Search Publications
Global 3D radiation magnetohydrodynamic simulations for FU Ori's accretion disc and observational signatures of magnetic fields
Jiang, Yan-Fei; Zhu, Zhaohuan; Stone, James M.
FU Ori is the prototype of FU Orionis systems that are outbursting protoplanetary discs. Magnetic fields in FU Ori's accretion discs have previously been detected using spectropolarimetry observations for Zeeman effects. We carry out global radiation ideal MHD simulations to study FU Ori's inner accretion disc. We find that (1) when the disc is th…
TOI-222: a single-transit TESS candidate revealed to be a 34-d eclipsing binary with CORALIE, EulerCam, and NGTS
Henning, Thomas; Latham, David W.; Jordán, Andrés +58 more
We report the period, eccentricity, and mass determination for the Transiting Exoplanet Survey Satellite (TESS) single-transit event candidate TOI-222, which displayed a single 3000 ppm transit in the TESS 2-min cadence data from Sector 2. We determine the orbital period via radial velocity measurements (P = 33.9 d), which allowed for ground-based…
Monitoring of the radio galaxy M 87 during a low-emission state from 2012 to 2015 with MAGIC
Maraschi, L.; Covino, S.; Antonelli, L. A. +186 more
M 87 is one of the closest (z = 0.004 36) extragalactic sources emitting at very high energies (VHE, E > 100 GeV). The aim of this work is to locate the region of the VHE gamma-ray emission and to describe the observed broad-band spectral energy distribution (SED) during the low VHE gamma-ray state. The data from M 87 collected between 2012 and…
Origins of Type Ibn SNe 2006jc/2015G in interacting binaries and implications for pre-SN eruptions
Sun, Ning-Chen; Crowther, Paul A.; Podsiadlowski, Philipp +2 more
Type Ibn supernovae (SNe Ibn) are intriguing stellar explosions whose spectra exhibit narrow helium lines with little hydrogen. They trace the presence of circumstellar material (CSM) formed via pre-SN eruptions of their stripped-envelope progenitors. Early work has generally assumed that SNe Ibn come from massive Wolf-Rayet (WR) stars via single-…
Scalable end-to-end recurrent neural network for variable star classification
Catelan, M.; Nikzat, F.; Protopapas, P. +3 more
During the last decade, considerable effort has been made to perform automatic classification of variable stars using machine-learning techniques. Traditionally, light curves are represented as a vector of descriptors or features used as input for many algorithms. Some features are computationally expensive, cannot be updated quickly and hence for…
Shapes and alignments of dark matter haloes and their brightest cluster galaxies in 39 strong lensing clusters
Oguri, Masamune; Suto, Yasushi; Kitayama, Tetsu +6 more
We study shapes and alignments of 45 dark matter (DM) haloes and their brightest cluster galaxies (BCGs) using a sample of 39 massive clusters from Hubble Frontier Field (HFF), Cluster Lensing And Supernova survey with Hubble (CLASH), and Reionization Lensing Cluster Survey (RELICS). We measure shapes of the DM haloes by strong gravitational lensi…
Exploring AGN and star formation activity of massive galaxies at cosmic noon
Papovich, Casey; Finkelstein, Steven L.; Kirkpatrick, Allison +11 more
We investigate the relation between active galactic nucleus (AGN) and star formation (SF) activity at 0.5 < z < 3 by analysing 898 galaxies with X-ray luminous AGNs (LX > 1044 erg s-1) and a large comparison sample of ~320 000 galaxies without X-ray luminous AGNs. Our samples are selected from a large (11.…
The Pristine Dwarf-Galaxy survey - II. In-depth observational study of the faint Milky Way satellite Sagittarius II
Navarro, Julio F.; Martin, Nicolas; Ibata, Rodrigo A. +11 more
We present an extensive study of the Sagittarius II (Sgr II) stellar system using MegaCam g and I photometry, narrow-band, metallicity-sensitive calcium H&K doublet photometry and Keck II/DEIMOS multiobject spectroscopy. We derive and refine the Sgr II structural and stellar properties inferred at the time of its discovery. The colour-magnitud…
Constraints on the circumburst environments of short gamma-ray bursts
Kouveliotou, Chryssa; O'Connor, Brendan; Beniamini, Paz
Observational follow up of well localized short gamma-ray bursts (SGRBs) has left $20\!-\!30{{\ \rm per\ cent}}$ of the population without a coincident host galaxy association to deep optical and NIR limits (≳26 mag). These SGRBs have been classified as observationally hostless due to their lack of strong host associations. It has been argued that…
Full of Orions: a 200-pc mapping of the interstellar medium in the redshift-3 lensed dusty star-forming galaxy SDP.81
Andreani, P.; Vegetti, S.; McKean, J. P. +4 more
We present a sub-kpc resolved study of the interstellar medium properties in SDP.81, a $z$ = 3.042 strongly gravitationally lensed, dusty star-forming galaxy, based on high-resolution, multiband ALMA observations of the far-infrared (FIR) continuum, CO ladder, and the [C II] line. Using a visibility-plane lens modelling code, we achieve a median s…