Search Publications
Detection and characterization of two VLM binaries: LP 1033-31 and LP 877-72
Karmakar, Subhajeet; Homeier, D.; Allard, F. +1 more
Using the high-resolution near-infrared adaptive optics imaging from the NaCo instrument at the Very Large Telescope, we report the discovery of a new binary companion to the M-dwarf LP 1033-31 and also confirm the binarity of LP 877-72. We have characterized both the stellar systems and estimated the properties of their individual components. We …
X-ray properties of the X-CLASS-redMaPPer galaxy cluster sample: the luminosity-temperature relation
Raychaudhury, Somak; Clerc, Nicolas; Lieu, Maggie +7 more
This article presents the results of a spectroscopic analysis of the X-CLASS-redMaPPer (XC1-RM) galaxy cluster sample. X-CLASS is a serendipitous search for clusters in X-ray wavebands based on the XMM-Newton archive, whereas redMaPPer is an optical cluster catalogue derived from the Sloan Digital Sky Survey (SDSS). The present sample comprises 92…
The ULX source X-3 in NGC 4258: a search for its X-ray and optical properties
Balman, S.; Akyuz, A.; Aksaker, N. +3 more
We present the results of a search for the nature of ultraluminous X-ray source (ULX) X-3 in the nearby galaxy NGC 4258. We use archival data from XMM-Newton, Chandra, NuSTAR, and Hubble Space Telescope (HST) observations. Total X-ray data were analysed to find that the model parameters of the system are indicative of a stellar-mass black hole, ∼1…
Gas-dust correlations in nearby galaxies: a case study of NGC 3184 and NGC 7793
Saikia, Gautam; Roy, Nirupam; Patra, Narendra Nath +1 more
The study of gas-dust interactions occurring in the interstellar medium of a galaxy is essential for understanding various physical processes taking place within it. A comparison of such events at different locations corresponding to diverse astrophysical environments provides more insight into the star formation as well as dust destruction condit…
BEER analysis of Kepler and CoRoT light curves - V. eBEER: extension of the algorithm to eccentric binaries
Mazeh, T.; Faigler, S.; Shahaf, S. +1 more
We present an extension of the BEER model for eccentric binaries - eBEER, approximating the BEaming, Ellipsoidal, and Reflection effects by harmonic series of the Keplerian elements of their orbit. As such, it can be a tool for fast processing of light curves for detecting non-eclipsing eccentric binary systems. To validate the applicability of th…
Constraining the oblateness of transiting planets with photometry and spectroscopy
Serrano, L. M.; Barros, S. C. C.; Santos, N. C. +2 more
Rapid planetary rotation can cause the equilibrium shape of a planet to be oblate. While planetary oblateness has mostly been probed by examining the subtle ingress and egress features in photometric transit light curves, we investigate the effect of oblateness on the spectroscopic Rossiter-McLaughlin (RM) signals. We found that a giant planet, wi…
The spatial distribution of circumstellar material of the wind-fed system GX 301-2
Gou, Lijun; Liu, Jiren; Zheng, Xueying
The distribution of the circumstellar material in systems of supergiant X-ray binaries (SgXBs) is complex and not well probed observationally. We report a detailed study of the spatial distribution of the Fe K α-emitting material in the wind-fed system GX 301-2, by measuring the time delay between the Fe K α line and the hard X-ray continuum (7.8-…
NGC 6712: the variable star population of a tidally disrupted globular cluster
Arellano Ferro, A.; Calderón, J. H.; Lázaro, C. +4 more
We present an analysis of {VI} CCD time-series photometry of globular cluster NGC 6712. Our main goal is to study the variable star population as indicators of the cluster mean physical parameters. We employed the Fourier decomposition of RR Lyrae light curves to confirm that {}[Fe/H]_{UVES} = -1.0 ± 0.05 is a solid estimate. We estimated the redd…
Spectropolarimetric follow-up of 8 rapidly rotating, X-ray bright FK Comae candidates
Wade, G. A.; Mason, E.; Sikora, J. +2 more
Our understanding of the evolved, rapidly rotating, magnetically active, and apparently single FK Comae stars is significantly hindered by their extreme rarity: only two stars in addition to FK Com itself are currently considered to be members of this class. Recently, a sample of more than 20 candidate FK Comae type stars was identified within the…
Constraining spatial pattern of early activity of comet 67P/C-G with 3D modelling of the MIRO observations
Keller, H. U.; Hartogh, P.; Rezac, L. +3 more
Our aim is to investigate early activity (2014 July) of 67P/C-G with 3D coma and radiative transfer modeling of Microwave Instrument on the Rosetta Orbiter (MIRO) measurements, accounting for nucleus shape, illumination, and orientation of the comet. We investigate MIRO line shape information for spatial distribution of water activity on the nucle…