Search Publications

The echo of the bar buckling: Phase-space spirals in Gaia Data Release 2
DOI: 10.1051/0004-6361/201834707 Bibcode: 2019A&A...622L...6K

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…

2019 Astronomy and Astrophysics
Gaia 105
KiDS+VIKING-450: A new combined optical and near-infrared dataset for cosmology and astrophysics
DOI: 10.1051/0004-6361/201834879 Bibcode: 2019A&A...632A..34W

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…

2019 Astronomy and Astrophysics
Gaia 104
Massive star cluster formation under the microscope at z = 6
DOI: 10.1093/mnras/sty3311 Bibcode: 2019MNRAS.483.3618V

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…

2019 Monthly Notices of the Royal Astronomical Society
eHST 104
An X-ray chimney extending hundreds of parsecs above and below the Galactic Centre
DOI: 10.1038/s41586-019-1009-6 Bibcode: 2019Natur.567..347P

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…

2019 Nature
XMM-Newton 104
On the estimation of the local dark matter density using the rotation curve of the Milky Way
DOI: 10.1088/1475-7516/2019/10/037 Bibcode: 2019JCAP...10..037D

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…

2019 Journal of Cosmology and Astroparticle Physics
Gaia 104
The population of hot subdwarf stars studied with Gaia. II. The Gaia DR2 catalogue of hot subluminous stars
DOI: 10.1051/0004-6361/201834236 Bibcode: 2019A&A...621A..38G

Geier, S.; Marsh, T. R.; Raddi, R. +1 more

Based on data from the ESA Gaia Data Release 2 (DR2) and several ground-based, multi-band photometry surveys we have compiled an all-sky catalogue of 39 800 hot subluminous star candidates selected in Gaia DR2 by means of colour, absolute magnitude, and reduced proper motion cuts. We expect the majority of the candidates to be hot subdwarf stars o…

2019 Astronomy and Astrophysics
Gaia 104
New Insights on Lyα and Lyman Continuum Radiative Transfer in the Greenest Peas
DOI: 10.3847/1538-4357/ab3d3b Bibcode: 2019ApJ...885...96J

Scarlata, Claudia; Jaskot, Anne E.; Dowd, Tara +2 more

As some of the only Lyman continuum (LyC) emitters at z ∼ 0, Green Pea (GP) galaxies are possible analogs of the sources that reionized the universe. We present HST COS spectra of 13 of the most highly ionized GPs, with [O III]/[O II] = 6-35, and investigate correlations between Lyα, galaxy properties, and low-ionization UV lines. Galaxies with hi…

2019 The Astrophysical Journal
eHST 104
Identification of the long stellar stream of the prototypical massive globular cluster ω Centauri
DOI: 10.1038/s41550-019-0751-x Bibcode: 2019NatAs...3..667I

Bianchini, Paolo; Martin, Nicolas; Malhan, Khyati +2 more

Omega Centauri (ω Cen) is the Milky Way's most massive globular cluster, and has long been suspected of being the remnant core of an accreted dwarf galaxy. If this scenario is correct, ω Cen should be tidally limited and tidal debris should be spread along its orbit. Here we use N-body simulations to show that the recently discovered `Fimbulthul' …

2019 Nature Astronomy
Gaia 104
Is every strong lens model unhappy in its own way? Uniform modelling of a sample of 13 quadruply+ imaged quasars
DOI: 10.1093/mnras/sty3397 Bibcode: 2019MNRAS.483.5649S

Smith, M.; Abbott, T. M. C.; Allam, S. +70 more

Strong-gravitational lens systems with quadruply imaged quasars (quads) are unique probes to address several fundamental problems in cosmology and astrophysics. Although they are intrinsically very rare, ongoing and planned wide-field deep-sky surveys are set to discover thousands of such systems in the next decade. It is thus paramount to devise …

2019 Monthly Notices of the Royal Astronomical Society
eHST 103
The VANDELS survey: the stellar metallicities of star-forming galaxies at 2.5 < z < 5.0
DOI: 10.1093/mnras/stz1402 Bibcode: 2019MNRAS.487.2038C

Cimatti, A.; Cullen, F.; McLure, R. J. +24 more

We present the results of a study utilizing ultradeep, rest-frame UV, spectroscopy to quantify the relationship between stellar mass and stellar metallicity for 681 star-forming galaxies at 2.5 < z < 5.0 (<z> = 3.5 ± 0.6) drawn from the VANDELS survey. Via a comparison with high-resolution stellar population synthesis models, we determ…

2019 Monthly Notices of the Royal Astronomical Society
eHST 103