Search Publications
Discovery of a nitrogen-enhanced mildly metal-poor binary system: Possible evidence for pollution from an extinct AGB star
Beers, Timothy C.; Placco, Vinicius M.; Robin, Annie C. +12 more
We report the serendipitous discovery of a nitrogen-rich, mildly metal-poor ([Fe/H] = -1.08) giant star in a single-lined spectroscopic binary system found in the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) survey, Data Release 14 (DR14). Previous work has assumed that two percent of halo giants with unusual elemental…
New near-infrared JHKs light-curve templates for RR Lyrae variables
Minniti, D.; Walker, A. R.; Mateo, M. +35 more
We provide homogeneous optical (UBVRI) and near-infrared (NIR, JHK) time series photometry for 254 cluster (ω Cen, M 4) and field RR Lyrae (RRL) variables. We ended up with more than 551 000 measurements, of which only 9% are literature data. For 94 fundamental (RRab) and 51 first overtones (RRc) we provide a complete optical/NIR characterization …
VIS3COS. II. Nature and nurture in galaxy structure and morphology
van der Wel, Arjen; Sobral, David; Darvish, Behnam +7 more
We study the impact of local density and stellar mass on the structure and morphology of approximately 500 quiescent and star-forming galaxies from the VIMOS Spectroscopic Survey of a Superstructure in COSMOS (VIS3COS). We perform bulge-to-disc decomposition of the surface brightness profiles and find ∼41 ± 3% of > 1010 M<…
Mapping the stellar age of the Milky Way bulge with the VVV. II. Deep JKs catalog release based on PSF photometry
Minniti, D.; Rejkuba, M.; Zoccali, M. +6 more
Context. The bulge represents the best compromise between old and massive Galactic components, and as such its study is a valuable opportunity to understand how the bulk of the Milky Way formed and evolved. In addition, being the only bulge in which we can individually resolve stars in all evolutionary sequences, the properties of its stellar cont…
The chemical structure of the very young starless core L1521E
Nagy, Z.; Caselli, P.; Spezzano, S. +5 more
Context. L1521E is a dense starless core in Taurus that was found to have relatively low molecular depletion by earlier studies, thus suggesting a recent formation.
Aims: We aim to characterize the chemical structure of L1521E and compare it to the more evolved L1544 pre-stellar core.
Methods: We have obtained 2.5 × 2.5 arcminute maps to…
A deep X-ray view of the bare AGN Ark 120. V. Spin determination from disc-Comptonisation efficiency method
Stern, D.; Farrah, D.; Done, C. +13 more
Context. The spin of supermassive black holes (SMBH) in active galactic nuclei (AGN) can be determined from spectral signature(s) of relativistic reflection such as the X-ray iron Kα line profile, but this can be rather uncertain when the line of sight intersects the so-called warm absorber and/or other wind components as these distort the continu…
Greening of the brown-dwarf desert. EPIC 212036875b: a 51 MJ object in a 5-day orbit around an F7 V star
Cochran, William D.; Endl, Michael; Redfield, Seth +55 more
Context. Although more than 2000 brown dwarfs have been detected to date, mainly from direct imaging, their characterisation is difficult due to their faintness and model-dependent results. In the case of transiting brown dwarfs, however, it is possible to make direct high-precision observations.
Aims: Our aim is to investigate the nature and…
Multi-wavelength variability of the young solar analog ι Horologii. X-ray cycle, star spots, flares, and UV emission
Sanz-Forcada, J.; Stelzer, B.; Raetz, S. +2 more
Context. Chromospheric activity cycles are common in late-type stars; however, only a handful of coronal activity cycles have been discovered. ι Hor is the most active and youngest star with known coronal cycles. It is also a young solar analog, and we are likely facing the earliest cycles in the evolution of solar-like stars, at an age ( 600 Myr)…
Using ALMA to resolve the nature of the early star-forming large-scale structure PLCK G073.4-57.5
Frye, Brenda; Hill, Ryley; Béthermin, Matthieu +10 more
Galaxy clusters at high redshift are key targets for understanding matter assembly in the early Universe, yet they are challenging to locate. A sample of more than 2000 high-z candidate structures has been found using Planck's all-sky submillimetre maps, and a sub-set of 234 have been followed up with Herschel-SPIRE, which showed that the emission…
The AMBRE Project: [Y/Mg] stellar dating calibration with Gaia
Titarenko, A.; Recio-Blanco, A.; de Laverny, P. +2 more
Chemical abundance dating methods open new paths for temporal evolution studies of the Milky Way stellar populations. In this paper, we use a high spectral resolution database of turn-off stars in the solar neighbourhood to study the age dependence of the [Y/Mg] chemical abundance ratio. Our analysis reveals a clear correlation between [Y/Mg] and …