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Lyman alpha and Lyman continuum emission of Mg II-selected star-forming galaxies
Chisholm, J.; Schaerer, D.; Izotov, Y. I. +3 more
We present observations with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope of seven compact low-mass star-forming galaxies at redshifts, z, in the range 0.3161-0.4276, with various O3Mg2 = [O III] λ5007/Mg II λ2796+2803 and Mg2 = Mg II λ2796/Mg II λ2803 emission-line ratios. We aim to study the…
The VMC survey - XLVIII. Classical cepheids unveil the 3D geometry of the LMC
Girardi, Léo; Chemin, Laurent; de Grijs, Richard +12 more
We employed the VISTA near-infrared YJKssurvey of the Magellanic System (VMC) to analyse the $Y,\, J,~\mathrm{ and}~ K_\mathrm{s}$ light curves of δ Cepheid stars (DCEPs) in the Large Magellanic Cloud (LMC). Our sample consists of 4408 objects accounting for 97 per cent of the combined list of OGLE IV and Gaia DR2 DCEPs. We determined a…
Variable star classification across the Galactic bulge and disc with the VISTA Variables in the Vía Láctea survey
Smith, Leigh C.; Belokurov, Vasily; Minniti, Dante +3 more
We present VIVACE, the VIrac VAriable Classification Ensemble, a catalogue of variable stars extracted from an automated classification pipeline for the Vista Variables in the Vía Láctea (VVV) infrared survey of the Galactic bar/bulge and southern disc. Our procedure utilizes a two-stage hierarchical classifier to first isolate likely variable sou…
SN 2009ip after a decade: the luminous blue variable progenitor is now gone
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Smith, Nathan +3 more
We present new Hubble Space Telescope (HST) imaging photometry for the site of the Type IIn supernova (SN) 2009ip taken almost a decade after explosion. The optical source has continued to fade steadily since the SN-like event in 2012. In the F606W filter, which was also used to detect its luminous blue variable (LBV) progenitor 13 yr before the S…
Radio fossils, relics, and haloes in Abell 3266: cluster archaeology with ASKAP-EMU and the ATCA
Diego, J. M.; Tasse, C.; Eckert, D. +21 more
Abell 3266 is a massive and complex merging galaxy cluster that exhibits significant substructure. We present new, highly sensitive radio continuum observations of Abell 3266 performed with the Australian Square Kilometre Array Pathfinder (0.8-1.1 GHz) and the Australia Telescope Compact Array (1.1-3.1 GHz). These deep observations provide new ins…
New low mass ratio contact binaries in the Catalina Sky Survey
Ferreira Lopes, C. E.; Drake, Andrew J.; Catelan, Márcio +3 more
We present the identification and photometric analysis of 30 new low mass ratio (LMR) totally eclipsing contact binaries found in Catalina Sky Survey data. The LMR candidates are identified using Fourier coefficients and visual inspection. We perform a detailed scan in the parameter plane of mass ratio (q) versus inclination (i) using PHOEBE -0.31…
Six new compact triply eclipsing triples found with TESS
Mitnyan, T.; Pál, A.; Vanderburg, A. +21 more
In this work, we report the discovery and analysis of six new compact triply eclipsing triple star systems found with the TESS mission: TICs 37743815, 42565581, 54060695, 178010808, 242132789, and 456194776. All of these exhibit distinct third-body eclipses where the inner eclipsing binary (EB) occults the third ('tertiary') star, or vice versa. W…
Investigating the architecture and internal structure of the TOI-561 system planets with CHEOPS, HARPS-N, and TESS
Guterman, P.; Alonso, R.; Deleuil, M. +115 more
We present a precise characterization of the TOI-561 planetary system obtained by combining previously published data with TESS and CHEOPS photometry, and a new set of 62 HARPS-N radial velocities (RVs). Our joint analysis confirms the presence of four transiting planets, namely TOI-561 b (P = 0.45 d, R = 1.42 R⊕, M = 2.0 M⊕)…
PHANGS-HST: new methods for star cluster identification in nearby galaxies
White, Richard L.; Kruijssen, J. M. Diederik; Rosolowsky, Erik +14 more
We present an innovative and widely applicable approach for the detection and classification of stellar clusters, developed for the PHANGS-HST Treasury Program, an NUV-to-I band imaging campaign of 38 spiral galaxies. Our pipeline first generates a unified master source list for stars and candidate clusters, to enable a self-consistent inventory o…
Intermediate- and high-velocity clouds in the Milky Way - I. Covering factors and vertical heights
Lehner, Nicolas; Howk, J. Christopher; Marasco, Antonino +1 more
Intermediate- and high-velocity clouds (IVCs, HVCs) are a potential source of fuel for star formation in the Milky Way (MW), but their origins and fates depend sensitively on their distances. We search for IVCs and HVCs in HST high-resolution ultraviolet spectra of 55 halo stars at vertical heights $|z|\gtrsim \,1$ kpc. We show that IVCs (40 ≤ |$v…