Search Publications
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…
OMEGA-OSIRIS mapping of emission-line galaxies in A901/2-V. The rich population of jellyfish galaxies in the multicluster system Abell 901/2
Chies-Santos, Ana L.; Aragón-Salamanca, A.; Bamford, Steven P. +3 more
We present the results of a systematic search and characterization of galaxies with morphological signatures of ram pressure stripping, known as jellyfish galaxies, in the multicluster system A901/2, at z ∼ 0.165, as part of the OMEGA survey. By visually inspecting Advanced Camera for Surveys/Hubble Space Telescope F606W images looking for morphol…
Investigating the diversity of Type Ia supernova spectra with the open-source relational data base KAEPORA
Foley, R. J.; Jones, D. O.; Siebert, M. R. +10 more
We present a public, open-source relational data base (we name KAEPORA) containing a sample of 4975 spectra of 777 Type Ia supernovae (SNe Ia). Since we draw from many sources, we significantly improve the spectra by inspecting these data for quality, removing galactic emission lines and cosmic rays, generating variance spectra, and correcting for…
Three new Galactic star clusters discovered in the field of the open cluster NGC 5999 with Gaia DR2
Corradi, W. J. B.; Ferreira, Filipe A.; Santos, J. F. C. +2 more
We report the serendipitous discovery of three new open clusters, named UFMG 1, UFMG 2, and UFMG 3 in the field of the intermediate-age cluster NGC 5999, by using Gaia DR2 data. A colour-magnitude filter tailored for a proper selection of main-sequence stars and red clump giants turned evident the presence of NGC 5999 and these three new stellar g…
The white dwarf mass-radius relation and its dependence on the hydrogen envelope
Kepler, S. O.; Romero, Alejandra D.; Joyce, S. R. G. +2 more
We present a study of the dependence of the mass-radius relation for DA white dwarf stars on the hydrogen envelope mass and the impact on the value of log g, and thus the determination of the stellar mass. We employ a set of full evolutionary carbon-oxygen core white dwarf sequences with white dwarf mass between 0.493 and 1.05 M⊙. Compu…
A stellar relic filament in the Orion star-forming region
Anderson, Richard I.; Boffin, Henri M. J.; Jerabkova, Tereza +1 more
We report the discovery of the oldest stellar substructure in the Orion star-forming region (OSFR), the Orion relic filament. The relic filament is physically associated with the OSFR, as demonstrated by Gaia DR2 photometry and astrometry, as well as by targeted radial velocity follow-up observations of a bright subsample of proper motion-selected…
HST unveils a compact mildly relativistic broad-line region in the candidate true type 2 NGC 3147
Laor, Ari; Bianchi, Stefano; La Franca, Fabio +9 more
NGC 3147 has been considered the best case of a true type 2 AGN: an unobscured AGN, based on the unabsorbed compact X-ray continuum, which lacks a broad-line region (BLR). However, the very low luminosity of NGC 3147 implies a compact BLR, which produces very broad lines, hard to detect against the dominant background host galaxy. Narrow (0.1 arcs…
Gaia stellar kinematics in the head of the Orion A cloud: runaway stellar groups and gravitational infall
Garmire, G. P.; Getman, K. V.; Kuhn, M. A. +1 more
This work extends previous kinematic studies of young stars in the head of the Orion A cloud (OMC-1/2/3/4/5). It is based on large samples of infrared, optical, and X-ray selected pre-main-sequence stars with reliable radial velocities and Gaia-derived parallaxes and proper motions. Stellar kinematic groups are identified assuming they mimic the m…