates for non-pulsating stars located in the Cepheid instability strip in the Large Magellanic Cloud based on Strömgren photometry
Soszyński, I.; Smolec, R.; Udalski, A. +14 more
We present candidates for non-pulsating stars lying in the classical Cepheid instability strip based on the Optical Gravitational Lensing Experiment (OGLE) photometric maps combined with Strömgren photometry obtained with the 4.1-m Southern Astrophysical Research (SOAR) telescope, and Gaia Data Release 2 data in four fields in the Large Magellanic…
Outflowing gas in a compact ionization cone in the Seyfert 2 galaxy ESO 153-G20
Robinson, Andrew; Fischer, Travis C.; Schnorr-Müller, Allan +14 more
We present two-dimensional ionized gas and stellar kinematics in the inner 1.4 × 1.9 kpc2 of the Seyfert 2 galaxy ESO 153-G20 obtained with the Gemini-South/Gemini multi-object spectrograph integral field unit (GMOS-IFU) at a spatial resolution of 250 pc and spectral resolution of 36 km s-1. Strong [O III], Hα, [N II] and [S …
Dust evolution in the circumstellar disc of the unclassified B[e] star HD 50138
Ábrahám, P.; Chen, L.; Varga, J. +3 more
We studied the disc of the unclassified B[e] star HD 50138 in order to explore its structure and to find indications for the evolutionary status of this system, whether it is a young Herbig Be or a post-main-sequence star. Using high spatial resolution interferometric measurements from MIDI instrument (N-band) on the Very Large Telescope Interfero…
Molecular environs and triggered star formation around the large Galactic infrared bubble N 24
Li, Dalei; Tang, Xindi; Zhou, Jianjun +10 more
A multi-wavelength analysis of the large Galactic infrared bubble N 24 is presented in this paper in order to investigate the molecular and star-formation environment around expanding H II regions. Using archival data from Herschel and ATLASGAL, the distribution and physical properties of the dust over the entire bubble are studied. Using the Clum…
WASP-92, WASP-93, and WASP-118: transit timing variations and long-term stability of the systems
Evans, Phil; Gajdoš, Pavol; Vaňko, Martin +8 more
We studied three exoplanetary systems with transiting planets: WASP-92, WASP-93, and WASP-118. Using ground-based photometric observations of WASP-92 and WASP-93 and Kepler-K2 observations of WASP-118, we redetermined the orbital and physical parameters of these planets. The precise times of all transits were determined. We constructed O-C diagram…
3D hydrodynamical models of point-symmetric planetary nebulae: the special case of H 1-67
Velázquez, P. F.; Peña, M.; Rechy-García, J. S.
We present 3D hydrodynamical simulations of a precessing jet with a time-dependent ejection velocity or a time-dependent ejection density, interacting with a circumstellar medium given by a dense, anisotropic, and slow AGB wind, forming a torus. We explore a set of configurations with different values for the precession angle and number of ejectio…
Primeval very low-mass stars and brown dwarfs - V. A halo L3 subdwarf with prograde eccentric orbit in the Galactic plane
Burgasser, A. J.; Zhang, Z. H.; Smith, L. C.
VVV J12564163-6202039 is an L subdwarf located in the Galactic plane (b = 0{^{circ}.}831) discovered by its high proper motion (1.1 arcsec yr-1). We obtained an optical to near-infrared spectrum of it with the X-shooter on the Very Large Telescope, and re-classified it as an sdL3 subdwarf. Its best-fitting BT-Dusty model spec…