Search Publications
AstroSat observations of the dipping low-mass X-ray binary XB 1254-690
Rao, A. R.; Misra, Ranjeev; Navale, Nilam R. +4 more
XB 1254-690 is a neutron star low-mass X-ray binary with an orbital period of 3.88 h, and it exhibits energy-dependent intensity dips, thermonuclear bursts, and flares. We present the results of an analysis of a long observation of this source using the AstroSat satellite. The X-ray light curve gradually changed from a high-intensity flaring state…
Quasars with flare/eclipse-like variability identified in ZTF
Dannerbauer, H.; Jin, Shuowen; Shi, Yong +4 more
Active galactic nuclei (AGNs) are known to exhibit optical/ultraviolet variability and most of them can be well modelled by the damped random walks. Physical processes that are not related to the accretion disc, such as tidal disruption events (TDEs) or moving foreground dusty clouds, can cause flare-like and eclipse-like features in the optical l…
Modelling stellar variability in archival HARPS data: I - Rotation and activity properties with multidimensional Gaussian processes
Aigrain, Suzanne; Mortier, Annelies; Klein, Baptiste +4 more
Although instruments for measuring the radial velocities (RVs) of stars now routinely reach sub-metre per second accuracy, the detection of low-mass planets is still very challenging. The rotational modulation and evolution of spots and/or faculae can induce variations in the RVs at the level of a few m s-1 in Sun-like stars. To overcom…
Ultraviolet extinction correlation with 3D dust maps using white dwarfs
Redfield, Seth; Sahu, Snehalata; Gänsicke, Boris T. +2 more
Accurate astrometric and photometric measurements from Gaia have led to the construction of 3D dust extinction maps which can now be used for estimating the integrated extinctions of Galactic sources located within 5 kpc. These maps based on optical observations may not be reliable for use in the ultraviolet (UV) which is more sensitive to reddeni…
A morphological analysis of the galaxy cluster XLSSC 122 at z = 1.98
Canning, R. E. A.; Willis, J. P.; Rennehan, D. +1 more
We present a morphological analysis of 29 spectroscopically confirmed members of XLSSC 122, a massive galaxy cluster at
Orbital architectures of planet-hosting binaries - III. Testing mutual inclinations of stellar and planetary orbits in triple-star systems
Huber, Daniel; Dupuy, Trent J.; Ireland, Michael J. +7 more
Transiting planets in multiple-star systems, especially high-order multiples, make up a small fraction of the known planet population but provide unique opportunities to study the environments in which planets would have formed. Planet-hosting binaries have been shown to have an abundance of systems in which the stellar orbit aligns with the orbit…
Unveiling gas kinematics and stellar populations in H II regions inside the low-metallicity dwarf nearby galaxy SDSSJ0859 + 3923 with MEGARA at the GTC
Castillo-Morales, A.; Gallego, J.; Mollá, M. +8 more
In this study, we present Integral Field Unit observations of the galaxy SDSSJ0859 + 3923, utilizing the MEGARA (Multi Espectrógrafo en GTC de Alta Resolución para Astronomía) instrument on the GTC (Gran Telescopio Canarias) 10.4m telescope. These observations were conducted in two distinct spectral ranges: 4332-5222 Å and 6097-7345 Å, with a high…
The PARSEC view of star formation in galaxy centres: from protoclusters to star clusters in an early-type spiral
Bruzual, Gustavo; Burkert, Andreas; Fernández-Ontiveros, Juan A. +2 more
Understanding star formation in galaxies requires resolving the physical scale on which star formation often occurs: the scale of star clusters. We present a multiwavelength, eight-parsec resolution study of star formation in the circumnuclear star cluster and molecular gas rings of the early-type spiral NGC 1386. The cluster ring formed simultane…
Mitigating astrometric bias in barycentric correction with PEXO
Feng, Fabo; Rui, Yicheng
Extremely precise radial velocity is essential for the detection of sub-m s-1 radial velocity of stars induced by Earth-like planets. Although modelling of the barycentric correction of radial velocity could achieve 1 mm s-1 precision, the input astrometry could be biased due to non-linear motions of stars caused by companion…
Semi-supervised spectral classification of DESI white dwarfs by dimensionality reduction
Bonsor, Amy; Manser, Christopher J.; Rogers, Laura K. +1 more
As a new generation of large-sky spectroscopic surveys comes online, the enormous data volume poses unprecedented challenges in classifying spectra. Modern unsupervised techniques have the power to group spectra based on their dominant features, circumventing the complete reliance on training data suffered by supervised methods. We outline the use…