Search Publications
A statistically significant lack of debris discs in medium separation binary systems
Wyatt, Mark C.; Kennedy, Grant M.; Su, Kate Y. L. +1 more
We compile a sample of 341 binary and multiple star systems with the aim of searching for and characterizing Kuiper belt-like debris discs. The sample is assembled by combining several smaller samples studied in previously published work with targets from two unpublished Herschel surveys. We find that 38 systems show excess emission at 70 or 100 &…
Random Forest identification of the thin disc, thick disc, and halo Gaia-DR2 white dwarf population
Solano, E.; Rebassa-Mansergas, A.; Torres, S. +3 more
Gaia-DR2 has provided an unprecedented number of white dwarf candidates of our Galaxy. In particular, it is estimated that Gaia-DR2 has observed nearly 400 000 of these objects and close to 18 000 up to 100 pc from the Sun. This large quantity of data requires a thorough analysis in order to uncover their main Galactic population properties, in pa…
OCCASO - III. Iron peak and α elements of 18 open clusters. Comparison with chemical evolution models and field stars
Jordi, C.; Casamiquela, L.; Anders, F. +10 more
The study of open-cluster chemical abundances provides insights on stellar nucleosynthesis processes and on Galactic chemo-dynamical evolution. In this paper we present an extended abundance analysis of 10 species (Fe, Ni, Cr, V, Sc, Si, Ca, Ti, Mg, O) for red giant stars in 18 OCCASO clusters. This represents a homogeneous sample regarding the in…
PAHs as tracers of the molecular gas in star-forming galaxies
Daddi, E.; Elbaz, D.; Gómez-Guijarro, C. +12 more
We combine new CO(1-0) line observations of 24 intermediate redshift galaxies (0.03 < z < 0.28) along with literature data of galaxies at 0 < z < 4 to explore scaling relations between the dust and gas content using polycyclic aromatic hydrocarbon (PAH) 6.2 µm (L6.2), CO (L^' }_CO), and infrared (LIR) lumino…
A deep view of a fossil relic in the Galactic bulge: the Globular Cluster HP 1
Bica, E.; Nardiello, D.; Barbuy, B. +7 more
HP 1 is an α-enhanced and moderately metal-poor bulge globular cluster with a blue horizontal branch. These combined characteristics make it a probable relic of the early star formation in the innermost Galactic regions. Here, we present a detailed analysis of a deep near-infrared (NIR) photometry of HP 1 obtained with the NIR GSAOI + GeMS camera …
Jets blowing bubbles in the young radio galaxy 4C 31.04
Groves, Brent; Mukherjee, Dipanjan; Wagner, Alexander Y. +5 more
We report the discovery of shocked molecular and ionized gas resulting from jet-driven feedback in the low-redshift (z = 0.0602) compact radio galaxy 4C 31.04 using near-IR imaging spectroscopy. 4C 31.04 is a ∼100 pc double-lobed Compact Steep Spectrum source believed to be a very young active galactic nucleus (AGN). It is hosted by a giant ellipt…
Probing the final-stage progenitor evolution for Type IIP Supernova 2017eaw in NGC 6946
Wang, Lifan; Wang, Xiaofeng; Zhang, Jujia +6 more
We presented a detailed analysis of progenitor properties of type IIP supernova 2017eaw in NGC 6946, based on the pre-explosion images and early-time observations obtained immediately after the explosion. An unusually red star, with MF814W = -6.9 mag and mF606W - mF814W = 2.9 ± 0.2 mag, can be identified at the SN …
Analysis of the physical nature of 22 New VVV Survey Globular Cluster candidates in the Milky Way bulge
Minniti, Dante; Hempel, Maren; Fernández-Trincado, José G. +11 more
In order to characterize 22 new globular cluster (GC) candidates in the Galactic bulge, we present their colour-magnitude diagrams (CMDs) and Ks-band luminosity functions (LFs) using the near-infrared VVV database as well as Gaia-DR2 proper motion data set. CMDs were obtained, on one hand, after properly decontaminating the observed dia…
On the Gaia DR2 distances for Galactic luminous blue variables
Drout, Maria R.; Smith, Nathan; Stassun, Keivan G. +3 more
We examine parallaxes and distances for Galactic luminous blue variables (LBVs) in the Gaia second data release (DR2). The sample includes 11 LBVs and 14 LBV candidates. For about half of the sample, DR2 distances are either similar to commonly adopted literature values, or the DR2 values have large uncertainties. For the rest, reliable DR2 distan…
Four stellar populations and extreme helium variation in the massive outer-halo globular cluster NGC 2419
Milone, A. P.; Cordoni, G.; Marino, A. F. +3 more
Recent work revealed that both the helium variation within globular clusters (GCs) and the relative numbers of first- and second-generation stars (1G, 2G) depend on the mass of the host cluster. Precise determination of the internal helium variations and of the fraction of 1G stars are crucial constraints to the formation scenarios of multiple pop…