Search Publications

Characterizing K2 Candidate Planetary Systems Orbiting Low-mass Stars. IV. Updated Properties for 86 Cool Dwarfs Observed during Campaigns 1-17
DOI: 10.3847/1538-3881/ab2895 Bibcode: 2019AJ....158...87D

Vanderburg, Andrew; Schlieder, Joshua E.; Crepp, Justin R. +15 more

We present revised stellar properties for 172 K2 target stars that were identified as possible hosts of transiting planets during Campaigns 1-17. Using medium-resolution near-infrared spectra acquired with the NASA Infrared Telescope Facility/SpeX and Palomar/TripleSpec, we found that 86 of our targets were bona fide cool dwarfs, 74 were hotter dw…

2019 The Astronomical Journal
Gaia 33
Latitudinal variation in the abundance of methane (CH4) above the clouds in Neptune's atmosphere from VLT/MUSE Narrow Field Mode Observations
DOI: 10.1016/j.icarus.2019.05.011 Bibcode: 2019Icar..331...69I

Bacon, Roland; Fletcher, Leigh N.; Irwin, Patrick G. J. +5 more

Observations of Neptune, made in 2018 using the new Narrow Field Adaptive Optics mode of the Multi Unit Spectroscopic Explorer (MUSE) instrument at the Very Large Telescope (VLT) from 0.48 to 0.93 µm, are analysed here to determine the latitudinal and vertical distribution of cloud opacity and methane abundance in Neptune's observable tropos…

2019 Icarus
eHST 33
Spatial distribution of stellar mass and star formation activity at 0.2 < z < 1.2 across and along the main sequence
DOI: 10.1051/0004-6361/201834559 Bibcode: 2019A&A...626A..61M

Popesso, P.; Oesch, P. A.; Illingworth, G. D. +5 more

High-resolution multi-wavelength photometry is crucial to explore the spatial distribution of star formation in galaxies and understand how these evolve. To this aim, in this paper we exploit the deep, multi-wavelength Hubble Space Telescope (HST) data available in the central parts of the Great Observatories Origins Deep Survey (GOODS) fields and…

2019 Astronomy and Astrophysics
eHST 33
Extreme starlight polarization in a region with highly polarized dust emission
DOI: 10.1051/0004-6361/201935266 Bibcode: 2019A&A...624L...8P

Tassis, Konstantinos; Hensley, Brandon S.; Blinov, Dmitry +2 more

Context. Galactic dust emission is polarized at unexpectedly high levels, as revealed by Planck.
Aims: The origin of the observed ≃20% polarization fractions can be identified by characterizing the properties of optical starlight polarization in a region with maximally polarized dust emission.
Methods: We measure the R-band linear polari…

2019 Astronomy and Astrophysics
Gaia 33
Filling in the Quasar Redshift Gap at z ∼ 5.5. II. A Complete Survey of Luminous Quasars in the Post-reionization Universe
DOI: 10.3847/1538-4357/aaf858 Bibcode: 2019ApJ...871..199Y

Fan, Xiaohui; Jiang, Linhua; McGreer, Ian D. +10 more

We present the final results from our survey of luminous z ∼ 5.5 quasars. This is the first systematic quasar survey focusing on quasars at z ∼ 5.5, during the post-reionization epoch. It has been challenging to select quasars at 5.3 < z < 5.7 using conventional color selections, due to their similar optical colors to those of late-type star…

2019 The Astrophysical Journal
eHST 32
The solar wind in time - II. 3D stellar wind structure and radio emission
DOI: 10.1093/mnras/sty3132 Bibcode: 2019MNRAS.483..873O

Petit, P.; Vidotto, A. A.; Jeffers, S. V. +6 more

In this work, we simulate the evolution of the solar wind along its main-sequence lifetime and compute its thermal radio emission. To study the evolution of the solar wind, we use a sample of solar mass stars at different ages. All these stars have observationally reconstructed magnetic maps, which are incorporated in our 3D magnetohydrodynamic si…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 32
Mass discrepancy analysis for a select sample of Type II-Plateau supernovae
DOI: 10.1051/0004-6361/201834818 Bibcode: 2019A&A...629A.124M

Bersten, Melina C.; Martinez, Laureano

The detailed study of supernovae (SNe) and their progenitors allows a better understanding of the evolution of massive stars and how these end their lives. Despite its importance, the range of physical parameters for the most common type of explosion, the type II supernovae (SNe II), is still unknown. In particular, previous studies of type II-Pla…

2019 Astronomy and Astrophysics
eHST 32
Spitzer Microlensing Parallax for OGLE-2017-BLG-0896 Reveals a Counter-rotating Low-mass Brown Dwarf
DOI: 10.3847/1538-3881/aafe12 Bibcode: 2019AJ....157..106S

Helling, Christiane; Maoz, Dan; Tan, Thiam-Guan +69 more

The kinematics of isolated brown dwarfs in the Galaxy, beyond the solar neighborhood, is virtually unknown. Microlensing has the potential to probe this hidden population, as it can measure both the mass and five of the six phase-space coordinates (all except the radial velocity) even of a dark isolated lens. However, the measurements of both the …

2019 The Astronomical Journal
Gaia 32
Spectroscopy and Differential Emission Measure Diagnostics of a Coronal Dimming Associated with a Fast Halo CME
DOI: 10.3847/1538-4357/ab2712 Bibcode: 2019ApJ...879...85V

Veronig, Astrid M.; Temmer, Manuela; Dissauer, Karin +2 more

We study the coronal dimming caused by the fast halo CME (deprojected speed v = 1250 km s-1) associated with the C3.7 two-ribbon flare on 2012 September 27, using Hinode/EIS spectroscopy and Solar Dynamics Observatory (SDO)/AIA Differential Emission Measure (DEM) analysis. The event reveals bipolar core dimmings encompassed by hook-shap…

2019 The Astrophysical Journal
Hinode SOHO 32
Revealing the Complicated Story of the Cetus Stream with StarGO
DOI: 10.3847/1538-4357/ab2e09 Bibcode: 2019ApJ...881..164Y

Chang, Jiang; Smith, M. C.; Liu, Chao +5 more

We use a novel cluster identification tool, STARGO, to explore the metal-poor ([Fe/H] < -1.5) outer stellar halo (d > 15 kpc) of the Milky Way using data from Gaia, LAMOST, and SDSS. Our method is built using an unsupervised learning algorithm, a self-organizing map, which trains a 2D neural network to learn the topological structures of a d…

2019 The Astrophysical Journal
Gaia 32