Search Publications

Uncovering the birth of the Milky Way through accurate stellar ages with Gaia
DOI: 10.1038/s41550-019-0829-5 Bibcode: 2019NatAs...3..932G

Ruiz-Lara, Tomás; Hill, Vanessa; Monelli, Matteo +4 more

Knowledge of the ages of the stars formed over a galaxy's lifetime is fundamental to an understanding of its formation and evolution. However, stellar ages are difficult to obtain since they cannot be measured from observations, but require comparison with stellar models1. Alternatively, age distributions can be derived by applying the …

2019 Nature Astronomy
Gaia 228
An Embedded X-Ray Source Shines through the Aspherical AT 2018cow: Revealing the Inner Workings of the Most Luminous Fast-evolving Optical Transients
DOI: 10.3847/1538-4357/aafa01 Bibcode: 2019ApJ...872...18M

Berger, E.; Hurley, K.; Götz, D. +42 more

We present the first extensive radio to γ-ray observations of a fast-rising blue optical transient, AT 2018cow, over its first ∼100 days. AT 2018cow rose over a few days to a peak luminosity L pk ∼ 4 × 1044 erg s-1, exceeding that of superluminous supernovae (SNe), before declining as L ∝ t -2. Initial s…

2019 The Astrophysical Journal
INTEGRAL XMM-Newton 225
Gaia Data Release 2. Specific characterisation and validation of all-sky Cepheids and RR Lyrae stars
DOI: 10.1051/0004-6361/201833374 Bibcode: 2019A&A...622A..60C

Szabados, L.; Audard, M.; Rimoldini, L. +21 more

Context. The Gaia second Data Release (DR2) presents a first mapping of full-sky RR Lyrae stars and Cepheids observed by the spacecraft during the initial 22 months of science operations.
Aims: The Specific Objects Study (SOS) pipeline, developed to validate and fully characterise Cepheids and RR Lyrae stars (SOS Cep&RRL) observed by Gaia…

2019 Astronomy and Astrophysics
Gaia 224
The Most Luminous Supernovae
DOI: 10.1146/annurev-astro-081817-051819 Bibcode: 2019ARA&A..57..305G

Gal-Yam, Avishay

Over a decade ago, a group of supernova explosions with peak luminosities far exceeding (often by >100 times) those of normal events has been identified. These superluminous supernovae (SLSNe) have been a focus of intensive study. I review the accumulated observations and discuss the implications for the physics of these extreme explosions. SLS…

2019 Annual Review of Astronomy and Astrophysics
eHST 220
Gaia Data Release 2. Properties and validation of the radial velocities
DOI: 10.1051/0004-6361/201833273 Bibcode: 2019A&A...622A.205K

Smith, M.; Gosset, E.; Allende Prieto, C. +52 more

Context. For Gaia DR2, 280 million spectra collected by the Radial Velocity Spectrometer instrument on board Gaia were processed, and median radial velocities were derived for 9.8 million sources brighter than GRVS = 12 mag.
Aims: This paper describes the validation and properties of the median radial velocities published in Gaia D…

2019 Astronomy and Astrophysics
Gaia 220
An Older, More Quiescent Universe from Panchromatic SED Fitting of the 3D-HST Survey
DOI: 10.3847/1538-4357/ab1d5a Bibcode: 2019ApJ...877..140L

Franx, Marijn; van Dokkum, Pieter; Conroy, Charlie +8 more

Galaxy observations are influenced by many physical parameters: stellar masses, star formation rates (SFRs), star formation histories (SFHs), metallicities, dust, black hole activity, and more. As a result, inferring accurate physical parameters requires high-dimensional models that capture or marginalize over this complexity. Here we reassess inf…

2019 The Astrophysical Journal
eHST 218
Inferences on the timeline of reionization at z ∼ 8 from the KMOS Lens-Amplified Spectroscopic Survey
DOI: 10.1093/mnras/stz632 Bibcode: 2019MNRAS.485.3947M

Fontana, Adriano; Pentericci, Laura; Schmidt, Kasper B. +12 more

Detections and non-detections of Lyman alpha (Lyα) emission from z > 6 galaxies (<1 Gyr after the big bang) can be used to measure the timeline of cosmic reionization. Of key interest to measuring reionization's mid-stages, but also increasing observational challenge, are observations at z > 7, where Lyα redshifts to near infra-red wavele…

2019 Monthly Notices of the Royal Astronomical Society
eHST 218
Age determination for 269 Gaia DR2 open clusters
DOI: 10.1051/0004-6361/201834693 Bibcode: 2019A&A...623A.108B

Jordi, C.; Casamiquela, L.; Cantat-Gaudin, T. +9 more

Context. The Gaia Second Data Release provides precise astrometry and photometry for more than 1.3 billion sources. This catalog opens a new era concerning the characterization of open clusters and test stellar models, paving the way for better understanding of the disk properties.
Aims: The aim of the paper is to improve the knowledge of clu…

2019 Astronomy and Astrophysics
Gaia 213
Nine-hour X-ray quasi-periodic eruptions from a low-mass black hole galactic nucleus
DOI: 10.1038/s41586-019-1556-x Bibcode: 2019Natur.573..381M

Read, A. M.; Knigge, C.; Heywood, I. +11 more

In the past two decades, high-amplitude electromagnetic outbursts have been detected from dormant galaxies and often attributed to the tidal disruption of a star by the central black hole1,2. X-ray emission from the Seyfert 2 galaxy GSN 069 (2MASX J01190869-3411305) at a redshift of z = 0.018 was first detected in July 2010 and implies …

2019 Nature
XMM-Newton eHST 210
Mass and shape of the Milky Way's dark matter halo with globular clusters from Gaia and Hubble
DOI: 10.1051/0004-6361/201833355 Bibcode: 2019A&A...621A..56P

Helmi, Amina; Posti, Lorenzo


Aims: We estimate the mass of the inner (< 20 kpc) Milky Way and the axis ratio of its inner dark matter halo using globular clusters as tracers. At the same time, we constrain the distribution in phase-space of the globular cluster system around the Galaxy.
Methods: We use the Gaia Data Release 2 catalogue of 75 globular clusters' pr…

2019 Astronomy and Astrophysics
Gaia eHST 208