Search Publications
Swift and XMM-Newton observations of an RS CVn-type eclipsing binary SZ Psc: superflare and coronal properties
Karmakar, Subhajeet; Naik, Sachindra; Pandey, Jeewan C. +1 more
We present an in-depth study of a large and long duration (>1.3 d) X-ray flare observed on an RS CVn-type eclipsing binary system SZ Psc using observations from Swift observatory. In the 0.35-10 keV energy band, the peak luminosity is estimated to be 4.2 × 1033 $\rm {erg}~\rm {s}^{-1}$. The quiescent corona of SZ Psc was observed ~5.…
Intermediate-mass black holes: finding of episodic, large-scale, and powerful jet activity in a dwarf galaxy
Paragi, Zsolt; Frey, Sándor; Varenius, Eskil +10 more
Dwarf galaxies are characterized by a very low luminosity and low mass. Because of significant accretion and ejection activity of massive black holes, some dwarf galaxies also host low-luminosity active galactic nuclei (AGNs). In a few dwarf AGNs, very long baseline interferometry (VLBI) observations have found faint non-thermal radio emission. SD…
First light and reionization epoch simulations (FLARES) X III: the lyman-continuum emission of high-redshift galaxies
Wilkins, Stephen M.; Conselice, Christopher J.; Simmonds, Charlotte +10 more
The history of reionization is highly dependent on the ionizing properties of high-redshift galaxies. It is therefore important to have a solid understanding of how the ionizing properties of galaxies are linked to physical and observable quantities. In this paper, we use the First Light and Reionization Epoch Simulations (FLARES) to study the Lym…
The volume density of giant low surface brightness galaxies
Galaz, Gaspar; Chilingarian, Igor V.; Saburova, Anna S. +5 more
Rare giant low surface brightness galaxies (gLSBGs) act as a stress test for the current galaxy formation paradigm. To answer the question 'How rare are they?', we estimate their volume density in the local Universe. A visual inspection of 120 deg2 covered by deep Subaru Hyper Suprime-Cam data was performed independently by four team me…
A tale of a tail: a tidally disrupting ultra-diffuse galaxy in the M81 group
Cuillandre, Jean-Charles; Arimoto, Nobuo; Okamoto, Sakurako +4 more
We present the discovery of a giant tidal tail of stars associated with F8D1, the closest known example of an ultra-diffuse galaxy (UDG). F8D1 sits in a region of the sky heavily contaminated by Galactic cirrus and has been poorly studied since its discovery two decades ago. The tidal feature was revealed in a deep map of resolved red giant branch…
Magnetic fluxes of solar active regions of different magneto-morphological classes - I. Cyclic variations
Abramenko, Valentina I.; Suleymanova, Regina A.; Zhukova, Anastasija V.
Data for 3046 solar active regions (ARs) observed since 1996 May 12 to 2021 December 27 were utilized to explore how the magnetic fluxes from ARs of different complexity follow the solar cycle. Magnetograms from the Michelson Doppler Imager instrument on the Solar and Heliospheric Observatory and from the Helioseismic and Magnetic Imager instrumen…
Gaia DR3 features of the phase spiral and its possible relation to internal perturbations
Li, Chengdong; Siebert, Arnaud; Famaey, Benoit +2 more
Disc stars from the Gaia DR3 RVS catalogue are selected to explore the phase spiral in the Galaxy. The data reveal a two-armed phase spiral pattern in the local z-vz plane inside the solar radius, which appears clearly when colour-coded by ⟨vR⟩(z, vz): this is characteristic of a breathing mode that can in principl…
A brown dwarf donor and an optically thin accretion disc with a complex stream impact region in the period-bouncer candidate BW Sculptoris
Neustroev, Vitaly V.; Mäntynen, Iikka
We present an analysis of multi-epoch spectroscopic and photometric observations of the WZ Sge-type dwarf nova BW Scl, a period-bouncer candidate. We detected multiple irradiation-induced emission lines from the donor star allowing the radial velocity variations to be measured with high accuracy. Also, using the absorption lines Mg II 4481 Å and C…
Beyond the ultradeep frontier fields and legacy observations (BUFFALO): a high-resolution strong+weak-lensing view of Abell 370
Sharon, K.; Diego, J. M.; Zitrin, A. +16 more
The HST treasury programme BUFFALO provides extended wide-field imaging of the six Hubble Frontier Fields galaxy clusters. Here we present the combined strong and weak-lensing analysis of Abell 370, a massive cluster at z = 0.375. From the reconstructed total projected mass distribution in the 6 arcmin × 6 arcmin BUFFALO field-of-view, we obtain t…
How close dark matter haloes and MOND are to each other: three-dimensional tests based on Gaia DR2
Huang, Yang; Chang, Liang; Dong, Xiao-Bo +7 more
Aiming at discriminating different gravitational potential models of the Milky Way, we perform tests based on the kinematic data powered by the Gaia DR2 astrometry over a large range of (R, z) locations. Invoking the complete form of Jeans equations that admit three integrals of motion, we use the independent R- and z-directional equations as two …