Search Publications

SMASHing the low surface brightness SMC
DOI: 10.1093/mnras/staa2451 Bibcode: 2020MNRAS.498.1034M

Bell, Eric F.; Monachesi, Antonela; Choi, Yumi +22 more

The periphery of the Small Magellanic Cloud (SMC) can unlock important information regarding galaxy formation and evolution in interacting systems. Here, we present a detailed study of the extended stellar structure of the SMC using deep colour-magnitude diagrams, obtained as part of the Survey of the MAgellanic Stellar History (SMASH). Special ca…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 28
Onset of Turbulent Fast Magnetic Reconnection Observed in the Solar Atmosphere
DOI: 10.3847/2041-8213/ab6f0a Bibcode: 2020ApJ...890L...2C

Chitta, L. P.; Lazarian, A.

Fast magnetic reconnection powers explosive events throughout the universe, from gamma-ray bursts to solar flares. Despite its importance, the onset of astrophysical fast reconnection is the subject of intense debate and remains an open question in plasma physics. Here we report high-cadence observations of two reconnection-driven solar microflare…

2020 The Astrophysical Journal
IRIS 28
The solar wind from a stellar perspective. How do low-resolution data impact the determination of wind properties?
DOI: 10.1051/0004-6361/201937107 Bibcode: 2020A&A...635A.178B

Güdel, M.; Airapetian, V. S.; Jin, M. +5 more

Context. Due to the effects that they can have on the atmospheres of exoplanets, stellar winds have recently received significant attention in the literature. Alfvén-wave-driven 3D magnetohydrodynamic models, which are increasingly used to predict stellar wind properties, contain unconstrained parameters and rely on low-resolution stellar magnetog…

2020 Astronomy and Astrophysics
Ulysses eHST 28
Globular Cluster Systems and Galaxy Formation
DOI: 10.1007/978-3-030-38509-5_9 Bibcode: 2020rfma.book..245B

Beasley, Michael A.

Globular clusters (GCs) are compact, gravitationally bound systems of up to ∼¼1 million stars. The GCs in the Milky Way contain some of the oldest stars known, and provide important clues to the early formation and continuing evolution of our Galaxy. More generally, GCs are associated with galaxies of all types and masses, from low-mass dwarf gala…

2020 Reviews in Frontiers of Modern Astrophysics; From Space Debris to Cosmology
Gaia 28
Time-resolved photometry of the young dipper RX J1604.3-2130A. Unveiling the structure and mass transport through the innermost disk
DOI: 10.1051/0004-6361/201936565 Bibcode: 2020A&A...633A..37S

Bouvier, J.; Manara, C. F.; Pinilla, P. +3 more

Context. RX J1604.3-2130A is a young, dipper-type, variable star in the Upper Scorpius association, suspected to have an inclined inner disk, with respect to its face-on outer disk.
Aims: We aim to study the eclipses to constrain the inner disk properties.
Methods: We used time-resolved photometry from the Rapid Eye Mount telescope and K…

2020 Astronomy and Astrophysics
AKARI Gaia 28
Crystalline silicate absorption at 11.1 µm: ubiquitous and abundant in embedded YSOs and the interstellar medium
DOI: 10.1093/mnras/staa396 Bibcode: 2020MNRAS.493.4463D

Wright, Christopher M.; Fujiyoshi, Takuya; Siebenmorgen, Ralf +5 more

Utilizing several instruments on 4-8 m telescopes, we have observed a large sample of objects in the mid-infrared (8-13 µm). These comprise a few evolved stars, multiple envelopes of embedded young stellar objects (YSOs) or compact H-II regions, and several sightlines through the interstellar medium (ISM). The latter is where dust resides - …

2020 Monthly Notices of the Royal Astronomical Society
ISO 28
The frequency of extreme X-ray variability for radio-quiet quasars
DOI: 10.1093/mnras/staa2661 Bibcode: 2020MNRAS.498.4033T

Brandt, W. N.; Liu, H.; Luo, B. +3 more

We analyse 1598 serendipitous Chandra X-ray observations of 462 radio-quiet quasars to constrain the frequency of extreme amplitude X-ray variability that is intrinsic to the quasar corona and innermost accretion flow. The quasars in this investigation are all spectroscopically confirmed, optically bright (mi ≤ 20.2), and contain no ide…

2020 Monthly Notices of the Royal Astronomical Society
XMM-Newton 28
The Next Generation Virgo Cluster Survey. XXXIV. Ultracompact Dwarf Galaxies in the Virgo Cluster
DOI: 10.3847/1538-4365/abad91 Bibcode: 2020ApJS..250...17L

Zhang, Hongxin; Liu, Chengze; Gwyn, Stephen +26 more

We present a study of ultracompact dwarf (UCD) galaxies in the Virgo cluster based mainly on imaging from the Next Generation Virgo Cluster Survey (NGVS). Using ∼100 deg2 of u*giz imaging, we have identified more than 600 candidate UCDs, from the core of Virgo out to its virial radius. Candidates have been selected through a combination…

2020 The Astrophysical Journal Supplement Series
Gaia eHST 28
A Tidal Disruption Event Candidate Discovered in the Active Galactic Nucleus SDSS J022700.77-042020.6
DOI: 10.3847/1538-4357/ab880f Bibcode: 2020ApJ...894...93L

Lu, Youjun; Liu, Zhu; Yuan, Weimin +4 more

We report the discovery of a tidal disruption event (TDE) candidate occurring in the active galactic nucleus (AGN) SDSS J022700.77-042020.6. A sudden increase in flux from J0227-0420 during the second half of 2009 appears in the long-term optical, UV, and near-IR (NIR) light curves. A plateau phase, following an initial decline, is seen in the nea…

2020 The Astrophysical Journal
XMM-Newton eHST 28
Bar resonances and low angular momentum moving groups in the Galaxy revealed by their stellar ages
DOI: 10.1051/0004-6361/202038740 Bibcode: 2020A&A...643L...3L

Laporte, Chervin F. P.; Famaey, Benoit; Gerhard, Ortwin +3 more

We use the second Gaia data release to dissect the Milky Way disc in phase-space and relative ages. We confirm and report the existence of multiple velocity moving groups at low azimuthal velocities and angular momenta, below Arcturus, regularly separated by ∼18-20 km s-1 in azimuthal velocity. Such features were predicted to exist more…

2020 Astronomy and Astrophysics
Gaia 28