Search Publications

Imaging [CI] around HD 131835: reinterpreting young debris discs with protoplanetary disc levels of CO gas as shielded secondary discs
DOI: 10.1093/mnras/sty2923 Bibcode: 2019MNRAS.489.3670K

Kral, Quentin; Wyatt, Mark C.; Marino, Sebastian +2 more

Despite being >10 Myr, there are ∼10 debris discs with as much CO gas as in protoplanetary discs. Such discs have been assumed to be 'hybrid', i.e. with secondary dust but primordial gas. Here, we show that both the dust and gas in such systems could instead be secondary, with the high CO content caused by accumulation of neutral carbon (C

2019 Monthly Notices of the Royal Astronomical Society
Gaia 71
In the Galactic Disk, Stellar [Fe/H] and Age Predict Orbits and Precise [X/Fe]
DOI: 10.3847/1538-4357/ab3e3c Bibcode: 2019ApJ...883..177N

Rix, H. -W.; Hawkins, K.; Bird, J. C. +4 more

We explore the structure of the element abundance-age-orbit distribution of the stars in the Milky Way’s low-α disk, by (re-)deriving precise [Fe/H], [X/Fe], and ages, along with orbits, for red clump stars from the APOGEE survey. There has been a long-standing theoretical expectation and observational evidence that metallicity ([Fe/H]) and age ar…

2019 The Astrophysical Journal
Gaia 71
Cosmological constraints on post-Newtonian parameters in effectively massless scalar-tensor theories of gravity
DOI: 10.1103/PhysRevD.100.103524 Bibcode: 2019PhRvD.100j3524R

Rossi, Massimo; Ballardini, Mario; Braglia, Matteo +4 more

We study the cosmological constraints on the variation of Newton's constant and on post-Newtonian parameters for simple models of the scalar-tensor theory of gravity beyond the extended Jordan-Brans-Dicke theory. We restrict ourselves to an effectively massless scalar field with a potential V ∝F2, where F (σ )=Npl2

2019 Physical Review D
eHST 71
Near-infrared Spectroscopy of Galaxies During Reionization: Measuring C III] in a Galaxy at z = 7.5
DOI: 10.3847/1538-4357/ab22a2 Bibcode: 2019ApJ...879...70H

Papovich, Casey; Finkelstein, Steven L.; Dickinson, Mark +9 more

We present Keck/MOSFIRE H-band spectroscopy targeting C III] λ1907, 1909 in a z = 7.5056 galaxy previously identified via Lyα emission. We detect strong line emission at 1.621+/- 0.002 µ {{m}} with a line flux of (2.63 ± 0.52) × 10-18 erg s-1 cm-2. We tentatively identify this line as [C III] λ1907, but we ar…

2019 The Astrophysical Journal
eHST 71
Molecular and Ionized Gas Phases of an AGN-driven Outflow in a Typical Massive Galaxy at z ≈ 2
DOI: 10.3847/1538-4357/aaf6a7 Bibcode: 2019ApJ...871...37H

Lutz, D.; Wuyts, S.; Genzel, R. +22 more

Nuclear outflows driven by accreting massive black holes are one of the main feedback mechanisms invoked at high-z to reproduce the distinct separation between star-forming disk galaxies and quiescent spheroidal systems. Yet our knowledge of feedback at high-z remains limited by the lack of observations of the multiple gas phases in galaxy outflow…

2019 The Astrophysical Journal
eHST 71
First Resolution of Microlensed Images
DOI: 10.3847/1538-4357/aaeffb Bibcode: 2019ApJ...871...70D

Kochanek, C. S.; Gould, Andrew; Stanek, K. Z. +12 more

We employ Very Large Telescope Interferometer GRAVITY to resolve, for the first time, the two images generated by a gravitational microlens. The measurements of the image separation {{Δ }}{θ }-,+=3.78+/- 0.05 mas, and hence the Einstein radius θ E = 1.87 ± 0.03 mas, are precise. This demonstrates the robustness of the method,…

2019 The Astrophysical Journal
Gaia 71
Multiple water band detections in the CARMENES near-infrared transmission spectrum of HD 189733 b
DOI: 10.1051/0004-6361/201834339 Bibcode: 2019A&A...621A..74A

Schmitt, J. H. M. M.; Alonso-Floriano, F. J.; Sánchez-López, A. +27 more


Aims: We explore the capabilities of CARMENES for characterising hot-Jupiter atmospheres by targeting multiple water bands, in particular, those at 1.15 and 1.4 µm. Hubble Space Telescope observations suggest that this wavelength region is relevant for distinguishing between hazy and/or cloudy and clear atmospheres.
Methods: We obs…

2019 Astronomy and Astrophysics
Gaia eHST 70
HD 202772A b: A Transiting Hot Jupiter around a Bright, Mildly Evolved Star in a Visual Binary Discovered by TESS
DOI: 10.3847/1538-3881/aaf1b7 Bibcode: 2019AJ....157...51W

Trifonov, Trifon; Reffert, Sabine; Kürster, Martin +58 more

We report the first confirmation of a hot Jupiter discovered by the Transiting Exoplanet Survey Satellite (TESS) mission: HD 202772A b. The transit signal was detected in the data from TESS Sector 1, and was confirmed to be of planetary origin through radial velocity (RV) measurements. HD 202772A b is orbiting a mildly evolved star with a period o…

2019 The Astronomical Journal
Gaia 70
A 10,000-solar-mass black hole in the nucleus of a bulgeless dwarf galaxy
DOI: 10.1038/s41550-019-0790-3 Bibcode: 2019NatAs...3..755W

Gallo, Elena; Woo, Jong-Hak; Hodges-Kluck, Edmund +5 more

The motions of gas and stars in the nuclei of nearby galaxies have demonstrated that massive black holes are common1 and that their masses correlate with the stellar velocity dispersion σ of the bulge2-4. This correlation suggests that massive black holes and galaxies influence each other's growth5-7. D…

2019 Nature Astronomy
eHST 70
Collisionless Magnetic Reconnection and Waves: Progress Review
DOI: 10.3389/fspas.2019.00070 Bibcode: 2019FrASS...6...70K

Khotyaintsev, Yuri V.; Graham, Daniel B.; Vaivads, Andris +1 more

Magnetic reconnection is a fundamental process whereby microscopic plasma processes cause macroscopic changes in magnetic field topology, leading to explosive energy release. Waves and turbulence generated during the reconnection process can produce particle diffusion, and anomalous resistivity, as well as heat the plasma and accelerate plasma par…

2019 Frontiers in Astronomy and Space Sciences
Cluster 70