Search Publications

The origin of galactic metal-rich stellar halo components with highly eccentric orbits
DOI: 10.1093/mnras/stz159 Bibcode: 2019MNRAS.484.4471F

Springel, Volker; Grand, Robert J. J.; Gómez, Facundo A. +6 more

Using the astrometry from the ESA's Gaia mission, previous works have shown that the Milky Way stellar halo is dominated by metal-rich stars on highly eccentric orbits. To shed light on the nature of this prominent halo component, we have analysed 28 Galaxy analogues in the Auriga suite of cosmological hydrodynamics zoom-in simulations. Some three…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 118
A Temporary Epoch of Stalled Spin-down for Low-mass Stars: Insights from NGC 6811 with Gaia and Kepler
DOI: 10.3847/1538-4357/ab2393 Bibcode: 2019ApJ...879...49C

Agüeros, Marcel A.; Curtis, Jason Lee; Douglas, Stephanie T. +1 more

Stellar rotation was proposed as a potential age diagnostic that is precise, simple, and applicable to a broad range of low-mass stars (≤slant 1 {M}). Unfortunately, rotation period ({P}{{rot}}) measurements of low-mass members of open clusters have undermined the idea that stars spin down with a common age dependence (i.e.…

2019 The Astrophysical Journal
Gaia 118
The GALAH survey: An abundance, age, and kinematic inventory of the solar neighbourhood made with TGAS
DOI: 10.1051/0004-6361/201833218 Bibcode: 2019A&A...624A..19B

Freeman, K. C.; Skúladóttir, Á.; Rix, H. -W. +32 more

The overlap between the spectroscopic Galactic Archaeology with HERMES (GALAH) survey and Gaia provides a high-dimensional chemodynamical space of unprecedented size. We present a first analysis of a subset of this overlap, of 7066 dwarf, turn-off, and sub-giant stars. These stars have spectra from the GALAH survey and high parallax precision from…

2019 Astronomy and Astrophysics
Gaia 117
YBC: a stellar bolometric corrections database with variable extinction coefficients. Application to PARSEC isochrones
DOI: 10.1051/0004-6361/201936612 Bibcode: 2019A&A...632A.105C

Fu, Xiaoting; Girardi, Léo; Marigo, Paola +7 more

We present the YBC database of stellar bolometric corrections, in which we homogenise widely used theoretical stellar spectral libraries and provide BCs for many popular photometric systems, including Gaia filters. The database can easily be extended to additional photometric systems and stellar spectral libraries. The web interface allows users t…

2019 Astronomy and Astrophysics
Gaia 116
Black Hole Mass Scaling Relations for Early-type Galaxies. I. M BH-M *, sph and M BH-M *,gal
DOI: 10.3847/1538-4357/ab0f32 Bibcode: 2019ApJ...876..155S

Graham, Alister W.; Davis, Benjamin L.; Sahu, Nandini

Analyzing a sample of 84 early-type galaxies (ETGs) with directly measured supermassive black hole masses -- nearly doubling the sample size of such galaxies with multicomponent decompositions -- a symmetric linear regression on the reduced (merger-free) sample of 76 galaxies reveals MBH ∝ M*,sph1.27+/-0.07 with a …

2019 The Astrophysical Journal
eHST 115
Optical Spectroscopy and Demographics of Redback Millisecond Pulsar Binaries
DOI: 10.3847/1538-4357/aafbaa Bibcode: 2019ApJ...872...42S

Strader, Jay; Bahramian, Arash; Cheung, C. C. +12 more

We present the first optical spectroscopy of five confirmed (or strong candidate) redback millisecond pulsar binaries, obtaining complete radial velocity curves for each companion star. The properties of these millisecond pulsar binaries with low-mass, hydrogen-rich companions are discussed in the context of the 14 confirmed and 10 candidate field…

2019 The Astrophysical Journal
Gaia 115
Piercing the Milky Way: an all-sky view of the Orphan Stream
DOI: 10.1093/mnras/stz457 Bibcode: 2019MNRAS.485.4726K

Li, T. S.; Evans, N. W.; Belokurov, V. +14 more

We use astrometry, broad-band photometry, and variability information from the Data Release 2 of ESA's Gaia mission (GDR2) to identify members of the Orphan Stream (OS) across the whole sky. The stream is traced above and below the celestial equator and in both Galactic hemispheres, thus increasing its visible length to ∼210° equivalent to ∼150 kp…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 114
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters - XIX. A chemical tagging of the multiple stellar populations over the chromosome maps
DOI: 10.1093/mnras/stz1415 Bibcode: 2019MNRAS.487.3815M

Anderson, J.; Milone, A. P.; Cordoni, G. +8 more

The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters (GCs) has investigated GCs and their stellar populations. In previous papers of this series we have introduced a pseudo two-colour diagram, or `chromosome map' (ChM) that maximizes the separation between the multiple populations. We have identified two main classes of GCs: T…

2019 Monthly Notices of the Royal Astronomical Society
Gaia eHST 114
Homogeneous photometry - VII. Globular clusters in the Gaia era
DOI: 10.1093/mnras/stz585 Bibcode: 2019MNRAS.485.3042S

Pancino, E.; Sanna, N.; Stetson, P. B. +2 more

We present wide-field, ground-based Johnson-Cousins UBVRI photometry for 48 Galactic globular clusters based on about 90 000 public and proprietary images. The photometry is calibrated with the latest transformations obtained in the framework of our secondary standard project, with typical internal and external uncertainties of order a few millima…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 114
Structure and kinematics of the Taurus star-forming region from Gaia-DR2 and VLBI astrometry
DOI: 10.1051/0004-6361/201935928 Bibcode: 2019A&A...630A.137G

Bouy, H.; Covey, K.; Sarro, L. M. +9 more


Aims: We take advantage of the second data release of the Gaia space mission and the state-of-the-art astrometry delivered from very long baseline interferometry observations to revisit the structure and kinematics of the nearby Taurus star-forming region.
Methods: We apply a hierarchical clustering algorithm for partitioning the stars i…

2019 Astronomy and Astrophysics
Gaia 114