Search Publications
SNhunt151: an explosive event inside a dense cocoon
Drake, A. J.; Djorgovski, S. G.; Geier, S. +20 more
SNhunt151 was initially classified as a supernova (SN) impostor (nonterminal outburst of a massive star). It exhibited a slow increase in luminosity, lasting about 450 d, followed by a major brightening that reaches MV ≈ -18 mag. No source is detected to MV ≳ -13 mag in archival images at the position of SNhunt151 before the …
Three new barium dwarfs with white dwarf companions: BD+68°1027, RE J0702+129 and BD+80°670
Wang, L.; Zhao, G.; Zhao, J. K. +6 more
We report three new barium (Ba) dwarfs lying in Sirius-like systems. They provide direct evidence that Ba dwarfs are companions to white dwarfs (WDs). Atmospheric parameters, stellar masses and the chemical abundances of 25 elements, including light, α, Fe-peak and s-process elements, are derived from high-resolution and high S/N spectra. The enha…
Automated cross-identifying radio to infrared surveys using the LRPY algorithm: a case study
Vaccari, M.; Seymour, N.; Norris, R. P. +5 more
Cross-identifying complex radio sources with optical or infra red (IR) counterparts in surveys such as the Australia Telescope Large Area Survey (ATLAS) has traditionally been performed manually. However, with new surveys from the Australian Square Kilometre Array Pathfinder detecting many tens of millions of radio sources, such an approach is no …
Constraining the presence of giant planets in two-belt debris disc systems with VLT/SPHERE direct imaging and dynamical arguments
Hinkley, Sasha; Matthews, Elisabeth; Stapelfeldt, Karl +10 more
Giant, wide-separation planets often lie in the gap between multiple, distinct rings of circumstellar debris: this is the case for the HR 8799 and HD 95086 systems, and even the Solar system where the Asteroid and Kuiper belts enclose the four gas and ice giants. In the case that a debris disc, inferred from an infrared excess in the SED, is best …
No evidence for an Eddington-ratio dependence of X-ray weakness in BALQSOs
Brandt, W. N.; Vignali, C.; Gilli, R. +3 more
Several works have studied the relation between X-ray, ultraviolet (UV), and wind properties in broad absorption line quasars (BALQSOs), generally concluding that the formation of strong winds is tightly connected with the suppression of the ionizing extreme ultraviolet (EUV)/X-ray emission. The Eddington ratio (λEdd), which measures th…
Suzaku observations of the Monogem Ring and the origin of the Gemini H α ring
Sasaki, Manami; Plucinsky, Paul P.; Knies, Jonathan R.
We present the analysis of Suzaku X-ray observations of the Galactic supernova remnant (SNR) `Monogem Ring', a large structure observed in X-rays with an extent of ≈25°, located at an anticentre position. One observation close to the shock also coincides with a large ring-like structure observed in H α, which is called the `Gemini H α ring'. We in…
Long-term X-ray variability characteristics of the narrow-line Seyfert 1 galaxy RE J1034+396
Singh, K. P.; Rao, A. R.; Dewangan, G. C. +8 more
We present the results of our study of the long-term X-ray variability characteristics of the narrow-line Seyfert 1 galaxy RE J1034+396. We use data obtained from the AstroSat satellite along with light curves obtained from XMM-Newton and Swift-XRT. We use the 0.3-7.0 keV and 3-20 keV data, respectively, from the SXT and the LAXPC of AstroSat. The…
Stellar populations, stellar masses and the formation of galaxy bulges and discs at z < 3 in CANDELS
Kocevski, Dale D.; Conselice, Christopher J.; Mortlock, Alice +5 more
We present a multicomponent structural analysis of the internal structure of 1074 high-redshift massive galaxies at 1 < z < 3 from the CANDELS HST Survey. In particular, we examine galaxies best fitted by two structural components, and thus likely forming discs and bulges. We examine the stellar mass, star formation rates (SFRs) and colours …
Observation of variable pre-eclipse dips and disc windsin the eclipsing LMXB XTE J1710-281
Maitra, Chandreyee; Paul, Biswajit; Raman, Gayathri
We report the first detection of highly ionized Fe species in the X-ray spectrum of the eclipsing and dipping Low-Mass X-ray Binary XTE J1710-281. Using archival Chandra and Suzaku observations, we have carried out a spectro-timing analysis of the source during three different epochs. We compare the average orbital profile and obtain differences i…
Synchronized observations of bright points from the solar photosphere to the corona
Tavabi, Ehsan
One of the most important features in the solar atmosphere is the magnetic network and its relationship to the transition region (TR) and coronal brightness. It is important to understand how energy is transported into the corona and how it travels along the magnetic field lines between the deep photosphere and chromosphere through the TR and coro…