Search Publications
The Faint End of the Centaurus A Satellite Luminosity Function
Crnojević, D.; Sand, D. J.; Simon, J. D. +9 more
The Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS) is constructing a wide-field map of the resolved stellar populations in the extended halos of these two nearby, prominent galaxies. We present new Magellan/Megacam imaging of a ∼3 deg2 area around Centaurus A (Cen A), which filled in much of our coverage to its south, leavi…
A magnetar-powered X-ray transient as the aftermath of a binary neutron-star merger
Lehmer, B. D.; Bauer, F. E.; Brandt, W. N. +14 more
Mergers of neutron stars are known to be associated with short γ-ray bursts1-4. If the neutron-star equation of state is sufficiently stiff (that is, the pressure increases sharply as the density increases), at least some such mergers will leave behind a supramassive or even a stable neutron star that spins rapidly with a strong magneti…
Gaia DR2 reveals a star formation burst in the disc 2-3 Gyr ago
Luri, X.; Figueras, F.; Mor, R. +2 more
We use Gaia data release 2 (DR2) magnitudes, colours, and parallaxes for stars with G < 12 to explore a parameter space with 15 dimensions that simultaneously includes the initial mass function (IMF) and a non-parametric star formation history (SFH) for the Galactic disc. This inference is performed by combining the Besançon Galaxy Model fast a…
Gaia DR2 unravels incompleteness of nearby cluster population: new open clusters in the direction of Perseus
Castro-Ginard, A.; Jordi, C.; Cantat-Gaudin, T. +13 more
Context. Open clusters (OCs) are popular tracers of the structure and evolutionary history of the Galactic disc. The OC population is often considered to be complete within 1.8 kpc of the Sun. The recent Gaia Data Release 2 (DR2) allows the latter claim to be challenged.
Aims: We perform a systematic search for new OCs in the direction of Per…
Too big to fail in light of Gaia
Kaplinghat, Manoj; Yu, Hai-Bo; Valli, Mauro
We point out an anticorrelation between the central dark matter (DM) densities of the bright Milky Way dwarf spheroidal galaxies (dSphs) and their orbital pericenter distances inferred from Gaia data. The dSphs that have not come close to the Milky Way centre (like Fornax, Carina and Sextans) are less dense in DM than those that have come closer (…
The echo of the bar buckling: Phase-space spirals in Gaia Data Release 2
Gerhard, Ortwin; Khoperskov, Sergey; Di Matteo, Paola +5 more
We present a high-resolution numerical study of the phase-space diversity in an isolated Milky Way-type galaxy. Using a single N-body simulation (N ≈ 0.14 × 109) we explore the formation, evolution, and spatial variation of the phase-space spirals similar to those recently discovered by Antoja et al. in the Milky Way disk with Gaia Data…
KiDS+VIKING-450: A new combined optical and near-infrared dataset for cosmology and astrophysics
Sifón, Cristóbal; Heymans, Catherine; Kuijken, Konrad +22 more
We present the curation and verification of a new combined optical and near infrared dataset for cosmology and astrophysics, derived by combining ugri-band imaging from the Kilo-Degree Survey (KiDS) and ZYJHKs-band imaging from the VISTA Kilo degree Infrared Galaxy (VIKING) survey. This dataset is unrivaled in cosmological imaging surve…
Massive star cluster formation under the microscope at z = 6
Castellano, M.; Gilli, R.; Grillo, C. +12 more
We report on a superdense star-forming region with an effective radius (Re) smaller than 13 pc identified at z = 6.143 and showing a star formation rate density ΣSFR ∼ 1000 M⊙ yr-1 kpc-2 (or conservatively >300 M⊙ yr-1 kpc-2). Such a dense region is detected…
An X-ray chimney extending hundreds of parsecs above and below the Galactic Centre
Haberl, F.; Churazov, E.; Nandra, K. +6 more
Evidence has mounted in recent decades that outflows of matter and energy from the central few parsecs of our Galaxy have shaped the observed structure of the Milky Way on a variety of larger scales1. On scales of 15 parsecs, the Galactic Centre has bipolar lobes that can be seen in both the X-ray and radio parts of the spectrum2,3…
On the estimation of the local dark matter density using the rotation curve of the Milky Way
de Salas, P. F.; Malhan, K.; Freese, K. +2 more
The rotation curve of the Milky Way is commonly used to estimate the local dark matter density ρDM,solar. However, the estimates are subject to the choice of the distribution of baryons needed in this type of studies. In this work we explore several Galactic mass models that differ in the distribution of baryons and dark matter, in order to determ…