Search Publications

Mapping luminous hot stars in the Galaxy
DOI: 10.1051/0004-6361/202039726 Bibcode: 2021A&A...650A.112Z

Rix, H. -W.; Drimmel, R.; Poggio, E. +4 more

Luminous hot stars (MKs ≲ 0 mag and Teff ≳ 8000 K) dominate the stellar energy input to the interstellar medium throughout cosmological time, are used as laboratories to test theories of stellar evolution and multiplicity, and serve as luminous tracers of star formation in the Milky Way and other galaxies. Massive …

2021 Astronomy and Astrophysics
Gaia 56
Visible-light Phase Curves from the Second Year of the TESS Primary Mission
DOI: 10.3847/1538-3881/ac0c7d Bibcode: 2021AJ....162..127W

Kane, Stephen R.; Fetherolf, Tara; Vanderspek, Roland +10 more

We carried out a systematic study of full-orbit phase curves for known transiting systems in the northern ecliptic sky that were observed during Year 2 of the TESS primary mission. We applied the same methodology for target selection, data processing, and light-curve fitting as we did in our Year 1 study. Out of the 15 transiting systems selected …

2021 The Astronomical Journal
eHST 56
The first widespread solar energetic particle event observed by Solar Orbiter on 2020 November 29
DOI: 10.1051/0004-6361/202140937 Bibcode: 2021A&A...656A..20K

Kulkarni, S. R.; Lario, D.; Laitinen, T. +66 more

Context. On 2020 November 29, the first widespread solar energetic particle (SEP) event of solar cycle 25 was observed at four widely separated locations in the inner (≲1 AU) heliosphere. Relativistic electrons as well as protons with energies > 50 MeV were observed by Solar Orbiter (SolO), Parker Solar Probe, the Solar Terrestrial Relations Ob…

2021 Astronomy and Astrophysics
SOHO SolarOrbiter 56
Precise Dynamical Masses and Orbital Fits for β Pic b and β Pic c
DOI: 10.3847/1538-3881/abdc2e Bibcode: 2021AJ....161..179B

Dupuy, Trent J.; Brandt, Timothy D.; Li, Yiting +2 more

We present a comprehensive orbital analysis to the exoplanets β Pictoris b and c that resolves previously reported tensions between the dynamical and evolutionary mass constraints on β Pic b. We use the Markov Chain Monte Carlo orbit code orvara to fit 15 years of radial velocities and relative astrometry (including recent GRAVITY measurements), a…

2021 The Astronomical Journal
Gaia Hipparcos 56
UV Spectral Slopes at z = 6-9 in the Hubble Frontier Fields: Lack of Evidence for Unusual or Population III Stellar Populations
DOI: 10.3847/1538-4357/abdd3f Bibcode: 2021ApJ...909..144B

Conselice, Christopher J.; Bhatawdekar, Rachana

We present new measurements of the UV spectral slope β for galaxies at z = 6-9 in the Frontier Field cluster MACS J0416.1-2403 and its parallel field to an unprecedented level of low stellar mass. We fit synthetic stellar population models to the observed spectral energy distribution and calculate β by fitting a power law to the best-fit spectrum.…

2021 The Astrophysical Journal
eHST 56
Large metallicity variations in the Galactic interstellar medium
DOI: 10.1038/s41586-021-03780-0 Bibcode: 2021Natur.597..206D

Jenkins, Edward B.; Petitjean, Patrick; Fox, Andrew J. +5 more

The interstellar medium (ISM) comprises gases at different temperatures and densities, including ionized, atomic and molecular species, and dust particles1. The neutral ISM is dominated by neutral hydrogen2 and has ionization fractions of up to eight per cent3. The concentration of chemical elements heavier than he…

2021 Nature
Gaia eHST 56
PENELLOPE: The ESO data legacy program to complement the Hubble UV Legacy Library of Young Stars (ULLYSES). I. Survey presentation and accretion properties of Orion OB1 and σ-Orionis
DOI: 10.1051/0004-6361/202140639 Bibcode: 2021A&A...650A.196M

Lodato, G.; France, K.; Mendigutía, I. +69 more

The evolution of young stars and disks is driven by the interplay of several processes, notably the accretion and ejection of material. These processes, critical to correctly describe the conditions of planet formation, are best probed spectroscopically. Between 2020 and 2022, about 500orbits of the Hubble Space Telescope (HST) are being devoted i…

2021 Astronomy and Astrophysics
Gaia eHST 55
Hubble Space Telescope UV and Hα Measurements of the Accretion Excess Emission from the Young Giant Planet PDS 70 b
DOI: 10.3847/1538-3881/abeb7a Bibcode: 2021AJ....161..244Z

Fang, Min; Herczeg, Gregory J.; Schneider, Glenn +6 more

Recent discoveries of young exoplanets within their natal disks offer exciting opportunities to study ongoing planet formation. In particular, a planet's mass accretion rate can be constrained by observing the accretion-induced excess emission. So far, planetary accretion is only probed by the Hα line, which is then converted to a total accretion …

2021 The Astronomical Journal
Gaia eHST 55
VINTERGATAN III: how to reset the metallicity of the Milky Way
DOI: 10.1093/mnras/stab543 Bibcode: 2021MNRAS.503.5868R

Feuillet, Diane K.; Ryde, Nils; Bensby, Thomas +5 more

Using the cosmological zoom simulation VINTERGATAN, we present a new scenario for the onset of star formation at the metal-poor end of the low-[α/Fe] sequence in a Milky Way-like galaxy. In this scenario, the galaxy is fuelled by two distinct gas flows. One is enriched by outflows from massive galaxies, but not the other. While the former feeds th…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 55
A Local Baseline of the Black Hole Mass Scaling Relations for Active Galaxies. IV. Correlations Between MBH and Host Galaxy σ, Stellar Mass, and Luminosity
DOI: 10.3847/1538-4357/ac151a Bibcode: 2021ApJ...921...36B

Treu, Tommaso; Auger, Matthew W.; Birrer, Simon +6 more

The tight correlations between the mass of supermassive black holes (MBH) and their host-galaxy properties have been of great interest to the astrophysical community, but a clear understanding of their origin and fundamental drivers still eludes us. The local relations for active galaxies are interesting in their own right and form the …

2021 The Astrophysical Journal
eHST 55