Search Publications
Hidden cooling flows in clusters of galaxies
Fabian, A. C.; Pinto, C.; Ferland, G. J. +3 more
The radiative cooling time of the hot gas at the centres of cool cores in clusters of galaxies drops down to 10 Myr and below. The observed mass cooling rate of such gas is very low, suggesting that active galactic nucleus feedback is very tightly balanced or that the soft X-ray emission from cooling is somehow hidden from view. We use an intrinsi…
Astrometric excess noise in Gaia EDR3 and the search for X-ray binaries
Knigge, C.; Charles, P. A.; Gandhi, P. +6 more
Astrometric noise (ϵ) in excess of parallax and proper motion is a potential signature of orbital wobble (ω) of individual components in binary star systems. The combination of X-ray selection with astrometric noise could then be a powerful tool for robustly isolating accreting binaries in large surveys. Here, we mine the Gaia EDR3 catalogue for G…
The size-luminosity relation of lensed galaxies at z 6-9 in the Hubble Frontier Fields
Castellano, Marco; Fontana, Adriano; Treu, Tommaso +8 more
We measure the size-luminosity relation of photometrically selected galaxies within the redshift range z ~ 6-9, using galaxies lensed by six foreground Hubble Frontier Fields (HFF) clusters. The power afforded by strong gravitational lensing allows us to observe fainter and smaller galaxies than in blank fields. We select our sample of galaxies an…
Investigation of the orbital period and mass relations for W UMa-type contact systems
Poro, A.; Sabbaghian, G.; Madayen, T. +14 more
New relationships between the orbital period and some parameters of W Ursae Majoris (W UMa)-type systems are presented in this study. To investigate the relationships, we calculated the absolute parameters of a sample of 118 systems. For this purpose, we used the parallax values obtained from the Gaia Early Data Release 3 star catalogue for more p…
What are the spectroscopic binaries with high-mass functions near the Gaia DR3 main sequence?
Rix, Hans-Walter; El-Badry, Kareem
The third data release of the Gaia mission includes orbital solutions for >105 single-lined spectroscopic binaries, representing more than an order of magnitude increase in sample size over all previous studies. This data set is a treasure trove for searches for quiescent black hole + normal star binaries. We investigate one populati…
Two-spacecraft detection of short-period decayless kink oscillations of solar coronal loops
Berghmans, David; Nakariakov, Valery M.; Verbeeck, Cis +2 more
Decayless kink oscillations of an ensemble of loops are captured simultaneously by the High Resolution Imager (HRI) of the Extreme Ultraviolet Imager (EUI) and the Atmospheric Imaging Assembly (AIA) from 22:58 UT on 2021 November 5 to 00:27 UT on 2021 November 6. Oscillations are analysed by processing image sequences taken by the two instruments …
Lenses In VoicE (LIVE): searching for strong gravitational lenses in the VOICE@VST survey using convolutional neural networks
Vaccari, Mattia; Koopmans, Léon V. E.; Fan, Zuhui +8 more
We present a sample of 16 likely strong gravitational lenses identified in the VST Optical Imaging of the CDFS and ES1 fields (VOICE survey) using convolutional neural networks (CNNs). We train two different CNNs on composite images produced by superimposing simulated gravitational arcs on real Luminous Red Galaxies observed in VOICE. Specifically…
Constraining SIDM with halo shapes: Revisited predictions from realistic simulations of early-type galaxies
Vogelsberger, Mark; Sparre, Martin; Zavala, Jesús +3 more
We study the effect of self-interacting dark matter (SIDM) and baryons on the shape of early-type galaxies (ETGs) and their dark matter haloes, comparing them to the predictions of the cold dark matter (CDM) scenario. We use five hydrodynamical zoom-in simulations of haloes hosting ETGs ($M_{\rm vir}\sim 10^{13}\, \mathrm{M}_{\odot }$ and $M_{*}\s…
The chemical abundance pattern of the extremely metal-poor thin disc star 2MASS J1808-5104 and its origins
Placco, Vinicius M.; Meléndez, Jorge; Roederer, Ian U. +6 more
We present a high-resolution (R ~ 35 000), high signal-to-noise (S/N = 350) Magellan/MIKE spectrum of the bright extremely metal-poor star 2MASS J1808-5104. We find [Fe/H] = -4.01 (spectroscopic LTE stellar parameters), [Fe/H] = -3.8 (photometric stellar parameters), and [Fe/H] = -3.7 (spectroscopic NLTE stellar parameters). We measured a carbon-t…
An environmental analysis of the Type Ib SN 2019yvr and the possible presence of an inflated binary companion
Sun, Ning-Chen; Crowther, Paul A.; Zapartas, Emmanouil +5 more
SN 2019yvr is the second Type Ib supernova (SN) with a possible direct detection of its progenitor (system); however, the spectral energy distribution (SED) of the pre-explosion source appears much cooler and overluminous than an expected helium-star progenitor. Using Hubble Space Telescope (HST) images and MUSE integral-field-unit (IFU) spectrosc…