Search Publications
WISDOM project - V. Resolving molecular gas in Keplerian rotation around the supermassive black hole in NGC 0383
Williams, Thomas G.; Sarzi, Marc; Cappellari, Michele +7 more
As part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM), we present a measurement of the mass of the supermassive black hole (SMBH) in the nearby early-type galaxy NGC 0383 (radio source 3C 031). This measurement is based on Atacama Large Millimeter/sub-millimeter Array (ALMA) cycle 4 and 5 observations of the 12CO(…
Dramatic spectral transition of X-ray pulsar GX 304-1 in low luminous state
Doroshenko, Victor; Tsygankov, Sergey S.; Mushtukov, Alexander A. +5 more
We report on the discovery of a dramatic change in the energy spectrum of the X-ray pulsar GX 304-1 appearing at low luminosity. Particularly, we found that the cut-off power-law spectrum typical for accreting pulsars, including GX 304-1 at higher luminosities of LX ∼ 1036-1037 erg s-1, transformed at lo…
Torus model properties of an ultra-hard X-ray selected sample of Seyfert galaxies
Hernán-Caballero, A.; Carrera, F. J.; Acosta-Pulido, J. A. +15 more
We characterize for the first time the torus properties of an ultra-hard X-ray (14-195 keV) volume-limited (DL < 40 Mpc) sample of 24 Seyfert (Sy) galaxies (BCS40 sample). The sample was selected from the Swift/BAT nine-month catalogue. We use high angular resolution nuclear infrared (IR) photometry and N-band spectroscopy…
Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanets
Bouchy, F.; Vanderburg, A.; Poretti, E. +34 more
Super-Earths belong to a class of planet not found in the Solar system, but which appear common in the Galaxy. Given that some super-Earths are rocky, while others retain substantial atmospheres, their study can provide clues as to the formation of both rocky and gaseous planets, and - in particular - they can help to constrain the role of photoev…
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…
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…
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…
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…