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The Hawaii Infrared Parallax Program. IV. A Comprehensive Parallax Survey of L0-T8 Dwarfs with UKIRT
DOI: 10.3847/1538-3881/ab84f4 Bibcode: 2020AJ....159..257B

Magnier, Eugene A.; Dupuy, Trent J.; Liu, Michael C. +1 more

We present parallaxes, proper motions, and J-band photometry for 348 L and T dwarfs measured using the wide-field near-infrared camera WFCAM on the United Kingdom Infrared Telescope. This is the largest single batch of infrared parallaxes for brown dwarfs to date. Our parallaxes have a median uncertainty of 3.5 mas, similar to most previous ground…

2020 The Astronomical Journal
Gaia 63
A Sub-Neptune-sized Planet Transiting the M2.5 Dwarf G 9-40: Validation with the Habitable-zone Planet Finder
DOI: 10.3847/1538-3881/ab5f15 Bibcode: 2020AJ....159..100S

Endl, Michael; Mahadevan, Suvrath; Terrien, Ryan +32 more

We validate the discovery of a 2-Earth-radii sub-Neptune-sized planet around the nearby high-proper-motion M2.5 dwarf G 9-40 (EPIC 212048748), using high-precision, near-infrared (NIR) radial velocity (RV) observations with the Habitable-zone Planet Finder (HPF), precision diffuser-assisted ground-based photometry with a custom narrowband photomet…

2020 The Astronomical Journal
Gaia 63
AGN-driven outflows and the AGN feedback efficiency in young radio galaxies
DOI: 10.1051/0004-6361/202039077 Bibcode: 2020A&A...644A..54S

Morganti, R.; Holt, J.; Tadhunter, C. +2 more

Active galactic nuclei (AGN) feedback operated by the expansion of radio jets can play a crucial role in driving gaseous outflows on galaxy scales. Galaxies hosting young radio AGN, whose jets are in the first phases of expansion through the surrounding interstellar medium (ISM), are the ideal targets to probe the energetic significance of this me…

2020 Astronomy and Astrophysics
eHST 63
Is there Na I in the atmosphere of HD 209458b?. Effect of the centre-to-limb variation and Rossiter-McLaughlin effect in transmission spectroscopy studies
DOI: 10.1051/0004-6361/201937221 Bibcode: 2020A&A...635A.206C

Alonso-Floriano, F. J.; Sánchez-López, A.; López-Puertas, M. +22 more

HD 209458b was the first transiting planet discovered, and the first for which an atmosphere, in particular Na I, was detected. With time, it has become one of the most frequently studied planets, with a large diversity of atmospheric studies using low- and high-resolution spectroscopy. Here, we present transit spectroscopy observations of HD 2094…

2020 Astronomy and Astrophysics
eHST 62
On the Accuracy of Time-delay Cosmography in the Frontier Fields Cluster MACS J1149.5+2223 with Supernova Refsdal
DOI: 10.3847/1538-4357/ab9a4c Bibcode: 2020ApJ...898...87G

Grillo, C.; Rosati, P.; Mercurio, A. +3 more

We study possible systematic effects on the values of the cosmological parameters measured through strong lensing analyses of the Hubble Frontier Field galaxy cluster MACS J1149.5+2223. We use the observed positions of a large set of spectroscopically selected multiple images, including those of supernova "Refsdal" with their published time delays…

2020 The Astrophysical Journal
eHST 62
An ALMA Survey of H2CO in Protoplanetary Disks
DOI: 10.3847/1538-4357/ab64d9 Bibcode: 2020ApJ...890..142P

Wilner, David J.; Cleeves, L. Ilsedore; Andrews, Sean M. +13 more

H2CO is one of the most abundant organic molecules in protoplanetary disks and can serve as a precursor to more complex organic chemistry. We present an Atacama Large Millimeter/submillimeter Array survey of H2CO toward 15 disks covering a range of stellar spectral types, stellar ages, and dust continuum morphologies. H2…

2020 The Astrophysical Journal
Gaia 62
Possible evidence of ongoing planet formation in AB Aurigae. A showcase of the SPHERE/ALMA synergy
DOI: 10.1051/0004-6361/202038008 Bibcode: 2020A&A...637L...5B

Pantin, E.; Milli, J.; Boccaletti, A. +8 more

Context. Planet formation is expected to take place in the first million years of a planetary system through various processes, which remain to be tested through observations.
Aims: With the recent discovery, using ALMA, of two gaseous spiral arms inside the ∼120 au cavity and connected to dusty spirals, the famous protoplanetary disk around …

2020 Astronomy and Astrophysics
Gaia 62
Catalogue of new Herbig Ae/Be and classical Be stars. A machine learning approach to Gaia DR2
DOI: 10.1051/0004-6361/202037731 Bibcode: 2020A&A...638A..21V

Mendigutía, I.; Mowlavi, N.; Baines, D. +4 more

Context. The intermediate-mass pre-main sequence Herbig Ae/Be stars are key to understanding the differences in formation mechanisms between low- and high-mass stars. The study of the general properties of these objects is hampered by the lack of a well-defined, homogeneous sample, and because few and mostly serendipitously discovered sources are …

2020 Astronomy and Astrophysics
Gaia 62
A Dynamical Mass of 70 ± 5 MJup for Gliese 229B, the First T Dwarf
DOI: 10.3847/1538-3881/abb45e Bibcode: 2020AJ....160..196B

Dupuy, Trent J.; Bardalez Gagliuffi, Daniella C.; Bowler, Brendan P. +4 more

We combine Keck/HIRES radial velocities, imaging with HiCIAO/Subaru and the Hubble Space Telescope, and absolute astrometry from Hipparcos and Gaia to measure a dynamical mass of 70 ± 5 ${M}_{\mathrm{Jup}}$ for the brown dwarf companion to Gl 229. Gl 229B was the first imaged brown dwarf to show clear signs of methane in its atmosphere. Cooling mo…

2020 The Astronomical Journal
Gaia Hipparcos eHST 62
The NASA Ames PAH IR Spectroscopic Database: The Laboratory Spectra
DOI: 10.3847/1538-4365/abc2c8 Bibcode: 2020ApJS..251...22M

Boersma, C.; Allamandola, L. J.; Peeters, E. +7 more

The astronomical emission features, formerly known as the unidentified infrared bands, are now commonly ascribed to polycyclic aromatic hydrocarbons (PAHs). The laboratory experiments and computational modeling performed at NASA Ames Research Center generated a collection of PAH IR spectra that have been used to test and refine the PAH model. Thes…

2020 The Astrophysical Journal Supplement Series
ISO 62