Search Publications
The quiescent state of the neutron-star X-ray transient GRS 1747-312 in the globular cluster Terzan 6
Wijnands, Rudy; Degenaar, Nathalie; Vats, Smriti +3 more
We studied the transient neutron-star low-mass X-ray binary GRS 1747-312, located in the globular cluster Terzan 6, in its quiescent state after its outburst in August 2004, using an archival XMM-Newton observation. A source was detected in this cluster and its X-ray spectrum can be fitted with the combination of a soft, neutron-star atmosphere mo…
A D'-type symbiotic binary in the planetary nebula SMP LMC 88
Udalski, Andrzej; Kozłowski, Szymon; Miszalski, Brent +2 more
SMP LMC 88 is one of the planetary nebulae (PNe) in the Large Magellanic Cloud. We identify in its spectrum Raman scattered O VI lines at 6825 and 7083 Å. This unambiguously classifies the central object of the nebula as a symbiotic star (SySt). We identified the cold component to be a K-type giant, making this the first D'-type (yellow) SySt disc…
Catching Galactic open clusters in advanced stages of dynamical evolution
Maia, F. F. S.; Angelo, M. S.; Dias, W. S. +1 more
During their dynamical evolution, Galactic open clusters (OCs) gradually lose their stellar content mainly because of internal relaxation and tidal forces. In this context, the study of dynamically evolved OCs is necessary to properly understand such processes. We present a comprehensive Washington CT1 photometric analysis of six sparse…
The Gaia/IPHAS and Gaia/KIS value-added catalogues
Maccarone, T. J.; Knigge, C.; Pala, A. F. +7 more
We present a sub-arcsecond crossmatch of Gaia DR2 against the INT Photometric H α Survey of the Northern Galactic Plane Data Release 2 (IPHAS DR2) and the Kepler-INT Survey (KIS). The resulting value-added catalogues (VACs) provide additional precise photometry to the Gaia photometry (r, i, and H α for IPHAS, with additional U and g for KIS). In b…
Probing the 9.7 µm interstellar silicate extinction profile through the Spitzer/IRS spectroscopy of OB stars
Gao, Jian; Li, Aigen; Shao, Zhenzhen +3 more
The 9.7 {µ}m interstellar spectral feature, arising from the Si-O stretch of amorphous silicate dust, is the strongest extinction feature in the infrared (IR). In principle, the spectral profile of this feature could allow one to diagnose the mineralogical composition of interstellar silicate material. However, observationally, the 9.7 {&mic…
Constraining the star formation rate with the extragalactic background light
Rubtsov, G. I.; Korochkin, A. A.
The present day spectrum of the extragalactic background light (EBL) in UV, optical, and IR wavelengths is the integral result of multiple astrophysical processes going on throughout the evolution of the Universe. The relevant processes include star formation, stellar evolution, light absorption, and emission by the cosmic dust. The properties of …
Complex optical/UV and X-ray variability of the Seyfert 1 galaxy 1H 0419-577
Dewangan, Gulab C.; Naik, Sachindra; Kembhavi, Ajit K. +2 more
We present detailed broad-band UV/optical to X-ray spectral variability of the Seyfert 1 galaxy 1H 0419-577 using six XMM-Newton observations performed during 2002-2003. These observations covered a large amplitude variability event in which the soft X-ray (0.3-2 keV) count rate increased by a factor of ∼4 in six months. The X-ray spectra during t…
A contaminant-free catalogue of Gaia DR2-WISE Galactic plane matches: including the effects of crowding in the cross-matching of photometric catalogues
Wilson, Tom J.; Naylor, Tim
Faint, hidden contaminants in the point spread functions (PSFs) of stars cause shifts to their measured positions. Wilson & Naylor showed failing to account for these shifts can lead to a drastic decrease in the number of returned catalogue matches in crowded fields. Here, we highlight the effect these perturbations have on cross-matching, for…
Three small transiting planets around the M-dwarf host star LP 358-499
Poppenhaeger, K.; Wells, R.; Watson, C. A.
We report on the detection of three transiting small planets around the low-mass star LP 358-499 (K2-133), using photometric data from the Kepler-K2 mission. Using multiband photometry, we determine the host star to be an early M dwarf with an age likely older than a gigayear. The three detected planets K2-133 b, c and d have orbital periods of ca…
K2 spots rotation in the helium star HD144941
Ramsay, Gavin; Jeffery, C. Simon
HD144941 is an evolved early-type metal-poor low-mass star with a hydrogen-poor surface. It is frequently associated with other intermediate helium-rich subdwarfs and extreme helium stars. Previous photometric studies have failed to detect any variability. New observations with the K2 mission show complex but periodic variations with a full amplit…