Search Publications

An Inner Disk in the Large Gap of the Transition Disk SR 24S
DOI: 10.3847/1538-4357/ab1cb8 Bibcode: 2019ApJ...878...16P

Benisty, Myriam; Pinilla, Paola; Harsono, Daniel +3 more

We report new Atacama Large Millimeter/submillimeter Array (ALMA) Band 3 observations at 2.75 mm of the transition disk around SR 24S, with an angular resolution of ∼0.″11 × 0.″09 and a peak signal-to-noise ratio of ∼24. We detect an inner disk and a mostly symmetric ring-like structure that peaks at ∼0.″32, which is ∼37 au at a distance of ∼114.4…

2019 The Astrophysical Journal
Gaia 23
Discovery of weak magnetic fields in four DZ white dwarfs in the local 20 pc volume. Implications for the frequency of magnetic fields with cooling age
DOI: 10.1051/0004-6361/201936068 Bibcode: 2019A&A...630A..65B

Bagnulo, S.; Landstreet, J. D.

We report the discovery of weak magnetic fields in three white dwarfs within the local 20 pc volume (WD 0816-310, WD 1009-184, and WD 1532+129), and we confirm the magnetic nature of a fourth star (WD 2138-332) in which we had previously detected a field at a 3σ level. The spectra of all these white dwarfs are characterised by the presence of meta…

2019 Astronomy and Astrophysics
Gaia 23
The Extremely High Dark Matter Halo Concentration of the Relic Compact Elliptical Galaxy Mrk 1216
DOI: 10.3847/1538-4357/ab1008 Bibcode: 2019ApJ...877...91B

Barth, Aaron J.; Buote, David A.

Spatially compact stellar profiles and old stellar populations have established compact elliptical galaxies (CEGs) as local analogs of the high-redshift “red nuggets” thought to represent the progenitors of today’s early-type galaxies (ETGs). To address whether the structure of the dark matter (DM) halo in a CEG also reflects the extremely quiesce…

2019 The Astrophysical Journal
eHST 23
The Structure of the Orion Nebula in the Direction of θ 1 Ori C
DOI: 10.3847/1538-4357/ab2a6e Bibcode: 2019ApJ...881..130A

Abel, N. P.; O'Dell, C. R.; Ferland, G. J.

We have used existing optical emission and absorption lines, [C II] emission lines, and H I absorption lines to create a new model for a central column of material near the Trapezium region of the Orion Nebula. This was necessary because recent high spectral resolution spectra of optical emission lines and imaging spectra in the [C II] 158 µ…

2019 The Astrophysical Journal
eHST 23
A radio halo surrounding the Brightest Cluster Galaxy in RXCJ0232.2-4420: a mini-halo in transition?
DOI: 10.1093/mnrasl/slz061 Bibcode: 2019MNRAS.486L..80K

Kale, Ruta; Parekh, Viral; Shende, Krishna M.

Diffuse radio sources associated with the intra-cluster medium are direct probes of the cosmic ray electrons and magnetic fields. We report the discovery of a diffuse radio source in the galaxy cluster RXCJ0232.2-4420 (SPT-CL J0232-4421, z = 0.2836) using 606 MHz observations with the Giant Metrewave Radio Telescope. The diffuse radio source surro…

2019 Monthly Notices of the Royal Astronomical Society
eHST 23
Does black hole growth depend fundamentally on host-galaxy compactness?
DOI: 10.1093/mnras/stz2623 Bibcode: 2019MNRAS.490.1135N

Alexander, D. M.; Brandt, W. N.; Xue, Y. Q. +5 more

Possible connections between central black hole (BH) growth and host-galaxy compactness have been found observationally, which may provide insight into BH-galaxy coevolution: compact galaxies might have large amounts of gas in their centres due to their high mass-to-size ratios, and simulations predict that high central gas density can boost BH ac…

2019 Monthly Notices of the Royal Astronomical Society
eHST 23
Revisiting the HIP 41378 System with K2 and Spitzer
DOI: 10.3847/1538-3881/ab100c Bibcode: 2019AJ....157..185B

Gorjian, Varoujan; Kane, Stephen R.; Schlieder, Joshua E. +12 more

We present new observations of the multiplanet system HIP 41378, a bright star (V = 8.9, K s = 7.7) with five known transiting planets. Previous K2 observations showed multiple transits of two Neptune-sized bodies and single transits of three larger planets (R P = 0.33R J , 0.47R J , 0.88R J …

2019 The Astronomical Journal
Gaia 23
Mass variance from archival X-ray properties of Dark Energy Survey Year-1 galaxy clusters
DOI: 10.1093/mnras/stz2689 Bibcode: 2019MNRAS.490.3341F

Smith, M.; Annis, J.; Brooks, D. +77 more

Using archival X-ray observations and a lognormal population model, we estimate constraints on the intrinsic scatter in halo mass at fixed optical richness for a galaxy cluster sample identified in Dark Energy Survey Year-One (DES-Y1) data with the redMaPPer algorithm. We examine the scaling behaviour of X-ray temperatures, TX, with opt…

2019 Monthly Notices of the Royal Astronomical Society
XMM-Newton 23
Efficient Calculation of Non-local Thermodynamic Equilibrium Effects in Multithreaded Hydrodynamic Simulations of Solar Flares
DOI: 10.3847/1538-4357/aaf580 Bibcode: 2019ApJ...871...18R

Warren, Harry P.; Crump, Nicholas A.; Bradshaw, Stephen J. +1 more

Understanding the dynamics of the chromosphere is crucial to understanding energy transport across the solar atmosphere. The chromosphere is optically thick at many wavelengths and described by non-local thermodynamic equilibrium (NLTE), making it difficult to interpret observations. Furthermore, there is considerable evidence that the atmosphere …

2019 The Astrophysical Journal
IRIS 23
The EBLM project. VI. Mass and radius of five low-mass stars in F+M binaries discovered by the WASP survey
DOI: 10.1051/0004-6361/201833054 Bibcode: 2019A&A...626A.119G

Bouchy, F.; Queloz, D.; Ségransan, D. +26 more

Some M-dwarfs around F-/G-type stars have been measured to be hotter and larger than predicted by stellar evolution models. Inconsistencies between observations and models need to be addressed with more mass, radius, and luminosity measurements of low-mass stars to test and refine evolutionary models. Our aim is to measure the masses, radii and ag…

2019 Astronomy and Astrophysics
Gaia 23