Search Publications

Description of turbulent dynamics in the interstellar medium: multifractal-microcanonical analysis. I. Application to Herschel observations of the Musca filament
DOI: 10.1051/0004-6361/202039874 Bibcode: 2021A&A...649A..33Y

Schneider, N.; Bontemps, S.; Elia, D. +10 more

Observations of the interstellar medium (ISM) show a complex density and velocity structure, which is in part attributed to turbulence. Consequently, the multifractal formalism should be applied to observation maps of the ISM in order to characterize its turbulent and multiplicative cascade properties. However, the multifractal formalism, even in …

2021 Astronomy and Astrophysics
Gaia Herschel 13
Determination of Planetary Nebulae angular diameters from radio continuum spectral energy distribution modelling
DOI: 10.1093/mnras/stab687 Bibcode: 2021MNRAS.503.2887B

Filipović, M. D.; Galvin, T. J.; Parker, Q. A. +2 more

Powerful new, high-resolution, high-sensitivity, multifrequency, wide-field radio surveys such as the Australian Square Kilometre Array Pathfinder (ASKAP) Evolutionary Map of the Universe are emerging. They will offer fresh opportunities to undertake new determinations of useful parameters for various kinds of extended astrophysical phenomena. Her…

2021 Monthly Notices of the Royal Astronomical Society
eHST 13
The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. II. The Star-formation History of Andromeda I Derived from Long-period Variables
DOI: 10.3847/1538-4357/ac2d96 Bibcode: 2021ApJ...923..164S

Javadi, Atefeh; Saremi, Elham; van Loon, Jacco Th. +4 more

An optical monitoring survey in the nearby dwarf galaxies was carried out with the 2.5 m Isaac Newton Telescope. 55 dwarf galaxies and four isolated globular clusters in the Local Group were observed with the Wide Field Camera. The main aims of this survey are to identify the most evolved asymptotic giant branch stars and red supergiants at the en…

2021 The Astrophysical Journal
Gaia 13
Spatially Resolved BPT Mapping of Nearby Seyfert 2 Galaxies
DOI: 10.3847/1538-4357/abcfc1 Bibcode: 2021ApJ...908..155M

Elvis, Martin; Storchi-Bergmann, Thaisa; Fabbiano, G. +5 more

We present spatially resolved Baldwin-Phillips-Terlevich (BPT) mapping of the extended narrow-line regions (ENLRs) of seven nearby Seyfert 2 galaxies, using Hubble Space Telescope narrowband filter imaging. We construct the BPT diagrams using ≤0"1 resolution emission line images of [O III] λ5007, Hα, [S II] λλ6717, 6731, and Hβ. By mapping these d…

2021 The Astrophysical Journal
eHST 13
Predicting the Spectrum of UGC 2885, Rubin's Galaxy with Machine Learning
DOI: 10.3847/1538-4357/abffcc Bibcode: 2021ApJ...914..142H

Holwerda, Benne W.; Bailin, Jeremy; Böker, Torsten +10 more

Wu & Peek predict SDSS-quality spectra based on Pan-STARRS broadband grizy images using machine learning (ML). In this article, we test their prediction for a unique object, UGC 2885 ("Rubin's galaxy"), the largest and most massive, isolated disk galaxy in the local universe (D < 100 Mpc). After obtaining the ML predicted spectrum, we compa…

2021 The Astrophysical Journal
eHST 13
Mixed Modes and Asteroseismic Surface Effects. II. Subgiant Systematics
DOI: 10.3847/1538-4357/ac1e8b Bibcode: 2021ApJ...922...18O

Bieryla, Allyson; Latham, David W.; Basu, Sarbani +3 more

Models of solar-like oscillators yield acoustic modes at different frequencies than would be seen in actual stars possessing identical interior structure, due to modeling error near the surface. This asteroseismic "surface term" must be corrected when mode frequencies are used to infer stellar structure. Subgiants exhibit oscillations of mixed aco…

2021 The Astrophysical Journal
Gaia 13
Four Jovian planets around low-luminosity giant stars observed by the EXPRESS and PPPS
DOI: 10.1051/0004-6361/202038555 Bibcode: 2021A&A...646A.131J

Jones, M. I.; Trifonov, T.; Soto, M. G. +14 more

We report the discovery of planetary companions orbiting four low-luminosity giant stars with M between 1.04 and 1.39 M. All four host stars have been independently observed by the EXoPlanets aRound Evolved StarS (EXPRESS) program and the Pan-Pacific Planet Search (PPPS). The companion signals were revealed by multi-epoch p…

2021 Astronomy and Astrophysics
Gaia 13
The impact of massive stars and black holes on the fate of open star clusters and their tidal streams
DOI: 10.1051/0004-6361/202141838 Bibcode: 2021A&A...655A..71W

Wang, Long; Jerabkova, Tereza

Context. We use present-day observations to investigate how the content of massive OB stars affects the long-term evolution of young open clusters and their tidal streams, and how such an effect influences the constraint of initial conditions.
Aims: OB stars are typically found in binaries. They have a strong wind mass loss during the first f…

2021 Astronomy and Astrophysics
Gaia 13
The Solar Neighborhood. XLVII. Comparing M-dwarf Models with Hubble Space Telescope Dynamical Masses and Spectroscopy
DOI: 10.3847/1538-3881/abd2c2 Bibcode: 2021AJ....161..172D

Henry, Todd J.; Jao, Wei-Chun; Dieterich, Serge B. +1 more

We use HST/STIS optical spectroscopy of 10 M dwarfs in five closely separated binary systems to test models of M-dwarf structure and evolution. Individual dynamical masses ranging from 0.083 to 0.405 M for all stars are known from previous work. We first derive temperature, radius, luminosity, surface gravity, and metallicity by fittin…

2021 The Astronomical Journal
Gaia eHST 13
Lithium in red giants: the roles of the He-core flash and the luminosity bump
DOI: 10.1093/mnras/stab2022 Bibcode: 2021MNRAS.507..205D

Lambert, David L.; Deepak

Lithium abundances for red giants in the GALAH DR3 survey are studied. The rare examples of Li-enriched stars with abundances A(Li) ≥1.5 are confirmed to be He-core burning stars belonging to or evolved from the red clump with similar masses and metallicity: M ≃ 1.1 ± 0.2 M and [Fe/H] ≃ -0.3 ± 0.3. Li enrichment over the Li abundance p…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 13