Search Publications
Detecting shocked intergalactic gas with X-ray and radio observations
Ettori, S.; Roncarelli, M.; Vazza, F. +3 more
Detecting the thermal and non-thermal emission from the shocked cosmic gas surrounding large-scale structures represents a challenge for observations, as well as a unique window into the physics of the warm-hot intergalactic medium. In this work, we present synthetic radio and X-ray surveys of large cosmological simulations in order to assess the …
Cosmological test using the Hubble diagram of high-z quasars
Melia, Fulvio
It has been known for over three decades that the monochromatic X-ray and UV luminosities in quasars are correlated, though non-linearly. This offers the possibility of using high-z quasars as standard candles for cosmological testing. In this paper, we use a recently assembled, high-quality catalogue of 1598 quasars extending all the way to redsh…
KiDS-SQuaD. II. Machine learning selection of bright extragalactic objects to search for new gravitationally lensed quasars
Agnello, Adriano; Kuijken, Konrad; Spiniello, Chiara +9 more
Context. The KiDS Strongly lensed QUAsar Detection project (KiDS-SQuaD) is aimed at finding as many previously undiscovered gravitational lensed quasars as possible in the Kilo Degree Survey. This is the second paper of this series where we present a new, automatic object-classification method based on the machine learning technique.
Aims: Th…
Machine-learning approaches to exoplanet transit detection and candidate validation in wide-field ground-based surveys
Bouchy, F.; Queloz, D.; Boumis, P. +23 more
Since the start of the Wide-angle Search for Planets (WASP) program, more than 160 transiting exoplanets have been discovered in the WASP data. In the past, possible transit-like events identified by the WASP pipeline have been vetted by human inspection to eliminate false alarms and obvious false positives. The goal of this paper is to assess the…
Multiple Temperature Components of the Hot Circumgalactic Medium of the Milky Way
Nicastro, Fabrizio; Mathur, Smita; Gupta, Anjali +2 more
We present a deep XMM-Newton observation of the Galactic halo emission in the direction of the blazar 1ES 1553+113. In order to extract the Galactic halo component from the diffuse soft X-ray emission spectrum, accurately modeling the foreground components is crucial. Here we present complex modeling of the foregrounds with unprecedented details. …
Anisotropy of the Universe via the Pantheon supernovae sample revisited
Zhao, Dong; Chang, Zhe; Zhou, Yong
We employ the hemisphere comparison (HC) method and the dipole fitting (DF) method to investigate the cosmic anisotropy in the recently released Pantheon sample of type Ia supernovae (SNe Ia) and five combinations among Pantheon. For the HC method, we find that the maximum anisotropy level in the full Pantheon sample is ALmax = 0.361 ± …
The dust content of the Crab Nebula
De Looze, I.; Gomez, H. L.; Barlow, M. J. +7 more
We have modelled the near-infrared to radio images of the Crab Nebula with a Bayesian SED model to simultaneously fit its synchrotron, interstellar (IS), and supernova dust emission. We infer an IS dust extinction map with an average AV = 1.08 ± 0.38 mag, consistent with a small contribution ({≲ }22{{ per cent}}) to the Crab's overall i…
More than just a wrinkle: a wave-like pattern in Ug versus Lz from Gaia data
Schönrich, Ralph; Friske, Jennifer K. S.
We present a newly found wave-like pattern in mean Galactocentric radial velocity {\overline{U}_ g} versus guiding centre radius Rg or angular momentum Lz of stars in the RV subsample of Gaia DR2. The short-wave pattern has a wavelength of order 1.2 kpc in Rg or 285 kpc km s^{-1} in Lz. The pattern shows…
Multiple Components of the Jhelum Stellar Stream
Conroy, Charlie; Hogg, David W.; Price-Whelan, Adrian M. +1 more
In simple models of the Milky Way, tidally disrupting satellites produce long and thin—nearly one-dimensional—stellar streams. Using astrometric data from the Gaia second data release and photometry from the Dark Energy Survey, we demonstrate that the Jhelum stream, a stellar stream in the inner halo, is a two-dimensional structure. The spatial di…
Star formation at the edge of the Local Group: a rising star formation history in the isolated galaxy WLM
Dolphin, Andrew E.; Skillman, Evan D.; Williams, Benjamin F. +11 more
We present the star formation history (SFH) of the isolated (D ∼ 970 kpc) Local Group dwarf galaxy Wolf-Lundmark-Melotte (WLM) measured from colour-magnitude diagrams (CMDs) constructed from deep Hubble Space Telescope imaging. Our observations include a central (0.5 r_h) and outer field (0.7 r_h) that reach below the oldest main-sequence turn-off…